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FAQs on Oscar Behavior

Related Articles: Oscars, Neotropical Cichlids, African Cichlids, Dwarf South American Cichlids, Cichlid Fishes in General,

Related FAQs: Oscars 1, Oscars 2, Oscar Identification, Oscar Selection, Oscar Compatibility, Oscar Systems, Oscar Feeding, Oscar Disease/Health, Oscar Reproduction, Neotropical Cichlids 1, Cichlids of the World, Cichlid Systems, Cichlid Identification, Cichlid Behavior, Cichlid Compatibility, Cichlid Selection, Cichlid Feeding, Cichlid Disease, Cichlid Reproduction,

ANOTHER Oscar question      2/9/14
WWM, you guys are outstanding, and I constantly read your responses.
<Thanks for the kind words.>
I couldn't find my specific problem, so I'm writing to you, a befuddled man. I have a 110 gallon tank, 35 gallon sump, 1800gph return pump, UV sterilizer, etc etc. The tank is established (though my Ph is rather high at 8.2, but I'm not going to chase it.) I have 11 silver dollars, tons of live plants (I found a system that works. Haha) and one juvenile Oscar.
He's about 4 months old, and 5 1/2 inches long. I feed him daily, and his diet is varied. (NO FEEDERS.) Until the last week, we had no issues, but now he's attacking my silver dollars. He will literally swim up to one, and bite it in the side, sending scales flying! Is he just being a teenager?
<Probably not; he's stimulated by the sight of potential prey, and acting as nature programmed him too. If the Silver Dollars are too big to harm and the tank has enough space, you may find he eventually ignores them once he figures out they aren't easy to catch. Offering some equally stimulating alternatives might help, for example pieces of fresh seafood or even live
earthworms and/or river shrimps. But of course if the Silver Dollars are small ones, he might eventually catch and kill one of them, in which case separating them (perhaps with an egg crate divider) might be necessary until they get bigger. You might also try and see if your Oscar is being territorial (i.e., defending one end of the tank from oncoming Silver
Dollars) or predatory (i.e., just randomly sneaking up and attacking wherever in the tank he happens to be). That would give a clue to what's going on. Oscars generally aren't territorial to dissimilar non-cichlid fish given space, but if yours is, then the old "take the aggressive fish out, move all the rocks and plants about, then reintroduce the fish" trick might work. Often does, with cichlids, tricking them into thinking they're somewhere new and so resetting their territorial instincts.>
I just picked up a 65 I plan to cycle, to move him to his own space, but this really confuses me. Help me with my jerk Oscar? Thanks for all you guys do!
-Tom
<Most welcome, Neale.>
<<I'd add one more statement to Neale's excellent input here. I suspect the Oscar may be reacting to its own (internal) reflection in the side/glass. I suggest you tape a piece of paper over this to see if it has a calming effect. This sort of territorial display is quite common amongst cichlids (and many marine Teleosts). Cheers, Bob Fenner>> 

Re: ANOTHER Oscar question      2/9/14
I will try that, too. I'd like to keep him where he is, so all of this is very appreciated.
<Real good. BobF>

re: ANOTHER Oscar question... add incomp. w/ silver $      2/9/14
Neale,
Yes, he seems to stalk them and attack them once in a while, definitely not confined to any one area. I will try re arranging the tank and reintroducing him, as per your recommendation. If that fails, I'll try giving him more worms, etc. I feel bad because the older silver dollar (7 inches, eight years old) is starting to get stressed, and has a bunch of scales missing from where he pecks at her. If all else fails, I'll just put him in his own tank. Thank you so much for your quick response!
-Tom
<Most welcome and good luck. Cheers, Neale.>
RE: fw: re: ANOTHER Oscar question

Bob,
This may seem weird, but I've noticed he gets a lot more aggressive right after I feed him his worms. Within two minutes of eating a few meal worms, he's nipped four silver dollars and uprooted a plant. Don't know if that helps or not.
<Bob may/may not agree, but there's a lot of experience to suggest that using live food increases aggression and predatory behaviour, whereas the use of obviously dead food (like pellets) has the opposite effect. One of many reasons why feeder fish are a bad idea. Cheers, Neale.>
<<I very much agree. You can see my similar stmt.s in this regard in several places on WWM, in writings elsewhere. B>>
RE: fw: re: ANOTHER Oscar question      2/10/14
You guys are truly genius! The distraction method works! I put a bobber, and a de hooked spinner in the tank. (What we used to catch wild Oscar in florida) Now he likes to sneak up and ambush my lure. Thank you, from my silver dollars and myself!
-Tom
(Pic included.)
<Looks cool! Neale.>

 Re: ANOTHER Oscar question     2/10/14
I swear Bob and I are different people… not the same person with American, British accents!
Neale
<Heeeee! I think I like domestic cats more! B>

Oscar fish... beh.      1/24/14
I've had my Oscar for about 6 months now and he's doing great; however, he has had a bad habit of jumping since he was a baby. He keeps skinning the top of his head and back. He hasn't done any serious damage or managed to fly out of the tank yet but it worries me. He always heals fast and has been doing it less lately but I'd really like to get him to stop. Is there
anything I can do to discourage him from jumping?
<Assuming there isn't a sudden pH or water quality change (which can make even mild fish jumpy) he/she almost certainly feels crowded, harassed. How big's the tank? What tankmates does he live with? Plecs for example are notorious Oscar-botherers, as are some of the so-called Sucking Loaches. A singleton Oscar needs, what, 75 gallons? Expect to add 20, 30 more gallons for each additional fish depending on the size of those fish. The addition of floating plants can also help, dramatically -- fish jump out of open water, but not normally from underneath plants. You are right to worry as fish that are jumpy and become damaged tend to be those fish that often suffer from more serious stress-related problems as well. So well done on spotting the problem and good luck on fixing it. Hope this helps. Cheers, Neale.>
re: Oscar fish     1/25/14

Thanks for your help. He is in a 75 gallon tank with a convict cichlid, 3 albino Cory cats,
<... you've written here before. I would not keep Corydoras with large neotropical cichlids. Too easily swallowed w/ disastrous result>
a golden algae eater, and two large Bala sharks(about 6-8 inches each). The water stays around 78 degrees, the pH stays around 8, nitrites, nitrates, and ammonia are 0. I am currently trying to re-home the Bala sharks because they constantly pick on each other and my Oscar has decided he doesn't like them. Since you mentioned over crowding, I'm thinking maybe it is the sharks stressing him out. They started picking on each other quite a bit lately and that's when he started jumping again. We just got another large tank and as soon as it is up and stable I will remove the Bala sharks.
<Ok. B>
Re: Oscar fish   1/26/14

<<Would reinforce Bob's point here with an observation reported in PFK Magazine some years back... a major part of the diet of Oscars is Corydoras! Those big-ass jaws your Oscar has evolved for crushing things: fruits, seeds, crabs, crayfish... and armoured catfish! Even if your Oscar isn't able to kill your Corydoras quickly, if he/she tries to swallow these little catfish, Corydoras can "lock" their pectoral and dorsal fin spines, and in doing so, choke (to death) the unfortunate Oscar. Doubtless the Corydoras will die, too, unless you somehow rescue them. A bad end for all concerned. Given space, the larger Callichthyidae can work though; do look at Hoplosternum littorale for example. Cheers, Neale.>>

Oscar questions. Longevity/beh., hlth. concern     1/16/14
Hello,
I am hoping you can help me with my Oscar.. He is a red tiger Oscar that I have had for about 10 years now. He was purchased as a baby and has done well over the years with minor battles of hole in the head back when I used to feed him live feeder fish.
<Disease city>

 He got to were he wouldn't eat them anymore about 3 years ago and now eats brine shrimp and Hikari cichlid gold med size pellets. He has been in a 200 gallon tank since I purchased him with the same tank mates for years. I have added new fish over the past two years as tank mates died out. Here is what I have noticed over the past few months. These are in the order I noticed them to the best of my recollection:
Started laying at bottom on left side (sometimes he was so still I had to poke him to make sure he was alive)
<What are the other fishes here? My concern is that the Oscar may be getting bullied>

Spends 99% of time on bottom of tank just laying down
Started loosing orange coloring...now has very little orange color left
Appetite has diminished..only eats about every 3 days and even then spits a lot of bit back out
About a week ago I noticed when he swallows he starts what looks to be like choking/gagging type movements and his head and mouth splash about while in the swallowing stage (this happens even with small pellets)
Noticed yesterday that he is developing small white holes on bottom side of his mouth under lower jaw..normally with hole in the head he always got em on the top of head?
Also he started spending a lot of time laying by the water heater (I checked and temp is at 78)
I have two large filters with the charcoal ( I use the white/black mixed charcoal) on back and the filter media in front (media also has charcoal in it) I have done 3 water changes over past month and added additional live bacteria.  Change filters every other week and charcoal once a month...
Any ideas on what maybe wrong with him other then old age?
<As stated... parasites from the years of feeders, bullying>
I appreciate any help you can give me as he has been a pet for a long time and although I know he is getting old I would like to try my best to keep him around as long as possible..the kids really get a kick out of hand feeding him.. Also, what is the normal life span on a tiger Oscar?
<Can live 15-20 years; though ten years is a good span>
Thanks again
Sheila
<Welcome. Bob Fenner>
Re: Oscar questions    1/16/14

Thank you for responding so quickly..
The other fish are:
2 Bala sharks (still small about 2.5/3" long)
1 blue Gourami(about 4" long)
2 silver dollars (about 3" long)
1 catfish (baby maybe 2" long"
2 Cory cats
<Mmm, are these still here? I ask in the concern that the Oscar might have swallowed one/both>

1 freshwater puffer (1.5 very small)
Oscar is huge probably 10/12" long..
All the other fish are tiny compared to him and I've never seen them going around him..they all take off to the other side of tank when Oscar does get up and gets moving...I also had forgot about this but a few months back I noticed I had a large amount of water lice (think that's what they are called)
<... see WWM re... and the compound you used to treat. Some are very toxic>
 I treated the tank and did water changes as per instructions and haven't noticed any since then but could that be causing him issues?
<... and review the exhaustive collection we have on WWM re Astronotus health period. BobF>
Re: Oscar questions    1/17/14

Yes the puffer is still in there  <<RMF asked re Corydoras...>>
<What sort of "freshwater" pufferfish? Most of the ones sold in aquaria (often by retailers who insist they're freshwater puffers) are brackish water species. In the US trade, really only two truly freshwater puffers sold commonly, the Dwarf Puffer (which Oscars will eat) and the South American Puffer (a sociable species best kept in groups, but a fin-nipper).
The standard Green Spotted Puffers and Figure-8 Puffers are brackish water fish.>
and I know it can be fatal if eaten and the only reason I tried it was because Oscar has not tried to eat any fish bait or otherwise on like 2
years.
<Does happen that Oscars become "tame" but they are predators... in the wild feeding mainly on crabs, crayfish, and small fish such as characins and Corydoras.>
Even when add new fish that are small he doesn't bother them.
<Lucky, but I wouldn't bank on it lasting.>
One other thing, I have been battling green algae ever since I stopped using the Plecos and went to Cory cats...will algae affect him at all?
<Not as such; but poor water quality is often indicated by algal blooms, especially nitrate levels above 20 mg/l. Such nitrate levels are toxic to Oscars in the long run, being linked to Hexamita and Hole-in-the-Head Disease. Do a nitrate test immediately, and if the nitrate is above 20 mg/l, that's a good sign there's a problem; if the nitrate is above 40 mg/l, it's SERIOUSLY BAD for Oscars.>
Doesn't seem to bother the other fish and I haven't had a death in my tank in probably over a year now  
<Oscars and other cichlids are much more sensitive to nitrate and low oxygen levels than the majority of other tropical fish. Understand that, look at your tank, and act accordingly. Most vague problems with cichlids come down to environment. Cheers, Neale.>
Re: Oscar questions    1/17/14
It's the dwarf and I've had him for about 4 months.
<I see. Dwarf Puffers really aren't big enough to live with Oscars, and in any event, are moderately delicate fish. They don't need much to do well, but they do need a 5-10 gallon aquarium with quite clean water, minimal nitrate levels. Puffers are paradoxical in some ways: quite hardy in terms of adaptability, but long term, easily stressed by not-quite-right conditions.>
I'll test the nitrate (hadn't tried that yet) I did check ammonia levels
about a month ago and it was good but I'll check again..
<Indeed. Often with cichlids people get the ammonia and nitrite problems tackled early on, keeping both at zero, thanks to good filtration. But nitrate is a MUCH tougher nut to crack; you need an approach that involves regular water changes, minimising the food put into the tank, and not overstocking.>
Anything you would recommend for algae treatment?
<There are no quick fixes. Short term, nothing beats a decent scraping sort of sponge (I use one of the sort used to clean pots and pans, obviously a new one!). After that, you can try Nerite snails in many tanks, but Oscars may well eat them, so buy a couple and see what happens before investing in the one per 5 gallons you probably need. Adding floating plants (Indian Fern especially) can have a huge benefit in cutting out light and using up nitrates. But realistically, in Oscar tanks, manual removal of algae is pretty much standard to some degree, especially if the tank lacks floating plants.>
I used some stuff per store sold me (can't remember the name) and it helped a bit but not much.
<Basically "potions" can/will kill the algae, but won't stop a fresh batch coming back, so they're little more than a quick fix for a week or two.>
I don't wanna use Plecos because they get to big and to me they make a big mess of the tank
<Indeed. My thoughts here:
http://wetwebmedia.com/ca/volume_6/volume_6_3/fwalgae.html
Do see elsewhere on the WWM site by following the links at the top. Cheers,
Neale.>
Re: Oscar questions        1/18/14

Just read your link and think a big part of my problem is that my tank is directly in front of a window and I leave lights on pretty much 24/7...
<A-ha!>
The lighting issue would explain why I never had algae issues prior to moving into this house a year ago...my tank at old house was not near a window and so it was not getting the sunlight and I had a timer on my lights to turn off at night...I will have to put a dark curtain up on window and get a new timer and see if that helps...will also try your other suggestions and I have a 30 gallon tank I can set up for my puffer because I only got one to see how he did and now want more but I'll separate em from the big guys.
<A wise approach. Keeping Dwarf Puffers in group can work well and isn't hard to do; just remember -- lots of lava rock and plants so they can't see
each other all the time!>
Thanks again for all your help
<Welcome, Neale.>

weird behavior with my Oscars, and Anglish      10/27/13
hi i have 2 Oscars one albino one tiger and there about 5.5 inches, a split jean Dempsey and a goldenspot pleko wich is about 10 in a 240l
<Mmm, they'll need more room than this>
tank, ammonia low or none
<Needs to be zero>
and ph i keep at 7.0 my Oscars attack each other every now and then but are calm and cozy most of the time and they constantly flutter near each other. ive done the sexing check with there anal glands and it seems one is female and the other male but still not 100% sure
<Too small size to tell>
as no eggs are lain i guess because of the pleco they are hesitant ive housed in this tank in my last lot i accidently killed buy not putting the heater in the temp tenk, i completely forgot got cold and they died there were 4 Oscars at about 7-8inch
<... insufficient room>
 2 were a donation from an inexperienced owner or there would have been only two coz of my tank size one big goldfish (comet)
<... misplaced here>
 wich my Oscars left to grow from a small size, they could easily eat it but left it. there are perks if you have plekos and can manage to have a goldfish live with the o, the pleko gets messy as it gets bigger and drops massive terds wich the goldfish eats and keeps the ammonia rate low the pleko is the biggest waist producer as it gets bigger so it helps maintain the tank i just wanted to add that in since you said they are bad for the tank and they all survived peacefully till i stuffed up. but to the other question could they be breeding
<May be practicing; leading up to... more likely just challenging each other...>
because i no they can get much more violent and can easily hurt each other more then a scratch or two but they don't this has been happening for a wile my split Dempsey is more aggressive but he needs to be because of his size and even then its a quick test of strength
<Yes>
then nothing peacefull is everything going ok or is the Dempsey maybe causing a lot of trouble?? it takes on the o’s and its half its size! any info will be great thanks in advance
<I'd be keeping an eye on all; and using a spelling/grammar checker. Bob Fenner>
Re: weird behavior with my Oscars      10/28/13

<<I would not (add) much to what Bob F has said, explained already. Oscars are not difficult to keep, but a singleton in 240 l (about 63 US gallons) is about right on its own; adding any additional fish doesn't make much/any sense. Two Oscars in such a tank, unless a confirmed mated pair, isn't going to work. Two males will be very aggressive, to the point of doing severe damage to each other (dislocated jaws are not uncommon in such situations, and such injuries are effectively death sentences as the fish can no longer feed). Do also remember that is virtually impossible to sex Oscars by looking at them. Much like freshwater Angelfish, males and females look the same, and while there are some hints and tips that get repeated among fishkeepers, none of them are reliable. The only sure way to sex them is to watch them spawning, in which case the one laying eggs is the female, the one shedding milt is the male. Obvious, really! To be fair, within a day before spawning they also have distinctly different spawning tubes ("genital papillae") but you can't usually see these the rest of the time. Your other tankmates don't really belong. I've seen standard (non-fancy) Goldfish living well with Plecs, but mixing Goldfish with
cichlids is almost always a bad idea. Jack Dempseys are great fish, but they can be lethally aggressive, and are best kept alone, in mated pairs, or as singletons in mixed communities of robust Central Americans larger than they are (e.g., with Jaguars and Midas Cichlids). Even then, such communities will be in tanks upwards of twice the size of yours. Hope this
helps. Cheers, Neale.>> 
Re: weird behavior with my Oscars   11/2/13

I only think they are paired because of there size and through venting with some research on how to do it.
<Be very skeptical of any "magic tricks" to help you sex Oscars. The science is categoric -- Oscars are monomorphic, meaning males and females are externally identical. Once the genital papillae come out, then you can sex them. But until such time, be very cautious. Oscars are notorious for being aggressive towards one another, which is why historically they've usually been kept singly. Oddly enough, they're otherwise quite peaceful, and work well with dissimilar fish such as Clown Loaches, Plecs, etc.>
They are calm now and have been for a while.
<Good.>
The comet was in the tank with the bigger Oscars from a small age to the size of them, there favourite food was a goldfish and yet they let it live even though it would easily enough fit in its mouth
<Perhaps your Oscars have good sense! Goldfish is a terrible, terrible diet for Oscars. In the wild they eat a range of foods, but with the accent on crunchy things, hence their massive jaws. So while a good quality pellet should be staple (Hikari Cichlid Gold for example) you can also give them occasional treats such as crayfish and whole shrimp. Earthworms are another favourite. Some green foods should be provided, frozen peas being easy and convenient. These are loaded with vitamins and fibre, and together make Oscars healthier and better looking (yes, green foods, alongside crustaceans, improve colouration because of the chemicals they contain).
Some Oscars may take a while to take peas, but persist, and if needs be, starve your Oscars for a few days, even a week or more. The fibre in peas deals with constipation before it becomes a problem, and the vitamins help to keep Hole in the Head and other similar complaints at bay. Do always remember that wild Oscars are omnivores, and a significant part of their diet is fruit, seeds and even some decaying plant material. Not Goldfish!!!>
i think its because it was cleaning there tank from the Pleco poo it was my newer Oscars that killed it
<Hmm... Well, anyway, hope the above helps. Cheers, Neale.>
Re: weird behavior with my Oscars     11/2/13

Also I will be up sizing my tank this is temporary temporary for funds reason. What size tank would they be happy in when the fish in my tank are grown up? I was thinking the next size up about 400-450l.
<450 l/120 US gallons would be a very good size for a singleton Oscar plus suitable tankmates (e.g., a Plec and some large barbs/characins) or else a pair of Oscars on their own, possibly with a Plec but not if you wanted them to breed.>
My tank at the moment may not seem like a lot of room but its wider then usual to make room for a bigger fish to turn
<The thing with cichlids is that there's a strong relationship between aquarium size and health, perhaps stronger than for most other commonly kept fish. Small tanks tend to have high nitrate levels unless you do very frequent water changes, and nitrate is a "silent killer" among cichlids, seemingly doing no harm until -- bam! -- you're dealing with a Hexamita outbreak or Hole-in-the-Head. By all means keep a young Oscar in a 200-litre aquarium for a while, but don't expect him to be safe there much beyond 8-10 cm/3-4 inches in size, and really, he should be moved up to a bigger aquarium well before then. Obviously if you have two Oscars, then such advice is even more urgent. Cheers, Neale.>

2 Oscars changed behavior    9/12/13
Hello.. . I've Have had these same 2 Oscars together for approximately 2 maybe 3 months they are about 5 inches long they immediately hit it off and became buddies swimming side by side hanging out constantly together...
<Mmmm; won't likely go on...>
Recently when I shut the light off at night time and wake up in the morning one of them looks like he's been beat on minor bangs and scrapes not anything serious but I'm just wondering why this behavior is going on and should I be worried about it?
<Yes you should be concerned... One is beating up the other. They should be separated; and may well need to be kept so, unless they can be kept in a very large volume (hundreds of gallons), and/or mated/paired>
 It has going on  for the last week. I've noticed it because I heard them splashing around and happened to notice or
biting at the other it but as soon as the lights turn back on within a couple of minutes they're back to being buddies....help I don't want to continue torturing one of my fish if that's what's going on...I will say that the fish being bitten on is passive and doesn't fight back so I'm wondering if this may be a sign of spawning or what it could be. ... Thank you for your time
<Have you read on WWM re Astronotus? Here:
http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm
and the linked files above. Bob Fenner>
Re: 2 Oscars changed behavior     9/12/13

Thank you for the information provided. . Why is this only mean behavior only occurring in the dark?
<Happens at times>
 How do I know that they are not in fact a pair?
<... too small for one. Keep reading. BobF>

Oscars, beh., sys.    3/30/12
Hi guys. Long time user of your site. I have read many of your forums about Oscar issues and I am not a first time owner but I am somewhat stumped here. I currently have five oscars, about 5 inches, in a 65 gallon tank.
<Hmm… a bit small.>
Their 295 in currently cycling, ready in a few days.
<Good.>
They were all bought together except one special one who I found by accident and couldn't resist. There are two tiger oscars, two albino tigers and one almost solid black with tiny bits of red on this gill and the "eye" on his tail. The water parameters are great, temp around 75-76. They eat a huge variety of pellets (sinking and floating) flakes, earth worms, beef heart and blood worms.
<Good so far.>
One time I folded and let them eat guppies from my guppy tank and 30 Rosie minnows.
<Not the smartest thing you've done in your life. Please, don't give Oscars live feeder fish. It only takes one feeder to introduce a parasitic or bacterial infection.>

They each have their own cave and are starting to pair off. Two of them fought on and off for two weeks, probably establishing a chain of command or something. They are all friendly now, they sometimes swim behind each other and suck another's fins into their mouths and rub on each other (which I never saw my other ones from previous years do). But over all they are friendly.
<Good.>
Now my problem. Sometimes recently they swim crazy around the tank.
<As they do, when confined. Bear in mind adults in the wild will hold territories some metres across, so even a big aquarium is a teeny-tiny volume of water so far as their instincts go. Sure, these have been bred in captivity for decades, but the instincts are still there, to some degree.>
Usually only one or two maybe (it's hard to tell with so many in there) and the others try to stay out of the way. Then they hit a wall or rock and float to the top, take some labored breaths and go back to normal. I thought it was bad fighting at first ending in an all and all brawl to the death where one was fleeing. The more I watched it this strand activity seems to happen out of the blue, nothing to start it, it lasts for ten seconds maybe, and mostly at night right before or after I turn off the lights. They seems unharmed, maybe a scratch or something but nothing bad. I change the water about 35% every weekend or every other weekend and filters every weekend. I have a Tetra Tec filter with the heater inside it so the oscars don't break it playing around and a small inside pump that circulates water inside (I have seen in saltwater tanks) I have Malaysian driftwood, slate, and java fern in the tank.
I was thinking maybe it was electrical but I frequently put my hands inside the tank and haven't felt anything. They seem fine during the day which is odd. Besides rough playing and mocking each others movements they don't fight or hurt each other. They are in a high traffic area as far as kids running up to see them.
<Ah, now, this could either scare them (low-frequency sounds and vibrations) or distract them (the promise of food). Either way, a factor.>
But they seem to love the attention. What ideas might you have here?
It sort of reminds me of the spinning type of death that happened to my discus when i had them. That was years ago and a different house, different tank and water type. They would freak out and dart around the tank hitting everything until they died. After I had them several years and introduced another one from a friends tank. This is what has caused me to write. The oscars were about an inch when I got them 6 months ago.  Any help would be great. I am still leaning electrical but am not sure cause the heater light isn't on when they do it.
Jamie
<Do think things will become more normal in the larger tank, so wouldn't worry too much right now. No obvious problems, at least. Cheers, Neale.>

Baby Albino Oscar not eating or growing properly    3/28/12
We got a baby Albino Oscar on January 1st. When we first got him, he had a huge appetite and was very energetic. In the last few weeks he refuses to eat almost all food. We have tried Cichlid flakes, pellets, freeze dried shrimp, freeze dried bloodworms, freeze dried plankton. The only thing he will eat is frozen baby brine shrimp. He hasn't grown much in the last
three months, but his head looks like it's growing, but not the rest of his body.
<Bad; because the skull is so solid, if the fish is wasting away, the body behind the skull ends up looking disproportionally large.>
He is in a 55 gallon tank with 2 algae eaters and a Pleco.
<Overstocked. Oscars need 75 gallons really, especially if kept with a single Plec. Add other fish, and things get bad, quickly. What's the nitrate (with an "a") level? That's the clue. If above 20 mg/l, your tank is overstocked and/or you're doing too few water changes with nitrate-free water. Needless to say, ammonia and nitrite MUST be zero as well.>
My boyfriend added a second red Oscar over the weekend hoping it would help to have a companion.
<Uh, no Oscars are territorial and aggressive, and surely do not need friends. Likely made things worse, and perhaps exposed this new Oscar to whatever's ailing the current one.>
When we change the water, he sits at the bottom for 24 hours and doesn't move or eat. Any suggestions?
<Environmental, probably exacerbating an underlying Hexamita infection.
Review living conditions, fix them, and treat for Hexamita with Flagyl (Metronidazole).>
We'd appreciate any advice. All the other fish are healthy and growing.
<Cheers, Neale.>

A few quick questions regarding my Oscars 12/10/11
Hi Guys & Girls at WWM
<Scotter>
Just to start with, thank you your site has to be 1 of the most valuable resources I've come across, the information gleaned from here has been useful to me with all of my aquarium endeavours.
<Heap on da praise!>
I have a 6ft 480 litre aquarium, currently stocked with 2 Oscars, 2 Clown Loaches,
<Hope the Oscars will leave them/these alone>
a Bala Shark,
<Finally in a large-enough system... though a social species as well>
4 Silver Dollars, 4 Severums (all female) and a Sailfin Pleco, nearly all the fish I have since the tank was setup 6 months ago. The Severums were an addition to the tank when I moved into the 6ft, previously the fish were housed in a 3ft, for a month while the 6ft was being made. The tank runs with a 2000l/hr wet/dry trickle system, Ammonia & Nitrite levels are 0 and Nitrates around 10, ph is about 7.8 varies slightly with water changes and returns to 7.8 within a couple of days, tank is cleaned (gravel Vac and 20-30% water changes) on a weekly basis.
<Good>
The Oscars were acquired by my partner when they were only 2in in length, they get along fine but in the last couple of days they have started to display some aggressive behaviour (only towards each other). The largest of the 2 is a little shy of 9in and the other is just over 7in. The large Oscar is gill flaring and rarely lip locking with the smaller, the smaller Oscar is submissive and usually retreats to shelter under plants, this behaviour is not constant but happens on and off all day, when they aren't flaring they are usually swimming side by side rubbing against each other, vibrating their tails and generally being really affectionate (well that's how it looks) my questions is, are my Oscars starting to reach sexual maturity or are the fighting for territory ?
<Likely, much more so, the former>
is this a problem I should be worried about?
<Mmm, not worried, but aware, watchful... In a system of this size, likely the other fishes will be able to stay out of the way... and should one or the other Oscar prove too belligerent, the other as well>
I do realize that if the Oscars decided to spawn that I will have to remove the other fish from the tank, arrangements have already been made to rehouse the other inhabitants in this event. Our Oscars are like pets and I really don't want to have to get rid of 1 of them but if this going to be the start of some major turf fights, 1 will have to go.
Scott
<Just keep an eye on all at this juncture... is what I'd do. Cheers, Bob Fenner>

My Tiger Oscar has changed his behavior 11/29/11
I'm going to start off by describing my tank conditions and it's inhabitants. I have a 15 gallon (yes, I know it's too small but it's the largest I have right now)
<?>
with three fish that belonged to my dad before he passed away. They were kept in a 75 gallon aquarium with a broken filter and were rarely fed. When I got them, they were in poor shape and I didn't think they would survive. There is Oscar, the 7 inch albino tiger Oscar, Mildred, the 2 and 1/2 inch red Oscar, and Ropey, the foot long Ropefish.
<Yikes... you need to get these fishes into larger/appropriate quarters... stat!>
Oscar suffered from hole-in-head disease and was listing to the left. He drastically improved under my care and became active. He was eating again, swam "excitedly" when he saw me, and wasn't aggressive towards the other fish (except when he thought Ropey was a worm and tried to eat him). I feed the Oscars pellets, bloodworms, mealworms, and earthworms to vary their diets. I also do cleanings on the sand and partials twice a week and have stuff added to remove ammonia, nitrates, and nitrites.
<Good>
My problem is that I went away for a week and my apartment-mate cared for them. Now, Oscar is listing again and has darkened in color. He only eats when I entice him by dangling a worm in the tank. The other fish act fine though, only he is behaving differently. I just need advice on what to do now, besides get a larger tank which I am working on (I can't take my dad's tank because my landlord is afraid it's going to fall through the floor due to it's weight). Thank you for your time and I hope you have some advice for me.
<Do know that Oscars, and many other Cichlid fishes are very change-able in their nature/behavior. Likely just your absence for the week has brought on this sullen posturing. I would increase the frequency of water changes... as metabolite build-up can also bring on such, and definitely be looking for a MUCH larger system... Now! Bob Fenner>
Re: My Tiger Oscar has changed his behavior 12/8/11

Thank you for responding! I found a 46 gallon tank for free so I moved them into that tank. Oscar did cheer up after I got back too, like you said he would.
<Ah, good>
My question now is about interactions with each other.
This started recently after Mildred changed from her juvenile color to a more adult pattern. Oscar goes up behind her and rubs his face on her tail.
<Mmm, pre-nuptials... reproductive behavior>
She then backs up into him with more tail rubbing then she runs away. I've read that this might be breeding behavior but "she" is only about 3 inches and I thought that was too small for sexual maturity.
What would explain the change in this behavior?
<Teenagers... Thank you for this follow-up. BobF>

Oscar Fish Acting Crazy 3/11/11
<Hello Dominique. You appeared to send a message with 16 MB of images attached, each more than 2 MB in size. Because of the limited e-mail space we have here, and because us crew members don't want to spend all evening downloading giant attachments, we don't accept that size attachments or that number of them. We do specifically state this on the "Ask WWM" page, likely where you found our e-mail address. Please resend your message with a few, smaller images. Programs like iPhoto will easily resize images. Try aiming for about 800 x 600 pixels, or about 500 KB per photo. Thanks, Neale.>

Re: Oscar Fish Acting Crazy [Fixed]... sys. 3/11/11
Hello Crew,
<Dominique,>
I tried to find an area on the website where I could post my question but I could not seem to locate it. I am e-mailing you guys today because I am concerned about my Oscar fish's behaviour. As well as awkward things happening to my Pleco.
<Okay, fire away!>
To start I have a 65 gallon tank with a 300 watt heater.
<Should be ample for a single Oscar, or a single adult Plec alongside small community fish, but Oscar and Plec together will need more space than this.
Even if water quality stays acceptable, I'd expect a fair amount of silt in the tank, reducing its clarity, and making it altogether less attractive.>
I have two Emperor filters which claim to filter 55 gallons each.
The tank contains 7 fish in total.
2 Oscars (1 is a red Oscar and the other is a albino Oscar)
<Yikes! If these are both males, you won't be able to keep them together in a tank this small.>
2 Zebra Danios (There use to be 3 but one disappeared last month)
<I bet! Zebra Danios are Oscar food. They shouldn't be in the tank at all.
While a single or even three Danios won't poison an Oscar, they are minnows, and that means, like Goldfish, they contain thiaminase, and over the long term that will cause problems. In any case, there's a risk of introducing disease, and simply by giving predators like Oscars live food, you increase the chances they'll become aggressive. Remove to another aquarium, ASAP.>
2 Fire and Ice (This is the name of the fish given at the pet store)
<Need a photo of these.>
1 Leopard Pleco
<Pterygoplichthys gibbiceps; a very, VERY large Plec with the potential to reach 60 cm/24 inches within three years. Sometimes Plecs damage Oscars by scraping at their flanks. I would not keep Oscars and Plecs together, but if you must, do look out for signs of damage on the flanks, like odd white scratches.>
The fish generally get along together. I have not seen them fighting with each other.
<Yet. Sexual maturity in Oscars occurs around 20 cm/8 inches, from which point males become increasingly intolerant of other males and sometimes females.>
The Oscars swim together regularly and are usually found floating beside each other.
<For now. While Oscars *are* comparatively peaceful by cichlid standards, they are *not* schooling fish. Some specimens coexist indefinitely, especially in large (100+ gallon) tanks. But there's always a risk, and mouth wrestling is a good sign they aren't getting along. Prolonged aggression leads to shredding fins, stress, and worse.>
The weird behaviour I have noticed with my albino Oscar is that whenever I walk into the room, turn the room or tank lights on or even open the top lid of the tank he will begin to swim as fast as possible into any decoration then right into the glass side of the tank and finish off by swimming directly up and hitting the top of the tank.
<Stress, alarm.>
Afterwards he will just float on his side at the top of the tank for a couple minutes and have multiple cuts and scratches on his head. This has been happening for the last couple of weeks and its really beginning to worry me. The red Oscar will sometimes swim away from the albino while he is having his fit and cut himself as well. So I'm left with both Oscars cut sometimes. I am just wondering why he is acting this way. Also my red Oscar is not black. When I purchased him his back was black but after a few weeks the colour has turned pale.
<Indeed. He is trying to blend into the background, but can't.>
I would like you to note that I did not know that I should wet the food pellets before feeding the Oscars since a couple weeks ago. Prior to knowing I would just throw the pellets in, this would have occurred for about 2 months. During which the albino would float on his side occasionally but he seems to be doing better now.
<Okay.>
The other thing I would like to ask you is why is my Pleco miss coloured.
He has some dark areas and along his back in a symmetrical shape he has these brown areas and it looks weird.
<Again, altering colours to blend in.>
Sometimes his fins will split as well.
<Could easily be damage by/from the Oscars.>
I have attached some photos of my tank and fish in this email. I am doing a water change tomorrow. The red cup in the tank has saltwater in it to help heal the wounds. If it is possible could you recommend what decorations I should keep in my tank and what I should remove?
Thank You Very Much!, Dom
<Bottom line is that your aquarium is terrifying your fish. Why? Because of the white substrate. Fish HATE white substrates. Think about it -- in the wild many predators attack from above, like Herons. The brighter the substrate, the easier the fish will be seen. So fish prefer to swim over dark substrates. If you stick a white substrate in the tank, you're making your Oscar feel like it's in full view of any passing predator. End result -- constant fear. Replace with plain vanilla gravel or, if you must use something trendy, matt black gravel. Providing some overhead shade, for example floating Indian Fern, will help as well. Problem solved. Cheers, Neale.>

Re: Oscar Fish Acting Crazy 3/15/11
Sorry about the late response, I just wanted to say thank you for your help.
<Nice to hear back. Glad to have helped. Cheers, Neale.>

Oscar fish... beh., lack of data 1/13/11
hey I have a 125 gallon aquarium, I have multiple south American fish. They all get along and there has never been any real problems. I have 2 6 inch Oscars, I believe the male is the albino red who is a bit smaller. Today I noticed his diving hard into the rocks multiple times,
<Yikes!>
swimming back and forth fast acting aggressive towards every fish other than the other Oscar. The water was just changed and some decorations were just added, this Oscar has been docile everyday before this
<? Please read here: http://wetwebmedia.com/FWSubWebIndex/oscarbehfaqs.htm
and the linked files above... for background, and to give you an idea of the sorts of information we're looking for to help you. Bob Fenner>

Awkward/Erratic behaviors and Symptoms of My Tiger Oscars 3/8/10
Hello,
<Hello! Melinda with you here tonight.>
I'm emailing you with some concerns about my two Tiger Oscars.
About a week and a half ago my two tiger Oscars have been showing some awkward behavior, and symptoms.
<Okay.>
The bigger one has more awkward behavior than the smaller Oscar which shows more physical symptoms. I have a 30 gallon tank with a Fluval U2 blower/filter, and a 150Watt water heater.
<How large are these fish? The reason I ask is that they should be at least six to seven inches long now, and I can't imagine fitting both of them into a 30 gallon aquarium. The minimum for one Oscar would be 55 gallons, though I'd be more comfortable with 75, and for two Oscars who aren't a breeding pair, you'd need at least a six-foot tank to house them both, especially after they reach sexual maturity. This is due to a number of factors: The necessary dilution of waste, the resulting water quality, and territoriality on the part of each Oscar.>
The blower/filter is kept clean and maintained every
time I clean the tank. The tank is cleaned once a week.
<How are you "cleaning?" Is this just a partial water change/gravel vacuum, or are we talking about a total overhaul? How are you cleaning the filter? Are you using tap water to clean the biological media, or swishing it in old tank water to clear debris? Please be more detailed here. The reason I ask is that something's wrong with water quality in this tank. These fishes' symptoms are typical of fish kept in dirty tanks. Now, a lot of this has to do with how much bioload you've got, and part of it may have to do with an interrupted biological cycle. Please read here on the biological cycle: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm. Please test Ammonia, Nitrite, Nitrate, and pH. You can have this done at your fish store, or purchase the test kits yourself. Ultimately, what I'd like you to provide me with are actual numbers which correspond to each of those tests if you feel they're off in any way. If you show Ammonia, Nitrite over zero, or Nitrate above 20, then you can be sure that what you're seeing going wrong with your fish is easily fixed by providing what they need in terms of a cycled, larger system.>
Both Oscars are fed with Hikari Bio Gold+ cichlid pellets, frozen blood worms (occasionally), and minnows (once in a blue moon). Both Oscars eat well. They are both about 6 months old.
<Not necessary, and bad for your fish -- in a number of ways. Other than introducing parasites, they contain thiaminase, which is bad for fish. Please read here: http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm. Every now and then a fishkeeper will have a fish that absolutely refuses anything but live foods. I have one of these fish, and as a result, have to dedicate a 55-gallon aquarium to quarantining enough minnows, ensuring they're healthy, to feed this fish. It's an absolute pain, and it's not even ensuring the feeders are 100% healthy. I would avoid feeding your fish minnows, due to all of the reasons stated above. They obviously take other foods, and it's just not worth the trouble.>
Larger Tiger Oscar:
He seems fine but when I observe him over a period of time, I notice that his entire body twitches. His anal fin looks as if something has eaten away at it. Occasionally, he will take erratic aggression towards the water heater by biting it quite roughly, or constantly swimming around it. This I do not understand at all. It is a newer water heater so maybe this can contribute to it? He also has a white patch on his side near his tail fin, about the size of a pencil eraser.
<Please test water and get water quality to where it should be. These symptoms sound indicative of Finrot, and can be treated with Maracyn. Please read here on Finrot: http://www.wetwebmedia.com/FWSubWebIndex/BetDisInfeF.htm. However, treating without first correcting water quality isn't going to do you any good. For one thing, it will cost a lot more, because you'll be continuously replacing medication removed during water changes that you're doing in order to try and correct poor water quality. The reason that water quality needs to be spot-on is that your fishes' immune systems have been compromised by poor conditions; without first correcting environment, it's going to be that much harder for them to heal.>
Smaller Tiger Oscar:
He seems to be worse off than the other. His scales look to be scraped off, possibly by scratching his side on the gravel, though I have yet to see him actually do this. He lies on his side sometimes, if he is startled. Occasionally I notice him breathing heavily. Fins are fine in shape but they are beginning to have white spots on them. He has lightened in color. Once, every night, while sleeping, I will hear him jolt very abruptly/violently, and harshly enough to make a loud noise and wake me. This has been happening once a night, every night just before sunrise. Currently I am watching him as I am typing this, he is biting at the glass walls of the tank.
<You're also dealing with something else, here, other than poor water quality. The problem is, Oscars are very territorial, and as they reach sexual maturity, can become very violent towards other Oscars who encroach upon their space. Unless you have a mated pair, keeping these fish in a 30 gallon tank means that pretty soon, even if they both survive the toxic water conditions they're living in, only one will be left, due to fighting.>
I've done a 25% water change, added the water conditioner and Rid- ich,
<Why do you believe these fish have ich? You stated that you have not actually observed them flashing (rubbing on rocks and decor), and you mention nothing of the salt-speck type grains which are associated with ich. If I'm misunderstanding you, and the fish are flashing, with the absence of those salt-type specks, flashing can likely be attributed to ammonia burn, not ich. I'm asking this because randomly treating is only going to stress your fish more.>
and also the water temperature has been set to 82-84 degrees.
<This could explain the gasping. Warmer water holds less dissolved oxygen. I'd turn the temp down, stop dosing with ich medication, and get this water tested.>
The carbon filters have also been removed from the Fluval U2. The day before, I dissolved about 3 tablespoons of pure salt into a cup of the tank water, and gradually put it into the tank within a time span of about 6 hours.
<Is this for the ich? You don't need salt, you need big, big water changes until you can get the biological filter established. Then, maybe an antibacterial.>
It seemed to help a bit (calming the fish), but its effects seem to have worn off. I have done this, two days in a row, so far.
Please advise me as to what I should do for them.
<Test your water. If you have any questions about the results after reading where I've linked you, please feel free to write back. Also, the problems we see with Oscars often match the ones you've written in with -- meaning, of course, that there are way too many Oscars in too-small tanks, suffering from the effects of poor water quality. Please see WWM on Oscars and their needs, especially where system size, filtration are concerned, as well as behavior: http://www.wetwebmedia.com/FWSubWebindex/oscars.htm and the linked files above.>
~Abraham
<Abraham, Oscars are really wonderful fish. Unfortunately, their needs often surpass the care that is offered them, and many die prematurely as a result. These fish already need more room than you're giving them, and that's only going to get worse. Also, they need for you to never think that clear water is clean water, and test regularly, and maintain the tank in order to keep those parameters in check. Please write back if you have any questions at all after reading.
--Melinda>

Oscar With Erratic Behaviour 2/10/10
Please help. 7 year old Oscar in 100 gallon tank. About 1 week ago fish was swimming erratic, tried jumping out of tank, eye problems. Changed water, tank conditions fine, treated with Erythromycin. Was better until began swimming in circles as if chasing his tail. Now floating on top one eye bulged, labored breathing, "arms" still moving. Please help me save him,
< Check the water quality. The ammonia and nitrites should be zero. The nitrates should be under 20 ppm. Check it yourself. Don't take a water sample to a store and have it come back "fine". Get the numbers. IN the meantime place the fish in a hospital tank and treat with a combination of Metronidazole and Nitrofuranace. Both can be found online at Drsfostersmith.com.-Chuck>

Aggressive Oscar 01/30/10
I have an Oscar that is about 8 inches long. I would guess that he is about 6 or 7 years old and in a about a 45 gallon tank.
<... needs more room than this>
I have a Fluval filter that works very well and keeps the tank clean.
There are two Severum cichlids
<Need more room...>
and a Plecostomus as well and they've been in the tank with each other from the beginning. Recently my Oscar has been picking up rocks and spitting them out in a corner of the tank,
<Natural behavior>
he/she has recently started shaking and splashing all over whenever anybody walks by the tank or the other fish get close to that side of the tank. There aren't any eggs that I can see so I can't figure out what the problem is...my fish has never had a problem with anybody walking by the tank....any ideas why this might be happening?
<Space. Read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm
and the linked files above. Bob Fenner>
Re: Aggressive Oscar
The 6 years they've been in their they have been fine and NEVER acted like this before. Not helpful.
<Please... read where you've been referred to. This/WWM is NOT a bb. B>

Oscar Behavior questions
Cichlid Communication 1/26/10

Hi, Have some quick questions regarding my new cichlids.
Rescued 1 tiger Oscar, 1 Albino Oscar, and 1 Golden Severum
They were in a 60 gallon tank with no rockwork plant life or sand in the tank. They are now in a 130 gallon tank with driftwood rocks sand with amphipods in it to hunt etc etc. Overall they get along fine. Minor aggression but nothing that risks the health of any of them.
The tail and dorsal fin shaking: Is that an Oscar saying "back off"
It also seems the Golden Severum does a "fluttering move with it's pectoral fins: sometimes to me in the morning and sometimes to the Albino Oscar. What does this mean?
< When cichlids want to get the attention of another fish they communicate by means of flaring fins, shaking their body, extending their gill covers and outright charging the other fish. Sometimes their is tail slapping and jaw locking to determine territories. In most instances it is a way to determine the pecking order in the tank.>
Who does the cleaning of the rock before mating the male or the female?
< Both may do some of the nest building but the female may do more of it.>
Is there a book or website that has more detailed descriptions of social behavior/body communications of Oscars?
< I am not aware of Oscar books detailing interaction between fish. Some websites do specialize in Oscars but they really don't go into the detail that you are looking for. I would recommend that you go to an Oscar site that has a forum, then start a forum thread to see what other Oscar owners are seeing with their fish. Could be very interesting.-Chuck>
Thank you in advance Kat

Oscars fighting 01/03/10
Hello WWM,
<Hello Phil,>
I have kind of a two part problem here and am finding it difficult to find any search results (WWM or www) that are what I'm looking for.
<Oh?>
My situation is that I have a 55gal tank and would ultimately like to cohabitate 2 Tiger Oscars in it.
<Not likely to happen. A mated pair -- and I stress, already mated, not some random male/female grouping -- may well use a tank this size without problems, but Astronotus spp. are territorial and outside of mating prefer to exclude adults from their patch. On top of that, 55 gallons is barely, and I mean barely, adequate for a single adult Astronotus, let alone two.
Nitrate is a real killer, and once these fish top 20 cm/8 inches they are nitrate generating machines. End result is you need lots and lots of water to dilute the nitrate that accumulates between water changes.>
I am aware that a 75 gal is preferred for 2 Oscars due to the large bio-load of the species but I have a filter that turns over the water about 7 times an hour and I perform 2-3 25%-33% water changes a week all the while keeping an eye on the ammonia and nitrite/nitrate levels in the tank.
<I hear what you're saying, but I just don't see this working long term. 55 US gallons is less than 210 litres or 46 Imperial gallons, and by any standards that isn't a lot of water. A tank this size would be adequate for cichlids around the 15 cm/6 inch mark, but Oscars are more than twice that length (and therefore eight times the mass) and really need big aquaria.
Chronic nitrate levels above 20 mg/l can be lethal to Astronotus, and indeed Cichlidae generally, making them especially prone to Hexamita infections. Do understand that while a big filter can deal with ammonia and nitrite, it won't do anything about nitrate. That's all about [a] water changes; [b] controlling the food that goes into the tank; [c] removing uneaten food; and [d] using water volume to dilute nitrate between water changes.>
I added both of the Oscars within a week of each other, made sure they were both juveniles (about 3-4" a piece) and when I introduced the second I made sure to completely rearrange the tank setup so that no current territory was established.
<At this size are only mildly territorial. Likely not even sexually mature.>
Nonetheless they immediately begin to "dance" with each other and gradually became more and more nippy and violent which I had assumed was them working out the dominance and territory of the tank.
<Indeed.>
It's been 7 days now and they are still going at it sporadically usually ending with the slightly larger of the two establishing more of a foothold.
<Will likely get worse with time. With cichlids, there's plenty of experience to suggest that the bigger fish eats more food and therefore grows faster, and by stressing the weaker fish, keeps the weaker fish smaller and less of a threat. In the worst case scenario, the weaker fish eventually either starves, is physically bullied to death, or because it is stressed, succumbs to a secondary infection of some sort.>
In all of my Internet searching all I can find is either people who say "don't have more than one Oscar" or "my two Oscars get along fantastically."
<Indeed. The problem is Astronotus cannot be sexed. If you get two females, the minimal belligerence between them will be easily managed by providing enough space. If you get a male and a female, and they pair off, again, you should be okay given space and a certain amount of wrestling. But get a male and female who don't get on, and the male will stress/bully the female (he's actually only trying to drive her away from his territory so he can make space for a fertile female). If you get two males, then all Hell can break loose. Frankly, since you only have a 25% chance of getting two females, assuming males and females are equally distributed in the stock sold in pet stores, that's about the odds of any two random Astronotus "working out" with minimal fuss.>
I can't find anywhere how long might it take for them to establish dominance and get along or if it should be an immediate thing.
<It isn't something that happens once and for all. Astronotus aren't monogamous for life, so even if you have a pair, there's a constant process of bond forming as the two fish fall in and out of love (for want of a better term). On top of that, belligerence increases as fish become sexually mature, so while two fish might get alone one day, a month later they may well be much less tolerant. In theory at least, Astronotus are sexually mature at about 1 year old, at which point they should be about 20 cm/8 inches long. As noted already, sexual dimorphism is practically non-existent, save for the appearance of the genital papillae within a day of actual spawning.>
Should I wait it out and see if they are still just butting heads or should it have already happened and they're never going to live together?
<Likely the latter, at least in a tank this small.>
My second problem is that the albino and smaller of the two (by about a half inch) came home from the LFS with a small cyst of some kind on its belly directly anterior to the anal fin. It looks like its filled with either a clear fluid or air. It doesn't look like a pro-lapsed anus but I'm not exactly familiar with that so I could be wrong.
<Anal prolapses are quite common among Astronotus and indeed large cichlids generally. They are usually related to exposure to chronically poor water quality (especially with regard to nitrate). Metronidazole is the remedy, used as instructed on the packaging, but this absolutely must go along with optimal water quality. It's also important to check diet is appropriate. Feeder fish for example are bad, but earthworms are good, and things like unshelled shrimp and crayfish provide valuable fibre that help keep the digestive tract healthy. Some Astronotus enjoy cooked peas, and these are certainly worth offering on a regular basis. Wild Astronotus consume a range of things from snails and crayfish on the one hand to fruit on the other, and not just smaller fish. As is well known by now, feeder fish aren't safe, but you should still provide at least some fish, primarily thiaminase-free types such as wet-frozen lancefish or chunks of fresh tilapia fillet. Don't use fatty, thiaminase-rich fish (notably minnows and goldfish).>
The albino hasn't eaten anything directly but has been sort of filtering the sand and gravel. It spends most of its time laying still on the substrate though and might just not want to compete with the other fish for food I think.
<Indeed; see above.>
I did trying hand feeding but it just swam into the nearest plant and hid from me. I contemplated removing it into a hospital tank and treating for infection which would also allow for easier more direct feeding but I'm afraid it may disrupt whatever territory establishment progress that may have already been made with the other Oscar.
<Moving to a hospital tank is fine, provided the hospital tank is AT LEAST as good as the display tank in terms of water quality and oxygenation. No point at all moving a sick fish to a bad tank...>
I know that the easy option here would be to re-home the fish but if possible
<Yep.>
I would really like to have an albino and a regular tiger Oscar together in my tank and would like to (within reason) try and make this work.
<Good luck on that... Seriously, it's really not a plan. For a tank this size, you'd have much more fun choosing cichlids that would thrive rather than struggle. For example, you could create quite a nice reef of Tufa rock and keep a colony of one of the Dwarf Mbuna species, maybe a couple of males and half a dozen females. You'd get to watch territorial behaviour rather than outright murder, and since you'd have a harem of females, the males would be busy all the time. Alternatively, a planted aquarium with a few pairs of something like Pelvicachromis taeniatus would offer a range of behaviours including pair forming, broodcare and so on. Watching cichlids exhibit the full range of behaviours, rather than just fight, is why aquarists keep them.>
Thank you in advance for your time.
Phil
<Cheers, Neale.>

Tiger Oscar's Behaviour 11/16/09
Oscar Swimming Funny

Hi, I have four tiger Oscars in a 6 foot tank, they are approx 1 1/2 years old and were placed in the tank together when they were about an inch long. I have one Oscar that has currently changed his behaviour - He
has always lived and built his nest behind a structure in the tank and usually sits within the area of his hole, however lately he is lying vertically (nose up, tail down) against the structure, he has slowed down on his eating, not swimming much, and I've noticed over the past two weeks that when he is resting (and sometimes swimming) he floats on his side, his top fin is laid against his body and also "lays" his tail on the bottom of the tank. He doesn't have a swollen abdomen, no hole in the head and no white spots. The other fish are acting as normal (they have built their owns nests within the tank and seem content). I have been changing the water twice a week (about 50%) for the last two weeks - I usually do my water change every 2nd week. I do regular water tests (about twice a week) and act upon any inconsistencies of the water. I feed the Oscars pallets once a day. Any advice would be greatly appreciated. Regards, Donna.
< Sounds like an internal infection. It could be caused from stress, diet or poor water quality. Isolate the infected fish in a hospital tank and treat with Metronidazole and Nitrofuranace as per the directions on the
packages.-Chuck>

Please help
Oscar In Mourning, Probably Not 8/23/2009

Hi my name is Selena. I have a tiger Oscar which I'm worried about. He recently lost his mate, I have fed him feeder fish to help cheer him up but that has not seemed to work. About a week ago he has stopped eating and also been swimming on his side. He is curled like he is dead but he is not.
I have checked. If u could please help me that would be great. Thanks Selena
< I think you should be concerned with why the other Oscar died. The same disease could be affecting this Oscar too and not the death of his tankmate. Do a 50% water change , clean the filters and vacuum the gravel. Remove the feeder fish. They introduce lots of diseases. If your Oscar acts hungry then feed him a high quality cichlid pellet. If not then he may have an internal infection. treat with a combination of Metronidazole and Nitrofuranace. This will affect the biological filtration so watch for ammonia spikes.-Chuck>

Oscar Social Behavior 7/29/09
I had a few quick questions about how social Oscars are in the aquarium hobby.
<Fire away!>
I know when they are young they like to cluster in groups because of safety in numbers I am assuming.
<Something like that, anyway.>
I was just wondering if an Oscar that is about four to five inches in length is mature enough to start breaking away the group?
<Yes.>
I am asking this because if I purchased and Oscar I would like to keep only one because of their size and narrow range of tankmate compatibility.
<Single Oscars are fine, even when "pups". In fact they are among the more compatible large cichlids, being relatively peaceful outside of breeding.
They mix very well with other large community fish: Silver Dollars, Spanner Barbs, Plecs, Clown Loaches, Hoplosternum catfish, and so on. Similarly, while predatory, their diet in the wild tends more towards the crunchy, hence their massive jaws rather than high speed: things like snails, crabs, crayfish being major parts of their diet. I mention this because some folks assume their Oscar needs live fish -- they don't, and should be given Goldfish or Minnows at all -- and live feeder fish does seem to increase aggression. So best stick with pellets or invertebrate foods, so they'll be less interested in their fishy tankmates.>
Also I was thinking an Oscar that is larger would be more comfortable about being taken away from a group of his buddies at the fish retailer. One more thing, do Oscars when they are all grown up prefer to be alone, have some company or makes no difference?
<Adults are territorial outside of breeding, but to excessively so, and in very large tanks you can keep multiple specimens. For that, people typically allow around 50 gallons per Oscar. But they also form very stable pairs, and so if you want to breed them, buying a mated pair usually works quite well.>
So am I in the ballpark of being right, kind of right or just completely wrong? Thank you for your time and advise.
<Cheers, Neale.>

my Oscar crazy 7/27/09
Hello, I have been reading your site and can not find the answer to my problem.
<I see.>
I have an Oscar about 3 yrs old in a 55 gallon tank, the last three days he has started this crazy behavior of filling his mouth with gravel and moving it to on side of his tank and building a large pile.
<Quite normal.>
He has been staying vertical in the tank, not upside down, head down and tail up, strange to me, he has stirred up a mess in his tank, my kids have fed him pieces of hot dogs and he loves them, but we usually feed him washed earth worms or shrimp.
<I really wouldn't recommend using human foods such as these. Besides the obvious statement that they aren't their natural diet in the wild, the critical thing is that mammal meat contains oils that are liquid at mammalian body temperature (37 degrees C) but solid at the body temperature of a "cold blooded" animal like a fish (i.e., the temperature of your aquarium, ideally 25 degrees C for an Oscar). Once those oils become solid in the gut or worse, the blood vessels, they can cause very real damage.
Much better to concentrate on what Oscars eat in the wild: snails, shrimps, fish meat, fruits, worms, insect larvae, and so on. A mixed bag of frozen seafood coupled with a good quality cichlid pellet such as Hikari Cichlid Gold would provide an economical and extremely healthy diet for these fish.>
His mouth is like a big shovel and we can hear him working on moving the gravel all night, what's his deal.
<He's making a spawning pit, and may well be a male gearing up for breeding. His behaviour is absolutely normal. As you observe, these fish have large jaws, evolved for crushing crabs, crayfish and snails. These jaws are also extremely good earth-moving scoops, too. Assuming your don't have an undergravel filter, feel free to let him dig a pit whenever he wants, just watch he doesn't undermine any precarious rockwork or damage anything delicate, such as glass heaters.>
Mary
<Cheers, Neale.>

Tiger Oscar "Shedding" 7/23/09
My 4 year old tiger Oscar looks like he is "shedding skin." He isn't eating or swimming. He just lays on the bottom of the tank and looks like he is dead but isn't. He will only move if you make him. I have checked
the water and even did a partial water change..Usually when he gets to feeling "down and out" a partial water change helps revive him (approx every 4-6 weeks).
<<Water changes should be done... every week... RMF>>
What do I do now?
< Check the water quality. The ammonia and nitrites should be zero. The nitrates should be under 20 ppm. The water should be around 80 F. If all these parameters are within range then I would recommend doing a 50% water change, vacuuming the gravel, cleaning the filters and treating with Nitrofuranace. Follow the instructions on the package.-Chuck>

Astronotus (systems; behaviour; health) 04/22/09
My question is like many other ones, but also different in a few ways.
<Oh? Most Oscar questions boil down to too many specimens in too small an aquarium, with too little care being taken over water quality.>
I have a Orange Albino Oscar, and a Black Tiger Oscar, and for about 4-6 months they've been great together.
<Famous last words. Let's be crystal clear about something: Oscars aren't sociable fish. They are territorial, and except in big tanks, they often don't get along. Juveniles are gregarious to be sure, but as they age, they
become less accommodating. Mated pairs generally form loyal bonds and work well together, but territorial males will be hugely intolerant of one another, and will fight.>
Until recently, My Orange Oscar, looks kind of like it's shedding, on both of it's sides in the middle.
<Fish don't normally shed their scales. So if you have a fish obviously losing scales, that tends to mean either it's sick, or it's being physically damaged, e.g., through fighting.>
It lays on the bottom (not on it's side) either normal, or very slightly tilted. He's not to active, he comes to the top when i feed them, but won't eat much. The reason i said my question was different from the ones on your site at the moment, is because i have the tiger Oscar in there with it, and it seems like almost every time i feed them, the black Oscar will jump out of the water and land on the orange one.
<Sounds like aggression or bullying to me.>
The orange Oscar is also missing it's top fin since this morning. i don't see any pieces of it's fin in the tank, so I'm thinking it got eaten.
<Again, consistent with social behaviour issues.>
Last but not least, i have a odd tank I'm not to sure of the tank size, (30-50gal)
<Dismal. You need more than 50 gallons FOR JUST ONE OSCAR, let alone for three of them!>
i know that's a big difference but it's a half octagon tank, and i don't know how to measure it.
<Easy. Empty the tank. Fill the tank up again, counting how many buckets containing X gallons of water you need to fill it.>
I run two 20 gallon topside filters,. the kind that hang on the back.
<Hang-on-the-back filters are hopeless for large cichlids. You need big, heavy-duty filters with inlet and outlet pipes at different ends of the tank. External canister filters are the ideal, but wet/dry filters and
reverse-flow undergravel filters can work well too (though the latter will need a gravel tidy to keep the Oscar from upturning all the gravel). Allow 8 times the volume of the tank in turnover per hour; e.g., a 100 gallon tank would have a filter rated at 800 gallons per hour. Sounds a lot, but trust me, a 40 cm Oscar makes A LOT of mess.>
i have a air tube on the back of the glass letting air bubbles go into the water.
<OK.>
i feed them feeder minnows,
<Stop this! Feeder minnows are completely the wrong thing for these fish, and in the trade we call these "parasite bombs". Minnows, goldfish and other Cyprinidae contain thiaminase and fat, both of which cause serious health problems for Oscars. You certainly aren't doing your Oscars any favours here. See those strong jaws they have? They're for crushing shells. Oscars LOVE crayfish, shrimp, snails and other such things.>
and fish flakes, and algae pellets, which they seem to love oddly enough.
<They're omnivores, and plant foods (such as cooked peas) are a good addition to their diet.>
I do my 25% water change twice a month, and i notice that a lot of people say once a week?
<Yes, you should be doing AT LEAST 25% water changes per week. In an undersized, under-filtered tank like yours, twice a week would be better. Look up Hole-in-the-Head disease and Hexamita infections. These are difficult (and expensive) to treat, but plague Oscars kept in conditions such as yours.>
Please tell me if i should start doing the 25% change more often, such as once a week.
<Yes.>
Please help, thanks, Mike F.
<Done my best. Do read some more, here:
http://www.wetwebmedia.com/FWSubWebindex/oscars.htm
Cheers, Neale.>

Major color changing Oscar 4/19/09
hi there,
<Hello,>
i have two Oscars the same size one albino long fine and one tiger Oscar well my tiger Oscar is just about completely black with very few orange markings and has a white/orange trim along all of his fins well the albino Oscar is a female and the black one is a male and they are always all over each other there both about 5 inch or so long and well just recently my tiger Oscar has been going through this color changing phase i mean he's always faded in and out but never this much..
<Phew! That's a long sentence! No commas, no full stops (periods), no semi-colons. Wow. Anyway, usually when Cichlids go dark, it's a sign that the fish is stressed. There are some cichlids that turn dark when the age, as in the case of sexually mature male Melanochromis for example, but that's not the case with Oscars. They do have different colour markings when very young compared to the adults, but given the size that yours are now, I doubt that's the issue. Instead, it's more likely they're either a pair, or two fish that don't get along, and colour change implies stress. I doubt you have accurately sexed your fish; outside of spawning it is IMPOSSIBLE to spawn Oscars. If yours have bred before, and they are a known pair, and you've compared the genital papillae of the two spawning fish, then maybe you have sexed them. But do bear in mind sometimes Oscars of the same sex spawn together! You really MUST look at the genital papillae.>
it started when both the Oscars were acting weird they were swimming all over the place way more then normal just intertwining with each and all the sudden the tiger Oscar turns this light brown color and u can see all his stripes and his stripes are almost completely white and the black has faded to a brownish black its so strange i know Oscars orange or red can brighten up but I've never seen one change color as dramatic as him. im wondering what it is that would cause him to do that i don't know if it is just excitement or what but we are just trying to figure out what it is that caused him to just randomly do that.
<Addison, can you do me a favour next time you write and actually use some grammar and capital letters? I really have no idea what you're talking about here. We do, very specifically, ask for native, adult English
speakers to write at least basic English. It's the "currency" by which you "pay" for our help. We use these messages to create web pages, and the web pages get Google hits, and the Google hits sell advertising. Without good writing, the system that pays for this site doesn't work. Anyway, from your murky writing, I can just about tell that your fish have suddenly changed colour following what might be aggressive behaviour or what might be pre-mating behaviour. In any case, Oscars don't really get along in small
tanks, so for a start, check the tank is big enough for two adults; 55 gallons for a singleton, and another 30-40 gallons for each additional fish (at least). Males are less tolerant than females, but there's not much in
it. These issues are from where I'd start figuring out what's going on here. Cheers, Neale.>

Oscar behavior 10/9/08
I recently moved in to a large studio with a large tank housing what I believe is a Red Oscar. About a week after I moved in, he has started piling rocks into one corner of the tank. I have looked over your site for at least an hour, unable to find an answer. He just continuously grabs rocks with his mouth and piles them into the same corner.
<It's what they do. Most large cichlids will dig, particularly if they find some aspect of the tank size or decoration not to their liking. Do make sure that through digging the Oscar isn't undermining the stability of the decorations. Cheers, Neale.>

Oscar Acting Weird 9/17/08
Hi. We had 2 Oscars that were together in a 55 gallon tank for 5 years. One more aggressive, but for the most part they got along. About a year ago, the less aggressive one got very sick. He grew a large swollen lump on one side and began swimming sideways. He would lay upside down in the tank and didn't eat for weeks. I tried everything I could to save him but nothing seemed to work. When we finally decided to euthanize him, we went to scoop him out of the tank and he began swimming like nothing was wrong. He seemed to be getting better as far as eating again and swimming again (still had the lump). He ended up living another 6 months and began swimming in erratic circles and laying upside down again. I did research to try to figure out what was wrong with him, but nothing worked so we put him out of his misery.
The other Oscar never seemed to catch whatever it was he had. Its been about a year now, and all of a sudden he is doing summersault like actions, but only in one spot in the tank. And occasionally he will do a violent shake, its so strong the whole tank makes a loud noise. Other then that he seems to be normal. Im worried that he might me getting sick too and I don't was to see the same thing happen. He is about 6 years old now, and by himself (with a sucker fish) do you think he might be lonely/bored since he was with the other one for so long?
Any advice would be great! Kerrilynn
<Lets start with the basics. Check the water quality. Ammonia and nitrites should be zero and the nitrates should be under 10 ppm. The water temp should be 80 F. Do a 50% water change, vacuum the gravel and clean the filter. Change the diet to something with more vegetable matter. If there is no improvement after a couple of weeks then treat the tank with a combination of Metronidazole and Nitrofuranace.-Chuck.>

Tiger Oscars Behavior Question 8/8/8 Hi there, I've read hours and hours of your FAQ's and I can't find the answers to my questions. I'll start with a little background info. I have a 75 gal tank which was housing (1) 5" Red Belly Pacu, (1) 7" Tiger Oscar, (2) 4" Tin Foil Barbs, (1) 4" Blue Labidochromis know I'm not supposed to mix Africans and S. Americans, but after the first major battle and a brief separation, the Oscar outsized him and my Lab is behaving now), (1) 3" Opaline Gourami (another strange addition, but was doing well and not being harried by the larger, more aggressive fish), and (3) 2-3" Plecos. <Certainly an interesting mix of fish.> I know that this is a lot of fish for the size of my tank, but I got them all when they were about 1 1/2" and figured that natural selection would leave me with the strongest and most compatible group. <OK, now don't say that sort of thing around people who are interested in animal welfare, like us. You've already started poorly in my estimation just by crazily overstocking your tank (that Pacu can reach over 1 m/3.5' in length and weigh up to 40 kg/88 lb). Telling us you're basically leaving your fish to fight for their survival so the best fish wins is just making things worse.> They haven't had any problems though so I still have them all except for the Gourami which I traded yesterday for two 5" Oscars (one Tiger one Albino Red, I believe). <You do understand that "two" Oscars aren't going to get along with each other, let alone the resident Oscar?> These two I actually kind of rescued from a 20 gal tank and a VERY inexperienced owner. <Hmm...> My tank is very clean, I have a huge canister filter that's rated for a 175 gal tank and I do regular maintenance on it and the tank itself. The water temp is right about 76* without a heater so I don't bother with one, <Seriously? Your house is this hot 24 hours a day, 7 days a week, 365.25 days a year? If the answer is NO, then YES, you need a heater.> I have the lights on a timer and I keep the temp in the house at the level most conducive to the fish. (I know that they can't adjust it on their own so I work around them) I haven't checked the chemical levels lately, but everything has been fine so I haven't been concerned. <Hmm... this isn't really what I want to hear.> To get down to business now... When I got the two new Oscars, one was very badly injured in the process of removing it from the other tank, the owner had shells and sharp rocks that it beat itself up on for several minutes trying not to be caught. I know that it will heal, but was only worried that my existing fish would pick on it due to it's weakness... this did not happen, much to my relief. What did happen is what confuses me. When introducing the new fish, I made sure to feed everyone to confuse them and moved all of the plants and decorations to eliminate existing territorial patterns. This of course elicited a very active environment for several minutes. I expected that and was glad that my existing fish, who are very healthy, did not pick on the new guys. <OK.> What happened between the new Oscars and my existing Oscar seemed to be normal at first, the old one circled around them and between them a few times, did the little dominance twitch, head butted them a few times and seemed to be more attracted to the injured Tiger. At first I was worried that I was going to have to quarantine the injured one until it healed, but the strangest things began to happen. My older Oscar sort of cornered the injured one and started flaring his gills and opening his mouth, but in no particular direction. He mouth bumped the injured Tiger, then the Albino, then turned and bit my Pacu (no damage was done). He then started backing up to the Tiger and rubbing his tail on the other fishes tail area. This went on for several minutes and then he set about attacking everything that came near him and the injured Tiger. I put my hand into the tank and diverted the other fish away and they seemed to get the hint and left them alone. <Fish don't "get the hint". They're doing something. A hand appears. They get scared. They swim off. The hand vanishes. They (eventually) go back to what they're doing. You have to be realistic with fish, and think at their level, and be careful not to project your optimistic hope onto what you observe happening.> I was a little worried when I went to bed last night, but when I got up this morning everything was peaceful. The two Tiger Oscars (one old, one new) were still staying close to each other, but they were behaving like normal fish again. So my question is this: Was my Oscar attempting to establish dominance, attempting to mate, or protecting the injured fish from the other tank mates? <If you have two adults who tolerate each other, they're likely a pair. They don't "help" each other out.> I've had Oscars before and I've never had any mate, but I've also never seen one act quite that way, especially towards a new member of the community. The tail rubbing and the aggressiveness toward the other fish are what really confuse me, because the rest is normal behavior for an Oscar in my experience. <Sounds pretty normal to me. It's going to get rougher in there as the fish mature, and may the Fish Gods help if a pair decides to spawn.> Is it possible that the new Tiger is a female? <Absolutely no idea. Your can't sex Oscars until they spawn.> Or is it likely that my older Oscar was defending a weaker member of the species (I know that sounds strange, but that's really what it looked like). <Well it isn't.> I hope you can help me figure it out because I would hate to have the "you know what" hit the fan and come home to a bunch of dead fish. <Eventually, more than possible.> Should I be worried? <Yes.> Thanks for your input, Rory H. <Happy to help. Good luck, Neale.>

Re: Tiger Oscars Behavior Question 8/8/8 Apparently I didn't clarify properly. <Oh?> I didn't mean to sound like a meanie who lets their fish fight to the death, what I meant when I said "natural selection" is what normally happens when you begin a new community of fish and some tend to die from being overly stressed through transportation or possible mishandling at the pet store. <Well, this shouldn't happen. Doesn't happen to me, anyway. When you buy quality fish from a reputable store, there's no reason to expect any to die. And you certainly shouldn't be banking on it.> I wouldn't be contacting a forum for the welfare of my fish if I was that heartless. <Good.> Also, the red belly Pacu I have must be a dwarf variety if there is one, because I was told it wouldn't get any bigger than an Oscar at full size. <There's no such beast. If it's Colossoma macropomum, the Red-belly Pacu, it's a big Big BIG fish. Adults are the size of sheep. So, you need a gigantic (1000s of gallons) aquarium for them. If this store told you it's a "dwarf" variety, they're either wrong about the species or ignorant/deceptive about the adult size. Either way, are you going to trust them on anything else? Not without checking in an aquarium book or Fishbase first, I hope!> That will give me 6 foot long fish and four 7" fish at full maturity and I know that I don't have room for that. <Well... no argument about this aquarium being overstocked anyway.> I also know how big Plecos can get, but 2 of the ones I have will not get over 6-8" at full size and the other is the smallest of the three so I have several years before I have too much to worry about. <What Pleco do you have? If it's the common sort -- Pterygoplichthys spp. -- these grow very big, very fast. We just had someone today send in an e-mail about their specimen going from one to twelve inches in a YEAR. There are smaller types, but they aren't sold as Plecs, they're sold as Ancistrus or Panaque maccus or whatever. Again, I'm not trying to be awkward, I'm simply telling you the truth. If you prefer not to know the truth, then that's fine but I can't really help you much if that's the case.> I suppose I also should have mentioned when I rescued the two Oscars I got yesterday, I don't mean to keep them and my other fish together in my 75 gallon tank for eternity, I am providing a temporary solution for two very abused fish and will find them another home soon. <Fine; I'd probably have done the same thing under the circumstances.> I'm actually working on getting a 125 gal tank put together for the other side of my living room and will split the fish between the two as soon as I finish setting it up. I am only worried that I may need to separate them before the two weeks I need to get the other tank in safe working order and stabilize the water. <You can clone a new filter from a mature filter simply by dividing the mature filter's media 50%, putting one half in the new filter. Provided the filters are of reasonable size for the job, and provided you don't overfeed either tank, this should work reliably and instantly.> By the time they get to be another few inches longer, I intend to have another tank that I will keep in the dining room. I'm thinking about a year or two. I've had fish as pets for twenty years and most of that time was spent on aggressive's. <OK.> I try to be very conscientious of my fishes living conditions, and yes, I keep my house at 75-76 degrees, year round 24/7-365. <Ack, I can't even imagine that! I prefer a cold climate...> I also make sure not to put my tanks in direct sunlight or near any vents. I am a little offended at how harsh the response was the my earlier query and would hope that you handle things a little more delicately in the future. <No offence meant.> I obviously should stick to local handlers to answer my questions. <Are these the guys that sold you the "dwarf" Pacu? Be my guest... but if you stick around here you'll be communicating with people who aren't out to sell anything, who love the hobby, and have serious expertise they're willing to share.> I'm sorry to have bothered you for your time. Rory H. <Not a bother if you're aware of what's amiss in your aquarium and can make a plan to deal with. I'd start telephoning around the public aquaria re: that giant Pacu you've got because it seriously isn't a "pet" fish by any standards. Or maybe it isn't the species they said they sold you, but something else entirely, and that really would make my case that your local retailer might not have all the answers. Good luck, Neale.>

In need of Oscar 'expert', beh., comp. Dear Crew, My Oscars are really starting to get super aggressive, but not toward one another! I have been bitten several times, these bites occasionally scratching deep enough to draw minimal blood. My Plecos are hiding in their driftwood with little tears in their fins. The air hoses are being torn out, decorations (heavy resin logs!) are being pushed around. Not to mention constant gravel throwing! This all sounds pretty normal... <Yikes... not uncommon behavior> I have two Oscars that are almost a year old (At least I believe so. They were about 3 inches when I got them in October 2007). One is an albino tiger about 11 inches long. The other is a red Oscar about 8.6 inches long. They really never fight with one another, but never leave each other's side. They shake their tails at one another and even eat together peacefully. I provided them with flat rocks and what not, thinking this would encourage egg laying. I don't know if I have a pair. From the pictures I've looked at and books I've read I think this is a possibility. I know sexing Oscars is difficult so I'm still not quite sure. The following picture is what they've been doing the past few days. I recently moved all the driftwood to one corner to allow the Plecs to hide and to give the Oscars more room to throw things around. They hate decorations so I figure I might as well make the tank the way THEY like it. View full size Recently the albino Oscar has some sort of tube extending from its anal area. This is not a prolapse as far as I know, because the tube is below its anus. I've included some pictures of the fish and their 'bottoms' to see what you guys think. At any rate the red Oscar's anal vent is not as distended as the albino's. View full size I apologize for the pictures being kind of poor. They get very upset when they see the camera and flare their gills and show me their mouths and all those cute Oscar threats. Thanks so much for your time! - Michelle <No pix came through. Please try attaching rather than embedding. The tube is likely a breeding device... I would remove the Plecos if they're getting too beat. You don't mention the size of the system, or what you feed exactly, but these are important factors re these animals behavior. Please read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

Oscars behavior strange... -actually... normal terr. and repro. 05/19/08 Hi all you wonderful crew of WWM who are always ready to help! I have found some fabulous information on your site, and thank you for it! Anyway I have a question now, and cant seem to find the answer. <Let's add to the site Tanya> First of all, I have 2 fish tanks. A 110 g reef tank and a 55g Oscar tank. Well I had two Oscars to begin with, a red velvet and a tiger, and by sexing them I found the smaller of the 2 (about 5-6") to be the female, and the larger to be the male (about 6-8"). Anyway, I set this tank up for my husband about 6 months ago, so it has been fully cycled, and I use only RO/DI water (learn a lot dealing in marine aquaria) Well the two were fine, and I went and bought a 3" albino Oscar to go in there with them, <Yikes...> which was a dumb thing to do, because the female did NOT like the new girl. The albino was constantly getting bit and bullied. So after about a month of waiting for it to get better, I looked closely at the albino and the poor little thing had bite marks and scrapes all over her, so I immediately removed it and gave it to a friend. Now after removing the albino, the male seems to be attacking the ORIGINAL female. But I don't know if this is normal, <Is not atypical> if it is a ritual for males and females to go through. She immediately takes on gold stripes all over, and lays on the bottom. <A submissive behavior. Not entirely analogous to dogs... They need to be separated... either a partition or individual tanks> We fed them when we saw her do this, and immediately she rose to the top for food and the stripes disappeared.. Immediately! I never saw anything like it. She was laying dramatically at the bottom, and then when the food came around she was 'all better' but after she ate, she was right back to the same thing, yellow stripes (about 1" thick) vertically down from her dorsal fin downward. She did not do this before the other fish was removed, or before I got the albino period. Is my male picking on her or are they planning to 'get busy', lol... Thanks in advance and hope to hear from you soon.. Tanya Shankles. <Too small to be this sort of "busy"... again, a physical barrier needs to be between these Oscars... at least for a few weeks... You may need a larger tank as well. Bob Fenner>

Oscars, beh. 5/1/08 Hello, My brother-in-law just purchased a red Oscar, and not ever keeping them myself I was not sure on any advice I could safely give him other than what I had been able to find on this site which has been a wealth of info for me and my particular tanks. He has a 55 gallon cycled tank. He purchased a 2 inch Jack Dempsey about a week ago and a 3 inch Oscar two days ago. <Mmm, will need more room in time... and this will show behaviorally> the ammonia, nitrite are 0 and the nitrate is at about 5, he has a ph of about 7.5, temp 78F and filtration of about 350 gph. The tank has been set up several years and use to house Central American Cichlids that his son took when he moved out the week that the Dempsey was purchased. The Jack Dempsey has been very active, but the Oscar hides a lot and laid on its side the first night in the tank. <Not atypical> He was very active at the LFS where he was with about 3 other similar sized Oscars. When the lights are off the Oscar swims all about the tank, but as soon as the lights are back on he hides.... does it take Oscars a bit of time to feel secure in a new tank and should the lights stay off for a couple of days or should he "encourage" the Oscar to get used to the lights on? Is he sulking? <Does take a while to adjust, I'd leave the lights on a regular schedule> Again, it has only been a couple of days, but never having this particular problem with any of my fish and never keeping Oscars I didn't want to tell him it's normal or have him promptly return the fish for another to find the same thing happening. Any help would be appreciated. Keith <As long as the fish is not being bullied by the Dempseys I would not be concerned. I urge patience here. Bob Fenner>

Sideways Oscar, beh. 4/26/08 Okay, I just spent about an hour looking through your site but could not find anything that fully describes my problem. I have 3 Oscars. I got them from a friend who bought a house and the Oscars came with the house. They are in a roughly 100 gal. tank with a jack Dempsey, plecostomus, one fire mouth, and 4 large goldfish. <... a poor mix. Remove the goldfish here> One of the Oscars has been sick for awhile now and is getting worse. The other 2 are very healthy looking and very active. I don't see any white fuzz on him or black rot. No bloating. He has been acting "retarded" according to my husband who feeds them (pellet food). He has been listless and seems to not be able to eat. He was striking at the food, but seemed to miss or not be able to keep it in his mouth. Now he has gotten worse and is lying on the bottom of the tank. When I go to the tank, he seems to become more active and try to upright himself, but can't get all the way upright. I don't know what to do. I don't know how old these fish are. They are at least 12" long and the other 2 are brilliantly colored - the sick one has become dull and pale (he is a tiger Oscar). I do 25 - 50 % water change every couple weeks. I have not recently added anything to the tank. I have had the tank and fish for over a year. Thanks <The one is likely "behaving" backward as a sort of submissive behavior toward the other "pair"... Removing the goldfish, spiffing up the water change maintenance, should largely alleviate the problem here... crowding. Bob Fenner>

Oscar turning grey. 4/15/08 I have an Oscar cichlid. We were given the Oscar in a 3-gallon tank, and while I didn't measure him, he was obviously too big for that tank, so I got a new 20-gallon tank and put him in there. He has so much space now and was moving all around. He rapidly turned a bit grey and red from his original black and red. I was wondering if this is just because he's getting used to the change of environment? Or because I have white gravel instead of colored gravel? <Well yes, white gravel will often make cichlids "fade" their colours. Most fish DO NOT like substrates that are brightly coloured. Use plain gravel. It might not be to your taste, but it will suit your fish so much better. And, after all, it's the fish who has to live in the aquarium -- not you! Anyway, you can't keep an Oscar in a 20 gallon tank. No way, no how. Let's be crystal clear about this: Oscars are big fish that produce a lot of waste and are easily prone to diseases like Hole-in-the-Head when kept in unhealthy conditions. You absolutely MUST upgrade his aquarium to at least a 55 gallon system within the next few weeks. This is non-negotiable. If you don't have space for a 55 gallon tank, you don't have space for an Oscar too, and sooner or later this fish will be poisoned by its own waste and die a slow, painful death. There are some lovely dwarf cichlids better suited to tanks 20 gallons in size. Do please research them as sensible alternatives. Cheers, Neale.>

Oscars and plants Oscars Redecorating The Tank 3/30/08 Dear Crew, As much as I like my Oscars, they are driving me insane. They are about eight months old and seems to hate everything in their tank. They are spitting gravel everywhere, pulling on tubing and attacking tank decorations. But this is not so much my problem. One of them is absolutely shredding any sort of plastic plants I put in there (She also tries to bite my hands when I clean the tank, but this is beside the point). She rips the plants apart and they get stuck in the filter. I want to have plants in my tank, it looks incredibly bare as is right now and it's really bothering me. Is there any sort of live plant, silk or plastic plant that can stand this kind of abuse? Do you have any recommendations? I realize that Oscars are notorious for this behavior, but I don't want my tank to look like a prison cell. <Your Oscars are cichlids that are very territorial. This includes moving things around to set up borders to their turf. This is pretty normal with large cichlids. Unfortunately live plants don't stand a chance and artificial plants won't be much better. Maybe large pieces of driftwood that has already been soaked to remove tannins can give your tank a different look.-Chuck.>

Question about my Oscar... crowded/aggressive-behavior, no useful data, or reading 2/25/08 I have 1 red and a tiger Oscar which are about 10" in a 55 gallon. <Need more room than this> All the water test came back normal according to the box. My question was today when I was watching them I noticed that my red (I believe is my female and my tiger to be male). Had some white cloudy stuff come out from her anal area. Fallowed by greenish cloud stuff . Was wondering if this was normal never notice it before. Never seen them spawn although they act like there going to but never do. <... Need to know what you're feeding... And you'd do well to read what is posted on WWM re this species. Start here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm then on to the linked files above. Bob Fenner>

Re: Question about my Oscar I feed them Hikari pellets and about once or twice a week I feed them krill and/or brine shrimp. <Please read where you were referred... this system is still too small... B>

Bellicose Oscars 11/1/07 Hello WWM, <Hi, Scott V. here.> I have two juvenile Oscars, one red and one tiger albino. I have questions about both of them. The first one is that the other night I went over to the tank and opened up the top to look in before I fed them, to let them know I'm coming because they seem to know what that noise means, and the red Oscar jumped out of the water about five inches to attack my face. While I was cleaning up the water he splashed all over the place? I saw that he had scratched himself a little on the side on his way back down. He has been healing up fine. Is there anything I should put in the water to aid in the healing process? <If he is healing ok, I would not worry. Best to keep good and stable water quality for healing.> Also, do you think his behavior is aggressive, or is he just excited that he's going to be fed? <Oscars tend to get excited when it comes to feeding. They also learn to recognize the face that feeds them, adding to the excitement.> I don't know if he has it out for me, he watches everything I do around his tank. The albino fish has been eating fine (they are fed a variety of Hikari cichlid food, and they eat the Plecos algae wafers on occasion if they find them). The first day I got her I noticed that one of her eyes (her left eye to be precise) was lighter than the other, and that this might have to do with her being an albino. I find, however, that when I go to hand feed them she is a little off the mark, not unlike someone who is blind in one eye. She seems perfectly capable of taking care of herself, I've enclosed a picture to see if there is any problem... (http://img.photobucket.com/albums/v470/MDBouchard1987/pechesfish.jpg) or if this is just a deformity. Thanks for your time, Michelle <Looks fine from what I can tell from the picture. She could possibly have diminished sight, but different colored/shaded eyes are not uncommon. Oscars have a lot of personality that manifests differently from fish to fish. Thank you, Scott V.>

Overly affectionate fish... Oscar beh. 10/3/07 Hello, This site has been invaluable to me today. My father bought me two baby Oscars to replace goldfish that died in what was one of the most disheartening parasitic diseases I have ever seen. (I hope someone will learn to quarantine their fish, because my father bought? goldfish as a surprise...and the surprise was a fish Holocaust.) Anyway, I sterilized the tank and let it cycle. After being let out of the bag and sulking for a half hour the two fish have not left one another alone since. They are constantly together, almost dancing around one another. I think they are much too young to mate, they are only three inches long. Is this normal? Will they stop being affectionate and more territorial as time passes? (I optimistically hope not, it is very cute that they are so close.) They both seem to have healthy appetites, and aside from being a little skittish this is the only quirk I've noticed. Thanks for your help in advance <Hmm... unlikely they are playing. Much more likely they are threatening one another. Oscars are not social fish. They are largely solitary, except at breeding time when they form pairs. Oscars are basically placid animals, but if two fish don't like each other they will fight, and can potentially cause a great deal of damage to one another. While they don't fight to the death, secondary infections can set into wounds, and those can become serious. Anyway, please understand that Oscars are also extremely big fish. A single adult specimen will need, at minimum, 200 litres/55 US gallons. Obviously two fish will need even more space, assuming they even get on. Please be sure and read this article on Oscars: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm . Cheers, Neale>

Oscars spawning and fighting badly. 7/28/07 hello I have two Oscar's about 2yrs old. they spawned about a month ago all the usual stuff occurred no fry were produced, just a fuzzy mess. <Almost certainly either [a] the eggs were not fertilized because the fish didn't spawn properly this time or [b] more likely they were fertilized but water quality was poor and fungus took over the batch. It's important to keep water in the breeding aquarium spotlessly clean and to ensure there is ample water movement across the eggs. Adding anti-fungal medication is also useful if you decide to "pull" the eggs are raise them yourself.> last night they started fighting after a tank change two days ago (20%) nothing abnormal figured here we go again. there is a Pleco and red eared slider who is in love with the tiger Oscar lol. took them out. <Strange combination to begin with, but okay...> and with in an hour my albino has ruined the tiger who I presume to be the female as she is smaller and stuck by the eggs nonstop last time. <Well, obviously they are no longer compatible. You will need to separate them, and if you do decide to re-introduce them, use the egg-crate tank divider method to begin with so they can see but not attack each other for a couple of weeks.> her sides are thrashed her gills have a chunk missing and her fins are strings. so I divided them hopefully in time. <Let's hope.> A) will she heal ok and what preventive measures should I take to help? <Yes, she will heal, provided you treat the water with anti-fungus/anti-Finrot medication RIGHT NOW and keep water quality PERFECT. We're talking 50% water changes every day for the first week, and then 50% water changes _at least_ weekly thereafter. With this amount of damage she's a sitting duck for every opportunistic pathogen in the tank. Take no chances, and cut no corners.> b) will they still produce and fertilize? I guess its possible I have 2 females but not sure yet. the tigers lower belly is long and swollen downwards. <Two females spawning together does happen. Sexing Oscars by eye is impossible. Can't be done. The only clue is the shape of the genital papillae, but you have to actually watch them spawning to see it. Everything else, like the shape of the belly, is myth not science.> c) will the missing scales and cuts regrow. they were so beautiful. <Yes, scales grow back.> please help. <Hope this helps. Please, next time, try using capital letters in your messages. Makes them easier to read. Cheers, Neale.>

Tiger Oscar Cichlid, beh., sys. - 7/23/07 Hi, I recently bought two tiger cichlids at about 1.5 inch for a 30 gallon tank. The two fishes are on the aquarium floor and do not move, although I can still see them wiggle a little bit. I was wondering if this is normal, or if there is some thing wrong with them? They also haven't eaten anything yet. Thanks for your time, John <Hello John. Tiger Oscars are, as you know, going to grow into huge cichlids that CANNOT be kept safely in a 30 gallon tank. In the meantime though, if any Oscar is not swimming about and not hungry, you can assume something is wrong. Precisely what, I cannot say without more information. What are the water conditions? Hardness, pH, nitrite, and nitrate all matter here. What sort of filtration are you using? Like all cichlids, Oscars are very sensitive to dissolved metabolites in the water, i.e., if you don't do big, regular water changes -- the fish WILL get sick. You're remembering to add dechlorinator each time you change the water? There are no aggressive fish in the tank (Oscars are rather gentle, and easily bullied). What foods are you using? Juvenile Oscars are generally quite outgoing fish, but if the tank has no shade for them, they might feel exposed. Oscars are often mistreated by retailers. Check for signs of parasitic infections. It is common for people to feed them cheap feeder fish, and this gets them infected with internal bacteria and parasites. As you probably know, the ideal diet for Oscars contains no live fish at all, but rather crunchy invertebrates (what they eat in the wild) plus good quality cichlid pellets (Hikari Cichlid Gold is excellent, but there are others). Cheers, Neale>

Oscars acting strange 7/7/07 <<Hello, Dan. Tom here.>> I just introduced two red Oscars to my tank, and since Ive done so they have been just laying on the bottom. It hasnt been very long, maybe two hours, but there hasnt been much movement, just the occasional swim-around. Was wondering if any concern is necessary? <<Assuming all else, including water quality/conditions, is appropriate for your new fish, Id suggest that this is simply part of their acclimating to new surroundings. Cichlids enjoy hiding places so they can feel secure and, absent these, will hang out at the bottom until theyve adjusted. Since its only been a couple of hours, at the time of your post, I wouldnt be concerned just yet. Theres a lot of detail missing from your letter such as tank size, tank mates (if any), future tank mates (if these are being considered), etc. These fish will stake out territories in large tanks and, if there are none defined, will likely see the entire tank as theirs. Depending on your personal vision for this set-up, this may be okay but be aware of the implications of your Oscars commanding the entire tank as their own space which they will vigorously defend.>> Dan <<Good luck, Dan. Tom>>

Oscar question, beh. 5/13/07 Hi! <Ali> I have a 4 yr old (approx) Tiger Oscar who has no tank mates as nothing seems to survive very long with him (even Plecos). I have had Oscars in the past and his personality is fairly normal for an Oscar. <Mmm, can be better socialized when young...> I don't have a lot of time to "spend" with him, and his tank (80 gal) is not near anything for him to really interact with and never has been. He exhibits normal behaviors, i.e. moving gravel, uprooting plants, looking at himself in the bottom of the tank, etc. I live in Florida and do not provide him with a tank heater, as a) he breaks them and b) his tank is normally around 75 degrees without one. My question is this. In the last 24 hours he has been literally thrashing in his tank. He isn't looking at himself in the sides of the tank, and it doesn't matter if I'm standing there watching him, or asleep in bed. He doesn't care what time it is when he decides to go postal and make all that noise and start beating himself. He seems to not be anywhere specific in his tank when he starts. Although I have seen him start flipping out on one side of the tank and zoom to the other side and bang himself against the side of the tank and thrash all over for several seconds. Again, he isn't "looking" at himself when he does it. The only recent change I've made to his tank is to move gravel back over his "mirror" hole on the bottom (his strange behavior started after i did this) and I tossed him a new ping pong ball to play with, although the dog found that on the floor this morning. It must have flown out during one of the Oscar's "episodes." When he does this, it makes me think of someone having a seizure. He doesn't appear to be ill...but he has lost a couple of scales in the last day. His tank is cleaned regularly (once a month). Any suggestions? Do they make fish Prozac? Thank you for your time. Ali <Well... perhaps this fish "ate a bug" that flew in... Maybe with the sun changing its position on the azimuth with the season it is seeing an internal reflection... I would check your water quality here... Could be the municipality has changed/pulsed the amount of sanitizer it is using... or this could be a result of ammonia, nitrite or nitrate toxicity/presence... many possibilities. Bob Fenner>

Please Help. Albino Oscar... beh. 2/6/07 I have a question about my albino Oscar. For some reason he seems to be losing his scales. His tale and fins are intact, but his scales are just falling off. <Environment...> I have also noticed that up on his head where he breaths he is only using one side. What should I do to treat whatever he has. He is in a tank with another Oscar which is the same age, but about one inch bigger in size and is dark in color with some red on him. <How large is this system?> I did not know if here is some medication that I can get to treat the albino one and not hurt the dark one. The dark one shows no sign of any sickness what so ever. Could they be fighting <Oh yes> and I'm not be aware of it? <Correct> The tank only has gravel on the bottom. There are no plants or big rocks in the tank. Please help, your knowledge will be much appreciated. Jenny <I'd be separating these fish... NOW. Bob Fenner>

Re: Please Help. Albino Oscar... beh. 2/7/07 My tank is a 35 gallon and the white Oscar is about three and a half inches and the dark one is about 4 and a half inches. <Need more room for sure... much more in the future> So you a saying that they are fighting and that is what is causing the white one to be sick. <Yes> I just want to be clear on this. So do you recommend that I get a bigger tank or just separate them completely? <The latter for now... and yes to the former> I know that there are times that just to little space causes fish to fight. Jenny <Yes... this is correct. Bob Fenner>

Oscar Attacking His Reflection 1/3/07 Hello and Happy New Year. I need your advice on a situation which is happening with one of my fishes. I have a 75 gallon tank which houses a 10 inch Tiger Oscar, 7 inch Jack Dempsey, 6 inch Jaguar Cichlid, as well as a Pleco and pictus catfish who are both about 5 inches. The problem is with my Oscar. Recently he has been banging himself against the tank wall and swimming sideways. I know that he is doing this because he sees his own reflection in the glass and thinks its another fish challenging him for his territory. He hits the tank wall in an attempt to get to the other fish. The side way swimming is his way of showing his size and intimidating the other fish. My water levels are all fine as well as his appetite. When the tank light is off he acts fine, this behavior only occurs when the light is on. I lowered the temperature of the water to 72 degrees. It has not changed his behavior he is still attacking the glass. In the process of swimming up and down and attacking the glass he scraps his body and fins against the gravel and tank decor and has injured himself pretty bad. Any advice you could lend me would be greatly appreciated. Thank you Jimmy K < You need to change the lighting. Try blocking out the aquarium light from the end that he is attacking. I would try a piece of wood for now and see if that works. If it looks like it is working then replace the wood with a piece of dark colored glass so it won't get too hot from the lights.-Chuck>

Re: Oscar Challenging His Reflection In The Glass 1/11/07 I changed the lighting and the Oscar's behavior changed slightly for the better. However the appearance of the tank suffered. It was very dark and gloomy due to the lighting change. Is there another way I can go to change the way my Oscar is behaving. Thank you again. Jimmy K <Try covering the end of the tank that he is seeing his reflection in paper. It may be light enough so he can't make out the other fish in the glass.-Chuck>

Oscar Attacking His Reflection III 1/12/06 He is not attacking one specific area of the glass. He attacking many different areas, mostly in the front of the tank. Jimmy K <In the front of the tank is where most of the light from the hood hits the front glass. Once he gets fired up he begins to see his reflection everywhere. Instead of the light fixture being at the very front, you could try and move it to the center of the tank. Other options would be to change the lighting bulbs to a different color temp. You are going to have to try different things. Maybe add a few silver dollars to distract him. These are referred to as dither fish. If your tank is big enough and you have enough filtration these big round tetras move in a big school. There usually are not aggressive and the Oscar would be more concerned with these guys and not notice his reflection as much.-Chuck>

Fighting Oscars Are Getting Hot 12/24/06 I have two four-year old Oscars in a 90 gallon tank with a Pleco. Up until about six months ago, I had three, and, periodically, they would do frequent battle, sometimes nearly to the death for at least one, but all had their turns at coming out on top and on the bottom. Just when it reached the point that I had decided to get rid of two of them (I put up a "free Oscar" poster at the local pet supply store but nobody bit), one died mysteriously and after that, there was peace. The other two got along for months with no trouble at all. That peace ended the day before yesterday, when they suddenly started fighting ferociously. They fought so hard and so violently that I fear one or both may have wound up with broken jaws. Neither have taken a bite of food sense and the way their mouths look, and the way they are both swimming about with their jaws hanging down, I am not certain they can take a bite right now. I was wondering why two peaceful fish would suddenly go to war with each other like that. As I have been traveling, I had not cleaned their tank for three weeks (my wife cared for them while I was gone but that care does not extend to tank cleaning) and I wondered if maybe there was a water-quality issue that had caused them to get cranky. This afternoon, I interrupted the continuing brawl to clean their tank and when my skin came in contact with their water, I surprised at how warm it was. So I looked at the thermometer and it was 84 degrees! I try to keep it at 76 and I don't know how that happened, as the setting on the heater was just where it was supposed to be. I have been cooling the tank down slowly and it is now down to 80 degrees. Tomorrow I will bring it down to 76. Could this warm water have triggered the battle? They are still making intimidating feints at each other, but there has been no more of the fierce fighting since I cleaned the tank.Thanks,Bill < This is probably a combination of too much food from an inexperienced aquarist and temperatures rising. Big fish can be pretty tough on aquarium equipment. I would recommend getting a titanium or stainless steel heater for this tank. As the water temps cool down things should settle down.> PS: After you answer this question, I have a green terror question for you. < You may have to wait awhile after x-mas to get a response.-Chuck> \ Oscars Acting Strange 12/17/06 I have had 2 Oscars for about a year. I got them both at the same time. One really took off and the other one grows slowly. They share the tank with a algae eater. Recently the larger one has been banging himself against the aquarium wall and swimming sideways. I have tested the water with normal results. I have taken water to pets smart and it was fine. I am not sure what else to do. He is starting to have some of his scales peel off as well. I truly need some help!!!!! < When you put two fish together in the same tank one always becomes dominant. This means one gets all the food and bullies the other around. The submissive fish tends to hide and stay out of the way so as not to get beat up. The larger Oscar now is seeing his reflection in the glass and thinks it is another fish challenging him for his territory. As he attempts to get the other fish he hits his head on the glass. swimming sideways is his way of showing how big he is and trying to intimidate the other fish. Try cooling the water down to the mid 70's and see if that calms him down.-Chuck> Semper Beatus Jon M Carroll

Re: Oscars Not Eating 12/21/06 Thank you for your help. I have gotten him to stop hitting his against the wall with a 2/3 water change and keeping the temp about 72 degrees. Now he is not eating, it has been about 3 days since I changed the water; the little one is not eating either. They are both just hiding in the rocks, any ideas? Thank you again. Semper Beatus Jon M Carroll <At 72 F that is a little too cold for them. Slowly get it up to around 75 F. You need to find a temp to where they will still be warm enough to eat but not warm enough to get territorial. -Chuck>

Re: Oscar Gone Wild 11/23/06 Hello again, I'm sorry to bother you again however I need your help. I have a 75 gallon tank that house a 10 inch tiger Oscar, 7 inch jack Dempsey, 6 inch jaguar cichlid, 4 inch pictus catfish, and two 4 inch Plecos. The problems began about a week ago. My Oscar was not eating, he would just lie on the bottom of the tank breathing heavily. The water levels of the tank were normal and there were no signs of internal disease. I treated the Oscar with Metronidazole and after the second day of treatment he was back to its normal behavior. <This is a great medication to use when no external signs of disease are apparent yet you know something is wrong.> <<Is toxic however... should not be used casually... will kill fish (and human) kidneys with over-exposure. RMF>> The next day I did a 30% water change and moved the rocks and drift wood in the tank around because my Jaguar cichlid was moving the gravel and making a mess. After the change to the tank my Oscar started to act unusual. It is chasing the other fish all over the tank without mercy. I assume he is doing this to establish his new territory since I moved the objects in the tank and that this behavior should pass soon. However this morning when I opened the tank light I noticed that the Oscar had a white cloudy spot on one of his side fins. Both side fins have a cloudy color to them instead of the clear look which the usually have. But it is his behavior today is what concerns me. He is still chasing the other fish. He is also swimming up and down the tank on his side with his mouth open very frantically. By doing this he has injured himself by hitting rocks in the tank. The water levels of the tank this as of this morning are fine. The temp is 81 degrees and I last did a water change two days ago, 30%. Any help you can lend would much appreciated. Thank you. Jim < As you pointed out that cichlids are territorial and now that everybody is feeling good they are going at each other to determine a pecking order. Lowering the temp to 77 F will help slow things down. The whitish patches are damage from fighting and scrapping against objects. Rearrange the tank tonight and then turn off the lights and lower the temp. In the morning they will still be picking on each other but things will be at a much slower pace and might reduce some of the damage until they can work things out.-Chuck>

Diving Oscar Pretty Beat Up - 10/25/06 Hello...After 2 hours of searching your site, I am unable to find an answer to my dilemma. My son brought his Tiger Red Oscar, Big Will, home when he graduated from college. My son has moved out. The Oscar has not. And so, I have been Will's sole caretaker for the past 2 years. Will is 6 years old, 11 inches long and 4.5 to 5 inches high excluding the fins. His home is a 55 gallon tank. Water tests okay; temperature is 80 degrees. He is on a mixed diet [krill, worms, etc.] but no pellets since suffering a rectal prolapse last year. Occasionally, a very small protrusion occurs [I assume it will be a weak spot] if I feed him too much at a time. I haven't been too happy since he bit my thumb drawing blood a few months ago. Last night I heard a very loud crash as if all my dishes were falling out of the cupboards. I ran downstairs and saw Will had jumped 5 ft out of his tank and was flopping in a plastic storage bin. I had left the top open with a 3.5 inch space. [I swear Oscars are magicians]. I freaked out and instinctively grabbed him. He jumped out of my hands twice before I got him in the tank. My hands were on fire. There were scales, puncture wounds and blood [mine] on them. His fins are razor sharp. I would not recommend using bare hands to pick up an Oscar. I have visited your site numerous times to obtain information. This is my first formal request for help and will appreciate advice. I need to know what to do for Will. He is missing a lot of scales. All fins are frayed. I see 2 very small [1/4 inch] streaks of blood in his tail fin. His slime coat has loosened, and there is a puncture below his left nostril. All was okay before he jumped. I keep a close eye on him since the rectal prolapse. I am surprised he's in such good shape considering 3 dives from 5 ft. He is fine, otherwise, his usual ornery self. Thank you. Holly <Keep the tank clean and watch for infections. PimaFix and Melafix are very good at preventing infections but don't seem to be very helpful at curing them once they have developed. Add one teaspoon of rock salt per 5 gallons of water. Use a water conditioner that adds a slime coat to the fish. Next time get a dish towel wet from the same aquarium and flip him into the wet towel to put him back into the tank. This will prevent both of you from getting hurt. If you see him getting worse then treat with Nitrofurazone.-Chuck> Re: Oscar Has Started To Jump - 10/28/06 Thank you so much Chuck for the quick reply and advice. I will follow up with your recommendations. Will tried to jump out of the aquarium 5 times today only to hit his head on the lid. I wonder why he just started his attempts to get out of the tank. He has never displayed this behavior since day one. Thanks again, Holly < usually they attempt to jump because they are startled and have no place to hide. Look at the new aquarium logs by ZooMed and see if you can find one large enough for him to hide in. This should help prevent him from jumping out.-Chuck>

Oscar Laying Low - 10/25/06 Hi, I have a pair of tiger Oscars that are about 7 - 8 inches in length and they have been with us from about 2 inches. One of them lately has been acting strange. It has taken to just lying at the bottom of the tank and not really moving. It still feeds ok and doesn't look in any way poorly. If I turn the tank light off it will eventually start swimming about again with the other Oscar. Any ideas would be greatly appreciated. thanks Steve < Oscars tend to sulk when not very happy. Could be the other Oscar picking on him or he could be getting sick. Do a 50% water change, vacuum the gravel and clean the filter. Offer some live or frozen foods as a treat and see if that gets him kick started to being his old self.-Chuck>

Oscars Spawning Or Fighting - 10/13/06 Mr. Fenner, I have two 1 year old, 6 inch Oscars, one tiger and one albino, who have been acting very interesting lately. Two weeks ago, the two fish began what I thought to be a mating process. They dug out holes in the gravel, which I assumed to be nests and they would swim besides each other and vibrate their fins back and forth as if in response to the other. However, for the past three or four days, they have done nothing but lay on the ground nearly on their sides and shake their tails back and forth. No visible signs of disease is on them and I recently did a 25% water change hoping that would fix it, but no difference came as a result. Also, there are two Plecos in the tank who are acting healthy just as they have since the day I bought them. Do you have any possible explanations for their odd behavior? Any help would be greatly appreciated. Thank you. Michael T. < They may be a mated pair but they are not in condition to breed. Raise the water temp. to 82 F and do a 50% water change. Increase the protein in their diet with some washed earthworms. Time will tell if they are going to spawn.-Chuck.>

Will a single Oscar get lonely? 9/4/06 Hello! <Hi there> You may have answered this, but I was wondering if just one Oscar would get lonely by itself? <Not likely... has you! As company> I do not currently own a large tank or an Oscar, but I like the idea of one Oscar with plenty of room for itself. However, I don't want to be cruel to an animal that would prefer companionship. Is one okay? <Yes> How big would one Oscar get alone? <About the same size... a foot or so> How big a tank should I get? <The bigger the better... at least forty gallons... sixty or more...> Thanks--I just found your website tonight and it's great! Dorothy Wilson <Thank you for writing, sharing. Bob Fenner>

Dancing Oscar 8/31/06 Hi, I've had my Oscar for about 6-7 months now. HeÃ'¹s about 10Ã'² long and best friends with my Parrot Cichlid which is about 5-6Ã'² long (they are attached at the hip from day 1). My Oscar has quite the personality from his daily feeding-happy-dances to him following me around the 55 gal tank. But this time, I wasnÃ'¹t near the tank. We were all in the living room watching TV on the couch, and I looked over in the dining room at the tank to see our Oscar facing the front of the tank. He started to wag and swim sideways down the whole length of the tank, almost in a zigzag like movement. And he held his mouth open really wide for the whole time as if he was yawning. I got up to check on him, and he stopped and was acting normal again. I havenÃ'¹t seen him do it since, but just wondering what on earth it meant. Was he just in a goofy mood? Stephanie Production Artist < Your Oscar is simply probably reacting to his reflection in the glass. When cichlids get larger and sexually mature they become territorial. This means that they defend their are from other fish and mainly other Oscars. Put a mirror up to the glass and see what happens.-Chuck> New Oscar hiding, Tom's input - 08/12/06 Hello there! <<Well, hello there, back, Gloria! Tom>> Is it considered common for a new juvenile tiger Oscar to hide and sulk for a few days after being introduced into a new tank? (55 gallon.. he will have it all to himself.) <<Absolutely. Well, I don't know about "sulking" unless you spanked him for getting into the cookie jar. :)>> The water parameters are normal and fine, and he has eaten some bloodworm. <<Good. It's when they don't eat that things get "dicey" and, even this can vary from fish to fish.>> It has been about 24 hours. Is this to be expected? <<Can be. These animals have their own "personalities". It would make our jobs easier if every species behaved in an identical fashion but it would take a little of the fun and adventure out of it.>> I am just so used to Oscars being outgoing and desiring attention. <<Your pet will come around. Remind yourself of the "unseen" variables at play here, Gloria. Handling and transportation. Habitat, conditions, tank mates prior to you acquiring your Oscar. All are potential "stressors". I understand your concern but don't let the fact that your new Oscar doesn't, thus far, "fit the mold" worry you. Give your Oscar attention and he'll start looking for it.>> thanks so much, Gloria <<Any time, Gloria. Tom>>

A Shy Oscar 8/12/06 Chris' go - 08/12/06 Hello there! <Hi> Is it considered common for a new juvenile tiger Oscar to hide and sulk for a few days after being introduced into a new tank. (55 gallon. he will have it all to himself) The water parameters are normal and fine, <Subjective, actual numbers are more helpful.> and he has eaten some bloodworm. <Good> It has been about 24 hours. Is this to be expected? I am just so used to Oscars being outgoing and desiring attention. <Most likely normal, just make sure your water parameters are 0 ammonia and nitrite and little nitrate.> Thanks so much, Gloria <Chris>

Oscars Acting Like Oscars 7/28/06 I have two Oscars on is a veil tale tiger Oscar and the is a zebra Oscar and lately the veil tale Oscar has been digging up the plants and moving all the rocks to one side of the tank. It is digging little pits in the gravel like a bluegill would in a pond. So I think it may be wanting to spawn. but Im not really sure. So what I did was I took most of the stuff out of the tank to make some more room, but it still does the same things. It also has been making his mouth real big all the time, but anyways I was wondering if you could tell me if they were going to breed or if I just need a bigger tank? < As cichlids grow up the mature and become very territorial. One way of marking their territory is to move the substrate and other objects around to show the boundaries. When fish or humans come close the Oscar shows he is aggressive by opening his mouth and chases others away.-Chuck>

Frightened Fish, Oscars 7/11/06 <<Hello, Krista. Tom with you.>> I currently have two Oscars and a pleco in a 55 gal tank. I have had them for about two months. At first they were extremely friendly. They would swim to the front of the tank when I came home from work and were friendly towards each other. <<Okay.>> Recently they seem to be extremely frightened by any movement at all. They will come out when I feed them but hide immediately after. I am thinking of taking their favorite hiding place out of the tank and rearranging some things. Is this a good idea or is there anything else I can do? <<Like taking a sick child's temperature, the first thing I would recommend is looking to your water conditions/parameters. Cichlids certainly like their hiding places and retreat there when feeling stressed. Since Oscars can be pretty outgoing animals, particularly when they recognize the person who provides the "yummies", I'd be looking for the reason that they now seem fearful of movement outside the tank. Sounds like there's more than meets the eye here, Krista.>> I don't want to stress them out but I don't want them to hide all day either? <<As a rule, I try to bear in mind that the tanks are my "displays" but they're my fishes' homes. Your pets have nowhere to "run" so taking away their "sanctuaries" will likely make matters worse. Again, I'd look at what's going on inside your tank before rearranging things. Specifically, I'd look to see if there are parameters that are in serious fluctuation like hardness, pH and temperature. Is there a possibility of an ammonia, or nitrite, spike that you might not be aware of? Even nitrate levels are something to be considered with these fish. Unlikely that this would manifest itself after only two months but do you feed them a varied diet? This is a misunderstood and very underestimated source of problems with fish. Even high quality foods, when there's no variety, can lead to health/stress problems. Usually these don't show up for quite some time but let's look at all possibilities here.>> Thank you Krista <<You're welcome, Krista. Tom>>

My Oscar, beh., systems 6/13/06 Hmm. I'm new to the raising of Oscars, and I have not actually had mine for more than two weeks, but I have some questions to ask that I couldn't find in the FAQ, or if the answers are there, I overlooked them. I have a tiger Oscar, barely two inches right now. He's in a 10 gallon tank, and I'm working on getting a larger one soon. <Good> The water balance appears suitable for him but he's shy. He hides at the bottom anytime I am in the room or the lights are on. <Still just getting used to your setting... This fish will become more outgoing in time> He eats, but only after I leave the room. (I know this because the food will be gone when I come back a few hours later and they won't be stuck in the filter.) I also know that Oscars are messy fish, so I clean the filter and the tank (never doing a full water change) regularly. I feed him Hikari Oscar pellet food. is there anything I'm doing wrong? <Not thus far> Or is it normal for a Oscar to do this for a couple of weeks until it is comfortable in its new tank? <Yes> I keep the water at 74 F.. and the only stuff in the tank with him are rocks and shells. Are the shells bad for him? <Possibly. I would leave these out> I keep a pleco in there as well.. <This fish also needs much more room...> and he leaves it alone.. I don't know. I would appreciate some insight, even if it's to tell me I'm being dense and there's no problem. Thanks. <No worries... Bob Fenner>

Re: My Oscar 6/13/06 I appreciate the quick reply. It really makes me feel better to know that, other than the too small tank, the fish is behaving normal. Thanks very much! (I removed the shells too) ~Jennifer <Ahh, good and thank you for sharing. Bob Fenner> Older Oscar Not Defending Himself Hello, my name is Liv. I have had a 215 gal. Oscar tank for about 2 years. I have 2 lrg. filters w/ bio wheels, 1 300 canister filter, do 25% water changes weekly and keep the temp. @ 80. I had 7 Oscars, 2 bala sharks, and 2 lrg. Plecos but started having trouble with hole in the head. I tried medications and vitamins in their food but it only seemed to make it worse. They are fed pellets, blood worms, brine shrimp, krill, sliver sides, and algae wafers every 2-3 days. I now have sold all but 2 lrg. Oscars (15 inches), 1 med (9 inches.), 1 sm. (6 inches), 2 bala sharks, and 1 lrg. Pleco in the hopes that this would improve their condition but now I seem to have a different problem. I biggest fish in the tank (the red tiger) was always the dominant fish but now he being attacked by all the other fish (in particular the 8inch white tiger). I thought it may be a breeding thing so I moved a few things around and decreased the temp. to 76. This has helped some but has not fully corrected the problem. I can only turn the light on, on one side of the tank or they will start fighting again, they act lethargic, and only eat about 1/4 of what they normally did. What is going on? Any information would be helpful! Thanks Liv < The larger fish may be ill and not up to defending himself against the younger healthier smaller fish. Try treating with Metronidazole for the hole in the head. It would be less expensive in a smaller hospital tank.-Chuck> And the Winner is...! Oscar beh. 03-21-06 Hi. I used to have 2 Oscars that would fight all the time, leaving them both wounded badly. Recently, one of them died, and the remaining one's scars still haven't healed. The pink of his skin is still showing. Should I be worried? Is there something I should do to keep him (or her) from getting an infection? Lemme know what you think. : ) -Person <Keep his water pristine with frequent water changes. You want zero ammonia and nitrite, nitrate below 20ppm. Use a gravel vac to remove as much organic matter as possible. Watch for signs of infection such as a cotton like growth or if the pink turns red and/or spreads. Otherwise he should be fine. Don>

Albino Oscar Not Growing - 03/12/2006 My albino Oscar jumped out of the tank when I was feeding it. Since this he does not seem to be growing. It has a spot on it's side but that has healed. I have a tiger Oscar also that was bought at the same time. It is almost three times the size of the albino. The albino also buried it's head in the gravel about a week after I got it. I thought it was dead when I got him out of the gravel but he started swimming around just fine. The albino seems to be swimming fine and is also eating it just is not growing. Any suggestions? < Typically albino fish are weaker and less aggressive than non albino fish. I think that the tiger is more aggressive and intimidating and pushing the albino around to the point that he will not aggressively eat. So he will not grow as fast until he is separated and allowed to feed without being hassled. If you place him in a second tank increase the water temp to 83, feed heavily and keep the water very clean you can increase the grow rate and maybe catch up with the tiger.-Chuck> Oscar, new and with Africans 3/10/06 I've had my little Oscar for about 2 days now and ever sense I put him in the tank he has mostly just sat at the bottom leaning towards one side. <Takes about a week to get situated> Occasionally he will jump up and do a quick swim after you scare him with the magnate scrubber. He won't eat anything. In the tank there are to other cichlids one small yellow lab <Not a good idea to mix Great Lakes African Cichlids with Neotropicals> and a little blue fish with black stripes but they don't bother Oscar at all. The tank is a 55 gallon. I think my fish may be sick. Are all Oscars this lazy or is mine just dying? <Neither... is new and likely frightened. Bob Fenner>

Oscar Setting Up Shop 2/22/06 My Oscar has stopped eating as much the last few days and is picking up the gravel in its mouth and dropping it at the edge of the tank, making a bowl shape in the middle of the tank. Is this normal, or is the beast ill. < Your Oscar is now more concerned with setting up his territory than with feeding. He is not ill but just busy setting up the tank to his liking.-Chuck>

Oscar May Be Overeating 2/10/06 She is an albino. We call ours a she because it's too pretty to be a he. We have 2 older Oscars one around 12-14in and the other around 9-10 in) in our tank as well but they are paired and pretty much ignore the albino although she does hang really close to them except when they are flirting with each other, they can be a little aggressive then. Any way, my albino is around 4-5 inches and eats like a pig, true to their supposed habits of eating anything that will fit into it's mouth (even if it just barely fits). The problem is that she is getting really fat, she is having bowel movements though so not sure whether she is sick from overeating or full of eggs if she is actually a female at all). She has been staring at the back wall of the tank all day today except when it's feeding time. As is the opposite of what she usually does. The other Oscars are very active but of course they aren't eating as bountiful as this one is. Could it just be trying to get what it can before the food is gone and therefore overdoing it? Cindy Thrasher < Don't feed them for three days and see if their appetite returns after a little fast. If they go back to eating and acting normal then feed them once a day and only enough food so that all it is gone in two minutes. If their appearance hasn't changed then there may be an intestinal blockage they may turn into an infection. Do a 50% water change, vacuum the gravel and clean the filter. Treat the tank with Metronidazole as per the directions on the package.-Chuck>

Oscars Fighting 2/6/06 Hi, I have two Oscars. I have had them about a month now. Everything is going fine but I did my normal water change and I have noticed one of my Oscars hiding. It started doing so because there is dominance going on but yesterday I noticed his scales turning white. It looks like they are being scraped off. My daughter said she has seen it rubbing on the rocks. It does eat when I put food in the tank. When the other Oscar swims by he cowards down by swimming sideways. He hides a lot, But now he just hangs at the bottom and leans against the sides of the tank. He has a split in his tail fin and his other fins are the same way. I don't want to lose him. Just not swimming around like he did. Thanks, Barbara Wells < When you only keep two cichlids together there will be a struggle for dominance. While the winner is out and about, the loser will be hiding and trying not to get beat up. There are a few things you can try and do. Move everything around to new locations. Lower the water temp to the mid 70s. Add other fast moving schooling fish like giant danios or rainbows to distract the dominant fish. Keep the water clean to prevent infection from the injured fish. Add Bio-Coat from Marineland to help the fish grow back its scales.-Chuck> Oscar Coloration - 2/4/2006 My Oscar is 10 inches long and I've had her for a year now. I haven't had to many problems as of yet (ich with the pleco at first). However as of lately I've noticed that my Tiger Oscar is becoming more "spotted" The fish was never "really" colorful...more of a dark brown with pale stripes. But now bright orange spots are coming out around her fins. Also some black spots on her head. Is this normal and can I expect my fish to continue getting "brighter"? Thanks, Jassy < Changes in diet and water conditions can affect a fishes coloration. If the spots are just superficial then it is probably a color pattern. If they develop into holes and sores then you have a problem and need to medicate.-Chuck> Oscar Not Swimming Much 2/1/06 Dear Crew, I have searched your forums, but I havent seen the answer to my question. Hopefully you can help me. I have a tiger Oscar about three inches long that is living in a 55 gallon tank. The tank has a gravel bottom, a few hiding places and a regular fluorescent light that runs on a 12 hour timer. My chemistry was tested yesterday to show near zero ammonia and nitrates. It did show my pH a little under 7. The problem is my fish is not moving and spends almost all the daylight hours sitting at the bottom of the tank, sometimes almost on his side. Other times he will be near the top under the overflow from the filter. He has not taken food in three days. When the light shuts off, he becomes more active but still hasnt taken any food that I can see. I keep the tank near 78 degrees. I have tried flakes and thawed shrimp which he usually enjoyed. I see not signs of external parasites or any fungus/bacteria. Do you think this might be something seasonal? Sincerely, Shana < Little Oscars are usually little pigs when it comes to eating and fish owners are more than happy to keep shoving food down their gullet because they are fun to watch eat. Sometimes they eat too much and get an intestinal blockage that becomes infected and causes the intestine to bloat. I would treat with Metronidazole as per the directions on the package.-Chuck> New Oscar Can't Swim 2/1/06 I have been reading through your website and find it to be one of the most informative I have seen. I hope you can help me with a problem I have with a new Oscar. I purchased one 3" tiger Oscar and one 3" red Oscar about 3 days ago and placed them in a 30 gallon quarantine tank. The red Oscar is doing fine and is eating two small feedings a day. The tiger Oscar however is our problem. He has been laying on his side at the bottom of the tank since we got him (he looked fine in the store), and has recently lost his ability to swim. He just does head over heals flips across the bottom of the tank and all his fins look fine. No one at any of my local fish stores have been able to help. I have tested the quarantine tank and all the levels look great. I have also treated with salt as I thought it may have something to do with swim bladder and read that it may help. Do you have any suggestions on what may be going on here? Thanks, Aaron < The stress from the move or the change in diet has caused an internal bacterial infection. Treat with Metronidazole as per the directions on the package.-Chuck>

Oscars Getting Aggressive 1/30/06 Hi there, I have 3 Oscars, a tiger and a red both from the same stock at a decent independent LFS, and a third, beautiful red Oscar from a fantastic LFS. The 2 decent Oscars are about 3 inches, and the fantastic red is about 4, 4 and a half inches. I had a fourth albino, but he passed away during a bout of ick. They all got along great for the first 3 weeks or so, always swimming together, they were actually schooling. Now all of a sudden, they have begun to get aggressive. At first I thought this was mating behaviour, as the 2 decent fish were lip locking and tail slapping. After a while though, they started biting each others fins and sides, and they have many many many very large superficial bites, with many missing scales and torn up fins. I built a quick and cheap tank divider, thinking that perhaps this was due to my larger Oscar in some way. So I separated them, and now the fighting is lessened, but still exists. It's a 55 gallon long tank, with at least 7 very obvious hiding places. I run an Aquaclear 500 and 300 on this tank, cycling 800 gallons per hour. I also vacuum up their waste every couple of days and replenish the water. This equates to about a 5 gallon water change every 2 days, of course conditioned water at the same temperature as the tank. My ammonia, nitrites and nitrates are all at zero, with my nitrates just a little bit higher, maybe 5ppm and the ph is 7.6. Now, I don't have any other fish in there right now, but it is a matured tank, fully cycled, with fantastic water quality. They are just on the tail end of being cured of ich, I used the salt and heat method, for 12 days (2 days more than usually required, just to be on the extra safe side). I replaced the salt every time I did a water change. What can I do to curb this aggression? I know the tank is small for 3 Oscars, it's just a growout tank for them for another 2 months or so. They are going to be moved to a 180 or 230 gallon tank, that will eventually house 2 green severums, a sun sucker cat, and possibly an iridescent shark or 2, or another kind of catfish. < Lower the water temp slowly to 75 F. and rearrange the tank. As you Oscars grow they are starting to get territorial. Lowering the temp will slow their metabolism.> In the meantime, would it help to add some juvenile iridescents as a sort of dither fish? < No. These catfish get big and will eventually contribute to the problem. Try looking at some barbs.> I'd really like to keep these fish together, but if I must I will consider giving away the 2 aggressive fish to separate good homes. I feed them New Life Spectrum Large Fish Formula, and when they were smaller I fed them New Life Spectrum Cichlid Formula. I feed twice a day, about 5-6 pellets each. I feed 1 pellet at a time to ensure nothing is wasted. < Great food. Maybe a reason why your fish are doing so well. You are doing everything right, keep up the good work and invest in a good fish book that will help you with you long term compatibility problems.-Chuck> Thanks in advance for any help you can offer.

Oscars Chasing Each Other I have 3 Oscars in a 55 gallon tank, One 6 inch, one 3 inch and one 21/2 inch. I don't understand why, but the 2 1/2 inch keep chasing around the 3 inch. Not biting but kinda opening its mouth and bumping it. Any information about this is greatly appreciated. < In all tanks there is a pecking order for food and territories. Your smaller Oscar is just more determined than the other. But he is smart enough to know not to provoke the biggest Oscar.-Chuck> Oscars Fighting 1/14/06 I have two baby Oscars about 2 inches overall and they have been in a 30gal tank together for about a month now. The tank has a bio-wheel 200 on it and I test levels daily, But the albino tiger has a clean tear through each clear side fin and the tiger has a tear on the very back part of his dorsal both down to the body. The fins otherwise are normal no fraying in them fish act normal eat normal. Maybe are these tears from fighting or something? Thanks, Buddy in Alaska < More than likely it is because your Oscars are fighting trying to establish a pecking order or territory.-Chuck>> Oscars Gone Wild 12/28/05 I have two Tiger Oscars. Both are about 3 inches long and in a 30 gal aquarium. I have two other fish and some snails in the tank with them. They have been swimming frantically across the tank slamming into the sides and everything else in the tank. When they are not doing that they float almost as if they are dead. They have been doing this for two - three days. I called the local fish store and they said change 50% of my water, add salt and double the dechlorinated drops which I did. The Oscars started swimming some but are still floating on their sides on the top and also swimming into the sides of the tank. They also don't seem to be eating. This all started after I was having problems with my filter, I changed the filter to a new one and done two water changes a couple of days apart. The local fish store told me I was over feeding my Oscars so I cut down on how much I was feeding them. That is when they started the hitting the tank and swimming as if dead. Any help would be appreciated. < Check the ammonia, nitrites and nitrates. When replacing a filter with a new one you may have remove all the good bacteria needed to break down the toxic fish waste. So you may be experiencing higher waste levels like in a new tank. Add carbon to the filter to remove any unwanted organics in the water. Remove any uneaten food after 2 minutes.-Chuck>

Oscar Acting Strangely 12/21/05 Hello, I have a 4" Oscar in a 30 gallon, cycled tank. I've had the Oscar for about a month and a half. The tank tests seem good (below). Ammonia: 0.15 ppm Nitrite: 0 ppm Nitrate: 10 ppm pH: ~8.2 Temp: 78-80 degrees My Oscar recently got over ich and cloudy eyes. I treated the ich with Rid-Ich and the cloudy eye with Maracyn. The ich and cloudy eyes seem to be gone, but my Oscar is acting strange. As a precaution, I cleaned out the gravel REALLY well using a gravel syphon. I also changed out the carbon in the filter (as I do every other week) and removed a lot of the decorations in the tank. He continued acting strange so I tried a ~20% water change. His condition still didn't improve and I noticed bubbles forming at the top of the tank. I never really noticed this before, so I changed out ~50% of the water. There are still bubbles forming, but not as much as before. Anyway, my Oscar is still very lethargic, breathing slowly and constantly swimming directly in the effluent from the filter. He also doesn't seem to "see" as well as before, but I can't tell for sure, obviously. He doesn't eat much and he doesn't react as quickly to movement in the room as he did before (he used to swim around the front of the tank like a little dog or something). Oh, the tank is also very well aerated. Any suggestions? Thank you,-Chris <The ammonia and nitrites should be zero. I think the medication may have affected the good bacteria used to break down the ammonia into nitrites. Do a 50% water change. Add some good carbon to the filter to remove any remaining medication. I would add Bio-Spira from Marineland to replenish the bacteria bed. Try a change in diet. Try live washed earthworms. That should get his attention. If his condition doesn't change then it could be an internal bacterial infection and will require treatment with Metronidazole.-Chuck.> Big Oscar that won't eat 11/21/05 Hi I have a ten inch Oscar in a 60 gallon tank that just doesn't seem to be interested in food. I just set up this new tank, but I don't think that that is the problem, since he wasn't eating well before the move. My temp. is fine <Fine?> and water conditions optimal, <What? Then I guess... all is "good"> I have tried a variety of foods now to peak his interest including, krill, his usual pellet food, and some other variety of Hikari cichlid food. I even tried some beef heart that a friend of mine had. Previous to this past week he was a voracious eater. He shows no signs of disease and acts quite normal except for the not eating part. I have heard of internal parasites, but what could be signs of that? <Maybe... or could have swallowed a "bug" from outside, but most likely is "just in a funk" over being moved. I would raise the water temperature to the low eighties F., and check your water quality for ammonia, nitrite, and keep offering different foods daily> Any suggestions would be appreciated. Thanks in advance for the help. Jason <Have you read here: http://www.wetwebmedia.com/FWSubWebIndex/oscarfdgfaqs.htm. Bob Fenner>

Splitting Up An Oscar Trio 11/6/05 Hello -It has been quite a long time since I have written you, but my three Oscars are now three years old. They go through cycles of peace, mild sparring, and all-out warfare. Usually, one (and it can be any of the three - they seem to be pretty equally matched) gets really whipped and I think it is going to die but then it recovers and all is well for awhile. A major battle seems to have ended and this time all three of them are utterly whipped, almost to the point of death. I think I have about had enough of this and am contemplating getting rid of two of them. How do you think one Oscar, who has had company, albeit belligerent company, all of its life would do all alone in a 90 gallon tank? < The single cichlid would get along just fine and start to interact with you and his surroundings a lot more.> Is there some kind of other cichlid that I might put with it without disastrous results? < No not really. Big cichlids get very territorial.> I am also thinking about moving all three of them out and moving in my very peaceful Severums from a 55 gallon tank that seemed fine when all these fish were little, but is now overcrowded. < These are great fish but get big as well but usually not as aggressive.> If I do send any or all of the Oscars away, I will have to take them on a drive of over an hour to reach the nearest pet store that takes fish in. The only think I can think of is to put each in a five gallon bucket and hope for the best. Any recommendations? <Line each bucket with a black plastic trash can liner. Rinse each liner in the bucket well. Fill the bucket up to about three quarters full with aquarium water and place an Oscar in each bucket. Tie off the plastic liner just above the top of the bucket. This will keep the water and the Oscar in the tank while transporting them to the store.-Chuck>

Bigger Oscar Has Become a Bully 10/22/05 The website seems much more organized since the last time I visited. Thank you! Much easier to find information without wading through pages of emails... Now, I need some advice on a tiger Oscar. Let me start by saying that I've had two tigers since they were the size of half dollars, and they are the newest additions to the tank. They live in a 75 gallon tank, with a four-inch armored catfish and an 8" Pleco. The Oscars are both slightly over 6". I run two 60 gallon Whisper filters and do a 25% water change every 7-10 days. They eat everything to Cichlid pellets to worms, crickets, and chicken. < Chicken?> <<Land mammal and poultry meats should never be offered as food to fish, with the exception of beef heart only in certain extreme cases. -SCF>> For the last couple of months, the two tigers have been lip locking and pushing one another around the tank. There are no sharp edges, and neither of them get beat up (minus a scale or two I find vacuuming). For the last week, the seemingly dominant tiger, has been bullying around the other roommates as well. Surprisingly, it has even been going after the Pleco, which has always been larger than itself. Now, when I clean the tank, it is charging and biting me, as well as the vacuum, plants, and even water drippings from the carbon filters as I pull them over the top of the tank. Although I find this slightly amusing and no one is getting physically hurt, I am beginning to be concerned for the psychological well being of the other tank mates. Should I move that Oscar to a tank of its own? < Your Oscar has now determined that this tank is his territory and that he is in charge. He will defend his territory against all intruders.> Will it become lonely? < No , he will start interacting with people walking by the tank or even in the same room.> Can this behavior be from diet related issues? or perhaps the vacation that I went on when I didn't change the water for 13 days? < This is actually pretty normal for every large New World cichlid.> Also, I've been thinking about buying a separation screen for the catfish so that it can eat without the Oscars snatching up everything. How long should I give it to eat before removing the screen? < Most fish I recommend leaving the food in for no more than two minutes. But with the Pleco I would make sure that he is eating for about 15 minutes each day. Vegetable fish food is high in fiber and not much protein, so they need to eat a lot of it to get enough nutrition.> It will not eat pelleted food for catfishes or anything that floats. I'm concerned that I'm not providing a wide enough arrangement of food with chicken, earthworms, and blood worms. Any suggestions? Beef doesn't seem to work in any form: hamburger, steak, or heart. Thank you very much for your time, Chris < Go with commercially prepared sinking pellets for algae eating fish and stay away from the grocery store. Try Spectrum, Hikari, OSI or Marineland pellets. You fish will learn to eat them after a few tries.-Chuck>

Angry Oscar Needs His Space 10/22/05 Thank you for the timely response to my last email. Should I make a new tank for the aggressive Oscar? <This would be best for all of your fish.-Chuck>

Oscar on Sit Down Strike 9/19.5/05 I have a three inch Oscar in a 15G tank (I know, to small. I'm transferring the Oscar to a 33G tank soon) When I first bought him he begged for food, and was very active. Now, he sulks and does not move around unless there is live food in the tank. Is it because of the size of my tank? He does not eat as much and "sits" on the bottom of the tank and doesn't move. Help! Jasmin < Do a 30% water change while vacuuming the gravel and clean the filter. Offer him some washed earthworms, add a couple tablespoons of rock salt and see if he acts any better. If not, he may have an internal bacterial infection and require treatment with Metronidazole and Nitrofuranace.-Chuck> Large gulp? Oscar behavior Hey there again, I was wondering, what are the Oscars doing when they open up there mouths really wide like a yawn? Just wondering if it is a normal thing? J <Some folks have speculated that this is akin to human yawning... i.e. a lack of oxygen, others say that they may be making a threatening gesture (to you!), all this and maybe just opening their mouths as this is part of what they enjoy most (eating). Bob Fenner> Oscars Dig Undergravel Filters 9/13/05 I want to first say that I am impressed by the wealth of information on your site and am very grateful for it. < Thank you for your kind words.> My question is regarding my Oscars which appear to be a mating pair of roughly 7" or so. They often will appear to be performing the normal mating rituals, fin slapping, quivering, and lip locking. Problem is that they don't seem to follow thru with it. They do all those things and then nothing happens, they just stop. I've done some searching in your archives and not found anything that appears to match this situation. Also they often dig at the gravel but don't attempt to clean the flat rock I provided. They dig to the point that the undergravel filter I added becomes exposed, which brings my next question. I've read that the more filtration the better, so I added the undergravel variety. I have recently been told that that was not a good idea, that it doesn't help, and that when the Oscars expose the crate they are allowing what I thought was supposed to be beneficial to come back up and pollute the water. Is this accurate? Thanks in advance. Jada < Your young pair of Oscars are going through the motions. As they get older and more experienced they will ultimately spawn. When the Oscars exposed the filter plates the water fins the path of least resistance and goes through the plates and not the gravel. No filtration is going to happen.-Chuck> Tiger Oscar... behavior 9/12/05 i <Capitalize, please> was given a Tiger Oscar about a month ago. He was in a 10 gallon tank. The water was black and he was laying sideways. I put him in a fresh 10 gal. tank and he was doing very good. When Oscar would see me, he would wag his tail like a puppy. He started growing, and the tank looked too cramped. <Is, was> I have a 30 gal. tank and took my black moors out and cleaned the tank real good. i make sure that i put the same temperature water back in. Well, now that he is in the bigger tank, he won't eat. Are Tiger Oscars temperamental? <Yes... they often sulk when moved... normal> Now when he see's me, he turns his back on me. It's like Oscar is snubbing me. Is that possible? <Good way to put this, yes> Thanks, Tilly P.S. do I chop up the lettuce? <Mmm, Oscars don't generally eat greens... but all foods need to be "mouth-sized" or smaller. Bob Fenner>

Oscars? 9/13/05 Hey there, I am wondering about my two new Oscars, they are 4 inches, just got them yesterday, they just sit in the corner and rest, I don't think they are hurting or sick, they are breathing slow and steady not labored, I checked all water conditions, ph is neutral, no ammonia, no nitrate, no nitrites, water is soft, I just don't know what is the deal, are they scared? <Likely so> They won't come up to eat, I scooped all food out after the first try at feeding and haven't tried since, I did see them early this morning swimming around, but as soon as they saw me or heard me they quit. Explain what is going on if you can and should I worry if they don't eat? <Not to worry... they're "just settling in"... Give them time... a few days, to adjust> They are in a 29 gallon tank, they do look small in it, don't worry I have a larger tank for them to go into later. Thanks for your time. Julie <Real good... Please take a read here: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

Re: Oscars? Behavior Thanks so much for your quick response, they are coming around and now are trying to get some food although they aren't really eating they spit it out, testing it I guess, but it is progress, thanks again! J <Welcome! Bob Fenner>

Sulking Oscars 9/3/05 I have two large red tiger Oscars about eleven inches in length. They have a very healthy appetite for dried food, frozen food, and live food such as guppies, goldfish, and earth worms. I've had them for about one year and two years. One of them is just sulking around the tank. All of the sudden, this monster that eats twenty-four hours a day hasn't eaten in three days. It has no apparent sores or illnesses, it is just weird that it doesn't move or eat all of the sudden. Please send me back some suggestions on what may be wrong with it or what I can do to fix it. Thank you very much. Eric Messenger Thank you very much P.S. Maybe is the breeding cycle setting in or beginning, I know nothing about the breeding of Oscars. Thanks < Try a couple of things. Do a 30% water change and vacuum the gravel while you are at it. Clean the filters. This would normally get them fired up. If this doesn't work then it may be a more serious matter. With no external symptoms then we have to think that maybe he has an internal bacterial infection or a damaged pharyngeal jaws. Not much you can do about the jaws so treat with Metronidazole as per the directions on the package.-Chuck>

Sulking Oscar, Add-on to Last Email 12/08/05 Hello again, I'm sorry There was one thing I forgot to mention/ask, he seems to swim around the tank a little bit when I'm not near it but when I am he drops to the bottom and stays there so I was wondering is all this lack of activity a response to stress from the move from the store to the Q-tank? Thanks again, Brian <Most likely. I missed the first part of your message, but assuming you have clean water and a big tank I am positive that your Oscar will come around, especially when he associates you with food. Although they are known as big mean eat'um up fish, Oscars have been one of the most emotional fish I have kept. I had an Oscar mope around the tank for weeks after being moved. Best Regards, Gage>

Oscars Act Like They Are Starving 8/31/05 First off. Love the site. Have learned a lot from it. I have 2 Oscars (Pedro & Napoleon) in a 75 gallon. Pedro is about 5 inches, while Napoleon is about 4. My problem is that they like to leap out of the water when I feed them. If I open up the lid and hold my hand over the water with food they will jump up to my hand (Pedro has been about 90% out of the water). And they splash water all over the place! I even got nipped once. It didn't hurt....Do you think they'd bite hard enough to hurt me? < They don't really have teeth but they will get larger and may develop some then.> I like my fingers and want to keep them. One time Pedro must have hit the side of the lid on his way back in, because I saw a section of his scales floating in the water. Maybe he'll learn his lesson? :) Is there anyway to stop them from jumping? I try to open the tank lid really quick and throw the food in and close it fast! But it's kind of difficult because I have a 2nd lid above it on my canopy. By the time the canopy lid is open, they are up top awaiting my feeding hands. Suggestions, comments, or jokes would be greatly appreciated...Dave < Lower the water temp and that will slow them down. Mid to upper 70s F will slow down their metabolism and they won't be starved all the time.-Chuck>

Upset Oscar 8/22/05 Hello everyone! Let me say to start that this is a top shelf website. <I agree - got my start in aquariums from the fine folks at WWM!> I have written to you a few times before and your help has always been appreciated. I have a question about Oscars. <OK - shoot!> I recently set up a 90 gallon tank which was cycling for about two weeks with no livestock. <Good choice, IMO, doing fishless cycling. I am assuming you noted a visible rise, then subsequent decline (to zero, hopefully) in ammonia, nitrite and nitrate levels, respectively? Two weeks seems a little short for a full cycle, but not unheard of. Just so long as you were sure a complete cycle did happen before introducing the fish.> Since then I have purchased two albino Oscars who are about an inch long. They have been doing great for about a week. <What conditions are they being kept in? Water temp., pH, and other water parameters would be helpful here.> Yesterday I decided to put some plastic plants in the tank. I probably had my hands in there playing around for 15-20 minutes. Ever since then one of the Oscars has been acting strange. He use to swim freely through the tank, playing with the other Oscar. Now he just sits in the corner of the tank with his fins down and hardly moves. He also will not eat. I have tried giving him flakes and small pellets. Every once in a while he will take a bite of food and then spit it out. <Again, my first step would be to measure the water's parameters. Ensure that everything is still good. Have you done any water changes since getting the fish? If so, have you carefully matched the old and new water for pH, temp., etc.? What is your normal water change routine? Also, did you thoroughly rinse the plastic plants before adding them? I always use super-hot water, but no chemicals. Finally, it's always a good idea to wear aquarium gloves while messing around in the tank, but if you don't, just be sure to wash off any perfumes, lotions, oils, etc. you may be wearing before putting your hands in the tank. Fish can be quite sensitive. If you are aware of something environmental you may have introduced into the tank, do several water changes and ensure you have fresh filter media in place.> The other Oscar is doing fine. He is still his playful self and eats great. I have checked all the nitrites and nitrates and they seem fine. <Subjective term...are you definition "fine" as "zero", since, in reality, any presence of nitrites or nitrates are poisonous to fish.> The ph is 7.2 Is there anything I can do to get this Oscar back to normal? Any different types of food that will entice him to eat more readily? This has me a little worried because I know Oscars are usually not shy about eating. Did I do anything wrong by putting plastic plants in the tank? <I like to use Kent's Garlic Xtract to entice my reticent fish to eat. I'm told you can also use pure garlic oil extract, as found in the spice aisle of most grocery stores. I don't think you did anything wrong by introducing plastic plants...how many did you put in? Does each fish have room for his own separate territory (in other words, did you introduce enough? I'm thinking perhaps if the one fish has "claimed" a plant or two as his own, and the other one has no where to hide, perhaps his answer is to hide in the corner. Just keep your eye on water parameters to make sure nothing's awry. Make sure there are adequate hiding areas for both fish. Another consideration is whether the one fish is bullying the other...I understand it is fairly difficult to sex Oscars, so perhaps you have a situation of an alpha male terrorizing a beta male? You didn't say anything about that, but do keep your eyes open for signs of this. I like the following source of information on Oscar fish as a good starting place: http://www.aquariacentral.com/articles/oscar1.shtml Hopefully I've given you enough food for thought! Good luck and enjoy your new pets!> Any insight would be greatly appreciated. Thanks for your time. <You are welcome. Jorie>

Oscar minus mate is bummed 8/17/05 Hi , am having a dilemma with Bubbles [my Oscar] she's two years old, and she's all alone in a 4ft tank . I did have two but unfortunately Henry died 2 months ago . i got really worried about her as she went off her food and sulked for a couple of days . <Happens> With lots of attention she started eating again and returned to her normal self , but recently she's been sat at the bottom off the tank looking really fed up . I've given her things to play with ,new plants to drag about ........but not much excites her for long . Would another fish [company] help , if so which type ? PLEASE HELP am worried about her . thank you Jane <Another fish might just do the trick here... but not an Oscar... likely to fight... Perhaps a smaller species of cichlid, a good-sized catfish? These changes do take time to heal. Bob Fenner> One Oscar with a Potential Problem 8/3/05 I have a 55 gallon with two 4" Oscars in it which I've enjoyed for a month now. Don't worry...I'm getting a 125 gallon for them this Christmas. These Oscars (Black Gold and Lava) have acted like best friends from the start swimming all over together and rubbing against each other. Last night I noticed that Lava was hiding in the big castle. I've seen it swim through the castle, but it never stays inside of it. This morning was the same thing. When I feed them I tap on the tank and they come rushing to me eager to eat. Black Gold still did that. Lava ignored me. I lifted the castle a bit to get Lava out. I noticed spots on Lava's gills that look like it may be shedding scales. They're clear and one is loose. Lava also swims vertical with its head to the top. When Lava does decide to come out of hiding, Black Gold seems to chase it and sometimes kind of headbutt Lava in the side. I sure don't know what to think of this...unless Black Gold is excited to see its best friend. LOL Lava only stays out for a minute and hides again. Could there be a problem? Thanx, Karen < Looks like one of your Oscars is dominating the other for territory, food, etc.... This could be serious. BG (Big Gold), probably bit the side of Lava and loosened some scales. If might be a scrape from hitting an ornament or a rock from trying to get away from BG. If the water is kept clean then they should heal up. If it looks like the area is starting to fungus then it needs to be treated with Nitrofuranace. The strange swimming position is a sign of internal damage to the swim bladder from the ramming or an internal bacterial infection from the stress of being dominated by the other fish. Place Lava in a hospital tank and treat for bloat with Metronidazole. When lava is cured you need to re-arrange all of the ornaments and rocks when you put lava back in so they can establish new territories. While Oscars are very intelligent for fish they are not "friends". They simply acknowledge each other and will always be in competition with each other. BG is taking advantage of the fact that lava may be sick.-Chuck>

Hiding Oscar 8/1/05 Hello crew thank you for using your time for other peoples aquatic needs. Anyway I have a 350 gallon tank and has these fish. !.Red devil 2.convicts both males 1.jack Dempsey 2.dojo loaches 1.large Pleco the biggest fish is the red devil and sometimes bites the Plecos tail. <And any, everyone else> Anyway I recently bought a tiger Oscar and it's 2inches long but right after I got home from a party I found it hiding and not swimming around with the other fish. Is this common? <Yes> Cause most of the fish I buy stay out in the open and not hide. And this is not my first time having a n Oscar but it's so weird it stays behind a rock and not eat. Please help me. thanks Sean <Help yourself... use the indices, search tool on WWM to read about "Oscar Behavior". Bob Fenner>

Beat Up Oscar Hello, My name is Josef Moran and I have a question about my Oscar. He is a red Oscar and he is getting bullied by my other two Oscars. They are albino . When this happens he floats there like he is dead. And I was wondering if you can tell me if there is any thing I can do to help my red Oscar. < The other two Oscars may be breeding. The pair will guard the eggs and fry from all other fish. they will even kill the other fish if they are too close. I think the best thing to do is remove the beat up Oscar before he is killed.-Chuck>

Oscar Going Black Hello, I have an 8 inch albino Oscar, his name is Humberto, in a 100 gallon tank. Almost three weeks ago he started developing black along the edges of his fins. I assumed it was fin-rot and treated it as such, but alas it continued to spread. His anal and pectoral fins are now half black and his top fin is black along the back part of it. I've doubled the filtration (I'm currently using a 200 gallon filter) and increased the aeration. He is still as feisty as ever and it hasn't seemed to effect his health. He still acts exactly the same as he did before the black started developing, but I'm still extremely worried about my little (but getting larger) Humberto. I would sincerely appreciate any, ANY, information you might have about this. < I would be concerned too. Check the nitrate levels. They should be under 25 ppm. Do a 30% water change , vacuum the gravel and clean the filters. Black usually indicates neurological damage. I would initially though that the problem was bacterial and treated just like you did. It may be a kind of protozoa so I would try Clout this time around. Check the food too. Color foods may add ingredients to their food to bring out pigments that some fish just don't have.-Chuck>

Oscar Changing Colors - Follow-up The nitrate levels were fine in my tank with Humberto. When I changed the tanks filter to a 200 gallon I replaced all of the filters and vacuumed the gravel as well. My lease is up at the end of this month so Humberto and I will be relocating. The stress might be a bit of a problem but at least there will be a complete water change. That should take care of anything that might have been caused by poor water conditions. Although the water conditions I try to keep at a fairly optimum level. If Humberto's health takes a turn for the worse or should the black disappear, I will be sure to update you. Thanks for your insight. < When moving to the new place make sure that your water conditioner will be able to handle any chloramines that may be in the water.-Chuck>

Oscar Bumped His Head, Now Afraid of Dark? Rapid Light Changes Hello, I'm quite concern about one of my Oscars. (I had them for about 3 months) About two weeks ago we moved my Oscars (2) from a 10 gallon tank to a 55 gallon. For the first week they seemed to be doing very well and loving there new home. One of my Oscars (my larger one) has had some missing fins since the first week we had him. Last week while at the pet store, I found some medication that was suppose to help with fin growth and repair. I started to apply the medication to the water last week Tuesday. Since last week Wednesday, my larger Oscar stopped eating and was very unsociable, hiding behind rocks and plants. My smaller Oscar is doing perfectly fine. I just figured the larger one was not feeling well and decided to leave him be for awhile. Over the weekend he still was being the same, so we did a 20% water change, but still no change in the larger Oscar. Then last night after eating supper, I was going to check on the Oscars, and could not find the larger one and then finally found him on the floor. We only have one tiny little opening on the tank and I'm quite amazed that he was able to fit through it. After we put him back in the tank, I'm notice that his scales around his eyes were all scraped up. He seemed to be very disoriented for awhile swimming vertically. After a few hours passed he seemed to be coming around. I tried to feed him again, and he still will not eat. Just before bed time, I went to turn the light off and he went crazy (swimming totally fast back and forth throughout the tank hitting all objects in his path). I was total freaked out over this and quickly turned the light back on. He instantly clammed down. We have a water testing kit and have been checking it daily. The water seems to be perfectly fine and so does my smaller Oscar. I just have no idea what's going on with my larger Oscar. Any help is must appreciated. Amy <Your answer is actually the title I placed on your question. Fish don't like "lights on-lights off". I think they have difficultly with their eyes rapidly changing from bright light to darkness and visa-versa. The trick is to place a small Christmas tree bulb sized night light on the same wall as the fish tank try turning the room lamp on first before turning on the fish tank light, and then turn off the fish tank light first before turning off the room light. It should make a difference.-Chuck>

Hurt Oscar - Rapid Light Change Follow-up Thanks Chuck, What should I do about the larger Oscar not eating? Its been about a week and 1 day now that he has not been eating. This worries me because he used to be the one that was always starving for more food and would often jump at my hand when it was feeding time. Also, he is very unsocial able now, where before he stopped eating he was quite entertaining. He doesn't even seem like the same fish anymore. The only thing that we did differently in the last week before he stopped eating was give them the medication for the fin repair and we fed them two goldfish as a treat which they haven't had in quite some time. I don't believe it was the medication because the smaller Oscar is doing perfectly fine. And I'm also afraid that he was injured in his jump out of the tank. He is missing a lot of scales around his right eye and on the tip of his head. Will these scales grow back?? Also, do you think that the larger one might have gotten sick from the goldfish? If so, what would you suggest that I give him to make him feel better and to start eating again. The last couple of days I've fed them flakes, frozen blood worm, frozen shrimp brim and pellets. The smaller Oscar eats like a pig and my larger Oscar just looks at the food and swims away. Amy < The larger Oscar took a pretty good shot to the head when he jumped. He knows he is hurt and so do the other fish. I would place him in his own tank for awhile until he heals up. once the wounds are healed he should start to come around.-Chuck>

Oscar Problems I have a tiger Oscar in a 55 gallon tank and sometimes he opens his mouth and charges at the glass, his color turns VERY white/yellow, and then he/she starts twitching (like a mini-nerve impulse). There has been no new fish introduced and no changes in water. The Oscar only does it every once in a while starting about 6 months ago (from what I've noticed). There is plenty of oxygen in the tank and no noticeable bacteria or fungus on any thing in the tank. the other fish (smaller jack Dempsey and catfish) are healthy and fine. The Oscar eats like a cow, I just don't know what he does this for. If it was a bacteria or fungus wouldn't the other fish have gotten it by now? also, are there any markings that distinguish a male from a female Oscar? Thank you, Meaghan < As Oscars grow they become territorial. I think you Oscar charged the tank to chase someone away and hit the glass and stunned himself. It is not a disease or anything like that. I would lower the water temp to 78 degrees and approach the tank slowly from now on. Maybe move the tank to an area with less walk-by traffic.-Chuck>

Oscar acting funny Hi. I just found your site and I think it's great. I posted a question in the forum but nobody seems to have an answer for me. I have an albino tiger Oscar. I've had him for a little over a year and he's about 7" long. For the past few weeks he's been digging a hole in the gravel. When he finally gets to the bottom of the tank, he stays in the hole appearing to stare at himself. He even at times tends to swim on his head in a circle as to try and get at his reflection. He still eats whenever I feed him, but he comes right up for the food and then goes right back down into the hole. Any ideas as to what this behavior could mean. Thanks in advance. >>>Greetings, Based in my experience with this species and cichlids in general, I'd say your "HE" is a SHE, and she is digging a nest. Don't be surprised if you see eggs soon. Jim<<<

Oscar Problems Hi, I own 5 tanks and have several different kinds of fish (not in the same tank!) my newest fish is an tiger Oscar. I have had him for about one week and he is not looking too good. I checked the water and it seems to all be ok. My poor Oscar lays on the bottom of the tank and doesn't move around unless I move him myself, not even to eat. what am I doing wrong? I'm hoping that he won't die, please help. thanks Jackie < Oscars like warm soft water at least 80 degrees F. Try some live food like worms or brine shrimp to get him up and about. If you think he is really sick then look closely for signs of disease and check back with the store you bought him from to see if they are having any problems with the rest of the tank.-Chuck.>

Oscar thrashing around tank..... help! Hello. I have a 1 1/2 year old tiger Oscar that is approximately 16" long. He is in a 135G tall tank and we have undergravel filtration w/3 550 powerheads (he took out the 4th one!) and recently we installed a Rena Filstar XL3 canister filter. We have a bubble strip on the left & right under the gravel & also one across the middle. His tankmates are 2 Plecos that are each about 14-16" long and two large comets (great bottom cleaners!). My problem is this.... he is thrashing around the tank and beating himself up! He does this about once every 2-3 months. It lasts a few days.... he stuns himself & floats a lot, then it's over. This time he is REALLY knocking the hood, splashing water all over, and he tore the up-tube off the back of the tank. He has tilted the powerheads/up-tubes and I am afraid he is going to kill himself. He doesn't have any external signs of parasites or fungus. His breathing is the same as it has always been. I tested the pH, hardness, alkalinity, nitrates, nitrites, and ammonia..... all are acceptable. The temperature is about 78-80F. I added Binox yesterday just in case it is something I can't see. This morning he thrashed so hard I thought he was coming out of the tank! We have about 12lbs of Weider weights on the top of the tank & he makes them jump! The other fish are acting normal. The only thing I noticed that is different is the one comet is darting around faster than normal, stopping, then darting in another direction.... not too terribly bad, but I'm trying to look at everything. Can you give me some help? I don't want him to die!!! Thank you! Robyn < Big fish such as Oscars sometimes get scared by shadows and external traffic around the tank. Things like people walking by or vibrations from tapping on the glass are just a couple of examples of these things. Look for sudden movements, shadows, vibrations, foot traffic, sudden lighting or distractions. Next time it happens cover the tank for a few days until things quiet down. Then gradually take the covers off and let him get reacquainted with his surroundings.-Chuck>

Keeping it Small?? Hey there! I have no idea if you remember me or not, I haven't written in forever and I'm sure you guys get tons of emails. In any case I'm writing again. And this time there's nothing wrong :) At least I don't think so. Since the frog I had committed suicide and the rest of my fish all died on my way back to school, I started the semester with a new set up. This includes two barbs, a common Oscar, a pleco, and a cichlid (there were two but the other one for some reason croaked) I plan to keep the tank small, at least smaller then it was. <Then please return the Oscar and Plec. Both will need a large tank. Eight inch Oscars are common, and a common Plec will hit a foot in time. What size tank is it?> Anyhow, I'm babbling. I'm writing really because Sir Orrick Van Leans A lot (Oscar; I call them by name) leans. He eats constantly, shows no signs of stress, and otherwise appears happy. The temp is fine, the filter is working, and as far as I can tell things are just fine. Except he leans, which is why I gave him his name. I was just wondering if this may just be some weird personal behavior (I hear Oscars have a lot of them) or if I should watch out for something. He doesn't do it often, mostly if he's not begging for food. At times he just leans one way, once in a while completely horizontal, and then pops back up. I wonder if he's bored. Anyway, that's my scoop. Let me know. <Could be a genetic problem with his swim bladder, or caused by infection or poor water. Since you seem to have some pretty dirty fish in a small tank I would try a series of water changes and see if it helps. If it does, remove some fish or up your normal water change schedule. Bottom line is you can expect more problems if this is less than a 29 gallon tank. Even that will be small when the Oscar and Plec are mature. Don>

Oscar Behavior I have 2 Oscars one is an albino tiger and the other a tiger Oscar. Both are about 3 1/2 to 4 inches in size. My cousin said that they will start to pick up rocks and depending on their temperament they could start ramming them into the side of the tank. I was just wondering if there was any truth to this or not. < Oscars like most cichlids are territorial. This means that they will move objects around the tank like box filters, gravel, rocks and plants to wherever they seem to like at the time.> Also I have a smaller Molly in the tank that seems to follow them around. Why is it that it gets to "tag along" and yet they eat other fish? < The probably the molly has learned that as long as it stays behind the Oscar it won't get eaten. Once it goes it front of the Oscar then it may become a potential meal. The Oscar cannot eat what it cannot see or find.> One last Question, I was wondering if u knew any tips or tricks to train your Oscars and the types of things they can learn? < Not really, but you can take advantage of its natural behaviour to make it seem like it is doing tricks. For example, years ago I had a large Lake Malawi cichlid that killed everything I put in with it. He ended up in 20 gallon aquarium all by himself. To keep himself entertained all day he excavated all the gravel from the center of the tank and placed along the edges to create a big bowl. Back at this time aquarium stores sold clear blue plastic balls to decorate aquariums. I placed one of these balls in his tank one day and it settled to the bottom of his tank in the center of the bowl. After he figured out that it wouldn't hurt him he would spend all of his time trying to push this plastic ball out of the tank at the corners. After awhile I felt sorry for him doing this every day so I took the ball out. A friend of mine came over to visit an asked what happened to the blue plastic ball. I told him the story and he did not believe me. I got out the plastic ball while he was there and placed it in the tank. It slowly sank to the bottom. After a few minutes he was back to his old self and pushed the ball back to the upper corner of the tank where I reached in and took it out. My friend said" WOW this is great you have a fish that can fetch like a dog". So from that point on I had a fish that would fetch a ball. I ended up selling him off to a friend who kept the fetching fish for years to show all of hid friends. So to answer your question, I think you can make other people think that they are performing , but in fact it is what the would be doing normally.-Chuck>

Re: Oscars Hi! This is in response to Tom, who had a question about lip-locking Oscars. My Oscars are kept in a 72 gal bow-front tank with a pleco, and an iridescent shark. that's it, just the four of them. My Oscars will swim side by side and then like every 3 months or so, they will lip-lock and they go around in a circle. Then it stops. Doesn't last longer than 1 day, the "arguing" as I call it. You replied to Tom that the tank was to small. is my tank to small? < If the nitrates are over 25 ppm then you need to do bigger water changes or change the water more often. If this doesn't work then a larger tank would keep from stressing your fish in between water changes.> I just took it as a sign of aggression, or an argument of sorts. They do the normal play stuff, like attack the glass (puff up, mouth open and swimming up and down), move the gravel and spit it out at the pleco (yes they do aim for him and spit the rocks out at him!) and of course rip any type of plant we have in there right out! The Oscars are around 12" long and the shark is about 13" long. The pleco is huge and I don't like it at all, but know that it is necessary for cleaning purposes. Other than the occasional lip-lock, they are best buddies. They look really healthy and happy. Anytime I go near the tank, they are so curious to check me out. Also, another question for you. We feed the Oscars live food every so often, not daily. The last time we purchased feeder fish for them, it took them almost a week or longer to finish them all off and I think the pleco did most of that. I feed them Cichlid sticks and Tetra flakes (for the other fish). Is it that now they are "lazy" and would rather get the sure food instead of hunting, cornering and eating the Rosies? Or are they just so used to the sticks that now they won't eat live food? Thank you for your help! Chalis < Fat healthy Oscars really don't need feeder fish. The feeders can carry diseases. Try washed earthworms, mealworms, crickets and king mealworms instead next time when you want to give them a treat.-Chuck>

Oscar spitting food Hi! Three weeks ago I was given a four year old male Red Oscar. He lives in a 6o gallon hexagon aquarium with two Bala Sharks, whom he seems to get along with just swimmingly. The problem I'm having is that the Oscar (Henry) begs for food (I feed him JumboMin sticks), he eats the food, but then spits out pretty much everything. So much food comes back out of his mouth and gills, that he couldn't possibly be swallowing enough. His previous owner told me that he is a very picky eater. I've tried several other kinds of food, I've even tried gut-loaded feeder goldfish, but he only likes the sticks. I'm already quit attached to him. Do you think he's spitting everything out because there's something wrong? Please help! Thanks, Jillian < I suspect that he has probably imprinted on one kind of food from a previous owner reluctant to vary his diet early and often. To get him back on track do not feed him for a week. After a week offer him only enough food so that all of is gone in two minutes. If any food remains then net it or siphon it out. Eventually he will get hungry enough and learn that if he does not eat when it is offered then he will not get to eat at all.-Chuck>

Oscars and .."How about some more beans, Mr. Taggert?" One last question. Do fish fart?? Mine seem to. Is it normal? <What would Ben Franklin say? "Fart proudly!"... yes, some do> They aren't gonna spontaneously explode? <No, another urban myth dispelled> hehe. But seriously, when they...."release waste", there are a lot of bubbles coming out with the feces. And their feces is HUGE. All normal? <Yes> Thanks for the quick response, by the way. Is a good thing you guys got going there. <Perhaps too much. Bob Fenner>

Attack Oscars Hi I have some Oscars that someone gave me, when I was putting one in my tank he caught my knuckle on my finger. Now it feels like I have a cactus needle in it. I have not found anything, I used a needle to open it up. Is there a chance of maybe some type of poison that he would have in his fin to make it feel that way. Thanks for your time. Connie < Oscars like all cichlids have sharp dorsal spines that protect them from predators. They are not know to contain poison but it is entirely possible and highly probable that their skin is covered with bacteria and could cause infection. It is also possible that there may still be a tip of a dorsal spine still embedded in your knuckle. thus causing your discomfort.-Chuck> Red Oscars changing colors...weird... Ok, this makes no sense to me, but my 2 Red Oscars (Knuckles and Jimmy Tight Lips) <Wow, are they "muscle" for a gang?> change colors constantly. I am not talking about a gradual thing either. I mean, today me and my wife came in, turned on the light for feeding time, and almost thought they were different fish. I will have to get some pics to show what I mean. The weirdest thing is, when we turned on the light today they were both very light green, and orange of course, but after having the light on and feeding them to make sure they aren't sick, they seemed to change back to normal color. I left the room for a few minutes, came back in and the very light green had turned almost black. They normally look like normal red Oscars, but yet sometimes their dark color will almost completely disappear. This CANT be normal?!? <It is though... Oscars are pretty temperamental and show their mood changes through their apparent color... to folks like yourselves who are adept at perception> I love these lil guys and I would really like it if I could keep them happy, but most of all, keep them healthy. <Mmm, one item... you mention turning their light/s on/off... better to put these on a timer, have come on, go off on a regular basis> Their behavior is pretty good, although the bigger one still seems a bit shy. He wont eat from my hand like the lil one will. I even got the lil one to jump out of the water a little ways to touch my hand. It is like a game to him. Even when I change their water and clean their fake plants he will play with my hands. lol I had no idea fish could be as smart as these guys are. They will knock the thermometer off and push it around to hit the sides to get my attention if I am ignoring them. They are a couple lil spoiled brats. hehe. But I love em. I am feeding them Cichlid floating pellets and sometimes I toss in a few shrimp pellets. I put in 2 Plecos and a tiny crayfish, but they were gone within the hour. lol...expensive feeders I guess. I really didn't want them to eat them...but these guys are spoiled I tell ya. So I am going without any algae eaters or anything. I just did a water change, since I have only had these guys for a few weeks now. They are in a 55gal tall tank with 2 Powerhead 201's and an Aquaclear 300 Power Filter. I am assuming that is enough to keep the water fairly clean. <Mmm, maybe... for now, but you will need/want more filtration as they get bigger... and are likely moved to larger quarters> I also clean the feces about twice a week just to keep it tidy. The reason for the color changing concern is that when I first got the tank, I only had a single algae eater, as soon as I added the red Oscars, the algae eater mysteriously died. But the red Oscars didn't touch it. It just turned almost white and died. I am completely new to fish, so I have no clue what is going on. I am trying to learn as fast as I can. Any advice is greatly appreciated. Dan <Sounds like you're doing fine... Bob Fenner> Pouting Oscar, Hidden Danger, not a new kung-fu film unfortunately I have had a my tiger Oscar for about a week now and he seems to be shy, I have heard they can pout is that true? And if so, how long will it take him to warm up to me and are there any ways to make it easier for him? Thank you <The key is food. They love us because we feed them. Try holding a small earthworm or other favorite food up to the glass until he gets excited. Then feed him. He will soon see you as a food source and beg whenever you walk by. Give him time though. These are smart fish that can be stressed in a new home. The danger lies in water quality. Is the tank also a week old? If so it has not yet cycled and ammonia is building up. This can be deadly. You should be testing for ammonia, nitrite and nitrate. Do water changes to keep the first two at zero, nitrates below 20ppm. Don>

Oscar gone mental (not girls gone wild...) Hi, I just discovered your web site, I was very impressed with all the info. I have been keeping fish for 20 year. I have gone from a 10 gallon tank to now a 55 gallon tank. I spent an hour going through previous questions and couldn't find mine. I have a 10 in., 5 yr. old red tiger Oscar, in a 55 gallon tank, with an 8 in. pleco as a tank buddy. Water quality is good. ph 7.0, temp. 80. I use a Fluval 304 canister filter. Tank is well established for many years. I have never had any problems with ick or parasites or fungus, I have been a very lucking fish keeper. I feed the Oscar cichlid jumbo food sticks and large floating pellets. About 3 months ago I started with some live food, to give him the thrill of the hunt. The live food was small minnows from my 10 gallon feeder tank. I had 25 at the time. Over the 1st month I would give him 2-3 fish once a week along with his regular food on the other days. When the supply of feeder fish ran out I think he started to rebel. Over the past 2 months he has been destroying my tank. He will go down to the bottom of the tank and wiggle and thrash on the bottom of the rocks. My fake plants are all floating. He also charges the glass and looks as though he is trying to bite it. His scales look good, aside from a few scrapes from thrashing about. His appearance is healthy. He is still eating his normal food. I get the feeling he is highly pissed off at me because I stopped his live food. I get the feeling, if he could jump out of the tank, he would bite me in the throat and kill me. I don't want to start giving him live food again until I figure out if there is anything wrong with him. I have done water changes and cleaned his gravel and still he continues to thrash about. Help me, I think he has gone mental. < Nothing wrong with your Oscar. You have given him a taste of the hunt and it has triggered all of his natural instincts of being territorial and seeking more of the good stuff. Try and vary his diet with earthworms, mealworms, crickets and kingworms.-Chuck>

Hey there, lonely Oscar, my only Oscar... I bought two small Oscars who have been together for about 11 years. I believe they are the same sex. Anyway, one of the Oscars died recently and the remaining one will not eat and just stays at bottom of tank. The Oscar has not eaten in a couple of weeks. There are no other fish in tank. Could an Oscar die from being alone and what can I do to help? Thank you very much. < Your Oscars have lived a long time. Any change in their routine may lead to some sulking if their is no disease problem. If being alone is really the problem then I would place a mirror along side the tank and see if he responds. If there is no response then start thinking about diseases and causes.-Chuck>

Oscar Behavior Question I have an albino Oscar and a black Oscar, they are about 6+ mo.s old and the albino is moving the gravel out of a spot on the bottom of my tank and its bottom is getting real yellow, does this mean that she is going to lay eggs? < Maybe , but probably not. Oscars like other large new world cichlids like to arrange the tank to their liking. The yellow green on the bottom is probably algae.> Will my Oscars fight with each other? <They will defend their territory against all other fish unless they decide to pair up and mate.> Can an albino mate with a black Oscar? < As long as one is a male and the other a female.> Do you think that is what is going on? < Just normal territorial differences between two cichlids.-Chuck> Thanks LJS

Oscar behavior Chuck - thanks for your quick response. However Percy is now snipping at Quincy and Quincy is not eating at all when I feed them. The food goes right by him, almost like he can't see it. I would like to get Quincy a separate tank, but because of Christmas, can't until I get paid, which is in 10 days. I am afraid he won't survive until then between Percy, who is thriving, and not eating. I feel so bad for him. Any suggestions? <How about a tank divider to separate the two?-Chuck>

Oscar drama. Won't eat, and puffs up at me!!!! Dear Bob, I'm hoping you can help me with a question. I've been to your web site, and couldn't find the question I was looking for so thought I'd drop you a line. I'm hoping you may help! I own an Oscar. He is about 16 cm.s long, and I've owned him about two years. He grew up in a smaller tank, and two months or more ago was move to a 4 foot by 2 foot tank. At first, he did the usual orcas sulk thing, and wasn't too alarmed at that as we've had many of those. He did come ok when he was used to his new environment. His appetite returned but he has never eaten the same huge amount as when he was in his small tank. He used to have about 8 pellets morning and night. It turned into about 4 per morning and night. Now - he rarely eats! He does seem ok but.......He's not eating! I've tried to vary his diet. Going from pellets to frozen dinners that he used to eat when he was young and love. I've also tried live food. He does eat that...but gets bored of it, and ends up chasing them, biting them, and spitting them out. One of the other peculiar things I've noticed is his behaviour. Every time I go near his tank he 'puffs up' in a defensive manner. He never used to do this. Any idea what may be wrong with my non-eating, 'puffing Oscar'? Thanks for your help. Lucy. < Oscars like to be warm so make sure that the water temp is up around 80 degrees. Cichlids go through growing spurts and your kinda missed the boat bring in a small aquarium for so long. Only feed him enough food so that all of it is gone in a couple minutes each day. Don't let the pellets float around all day and get caught in the filter to decompose. Try feeding washed earthworms instead of feeder fish. Cichlids are naturally territorial and you Oscar now has established his new home as his territory. As you walk by he is letting you know that that is his turf and that you are not welcome.-Chuck>

Oscar behavior I Have a 10 inch Oscar a and two nine inch Oscars. The ten inch Oscar bites at one of the 9 inch Oscar and the other 9 inch Oscar bites the other 9 inch Oscar. The one who is getting attacked is laying in the corner and tries to run from the attackers. He is a little scraped up and I was wondering if there was any water conditioner or something that would make the Oscars take a chill pill and be less territorial. Also they kinda don't let him eat and I have to feed him when the other Oscars are goring their face or he is afraid to eat. What should I do? And thanks and have a merry Christmas. < Oscars are cichlids and can be very territorial towards their fellow tank mates. If the two dominate fish are a pair and are getting ready to breed then it is best to remove the third fish before it gets killed. If it is just normal cichlids picking on another then you could try to reduce the water temp to 75 top slow the metabolism of the fish down. Use BioCoat by Marineland when changing the water to help the skin of the damaged fish.-Chuck> Bertha (red Oscar) hi everyone I adopted an Oscar a few days ago. since she has been home, she has been acting very sporadic. bertha will swim from the top of the tank to the bottom with her mouth open, as if she was going to eat a fish.. jiggling back and forth also. I have also noticed she likes to try to bite both of my filters as if she is trying to move them down or somewhere else). same thing with a silicone hose I have with a air rock at the end of it, she likes to bite it and try to move it is this normal behavior for bertha or is something up with her that I just don't see??,,she looks healthy, is eating a lot, and has no signs (at least I think) of any bacterial virus. water is fine( I did a 3/4 tank change today, and it seems that all is well. is it just bertha being bertha (her personality) or should I be scared?? < Welcome to the wacky world of Oscars and other large neotropical cichlids. The behavior is actually quite normal. Bertha is actually rearranging her territory to her liking.-Chuck> thanks for your help mike and bertha (the red Oscar) ps.,, love your web site!

Red tiger Oscar has lost his red :( Hi there :) I have read through your FAQ page in the hope that it could help with my Oscar problem but could not find my fishes problem. In fact, I don't even know if it IS a problem. If anything it is more aesthetic than anything! My Oscar is about 6 months old and about 4 inches long. He is a red tiger Oscar. I also have in the tank with him (until he is a little older when he moves to his own) a 7 inch Jack Dempsey, a 5 inch Gold Severum, a large silver dollar, small red forest cichlid,1 large and 1 small silver shark, 3 large sucking cats, 2 quite large and shy clown loaches, 1 ghost knife (who also keeps to himself), and 1 small kissing Gourami (who is very new to the tank). Now about a month back (most of them we have had about a year but the oscar-5 months and the Gourami -1 month) our tank got some funky green algae which I think was related to too much sunlight reaching the tank but regardless it took a while to fix the problem and in that time we also had the end of a snail plague which the clown loaches were sorting out. Ok so the tank got quite gross for a while and the filter was continually getting blocked (I have a canister filter Eheim-oh and a 200litre tank which the Eheim is quite capable of cleaning.) So I know I ramble but the problem is that the Oscar lost his red during this time. I had a very high gH during that time (we are in a new estate and the water is high), the water is beautiful now and the levels seem ok but he still hasn't regained his red.....he is a perfectly black fish with a green colour where the vibrant red used to be (except for a small red spot near his tail) he is quite happy and a pig of an eater, very personable and we love him but as I said its more aesthetic than anything. I have a very dull dark fish when I had a vibrant one before. I am hoping that he isn't unhappy. He got beat up the first day he was in the tank but since then no one has gone near him in an aggressive way and they all always let him feed first (the jack Dempsey stays close to him during feeding but swims away if it gets too crazy). Any help or advice would be much appreciated.( I also cant separate him for at least another 2 months ( I have another 200 litre tank with 2 salmon catfish over 15inches long and a huge red Severum and a rainbow shark and they will not let anyone else in the tank with them-but in January I will buy a 6 foot tank for Gimli-the Oscar and possibly the Dempsey to go with him). Many thanks Kirstie < Most of the time the color is the result of diet and lighting. With all other things being OK I would feed foods high in Krill or brine shrimp. For pellet foods I would recommend Spectrum by New Life, Marineland food or Hikari cichlid pellets. If your florescent light hasn't been changed in a while you might try a new light bulb and get a color range that has a heat range of 5000 to 5500 K.-Chuck.>

Shy/stressed-out Oscar Thanks for your advice on setting up my 55 gal aquarium with the Oscar in it. I put in some bigger brown gravel instead of the white and it looked 10 times better immediately. I am also going to get a big stick of driftwood for it. Ever since I moved Tiger, my tiger Oscar, such an original name right? Into the 55 gal he has been stressed and very shy. I made the move about 2-3 days ago, and he has been laying on the bottom hiding. He seems to be extremely shy. Would Doc Well Fishes Aquarium Salts help reduce his stress? <No> And do you have any advice on his shyness? <Leave the lights off for a couple of days until tiger gets use to his surroundings. Walk up to the tank and offer him a washed earth worm. It will squirm around for awhile but he will eventually eat it. Do the same thing for the next couple of days. He will learn to associate you with food and hopefully come out when you approach the tank. This is like training a dog . Don't worry if he doesn't eat for a few days. You could also try some dither fish. These are fast moving fish that do not hide and are active feeders. Get a group of 4 to 6 medium sized barbs about half the size of the Oscar. Smaller fish may work but then he may eat them too. These barbs are always hungry and your Oscar will be joining them in no time. > I know he is swimming when we aren't there, but I think he is scared of us right know b/c of all the stuff we have been doing to change tanks has frightened him. The main problem with this is I can't seem to get him to eat, since whenever I come by he hides. Any suggestions would be extremely appreciated. <Just be patient and give him a few days to settle in. Make sure the water temp is still around 80 degrees. If your heater can't keep up then the cooler water may be suppressing his appetite too. -Chuck > Thanks, Dylan Cobb

Oscar Hello; He isn't as shy as he was when I first got him know. He know comes out and swims around the tank vertically and horizontally on a regular basis. Although if I approach him quickly he tends to back off but doesn't go hide in the corner like he use to. He is know eating at least I think he is because the pellets which I put in are know missing, but I do see pieces of some of them laying on the bottom of tank- do you think he may have just taken some bites as they tend to get quite large when left in the tank for more than an hour or so? I was wondering if I should steal feed him some Earth Worms from my backyard even though he maybe eating, just as a treat to get him to like me. He is only about 3 Inches long. Should I minimize the size of the worm or does it really matter? < Don't feed him any pellets for a day and then try the earthworms. He should be eating them very vigorously. If not then we need to start looking at other things.-Chuck>

Oscar Hello I recently purchased an Oscar and he has been hiding in the corner of the tank. All he can do is lay on one side but he sometimes gets up and swims around when it is dark. I read someone else's question like mine but I think mine may be different. I think it maybe because of stress or that he is just new to the tank. Help, Thanks ( don't know how much longer ;( ) < New South American cichlids do sometimes take a while to get use to a new aquarium. If the water is 80 degrees and not too bright then he should be up and about in a couple of days. Try feeding him some washed earthworms. That should get up and about. If not then he might be getting sick. Watch for symptoms and get back to us.-Chuck>

Re: Oscar Thanks for the Advice. I think you are right because while I'm typing this message he is slowing going back and forth and watching me, Also last night I saw him again go for a swim. He went up and down and all over the tank. Although he is not eating I think I will do what you said and dig up some worms and rinse them and put them in ( I was feeding him Cichlid Floating Pellets from Wardley). < The worms will help bring him out of his shell. After awhile he should have his face plastered against the glass begging for more.-Chuck>

Tiger Oscar goes "Grrrr..!" I feed my know 4 inch Oscar medium sized pellets- I was just wondering how many times I should feed him and the amount, because whenever I grab the bag he gets all excited as if I'm going to feed him again after I already did. I was wondering if I'm not feeding him enough, I feed him three times a day three pellets each time. Thanks <As long as the food is all gone in a couple of minutes then three small feedings a day is fine.-Chuck>

Red jaguar Oscar acting funny To start off, what an excellent FAQ!!! My Oscar, a red jaguar, is 5 inches and in a 10gal tank. That's the first problem which is being solved very shortly. He has grown 2 inches this semester and the largest tank I'm allowed to keep in my dorm isn't going to work anymore. I have been feeding him feeder fish his whole life, and there hasn't been too much of a problem. Since I got him almost a year ago, his color has lightened a little, but not much. Yesterday I came out to check on him and found he had turned a bright white from his usual dark brown and he was floating. It was time to change the water, but I was in a rush so I put him in my feeder tank. The next morning he was a lot livelier and his color was fluctuating still. He would go from his normal dark brown to the pale white about every five minutes. It was an all of the sudden change in color, then steadiness. I took his tank today and did a full clean of it, and let it settle. Put him back in his normal tank with a few buddies (5 feeders). I don't expect him to eat any yet, and he will probably not eat for another day or so. I've noticed that back in his tank he tends to swim backwards towards the corners allot more than usual, and if he is not doing that he will do headstands. When he is in the corners he is usually on a 45 degree angle. Any ideas past a new tank (I should be getting a 55 gal soon) why he is acting funny? Maybe a diet of more pellets? < Your poor Oscar. At a year old he should be at least 12 inches in length or close to it. The high ammonia, nitrites and nitrates have probably stunted him for life. The high protein diet generates lots of waste. Your technique of waiting until your Oscar is near death before changing water has probably stressed him to a point to where he may not recover. If your Oscar is still alive when you get your 55 gallon tank then I would recommend a book so you can properly care for your fish. Anything else but an Oscar would have been dead a long long time ago. -Chuck> Thank you in advance Mike

Bosco Oscar I have any Oscar that is about 5 to 6 inches long in a thirty gallon tank by himself. I have had him for a year or so. Recently, he stopped eating as much and he always seems to stay at the top of the tank by the filter. He stays upright, but does not really swim around. he just stays in one area. any idea what may be causing this. < Change some water and rearrange the tank. If there is no medical problem and he is just bored then this might get him stimulated to check out his new habitat. If the problem still persists then I would look to change his diet. Try washed earthworms or pellets. Try different things and see what happens. -Chuck> Thanks, Greg

Oscars breathing one-sided. Hi, Just wondering if you could possibly give me some insight as to what could be going on with my 2 Oscars? I bought an adult pair of Golden Oscars on March.25. They had a host of problems.. all are gone now except for this gill issue. They seem to switch back and forth, and then use both gills normally. No particular gill is favoured. I thought they had gill flukes (although they are not breathing heavily).. using one gill seems to be a classic symptom of flukes. But they still continue to use one gill occasionally. After the first treatment I figured maybe I didn't dose the aquarium correctly. So I waited a few days, used carbon to remove the medication and treated for flukes a second time. Still no improvement. I'm completely stumped. They look and act healthy otherwise. It just bothers me to see them breathing that way. It's been just over 3 months now with no improvement. Could this be some sort of gill damage? < Based on their rather tough past it could be gill damage. Typically gills that have been "burned" by excessive ammonia do grow back. If they have been exposed to fungus as a secondary infection then they might not. I would recommend keeping the water well aerated so they don't have to labor to breath.> My water parameters are.. Ammonia=0, Nitrite=0 and Nitrate=10ppm. PH is 6.6. Water changes are done frequently.. I was hoping it would help. Aquarium is 75g and they are the only occupants. < Try and keep the water as clean as possible. Your numbers look good. Try and keep the nitrates under 25 ppm.-Chuck> Any help would be greatly appreciated. Thanks, Linda

Night Fright Hello WWM! <Hello back. Don here> I have a problem with my 2 red Oscars and my sailfin Pleco. I have a fluorescent light and when ever I turn it on the fish go to "their" corner and sit on the ground hardly moving except when spooked by the other fish. Another problem I have is at night when I'm asleep I hear a big splash and gravel hitting the glass. It makes me jump and scares me. The fish have scars on there head from this in the past and I am afraid its not the heater or electric. It's like the fish spook each other. pH, nitrites, nitrates, and temp. are all stable. <What are the readings? Ammonia and nitrite must be at zero. Nitrate below 20ppm. Water conditions could be a reason for the inactivity of your fish. You should be changing lots of water with these 3 fish. Up to 100% per week in 2 or 3 stages. Depends on the size of these fish.> The temp stays at 78. They're in a 55 gallon aquarium. <OK if the fish are small. But these are three large fish as adults. The Oscars can hit a foot, the sailfin Pleco can reach 18 inches! All are messy eaters and produce a ton of waste. Make sure you vacuum your gravel> <First, the splashing you here at night is either from your sailfin, or the Oscars being scared by the sailfin. Plecos are more active at night. He's just out looking for food and waking up the sleeping Oscars. It is not uncommon for a large, starving Pleco to try and take a bite from a sleeping fish. Try giving him a piece of zucchini, squash, cucumber or carrot. Attach it to a rock to keep it at the bottom and add just before you go to sleep. That may calm things down. About them being shy/hiding; Any chance another pet is bothering them. Maybe a cat? They may feel unsafe with the lights on. A cat may even explain the night fright. Make sure there are plenty of places for them to hide. They will come out more if they know they have a safe home to retreat to when scared.> I also have another problem. I have 4 cichlids, one electric yellow <nice, but can be aggressive> and 3 I don't have a clues <Also nice. I use to breed "Idonthaveaclues". Won a prize for my Idonthaveaclue whatelseisnew :)>, my friend gave me the tank. Its not good at all. It's a 10 gallon. The filtration is perfect <What is it?> but the space is cramped. <Agreed> The electric yellow is 3 inches while the others are abut 1 inch. The 3 unknown species (with vertical stripes. They are blue in color and the other one dark with a red fins. Not a red tailed shark I'm 100% sure on that. Doesn't even look like it) but anyways, the electric yellow seem to torment the smaller fish. <Yep> I'm going to return the 2 Oscars and move them into there, but I'm afraid of the Oscar problem happening to them. Please help. <Before you choose which fish to return, check your pH and hardness. The yellow is an African cichlid and likes a high pH and hard water. The Oscars and Pleco are South American and like a lower pH and softer water. If you match the fish to your local conditions you will have fewer problems. But if you go with the Oscars and Pleco, you will need a larger tank in time. If you put the Africans with the Pleco, he may still cause a commotion at night. Again, target feed your Plecos!>

Night Fright pt 2 I also have something to add to the Oscar problem. It seems that the light stay on thru the week at night Mon-Fri. <Not good> I'm not here on the weekends due to divorce problems. <Sorry to hear. Been there> Is this a problem and do they have timers so the light turn off and on by timer <Yes, or leave them off all day. Better than on all night> and some kind of automatic feeder. I'm trying to move them to the house I'm at Mon-Fri but it's slow happening. Also how can I move my fish long distances about 75 miles doing 60 the whole way.....thanks. <You can get a small timer to handle the lights. Any hardware or department store will have them for less than $10. You can also get auto feeders at some of the larger pet stores or online. Better if you can talk whoever is there during the week into feeding them. As to moving them, it really depends on the size of the fish. Small fish in a large plastic bag half filled will be OK for an hour or so. If they look like they are gasping for air, open the bag and splash the water around a little. Larger fish can go in a clean bucket or other container. A battery powered air pump with an air stone will help a lot. Take as much of the old water as you can, use it to refill the tank. If your filter has a bio wheel or pad, keep it in tank water and reinstall on the tank. Do not clean it or keep it in tap water.>

My red tiger Oscar Hi again chuck, I got a problem with my red tiger Oscar. I bought it and 4 more with it. Since that day it doesn't want to swim or eat like the others. What can I do so it can move and eat more? < Make sure the water is at 80 F and the filters are clean. There should be no ammonia and the nitrates should be under 25 ppm. If the fish do not eat at all then I would treat for an interior bacterial infection with Metronidazole until that are eating again. Remove dead fish ASAP so others will not become sick by ingesting the infected flesh of the dead companions. If the fish are eating but not very much then I would try washed earthworms.-Chuck> New baby Tiger Oscar acting strangely, and odd back coloring Hello there, I just bought a baby (1.5 inch) Tiger Oscar yesterday night, and *almost* all seemed well in the pet store and at home until this morning, when I was first able to get a really good look at it in the daylight, and I noticed a few things I'm now concerned about. Anyway, problem one: the little critter sometimes swims slightly lop-sided, with no side preference, but seems to be perfectly fine most of the time (this was the only odd thing I noticed in the pet store; the clerk said that it was because the store's filter was too strong for these tiny things, but mine now does it even when s/he's far from the filter) Is this something to be worried about, or am I just paranoid? Problem 2: the coloring on it's back is a different color than the rest of its body, like someone put a sheet of opaque brown plastic over it (sorry if my analogies don't make much sense, I just can't get a picture right now). The color that should be orange is nearly the same color as what should be black. Is this a disease, or how babies are supposed to look, or my paranoia? Problem 3: the fish is swimming to the surface sometimes, and either glaring at the bubbles from my filter, or otherwise just seeming to stare upwards for a while and maybe swim with its head pointed diagonally up. I'm just worried about this for some reason. Last problem: it seems to like to swim downwards through the bubbles my air stones produce. Is it having trouble breathing, or does it actually like to do that just for fun? As you can see, I'm completely new to this species (although it is already in a 30 gallon tank, with a 55 gallon in storage) and don't know much about its behavior. < None of the behaviors you describe sound normal. Make sure that the water is around 80 degrees F. The Oscar should be dark grey with a silver grey mottled pattern. It should act like a little puppy dog and follow you around begging to be fed. They should be this way in the store before you buy them. Try feeding him some live food and get him fattened up. If he does not come around in a day or two then he is probably ill and needs to be treated. With so many things wrong with your little Oscar it is hard to begin. Keep the water clean and your fish well fed a watch him closely for signs of a disease. Or you could isolate him and try treating with Nitrofuranace and see if it has any affect.-Chuck> Thanks for your help, and also for bearing with me.

Angry Oscar Hi you guys. First wanted to compliment you all on a terrific site. Your information has been critical to my success. I currently have a 60 gallon somewhat community tank, two eight month old albino Oscars, three clown loaches, and two Synodontis cats) and a 55 gallon tall for my marine fishes, (one zebra and one snowflake, one bursa trigger, and a stars and stripes puffer; all juvenile) I will get them they're 180 next summer. ALL fish seem to be thriving and I wanted to thank you all. O.k. Now that I got that out of the way, here's my question. My uncle has an overstocked 29 gal with an Oscar, two Pacus, two clown loaches, a tinfoil barb and Plecostomus. The other day he told me his fish shattered the glass heater while it was plugged in. (I figure it had to of been plugged in for at least a couple hours before he noticed it.) He unplugged it, cleaned out the glass and bought a new heater. Since it happened he said the Oscar has gone from good to bad. He hides all the time and doesn't hardly eat. He also bumps the new heater and stares at it a lot. I was just wondering what you make of this behavior, and what to expect. < Cichlids in general are territorial. As the Oscar chases the fish around it probably smashed the glass heater. Cichlids are not dumb and are quite capable of learning. I think you Oscar had a pretty bad experience with the heater and is not ready to go through the same experience again. Hopefully the new heater is unbreakable. Over time the Oscar will be back to his old self. Rearrange the tank and help take his mind off the heater. A new bigger tank probably wouldn't hurt either.-Chuck> Thanks again, Mike Lazy Oscar/High Nitrates Hello, I just purchased a 1" Tiger Oscar - by recently, I mean yesterday. When I got home, he seemed ill before I even got him out of the bag. He was just resting on the bottom of the bag on his side. When I moved the bag, he would swim around a bit, but then just settle back to the bottom again. Since the store was already closed by then, I let him loose into the tank to see how he fared. He swam about for a minute or two, but then settled down to the bottom again. Every once in a while for the rest of the night, I would take a look over, and he would be in a different spot - but never saw him swimming around. After I turned out the light for the night, I noticed he began swimming around quite a bit. Now this morning, I noticed that as soon as I turned on the light and went to feed him, he stopped swimming and rested down to the bottom again. Whenever I looked over today, he seemed to be on his side on the bottom. But now, from across the room, I see him swimming around rather energetically. But as I just walked over to the tank, he swam to the corner and rested on the bottom. However, there are no visual symptoms of any illnesses, that I can see. The only water condition that I am adjusting is the nitrates - any suggestions as to how to lower that? The only thing I've found so far is to do water changes, but that hasn't been successful in any of my tanks so far. So, basically, what I'm asking is do you think he could be lazy, or just nervous around me and his new surroundings? Or could there be something actually wrong with him? Thanks, Brian <Hi Brian, Don here. I think he may have been in the bag a little too long. That, combined with the stress of a new home. Don't feed him for a day or two. He won't eat anyway. Let him get good and hungry. Do a few extra water changes. He should recover and start to hunt around the tank in a few days. Don't feed until then. If there are other fish in the tank, they'll be fine. Watch for aggression though. Hope this is a big tank. As to the nitrate question. Nitrate is the end result of the ammonia cycle. It will always raise in a well established aquarium. In a cichlid tank there is nothing you can do except large and frequent water changes. With smaller fish plants would help. Make sure you use a gravel vac when removing water. The fish waste and uneaten food will add to the nitrates faster than your Oscar! Move rocks, driftwood and clean up under them. Then limit the number of fish per tank and feed lightly. Adjust your water change schedule to keep nitrates under 20ppm. If you're doing more than two a week, you have too many fish. Unless your source water has nitrate <US Federal Standard is under 5ppm for drinking water> the only way it enters your tank is in the fish's food. Eaten or not it ends up as nitrate and MUST be removed with water changes. Getting the waste out before it decays is very important to nitrate control>

Color changes? Do you happen to know what some factors are for color changes in Tiger Oscars? I have a black/gold Tiger that has changed his hue to almost a light blue where the black was that seems to match my aqua gravel. The only time that I have noticed him doing so was when I bought live feeder guppies. I do not feed them live food often so for my Oscar to change color on me like this seems strange. Any ideas? Thanks in advance! Jim <Color changes can be caused by any number of things. Stress, excitement, water quality, change in diet, adult coloration, and sometimes for no apparent reason at all. I wont go into details of each one but do have your water tested to make sure its fine. If so, I would say theres nothing to worry about, just keep an eye on him. Ronni>

Oscars Hi, First off I really like your site, it's very insightful. I have 2 Oscars that are in a 55 Gallon tank, they have been together for a little over 2 years now and have always gotten along, just recently though they have started locking lips with each other. I was wondering what caused this behavior? Thanks, Tom <Hello Tom, this is behavior can be expected with these large aggressive fish kept in small quarters. They are probably starting to feel cramped and are getting cranky. I would move these fellas to a larger tank as soon as possible. Best Regards, Gage>

My Oscar Bob, I just fed my Oscar's some goldfish and while one was going after a goldfish it accidentally swallowed a piece of the gravel at the bottom of tank. the fish is about 4 inches long and about 3 months old. I was wondering if he was going to die or if he will digest the rock? if you could respond I would appreciate it. thanks <In all likelihood "this too shall pass". Happens quite often with these gluttonous feeders. I would not be overly concerned. Bob Fenner>

Re: my Oscar Bob I just wanted to thank you for responding to my email. I really appreciate it. <You are welcome my friend. Glad to be of assistance. Bob Fenner>

Tiger Oscar Color Changes? Check the water quality weekly. The only thing that is abnormal is that I cant really seem to get my nitrite level down. 0 - ammonia, 2 ppm nitrite, and around 40 ppm nitrates. I normally do weekly water changes of around 1/3 of the 30 gallon tank. <Wow, thats really high on the nitrites but I wonder whats causing it? Are you testing the water at home? If so, take some water to your LFS and have them test it to see if you possibly have a faulty test kit. If it shows up at 2ppm for them too then you need to do some checking on your filtration. It may not be enough to handle the mess produced by your fish. The high nitrites could indeed be causing the color change for your fish and could easily prove fatal for him, especially at this level. Ronni>

Re: Tiger Oscar Color Changes? Well I am using the Fluval 404 canister filter on a 30 gallon tank. The filter is rated for 100 gallon tanks. I am using carbon, pre-filter cotton, pre-filter ceramic, and bio-max ceramic. Filtration should not be a problem. I do have a growth in the tank that keeps coming back. A whitish gunk grows on runner parts in the tank: outflow connector, suction cups for the filter hoses. I also have a growth of something on a fake plastic magma formation. I scrub the thing about every two weeks to clean it off. <Well... a thirty gallon system won't suffice for long for this specimen... and you may just have a "bunk" specimen... there are ones that just don't color up. I would keep trying to expand the food selection to include foods with carotenoids in them (like dried krill) in an attempt to restore your Oscar's color. Bob Fenner>

Oscar Coloring and Activity When I was younger I had many Oscars and recently I bought a albino tiger Oscar. This Oscar brings me much joy just being in the same room. When I bought it the fish had, and still has, a black outline around its fins and tail. It doesn't look to be harming it but I was wondering if this is normal? I noticed most their other albinos were this way too. Also I think my Oscar may be unhappy/sick, or just not like me. It just chills on the bottom of the tank in the far corner anytime the light is on and I am around, but if I turn the light off sometimes it will come out of hiding and swim around the tank. Any suggestions? Many Thanks, Larry <Hi Larry, the black edge on the fins is very common in the coloring of Albino Oscars, no worries there. The inactivity may or may not be a problem, I'm sure you are aware that Oscars are messy, so frequent water changes are important to maintain water quality. Poor water quality can lead to lethargy. The lights may make him uncomfortable, he will probably get used to it, but it could take a while. Some floating plants like water sprite, or duckweed are good for filtering the light, and sucking up excess nutrients in the water. Just give him time and good water, and he should be acting like an Oscar in no time. Best Regards, Gage> Super Sensitive Oscar Every time me or my wife makes changes to the tank, whether it's cleaning algae off the sides, or even at times just entering the room, our Oscar will go to the bottom of the tank and lie on its side until we leave the room. When we leave, it will start swimming around again. We have also witnessed this by just turning on the aquarium light; after about 10mins with the light on, it will begin swimming again. Why is it doing this? <I have seen this in Oscars that have been living with abusive tank mates, it takes them a little while to regain their courage. For being so big and aggressive they can be really sensitive, he is probably just getting scared. Tell him to take a man pill and start acting like an Oscar is supposed to. Just kidding, but seriously regular tank maintenance, pristine water quality, and a high quality varied diet, will ensure his physical health is taken care of. The aggressive behaviour should come back in time. Try hanging out with him for a while, don't make any sudden movements. You could try associating yourself with his favorite food, sooner or later he will be jumping out of the water to greet you. There is a good article on Oscars here http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm Best Regards, Gage>

Oscar Color Changing Good Morning, <Hey Rusty.> Just happened on your site, enjoy the info very much! <Excellent, be sure to check out this article http://wetwebmedia.com/FWSubWebIndex/oscars.htm > I have a question. I have a single Oscar, 55 gallon tank, and is about 6 inches long now. This is a wonderful pet, and is very personable. He (or she) was purchased at a PetSmart, and not sure what type of Oscar, was sold as a Red and he is sort of a grayish color with orange markings on his flanks. <Probably a Red Oscar, could be a Tiger Oscar, Astronotus ocellatus either way.> He seems to be very happy and healthy. Over the last month he has begun to display the oddest thing I have ever seen, and was wondering if this is common in Oscars as he is the first one I have ever owned? Occasionally, he will flash colors, and I do mean flash. His orange coloration will light up and literally "glow" I've never seen anything like this, almost like he swallowed a light bulb! CRAZY LOOKIN! I cant seem to identify anything in particular he is doing when this occurs, is sporadic, and when I approach him the colors will rather quickly fade back to his normal coloration. Is this normal Oscar behavior? <It is normal, and very cool. Oscars change their colors depending upon their mood, scared, happy, defensive, don't be surprised if he gets really excited when he sees you, he will recognize you as the guy with the food. Enjoy your Oscars moodiness, and do consider a larger tank in the future. If you are not already, pick up some color enhancing food to really get him glowing. Best Regards, Gage> Thanks, Rusty

I have two Oscars <Hi there, Just want to start off this email with the note that Oscars get very large, and you will need a large tank to handle both of these fish when they get older. They become aggressive and territorial, not to mention extremely messy. So, please make sure that you have a large enough tank to allow each room. I suggest a single Oscar should be kept in a minimum of a 55 gallon tank. Two Oscars, if they are a mated pair can do well in a 90 gallon breeder tank (larger footprint). If these pair aren't mated then +100 gallon tank is needed.> The other day I came home to find the smaller of the 2 (4 inches) with all of its scales off and in two spots its flesh was exposed <Your Oscars are fighting. The larger more dominant one is attacking the smaller one because it's invading it's "territory". This is a sign that you probably have to small of a tank. It's missing scales because the larger one is attacking and ripping them off. This is not good because that means that the fish will have damaged fins and skin and will run the risk of infections.> Now two days later it has this fluffy white substance coming out of the 2 wounds Im hoping its not a fungus but I have a feeling it is. <Yes it's fungus. In fact True Fungus which is described as Whitish tufts of cotton-like material on the fin, tail, and body at sites of injury.> Please let me know whats the best way to take care of this <separate the fish so that the little Oscar is not being attacked and scales ripped off is the first thing you should do. Set up a medicine tank to handle the fish, and you might want to set up a large one for it to be his permanent home. Once it's in a separate tank I suggest you start medicating him immediately body fungus is dangerous, and can spread quite easily on a stressed and sick fish. Treat with MarOxy (a medicine produced by the Mardel company). Use Maracyn-Two or Maracyn or Tetracycline or TriSulfa to prevent secondary infections.> and also if there is any food that may be more appealing to him (not to interested in eating since the whole thing happened) <That is to be expected, he is being attacked by a dominant fish, his natural reaction is to back down, hide and allow the larger fish to eat. There are many different foods for your Oscar, they aren't picky at all. Not sure what you are feeding, but Hikari makes some rather nice Oscar pellets that most Oscars go crazy for. If not, then you might want to try feeding you Oscar a couple of Crickets (yes the little bugs you get at the store) Oscars diets in the wild are over 60% bugs. Just float them on the surface and the Oscar might be intrigued by the bug to perk him up and then he will start eating again.> Thanks so much!!! Dena <Hope that helps. Good luck with the fish, and look around online there are some great forums totally dealing with Oscars. -Magnus>

Oscar doing Headstand. >I have two Oscars in a 55 gallon tank. Spooky is about 8 inches and Sleepy Jean is about 12. I changed the about 1/3 of the water two days ago, and Spooky has been pretty much standing on his head ever since. >>Hi Terri. How often do you normally do water changes? What are your ammonia, nitrite and nitrate readings? >He is very bloated. I'm not an expert in regards to PH balance and all that, unfortunately. I did put ammonia clear tank buddies tablets in there, and added Nutrafin waste control to the tank after the change. I know I need a bigger tank. >>You should really concentrate on water changes and proper filter maintenance, instead of adding chemicals. A nitrate test kit will help you determine how often to change your water, and without testing it for you, I can probably safely say you should be doing at least 50% of the volume TWICE a week. Yes, your tank is far too small for these fish. They are being poisoned by their own waste. >He may have eaten too much. I don't feed them feeders, just frozen bloodworms and Wardley Cichlid floating pellets. Yesterday morning I dropped in 10 Maracyn-Two tablets. >>Again, test your water to be sure. If you are adding medications, you will also need to test for ammonia and nitrite readings as well, since antibiotics will kill your biofiltration. >I'm sure that I've overfed them recently, because there is food at the bottom. >>By the way, how often do you vacuum the gravel? >Last night I added 5 tablespoons of Epsom Salt after reading over your e-mails. My questions are - do I continue with the Maracyn-two? How often on the Epsom Salt, what would be best to feed them at this time, what is the best temperature for the tank, should I separate Sleepy Jean, although I don't know where I would put her. She is really concerned and hovering but not biting him. She seems to be well. He's not eating anything. (I have a 30 gallon tank with a 5 inch goldfish and some plecos and striped Rafael's which she would definitely kill.) Any suggestions and prayers would be greatly appreciated. >>Do not move them. Do they show any signs of HITH? Please respond with your test readings :) >Thank you for being there... Terri >>You are welcome. -Gwen

Upside Down Oscar - Round 2! Dear Anthony/Crew, Kim here again searching for more advice for my poor upside down Oscar. : ( <Hmmm... not a good sign> As you will recall, my Oscar was upside down for several weeks over the summer due to a distention of the rectal area. In early September, at your wise counsel, I stopped all meds and started Epsom salt treatments (6 tablespoons for 30 gallons), which I repeated in 3 days and have continued once a week with water changes. For a long while, he was swelling free, but laying at the bottom of the tank. Then he began to hold himself upright and swimming normally for short periods of time. <'tis the case for most... slow and steady progress if the imbalance/blockage was minor> However, in the last two weeks the area has become distended on a daily basis, but only for short sporadic periods of time. When he made the effort to swim, such as at feeding time, it would almost instantly deflate. Unfortunately, this has changed in the last two days. The distention has returned and is constant. He has been upside down now for two days, floating at the top of the tank. The good news (I guess) is that he is still eager as ever to eat the brine shrimp and beef heart each night. Nonetheless the bloated area has grown larger in the last 24 hours, and he can not swim normally at all. Help! Perhaps, I am not feeding him enough (usually 3 brine shrimp gumdrops and two thumbnail size chunks of beef heart once a day at night. The last two or three water changes (w/Epsom), I slightly cleaned the gravel. Could I have disrupted the beneficial bacteria that I understand resides in the gravel? The Epsom salt and food has been a constant, nothing else has changed except that I started cleaning the gravel. Your thoughts and advice would be very much appreciated. Sincerely, Kim Olson <no worries on the gravel cleaning... it is quite necessary. I fear at this point that the problem with your Oscar is more serious. That still does not mean incurable. Internal parasites may have perforated organ/tissue walls internally and injured the swim bladder. There may be a persistent infection too. Using medicated pelleted foods (bacterial and parasitic) may help here. Else I wonder if there isn't a congenital defect that has developed or some irreparable damage. Alas, time will tell. Do try the medicated food sticks/pellets. Hoping for the best :) Anthony>

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