Logo
Please visit our Sponsors
FAQs on Oscar Reproduction/Breeding 

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 Behavior, Oscar Systems, Oscar Feeding, Oscar Disease/Health, Neotropical Cichlids 1, Cichlids of the World, Cichlid Systems, Cichlid Identification, Cichlid Behavior, Cichlid Compatibility, Cichlid Selection, Cichlid Feeding, Cichlid DiseaseCichlid Reproduction,

 

Breeding Oscar cichlids    4/8/14
Hello,
I read on your site as well as some forums that the best way to get a breeding pair of Oscars is to grow out 6 in a 125 gallon or larger aquarium. I understand I will have to remove the other four once a pair forms but am confused about how I can raise six large messy fish in a 125 gallon aquarium without having to make massive daily water changes.
<Pretty much! But to be fair, you aren't raising six adults. You're raising six youngsters, and you'll find them pairing off *long* before they reach adult size. They should start interacting in an aggressive way by the time they're about six inches in length, and by 7-8 inches, they'll be actively spawning given the chance. Put another way, while they're still small juveniles, weekly water changes in the 25-50% bracket will do the trick for keeping nitrate levels down. Change water more frequently as the fish get bigger and as your nitrate test kit suggests (you're aiming for under 20 mg/l nitrate for optimal health, and no more than 40 mg/l.>
Every thing I've read is for the most part states no more than two Oscars in a 125. I don't see how six could tolerate each other to adulthood in such an aquarium.
<Quite so; they won't if they pair off and start spawning, but that doesn't always happen, particularly if they're disturbed all the time.>
Can this be done? Thank you for your assistance.
-Mark
<Most welcome, Neale.>
Re: Breeding Oscar cichlids      4/8/14

Neale,
<Mark.>
Thank you for your reply. I understand but you have raised another question. I have read Oscars will not pair off and certainly not spawn until they are about 14 months old which puts the in the 12+ inch size.
<Not true at all, at least with regard to size. Indeed, not that many Oscars seem to get this big/much bigger anymore! But yes, Oscars are slow to pair off, more so than, for example, Convicts or Jewels, which tend to breed at less than half their nominal adult size. I'm not convinced Oscars are slow to become mature, but they are picky about pairing off, and won't spawn if they're disturbed (they really like somewhere quiet, dark and sheltered). Oddly enough, just finished a piece on Oscars for one of the US aquarium fish magazines, so was reading up on this today!>
Have you spawned Oscars or have you seen them do so at such a small size?
<I haven't bred Oscars. Not a huge demand for them in England. But have bred several other cichlids.>
So much info out there and much of it is contradictory. Also, if I do spawn say two albino or say lemon Oscars, will I end up with fry that look the same or will they be mixed.
<Depends whether a given trait (colour, fin shape) is dominant or recessive. But in all likelihood you will absolutely want two parents of a particular variety to maximise your chances of getting offspring similar to them.>
I ask because I read that the recessive genes of the none
<?>
"wild" type Oscars may result in some that look like the parents and some that look like a standard or wild Oscar.
<For sure there will be situations where offspring will be a mix of heterozygous and homozygous with regard to particular alleles, and these will indeed have differing phenotypes. Do you recall the AA, Aa, and aa stuff you did in high school biology? Punnett squares for predicting percentages of phenotypes among offspring? All is relevant here.>
Have not been able to find any good info on this.
Thank you again for your help.
-Mark
<Most welcome. Cheers, Neale.>
Re: Breeding Oscar cichlids      4/8/14
Neale,
<Mark,>
Very helpful indeed. What US aquarium magazine did you do an Oscar piece on? Would love to read it.
<Aquarium USA; presumably the 2014 edition.>
Thanks again!
<Most welcome, Neale.>

Solitary female laid eggs... Oscar, learning      7/16/13
I have a Oscar cichlid(that we thought was male), large goldfish,
<Should be elsewhere>
sucker fish, and 3 electric yellow cichlids. We discovered eggs in the Oscar's territory and had the assumption it was the yellows' but after more studying about the reproduction of electric yellow cichlids and trying to find pictures of eggs... Something seemed fishy. The Oscar is very territorial over the eggs, but hey, it's territorial over the whole tank.
You see, the problem is that we don't have a partner for it... We're very interested in breeding( especially learning that we could get $7-12 for each one ), but "cichlid breeders in California" didn't have many results on Google... What are your recommendations for finding breeders and also, how long will the unfertilized eggs be able to stay fresh?
<They won't... are infertile. Will fungus, decompose soon>
They've only been there for 1 day counting.
<... trying to "pair", match neotropicals, Astronotus as adults is not easy... easily kill each other. Read here:
http://www.wetwebmedia.com/FWSubWebIndex/oscarreprofaqs.htm
Bob Fenner>

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>

Oscar fish laid eggs, but buried them in rocks..   5/18/11
Hi!
Thank you for taking the time to read and respond to me. I have a couple of questions regarding my Oscars. They are a proven mated pair, I think a couple years old, I'm not sure, they have laid eggs before and some did indeed get fertilized, some wiggled!, but all died. Anyways, they laid eggs again on Monday night, but have swept them sort of all over the tank (100gal) and buried most under the gravel.
<Unusual>
I am wondering why they did that and what I can do to help keep at least a couple alive.
<Provide other spawning substrate...>
We decided letting the Oscars learn to be parents and doing things naturally would be best.
<In general I agree>
There is a very small Chinese algae eater
<I'd remove this>
and a still small Pleco in the tank as well both no more then 3inches long. So what all are we doing wrong?
<These last two may be eating the eggs, young... or bothering the parents, adding to their stress, perhaps to their consuming their reproductive products>
They still eat just fine and protect their cleaned area.
Thank you for your time,
Kelsey and Michael
<... Read here: http://wetwebmedia.com/FWSubWebIndex/oscarreprofaqs.htm
and why not, the linked files above. Bob Fenner>
Oscar fish buried eggs..   5/18/11
Sorry! I also forgot to mention that our Oscars are not petstore bought, they are in fact wild Oscars and the eggs would be F1.
<Really?>
They are tiger Oscars.
<Mmm, no; these and all other than "wild type" are human-produced sports>
We have a friend who is a marine biologist
<?>
and even he verified that they are 'wild'.
<... how?>
I don't know if that helps any! Thank you again!
Kelsey and Michael
<Keep reading. BobF>
re: Oscar fish buried eggs..   5/19/11

How? I don't know, because he is a marine biologist and knows a lot about Oscars.
<...>
Their colors and patterns are much different then inbred store bought Oscars, their behaviors are different (we understand Oscars are very smart and each has its own personality).
<Umm, no>
We were just wondering why they buried their eggs.
<An aberrant behavior>
Their water is on the warmer side already, I raised it when they first laid eggs.
<... warmer... than what?>
Sent via DROID on Verizon Wireless
<Sent via VAIO laptop. B>
re: Oscar fish buried eggs.. Got my mind straight warden     5/19/11

.....warmer then it usually is... its 'normal' is around 78-79 degrees and now its between 80-81 degrees. Should we take the algae and Pleco out or no?
<As stated in my first response; "yes", if you want to reproduce the Oscars... B>
A WWM dissatisfied customer   5/22/11

Neale, pls see your in-folder... an Oscar querior, w/ the expertise of a "marine biologist" id'ing their fish as wild caught... B
re: Oscar fish buried eggs..

What does 'Oscars....B>' mean?
<<The "B" stands for Bob Fenner, the person who replied, the owner of the site, not to mention one of the best known and most respected fishkeeping writers around today.>>
I am a little lost with everything you have asked me, maybe there is another member of the wet web who could help me?
<<For what it's worth, here I am, Neale Monks, one of the folks who helps with the freshwater queries.>>
Thank you for your time though. I hope someone else gets back to me and can answer my questions.
<<I haven't followed your conversation in detail, but Bob's gist is this:
[1] The Tiger Oscar as sold in aquarium shops is not a wild-caught fish, any more than a Persian Cat isn't a natural form of Felis silvestris. Wild Oscars are only very occasionally traded. That your friend is a marine biologist is neither here nor there when it comes to identifying these fish; my first degree was in marine zoology and nothing I learned at university would have helped me identify a wild-caught Oscar! In any case, not one in ten thousand of the Oscars sold in the United States is going to be wild-caught. The name "Tiger Oscar" simply means its one of the brownish varieties of the species with orange markings, as opposed to any of the other varieties, such as Red Oscars or the wild-type Common Oscar that has the same markings as wild fish. Next up, [2] as for breeding, you aren't going to have much success breeding Oscars in a tank with armoured catfish -- such catfish will eat the eggs during the night. Breeding pairs of Oscars need their own aquarium. Do think very carefully before breeding Oscars; they produce around a thousand eggs and it doesn't take much luck to end up with hundreds of fry. The market for Oscars is very small, and even allowing for the fact they are popular fish, you'd be hard pressed to find homes for a couple hundred juvenile Oscars. Don't forget that it'll be some months, perhaps 4-6 months, before the Oscars will be big enough to pass on to an aquarium shop, and housing a couple hundred two-inch Oscar fry will require a massive amount of space and frequent water changes. In almost all situations, it just isn't worth the bother, and it would certainly be irresponsible to breed the Oscars before first finding out where you're going to get house the fry and then where you're going to sell them on. Hope this helps, Neale.>>
re: Oscar fish buried eggs..
Thank you Neale for your response back, much more info then I had gotten before, although my actual question basically this whole time is why did my fish bury their eggs?
<They do sometimes make pits, but they aren't cichlids that produce spawning pits. Normally they lay their eggs on flat, smooth surfaces such as rocks. But if there's nothing they can use in the aquarium that fits the bill, they will move gravel or sand out the way to expose the glass underneath.>
We don't want to breed them and have hundreds, but 2 or 3 would be cool.
<Doesn't really work that way. And even assuming you euthanise a few hundred fry after a few weeks (that's how long it'll take to get them big enough to judge healthy and hearty) and just keep 2-3 of the good ones, that's a lot of work already. The adults will have kicked the juveniles out the nest within that time, so you'll be rearing these in their own tank. If you just want to raise cichlids for fun, there are infinitely better species to play with.>
We will take out the Pleco and algae eater today. I am aware what a 'tiger Oscar' is, my boyfriend had an Albino one as well a few years ago. Just because it would be rare to have an originally wild caught Oscar does not mean its impossible.
<Depends where you shop. Be under no illusions about this. If you spent a couple hundred dollars on your pair of Oscars, and the retailer was advertising them as wild caught, then I guess it's possible. But even then, there's "wild caught" feral Oscars from Florida, and then there's wild caught from South America, which is something else entirely. Furthermore, the wild caught ones from South America will need soft, acidic water to breed successfully, so if yours are spawning in generic tap water, again, it's highly unlikely these are truly wild Astronotus ocellatus.>
We trust our friend as he has gone and studied them and has some of his own.
<If you have scientist friend who's studied them in Brazil, then the best he can genuinely say is that the ones you have share similar markings to the ones he's seen in the wild. Print off this e-mail and show it to him. As one PhD to another, I'm sure we'd agree on this. Trust me, you cannot possibly know an Oscar in a pet shop is wild caught simply by looking at it.>
There doesn't seem to be too much info on wild Oscars, just the inbred store bought ones.
<Yes. The wild ones are hardly ever imported. In 25 years of fishkeeping I've seen them a couple times.>
Which is understandable, as you said, it would be rare to have wild ones. We happen to have gotten lucky and we only want the best for our fish.
<I fear you're a bit deluded here. Wild caught Oscars simply aren't traded for under $100 a piece, so it's highly unlikely you have them unless you paid big bucks and went to a retailer who specialises in high-end cichlids.>
So aside from what we (you and I) feel my boyfriend and I have (wild or not wild) we just want to know why they swished the eggs all around the tank and buried some.
<Any number of factors: inbreeding, stress, lack of proper spawning sites, the eggs were infertile, the wrong water chemistry meant the eggs failed'¦>
Did they already know they were bad eggs or what?
<Can be.>
Thanks again, I don't mean to offend B, as he according to you is a great writer, I just didn't understand what he was saying and why he was asking me questions that I had previously answered.
<Cheers, Neale.><<Sorry for the lack of clarity to any/all. Am out on holiday, w/ patchy connections... and trying to click/respond as quickly as I can to avoid losing.... BobF>>

Oscar babies (fry)
Raising Oscar Fry  11/12/10

Help We have a pair of breeding Oscars that produce fry. The first batch they laid 15 Oscars survived. They have laid eggs two more times. The 2nd batch hatched we had to put in a own new set up. They hatched and survived for about a week and now they have almost all died. What temperature is the best for hatching, is water changes good when they are so young? Any other suggestions? The Oscars are protecting the last eggs but I want to move them again but afraid my set up right. Dave
< Keep the water at about 80 to 82 F. After the eggs hatch the fry still absorb their egg sac for another three days. When they become free swimming they need to be fed a combination of baby brine shrimp, finely crushed flake food and Microworms numerous times per day. One feeding a day and the fry will starve. Also, the parents need to be kept well fed or they will start eating the fry too.-Chuck

Oscar Eggs  4/7/10
Hello my name is Scott.
<Hello. Melinda here with you tonight.>
I have a 200 gallon tank with two albino Oscars, One Red Oscar, One Catfish, One Jack Dempsey, One Eel, and a Pleco. I have had all of these fish for about five years.
<Sounds great!>
My Albino Oscars have laid eggs on a flat piece of slate rock.
<Ohhhh... is this the first time it's ever happened? I ask this because two female Oscars laying eggs isn't uncommon, and obviously, if that is the case, they would be infertile... this is sort of related to the advice I'll give below.>
My question is should I leave the eggs be or should I put them in a netted egg box.
<There are some things to be considered here. First of all, I would worry most about your Plec eating these eggs if the parents were caught unaware.
Secondly, unless you know this is a mated pair of Oscars, these eggs may be infertile. Thirdly, when eggs are removed, with the intention of hatching them without the parents present (not an option unless you'd like to separate the Oscars to another tank), increased aeration and the addition of Methylene Blue is usually suggested in order to avoid fungus growth (the parents would "fan" the eggs and keep them clean if they were left with the parents, but, as I mention above, I don't know that this is an option for this community). This addition of the Methylene Blue wouldn't really be possible in an in-tank net, like the one you're suggesting. However, if this is the first go-around, it might be a good idea to first make sure the eggs are fertile, and that you have a male and a female (or maybe you sexed during spawning? I'm not sure) before you purchase a whole setup to hatch the eggs. You could try leaving some eggs in the tank, and putting some in the box, with the hopes that one of these methods will keep the eggs safe long enough to see whether they turn a clearish-brown color (fertilized) or stay white (sterile). This way, the next time they reproduce, you'll know what you're dealing with, and will be more ready. If this is a mated pair,
they should spawn quite regularly (every month or so -- probably more Oscar babies than even your local fish store wants to take!) so you'll have plenty of eggs to work with. This also helpful because you'll need to prepare food for the young (please see the link provided below/other Oscar feeding pages on WWM.)>
I would really like to see them hatch.
<I think that the above suggestion is best if you have not yet determined that these eggs are produced from a male and female, and are viable. If, though, these fish have spawned and produced fry in the past, I'd go ahead and set up a cycled system in which to move the slate and care for the eggs and resulting fry there. You're going to need one, anyway, if you want to raise the young to the inch-and-a-half, two-inch size that most fish stores want.>
I have already talked to the fish store that I deal with and they said they would take them once I'm ready to get rid of them. I really want to go through with this experience. What should I do? The eggs were laid last night?
<I hope this information helps, and feel free to read on WWM about Oscars, reproduction: http://www.wetwebmedia.com/FWsubwebindex/oscarreprofaqs.htm.
Without knowing a little about the fishes' background, I hope that one of these two suggestions is helpful. Please feel free to write back if you have any other questions.
--Melinda>
Re: Oscar Eggs  4/7/10
Thank you for getting back to me.
<You're welcome!>
Would it help determine if I had a pair if I told you that both fish are taking turns protecting the eggs and fanning them?
<Well, again, if these are two females, and they're "paired up," with one laying eggs, and the other helping in care, it could still be a false alarm. I have seen Oscars "rear" eggs for days, until I eventually removed the eggs, which had begun to grow fuzzy. By now, you should see some of these eggs turning to a clearish-brown color, rather than white. This is what I would go on. Again, you've got a lot of choices here, but prior to setting up, cycling a tank for raising the fry, I'd be sure these eggs are viable! At least they haven't been eaten yet, which means that you can still watch for the color-change, thereby indicating these eggs are fertilized, and you've got a real, mated pair.
--Melinda>

Re: Oscar Eggs 4/8/10
<Hi!>
Well I am going to give it a shot.
<Cool.>
I believe the eggs have began to turn colors but maybe it's just the excitement of wanting to be a grandpa.
<Haha possibly... when and if they turn, it will be fairly obvious.
Instead of opaque and white, they'll be clear have a brown or tan hue to them.>
Thank you for your expertise. It has been greatly appreciated. Have a glorious day.
<Not a problem, and good luck with your breeding!
--Melinda>

My Oscars had only 3 eggs yesterday!!! Breeding Oscars Hello Crew, Yesterday my two biggest Oscars which are around 6 inches each had 3 eggs yesterday afternoon. Well I also have 2 other Oscars in the same tank that are around 3 to 4 inches each and 2 Corydoras. Well a couple of minutes after I noticed the eggs the largest of my Oscars ate them. The two larger ones are the ones that have been doing the mating rituals, and laid the eggs. Now the thing I am concerned about is that today the 2 bigger ones seem to not want to eat and are very low energy and are swimming around in just the one spot where the eggs were laid. They are also not being aggressive like they were and I was wondering if this means that they are going to have more? Or if there could possibly be something wrong? I am worried because I have been waiting a long time to see them breed and I also am very attached to them. All of the water conditions seem fine but I am hoping to find out what to expect next. I am going to the pet shop now to get a divider for the tank to keep them separate while they spawn, just so they are feeling safe enough to do it. Is there anything else I can do? Thank you so much for such a helpful website I have not found another that has been this much help. Thanks, Heidi <Usually when Oscars breed they have thousands of eggs and not just three. The pair then guard the spawn against all other fish. You Oscars are still a little small to be breeding so it is difficult to tell if there is really a pair bond or it is something else. Do a 50% water change, vacuum the gravel and clean the filter. Raise the water temp to 82 F Keep the water clean with frequent water changes. If they are a pair then this should get them going in the right direction.-Chuck>

Re: My Oscars had only 3 eggs yesterday!!! Breeding Oscars II 1/26/09 Chuck, Thank you for the advice I am very grateful. I did do the 50% water change and also cleaned up the filter. But I did check your site to make sure what I had seen was eggs and the picture had matched what I saw. So I guess I will just wait and keep you posted on what happens. However they are still not wanting to eat and I know that I should not be too concerned that they can be like that for a few days and be fine. But sometimes they get into a funk and don't want to do anything but hang in one spot. Thanks again. Heidi <Just in case they are not just sulking you may want to think about looking into getting some Metronidazole and Nitrofuranace just in case they are coming down with an internal infection.-Chuck>

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.>

Oscar gender 7/14/07 Hi: <Ave!> I have two great looking 9 and 10 inch red Oscars and until recently were inseparable. Suddenly they started fighting so I separated them by using a drilled piece of Plexiglas to divide the tank (75 gallon). I would like to know if I have a mating pair or two males or females. Is there a sure-way to tell? and if I do have a mating pair, how can I encourage them to re-bond rather than fight? Best Regards Francisco Toro <Oscars cannot be sexed reliably. All Oscars are mutually antagonistic towards one another once they become sexually mature, even males and females. There's no way to know you have a mated pair until they spawn together, and no, there's nothing you can do to change their minds if they don't like each other. The only foolproof method for getting a pair is to raise 6 and pull out the 4 that don't pair off. Be sure and read this: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm plus the connected FAQs on oscar reproduction. Cheers, Neale.>

Re: Oscar gender   7/16/07 Thank you very much for your feedback. I will keep up the wall (much to Pink Floyd's dismay...;-) Best regards Francisco <No problems. good luck with your Oscars. Cheers, Neale>

Convicts and Oscars, repro.   3/14/07 Hi, <Hello> I stumbled across your website during a google search and I found it very informative, however there are questions that I would like to ask about our convicts and Oscar fish. <Okay> Firstly, we have an adult size Oscar and recently introduced a much smaller Oscar into his tank.  These two fish interact with each other extremely well and we were wondering how we can determine if we have a breeding pair... <Mmm, they'll make this known in time... by successfully reproducing... There is such a thing as two females laying eggs together...> they seem very playful to each other and are always rubbing against each other but we would also like to know how we can tell the difference between a male and female Oscar? <Posted... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/oscarreprofaqs.htm and the linked files above>   A friend told me that you can tell the male from the female if their tale fin and dorsal fin overlap.....I have done heaps of research online and I have never come across this information....is their any truth to it? <Mmm, some... the unpaired fins on most Cichlid species are longer, more pointed in males than females... but individual care, early life history can alter appearances...> Secondly, we have a pair of convicts which every couple of weeks lay eggs that never hatch.  This has happened about 4 times now.  The first couple of times the female ate the eggs but more recently the some of the eggs turned a "yellow" colour and then these little worm like creatures appeared all over the eggs.  The eggs have since been eaten but the wormy things still remain.  Can you tell me what this means and what we need to do to get our convicts to breed properly? <Mmm... May be that there is some creature in your tank interfering here... I would move these fish to another system, and dump, clean the present tank... Perhaps bleach wash it and its contents... See WWM re> Thanks so much for your time... Peta and Simon <Welcome. Bob Fenner>

Egg Bound Oscar Is Probably Sick  - 10/25/06 I have a female Oscar who is VERY full of eggs. She is acting very strangely and differently than the times before. She is almost just floating and hardly moving on her own at all. She looks like she's about to explode but only in her bottom. No swelling is apparent in the head or dorsal fin area. She's been nose-first in the tank almost all day. We don't want to raise any newborn Oscars, we just don't want to lose her. Will it hurt her worse if a small amount of pressure is applied to her abdomen just to get the eggs moving out? I'm at a loss here and scared of my fish dying. Any help or suggestions would be greatly appreciated. < She probably has an internal infection and is not egg bound. Do a 50% water change, vacuum the gravel and clean the filter. Treat with Metronidazole and Nitrofuranace or Clout. This is best done in a hospital tank. Do not squeeze the fish as this may force pressure on the internal organs and cause problems. The key to a successful treatment is to treat early. You may already be too late.-Chuck>

Breeding Oscars  - 09/07/06 Hi crew, I just bought a pair of Oscars. They are about 4 inches. I wanted to know what is the best way of sexing Oscars? And at what size they can be bred? Thanking  you < Oscars are very difficult to sex. Males may be slightly larger and the fins may be slightly elongated too but not by much. Experienced cichlid keepers look at the ventral openings and refer this as "venting". You are looking for differences in the actual openings. Females would have a larger opening to lay eggs. Males would not need such a big opening so it is smaller. Since Oscar eggs are very small it is not a very reliable way to tell the sexes apart. Bottom line -almost impossible. They start to breed when they are around 8 inches. Sometimes smaller.-Chuck>

Breeding Oscars 07/04/06 Hi I have searched over your web site and there is a ton of info  that I've learned. But I do have a question that I couldn't find an answer for. I  have a 55g tank with (I know there are too many fish) 2 Oscars a pacu and 2  Dempseys. I have had the fish in the same tank for about a year. My Oscars are  about 7 inches. One Oscar has been hiding behind a rock and when the other comes  up they start going at each other with there mouths wide open. Also I just   noticed 2 holes in the gravel like they were starting a place to lay eggs???? I   REALLY HAVE NO IDEA HOW TO TELL THE SEX OF MY OSCARS???? CAN YOU PLEASE INFORM   ME OF HOW TO DO THIS??? AND OR MAYBE YOU KNOW WHAT'S GOING  ON? < Sexing Oscars is very difficult. Some experts look at the vent area. The male will have two holes that are about the same size. The female may one vent hole larger than the other. Watch when they spawn. One will have a larger tube. That is the female laying eggs. Both parents will guard the eggs and chase/kill all the other fish. At 80 F the eggs should hatch in three days. In three more days the fry will need to be fed some baby brine shrimp or microworms. At this stage they should be removed to their own tank as the parents may be getting ready to spawn again.-Chuck>

Re: Breeding Oscars? 07/04/06 So from the info that I've given you do you think they are getting ready to   spawn? < You fish are still relatively young, but the observations you reported could be a prelude to spawning.> The fish keep going at each other with there mouths wide open? < Occasionally cichlids will lip lock as a sort of test of strength to see if a potential mate is suitable.> <Digging holes and hiding in the corner? < If they are not pairing up, then one is becoming territorial and has bullied the other one into a corner. Digging holes in the gravel is a way to establish a territory.-Chuck> Sexing Oscars   1/10/06 Thank you for the advice. Which is easier to take care of: males or female and how do you tell the difference between the two? Jess < Oscars are very difficult to sex. The males may get slightly larger than the females but that is about it. Very large fish may be vented. This is done by turning them over and looking directly at the ventral openings. The females vent will usually be larger than the anus while the males vent may be the same size or smaller. I am sure the pro breeders in Florida Fish Farms can tell right away but they probably have been breeding Oscars  for years. there temperament is about the same for both.-Chuck

New to Oscar Breeding: A few Questions 6/31/05 I was at a fish store this weekend and saw a very lovely pair of what I was told Breeding Oscars. <Great find! Breeding pairs of Oscars are decently hard to locate!> I have raised Oscars off and on for some time now but never a breeding pair and normally in smaller form one at a time.  I was wondering if a 90 gal tank would be a suitable size for the pair. <Indeed, a 90 gallon is ideal for a breeding pair of Oscars.> The store has them in a 70 gal. But I really want to help them and take care of them the best I can. <That's always great to hear! Good job at being a responsible fishkeeper!> I am even looking at acquiring a 210 gal later on to accommodate them if I was to get them. <It could probably also accommodate another breeding pair or several other large cichlids, if you wished.> Anyways my second question is to tank setup.  What do you recommend.  I have herd using gravel, no gravel (with Large Slate for spawning), Or rocks or no Rock.  Please advise so I can do the best for them. <I <i>always</i> go for the natural environment for all of my tank setups, and I would recommend the same, even for a breeding pair. Tank setup is a very subjective factor, and there are many opinions on how to do it "best." I think you should research it on your own and decide what you like best and what would benefit your goals best. Good luck! Mike G> Josh  

Sexing Oscars Would it be easy to vent an Oscar of about 5-6  months? < No, Oscars are one of those fish that can be difficult to sex. The older the better. They take awhile to become sexually mature. Even experts have problems sexing these guys.> How do you keep them from wiggling out of your  grasp? < Siphon 5 gallons of water out of your aquarium into a bucket. Take a bath towel and cover the bucket. Push the center of the towel down into the bucket about half way to the bottom to create a little wet area. get the Oscar and place him inside the towel in the water. Then lift the towel while cradling the Oscar in the wet towel. At this time he can be turned over and held in the wet towel.-Chuck> Breeding Oscars? Hello! I am now seeking your help once again. I am having trouble with my smallest Oscar!!!!  Now, I have 3 Oscars in total, and the 2 of them are big both ranging from 10-12 inches in length if not bigger.  My small one is about 8-9 inches and is acting funny.  Lately they have been fighting.  Now, my boyfriend went to clean out our 77 gallon fish tank and the little one keeps trying to attack him, but the bigger ones stay in a corner and don't go near him.  My boyfriend also put the towel up to the glass and he tries to attack it through the glass, and the funny thing is that he tries to eat the vacuum that is cleaning the tank.  He has never done this before, and we have had them for a long time.  Why the change so soon? What do you think is wrong with him????  Is he bored?  If so what can we do to make him unbored??  What other reasons could he be doing this as he never did this before. All of our fish get along perfect, except for the odd fight.  We have had them for a long time and now he is acting weird.  If you could e-mail me back ASAP that would be great as I am lost and am having a hard time understand what he needs.  My fish are like my children, I love them and well do whatever I can to help them. What could be wrong with him?? Thank you for your time!  I look forward to hearing from you soon as your advice seems to help whenever I need it.  Thank you once more! Courtney < It could just be a case of getting ready to breed. The smallest one may be a female. After a period of time she has matured and is looking for a mate and is guarding a territory. Males are usually late bloomers and one of them will come around in time. When they decide to pair up then two of them will start to pick on the odd fish to the point that they may kill him. Remove the odd fish to save him. The pair will probably never let him back in the tank. The pair will clean off an area to lay their eggs. The eggs will hatch in three days and the fry will become free swimming in another three days. At that point they need to be fed. After two weeks the fry should be removed or they will be eaten by the parents.-Chuck>

Jermar's baby Oscars Hello, my name is Jermar. <Hello Jermar, Mike G here> This is my first time on your web site and I must say it is extremely helpful and resourceful. <I'll agree with you there.> I recently purchase two (baby) tiger Oscar fish both are about (3" inches). I've had them for about three days. there great fish but they beg a lot. My questions are simple and I'm almost embarrassed to ask but, I'm new to keeping fish as pets there are my first. I would greatly appreciate some simple starter tips. <I'd be happy to answer your questions.> (1) I want to know some tips to cleaning my tank like, how! And how often to clean the tank {10 gallon}. <Whoa, hang on... 2 3" Oscars in a 10 gallon tank? With such a set up, you are just begging for trouble about as eagerly as your Oscars beg for their food. As for cleaning a tank with such a heavy fish load, I would recommend removing and gravel, sand, or other decor to help prevent the accumulation of debris in hard-to-reach places. This will also facilitate cleaning and removal of solid wastes. I would recommend enlisting the help of a large filter rated for much larger tank sizes than 10 gallons to allow a bit of leeway if you miss a water change, which I think should be done every other day at around 25%. Oscars produce massive amounts of waste material for their size, and simply will not do well for an extended period of time in such a small tank without regular large water changes and much thought to maintaining the water quality within an acceptable range. Purchasing Ammonia, Nitrite, and Nitrate test kits could save you a lot of hassle in determining how clean their water is.> (2) I have 2 small baby Oscar's in a 10 gallon tank, I know I have to get a larger tank, how soon should I get it, and what size should I purchased? ( the Oscars are very small at the moment both are about 3" inches now, very active and eager to eat). <Ah, it is refreshing to hear that you intend to purchase a large tank when necessary. Honestly, I would recommend that you purchase a larger tank now. I would say that the bare minimum size tank would be 75 gallons, as I tend to like to take into account the adult size of a fish rather than its current size when determining an appropriate tank size. In a tank of 75 gallons, I would anticipate much growth in your Oscars. In a matter of months, I think they would be quite large and make such a tank look fuller. Of course, 75 gallons for small fish ca get boring, so you may decide to stock the tank with other similarly aggressive fishes, preferably cichlids. But please remember to keep the stocking densities low and to research any new purchase before it is brought home.> (3) I've used your web sites "FAQ's" to find feeding tip's for small Oscars, But how often should I feed them? I gave them 14 guppy fish yesterday they ate all of them with in 30 minutes I haven't feed them today and I'm very worried about over feeding. Please help? <I am not a fan of using feeder fishes as a source of nutrition with predatory fishes such as your Oscars. The risks of transferable disease are extremely high, and many of these fish have very little, if any, nutritional value. This is because they are kept in absolutely horrid conditions while they await being purchased. I am positive that your Oscars would accept pelleted or frozen foods specifically formulated for them, and would do better on such a diet. Hope this helps.>  

Breeding Oscars hi I've e-mailed you a bunch of times about althea (my red Oscar),, well she now has a new friend,  Jed (tiger Oscar) ,,is it possible that they will mate and bare children?? <Yes... possible... these are two varieties of the same species> I've noticed a lot of odd behavior from both my fish., the tiger Oscar will vibrate its tail (kind of like what a alligator does when its ready to mate) and the nibble at each other also. and they wont leave each others side. thanks for the help Mike <Do keep your eye on them... as Oscars can "turn on each other", becoming overly aggressive... trying each other out physically... and require you to either separate them into two tanks or with a divider. Bob Fenner>

Oscar Breeding

Thank you Chuck! They are separated just like you said, have been for two days now.  They look at each other through the divider. Is there anything I can do about them not eating? < Big cichlids usually don't like to be disrupted and may fast for a couple of days. Try washed earthworms to get them going.> I am putting the vitamins in the water which are supposed to help enhance their appetites.  The tiger just lays at the bottom of the tank and is not swimming around much.  He isn't beat up enough (as far as I can tell) to not be able to swim. So, they will still be able to "mate" separated? < Yes. As long as they can see each other and there is circulation in the tank, some of the 1000's of eggs will be fertilized.> Any idea how long I have to leave them separated? < I would not put them back together until they are both eating well and are active again.-Chuck> Thanks again. Joey from Alaska

Oscar Breeding, More Follow-up Another question for you, and this is an odd one... How long will it take for my Oscar's teeth to grow back in?  Now that the mating pair is separated and I'm medicating, my tiger Oscar's damaged flesh has sort of fallen off and has revealed that in the process of their brooding, his upper lip was so damaged that it has sort of come off.  Very sad site to see.  He had a pretty decent under bite before this all happened, so this doesn't surprise me.  But, his teeth lie just under that lip and I noticed that he only has 2 left.  This is why he is not eating I suspect. Not even interested so much in blood worms. Any idea how long they take to grow in?  I am medicating and watching him very carefully and there does not appear to be any infection.  Just a lot of facial damage. Hope you have an idea.  This is probably one of the stranger questions you get.  Even a ballpark figure would help so that I know what to sort of suspect.  Poor fish!!! < The teeth actually play a very small role in the fish's ability to eat. Once the gums and lips heal over then the appetite should pick up. Add some vitamins and keep the water clean to promote a quick recovery. White flesh is a sign that it healing. White cottony growth is fungus and needs to be treated.-Chuck> thanks again, Joey from Alaska

Oscars determining the sex of Oscars Could you please tell me how to determine what sex are my Oscars. Characteristics of the different sexes. thanks, Linda Perry < That is a great question, one I have been meaning to ask for a while now. There are a few ways to sex an Oscar. One is to wait for the Oscars to pair off, spawn, and watch to see which one lays the eggs. The second way is to remove the fish from the water, flip them over and compare their vents. I found a picture of someone doing it at the following link http://www.petsforum.com/personal/svoorwinde/Oscars/oscars.htm The above method does not sound like much fun to me. My Oscar (Buster) gets mad when I try to rub his belly. I asked Anthony about it and he told me the best way I have heard of yet. Below is what he said. 'there is an easier way: when most cichlids are first fed they will briefly express (extend/drop/flash/whatever) their "stuff". The ovipositor of a female is quite blunt and obviously wide enough to pass an egg through. Males have a pointed and tapered protrusion which generally is not extended as far as a females. Feed some tasty earth worms or small ghost shrimp to get them in the mood if necessary. When you are comfortable sexing African cichlids... you can apply this too to some Central and SA cichlids by looking for thicker lips and a larger buccal (chin) cavity on males' Hope this helps- Gage>

Longed Finned Albino Oscars Sir, PLEASE HELP ME!!! I have two Longed Finned Albino Oscars in a four foot tank. The larger of the two is about 14 inches long, the smaller is about 12 inches. I believe that they are about 2.5 years old and we hope that are a breedable pair. <Do keep your eyes on them... this is a very small tank for such mature specimens and things can go sideways quick should they start fighting> I have seen lip locking and some very industrious rock cleaning. The rock is a flat piece of slate. The larger fish does occasionally move small amounts of gravel. The smaller of the two Oscars laid eggs approx 12 months ago so I know that I have at least one female. The other fish showed no signs of interest. I feed them mainly with barramundi pellets and live fish and occasionally crayfish. I am disappointed that they have not bred. Could you offer any suggestions to push along the process? e.g. water temperature, PH level, hardness, water quality, water changes. Thank you for you time, Brad. <It's possible you have two females... and there is a hard fact I must convey. In order to keep the price and availability of these hybrids controlled, the folks who produce them in the Far East try to sterilize them (with high temperature, chemicals)... so breeding pairs outside the area are exceedingly rare. Care is per the "regular" Oscar, Astronotus ocellatus: pH range: 6.0 - 8.0; dH range: 5.0 - 19.0 temp. 22-25 C. Best to condition pairs, keep together, with large, regular water changes. Bob Fenner>

Rare Spawning Oscars please could you answer a couple of questions for me. firstly is it ok to have my 2 Oscars in a 350 L tank?  <Yes, certainly to both> how many could I have? <Two would be a good number for once they're about full size> secondly in my 4 foot tank is that big enough for a Volitans and a Odonus niger?  <Should be... just assure the Lion isn't large enough to swallow the Trigger when the latter is small, and that the Trigger doesn't harass, deprive the Lion of food when it is larger> the tank holds about 210 L both English litres the marine tank is run by a Fluval 303 and an AMiracle trickle filter and also another Fluval with a uv sterilizer attached to it. thanks for your help Alex <Be chatting my friend. Bob Fenner>

Oscars (spawning, rearing) I emailed u before about my tanks. my question for you though is that my Oscars just had there first spawning in the Trigon 350 and I am a little unsure if to leave them in there as there is a plec and a catfish in the tank. <If this is the first or second, third spawning, do leave them all be as they are now... too traumatic to be moving any, all fishes, young around. And this tank is big enough to allow the "plec and catfish" to get out of the Oscars way... and run away. In a few spawns, I would utilize an easy to remove spawning medium (like a large clay flower pot, piece of slanted slate... and remove this to a rearing tank... Do start studying up about these affairs, planning on space to raise whatever number of young you think you might want... raising foods for them... Bob Fenner> do u think I should set up another tank or leave them with their proud folks any help would be much appreciated Alex

Fuzzy Eggs My red tiger Oscar has laid eggs, 2days later the eggs turned into a white cotton-like substance.  This is the first time they have laid eggs and I don't know what to expect .I am a first time Oscar owner I have had them for a year now.  please help Mr. Curious <The white cotton-like substance, or fuzzy stuff, is most likely a fungus from the infertile eggs, or dirty water, they are rather messy fish.  I would use a small siphon tube to suck out the bad eggs and the fungus.  If you were to remove the good eggs to a separate tank some Methylene blue could be added to the water to help prevent the fungus.  Best of Luck, Gage>

Fertilizing Oscar Eggs - 8/15/03 Can Methylene blue be used to fertilize Oscar eggs. <Hmmm... I'm wondering if you mean to ask if it will prevent fungus from developing on the eggs? If so, yes. I'm assuming you already have a female that laid the eggs, and a male that fertilized them... and now wish to improve the chances for a successful hatch. Anthony>

Fuzzy Eggs My red tiger Oscar has laid eggs, 2days later the eggs turned into a white  cotton-like substance  this is the first time they have laid eggs and I don't know what to expect .I am a first time Oscar owner I have had them for a year now.  please help Mr. Curious <The white cotton-like substance, or fuzzy stuff, is most likely a fungus from the infertile eggs, or dirty water, they are rather messy fish.  I would use a small siphon tube to suck out the bad eggs and the fungus.  If you were to remove the good eggs to a separate tank some Methylene blue could be added to the water to help prevent the fungus.  Best of Luck, Gage>

Oscar Eggs Thanks gage,  but it has spread over all the eggs. (unable to save any) <bummer> I don't know ! maybe I have 2 females <it's possible> and then again maybe not. as I'm typing I looked over at the tank and they have begun to lip lock all over again and change in color a bit with their mouths open. <sounds like flirting to me.> HOPEFULLY NEXT TIME  MR. CURIOUS <I might consider a second tank to move the eggs to. -Gage>

Pairing Oscars Hello; I love your site as it has been very helpful to me in the past. <Thank you, I'm glad we could be of service.> I just bought two Oscars and I was trying to figure out if they had paired or not and if I needed to be prepared for them to spawn. <Oscar breeding can be quite a rewarding as well as demanding hobby.> They constantly follow one another around the tank and share the feeder fish I have given to them. They seem to be the best of friends. <These are not typically signs that instantly tell you it's a breeding pair, I have known fish that never bred to do similar actions.> They are only about 2-3 inches at this point so I am wondering if these two have paired with one another? <That is far to small to tell if they are paired or not,  When they get around 6-8 inches you will be able to tell if they are paired.  If not be careful some Oscars if not given enough room can become aggressive to one another.  If they continue to spend time with each other as they mature, then chances are good that you do have a male/female pair of Oscars.> Thanks for all of the help Eli, Pittsburgh, PA <There are loads of resources online to help with caring for Oscars, please look at our cichlid section on WetWebMedia.Com.  Good Luck.-Magnus.>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: