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FAQs on Pangasiid Cats; Mainly the Iridescent/ID "Shark" 1

Related Articles: Pangasiid Catfishes

Related FAQs: Pangasiid Catfishes 1Pangasiid Catfishes 2, & FAQs on: Pangasiid Catfishes Identification, Pangasiid Catfishes Behavior, Pangasiid Catfishes Compatibility, Pangasiid Catfishes Stocking/Selection, Pangasiid Catfishes Systems, Pangasiid Catfishes Feeding, Pangasiid Catfishes Disease/Health, Pangasiid Catfishes Reproduction, Related Catfish FAQs:  Identification, Behavior, Compatibility, Selection, Systems, Feeding, Disease, ReproductionMinnow Sharks 1,

ID Sharks and saltwater?     2/27/20
Hello! I, like many others, purchased some ID sharks a few years back not being aware of the size they would reach; my mistake.
<Yeah; up to some 1.3 m in length. Have seen some four footers in public aquariums. The group at the Wilhelma Aq. in Stuttgart my fave ex.>
Now I am doing the best I can to accommodate them and keep them healthy and happy. They are
currently 9in at the largest (of 4) in a 100gal tank, and I have plans to get a 300gal very soon.
<And beyond this?>
My issue is that I've been running into a lot of conflicting information about the salinity they should be kept in...many sources say brackish, another senior hobbyist told me as adults they would need salt, but here you say strictly fresh. Please help me keep my babies healthy, I made the mistake of purchasing them, they shouldn't have to suffer for it. Thank you, Mareena.
<Good to check other references. Here's FishBase:
This is an all-freshwater species of some tolerance in terms of pH and hardness... The keywords here in terms of practical husbandry are OVER sized system, filtration, circulation, aeration... And UNDER feeding. AND good sized weekly water changes (like half). No need to add salt/s. Bob Fenner>
Re: ID Sharks and saltwater?     2/27/20

Thank you so much! Knowing I don't have to step up a marine tank actually opens up my current options for getting a larger tank than even the 300. I really appreciate your help!
<Certainly welcome. Do remember to feed sparingly, keep temperatures in the low to middling seventies F to forestall the time when you'll need to move these monsters! BobF>
ID Sharks and saltwater? /Neale      2/27/20

Hello! I, like many others, purchased some ID sharks a few years back not being aware of the size they would reach; my mistake.
<Understood. Iridescent Shark Catfish do get large, and while 1.2 m or bigger lengths are possible in good conditions, typical aquarium specimens, even in public aquaria, are more likely to reach around 70 to 90 cm. So while still very large fish, they are, just about, manageable in really, really big tanks. In some ways the bigger problem>
Now I am doing the best I can to accommodate them and keep them healthy and happy. They are currently 9in at the largest (of 4) in a 100gal tank, and I have plans to get a 300gal very soon.
<Sounds good.>
My issue is that I've been running into a lot of conflicting information about the salinity they should be kept in...many sources say brackish, another senior hobbyist told me as adults they would need salt, but here you say strictly fresh.
<The true Iridescent Shark, Pangasianodon hypophthalmus, is absolutely a freshwater fish. There is a species, Pangasius krempfi, that appears to have a brackish or marine stage in its life cycle. But otherwise, no, they don't need salt.>
Please help me keep my babies healthy, I made the mistake of purchasing them, they shouldn't have to suffer for it. Thank you, Mareena.
<Hope this helps, and best of luck. Neale.>
ID Sharks and saltwater? Neale, re ID     2/27/20

<<Does strike me that there may be confusion here with Colombian Shark Catfish, Ariopsis seemanni. These are estuarine catfish that migrate back and forth between the sea and large rivers. While not ridiculously big (20-30 cm is typical) they are highly gregarious which means a big aquarium is necessary to keep a group of at least 3 and ideally 5+ specimens.
Cheers, Neale.>><Mmm, B>
Re: ID Sharks and saltwater?     2/27/20

Mareena; per Neale's query... are these cats ariids or pangasiids? The first ARE marine as they grow. BobF
Re: ID Sharks and saltwater?     2/28/20

As far as I've been able to determine, they are true Pangasianodon hypophthalmus, three regular and one albino. I feed them sinking carnivore pellets, baby shrimp, and bloodworms on a rotation.
<Well, the two species are quite distinct... Had me going on reading Neale's concern, as you stated you'd had these fish for years... Usually very fast (VERY) growers. Cheers, BobF>
Re: ID Sharks and saltwater?     2/28/20

Ah, of course. The oldest two are 3 1/2 years now, the younger two are 3. I would say the longest is around 9-10 inches at my best guess. Their only tankmates are two 6in angelfish currently.
<They will eventually ingest the angels if kept together. B>

Red patch near gills of ID Shark       5/31/17
Hi Team,
I have a albino (white) id shark. I suddenly noticed a red patch like mark which kind of looks like a wound on both the sides of the fish near the gills. I haven't seen this before in him. I added some Melafix to the tank last evening when I saw that he was looking little dull than usual.
Please advise.
Thanks and regards,
<Hello! I'm assume you have an albino Iridescent Shark, Pangasianodon hypophthalmus. This potentially huge fish struggles to survive well in home aquaria -- adults are routinely over 70 cm in length, and can reach almost twice that size. Like a lot of big fish, one sign that they're cramped (i.e., kept wrong) is the appearance of something called "Gill Curl", where the gill covers (opercula) become deformed. When this happens, the red gill filaments underneath the gill covers can be seen. As well as making the gill filaments more vulnerable to physical damage, gill curl affects the
ability of the fish to pressurise the inside of the gill chamber, reducing its ability to extract oxygen from the water. In short, your fish looks like it has red wounds around its gills, and because its getting less oxygen than it needs, it becomes steadily more lethargic. Does this sound plausible? Without a photo it's obviously hard for me to say 100% what's going on here, but Gill Curl would be my number-1 guess. How is Gill Curl treated? Primarily by fixing the environment. Iridescent Shark need thousands of litres of water. We're talking ponds, not fish tanks.
Substantial water changes will help, and increasing water circulation can add a bit more oxygen to the tank, improving things some more. But fundamentally it's all about getting the environment right: 2500+ litres (upwards of 650 US gallons); robust filtration with a lot of current; neutral water chemistry; no sharp or hot objects in the tank likely to
cause scratches or burns. While the Girl Curl itself might not actually get better, it won't get worse, and as the fish grows, the deformed part becomes less and less significant. Note that no medication is needed or helpful. Hope this helps! Neale.
Oh, and by way of a post scriptum -- Iridescent Sharks are not aquarium fish, and for other readers out there, unless you're planning on farming Iridescent Sharks, don't buy them! Juveniles sometimes get out of the fish farming business and end up in aquarium shops, and when they're small, they're undeniably cute. But given their adult size, and extremely rapid growth rate, they're virtually impossible to keep properly or healthily.
Peaceful predators they may well be, and ideally suited to big fish communities at zoos and public aquaria, but as home aquarium fish, they're useless. NM.>

Sucker       12/26/16
Dear find
I have a sucker fish from 2 year I have brought 2 sucker but one died with in 6months and other one is energetic and eating much but he/she is not growing in size
My question is if sucker is 2year old what will be its size?
Thank you
<This is a juvenile Pterygoplichthys multiradiatus or some very similar species. It should get to 45 cm/18 inches in length. Certainly 20 cm/8 inches within 1 year, 30 cm/12 inches by the end of the second year. If this catfish is not growing, despite being well fed, it may have intestinal worms. Treat with something like Praziquantel or Levamisole. Hope this
helps, Neale.>
<Oh! Enil, this is a friend of Neale Monk's; another WWM volunteer. I'd like to add that the albino Pangasius catfish in your photo will get VERY big... and could cause trouble in terms of waste production, possibly ingest some of your other livestock. Please read here re: http://www.wetwebmedia.com/fwsubwebindex/PangCatCompF.htm
and the linked files at top. Bob Fenner>

Iridescent shark with bleeding tail... Bonsai? Banzai!!!    11/19/13
Hi WWM Crew,
My 15 yr old

<? How small/stunted is this fish? It should be about three feet long>
 Iridescent shark's fins started getter shorter. Within the last few weeks, it's tail looked red on the inside of the fin. Now it's
very red inside, bleeding more, white spots on the fin, he swims with his tail hanging like it's too heavy.  In the last few days, the fish has been very irritable, splashing around and darting back and forth in the tank.  The fish was eating well but has started to not eat.  Water parameters are within normal range. Tanks mates are one other ID shark and a rotkeil Severum. I think it started from a water quality issue. The fish are very messy and living in a 55 gallon tank.
<... much too small>
I recently removed 2 other ID sharks
from this tank and the remaining 2 grew an extra 2 inches since. 
<... ah yes>
I try to change the tank often but being busy has me changing them less, at least once a week.  Usually I try to do it every 3 days.
<... whatever it takes to provide decent water quality. These fishes have suffered, are suffering for the ill-effects of metabolite accumulation... Living in their own filth>
I started medicating 
<Of no use... "it's" the environment>

him in a 30 gallon established tank with Maracyn and Maracyn2 thinking it was bacterial or fungal.  This combo usually works well on my sharks, but it's been a very long time since I've had to use medications of any kind.
Do you have any suggestions of what I could do further?
Regards, AL
<... see WWM re Pangasiids. Bob Fenner>

Iridescent shark with bleeding tail    /Neale, addenda, clarification, re-emphases       11/20/13
<<Hello Audra. Not a huge amount more to add to what Bob's said/suggested.
Pangasius catfish really don't do well in home aquaria, and sooner or later they seem to sicken in some way. Eye damage is very common, but fin problems like you're seeing are far from unusual. I am impressed by these fish having lived for 15 years, so obviously you must be taking good care of them at some level, but as you have seen, they will keep growing given the chance. You removed one of the fish, that reduced the "loading" on the tank, and the remaining fish, no longer stressed by an overloaded environment, grew that bit more. Now they're bigger, and between the two of them they've "filled" the tank, and once again you have an environment that's stressing the fish by being overloaded. In some ways it's a vicious circle. You may well be able to treat this round of (likely bacterial) infection using Maracyn 1 and 2, but ultimately, as Bob says, it's the environment, and it's a matter of time before their health goes bad again.
What to do? The obvious answer is to upgrade the aquarium. These fish, in all honesty, need tanks measured in (big) hundreds of gallons and realistically few people have that kind of space. Rehoming may be possible, but often zoos and public aquaria have their fill of these monster catfish and won't take them, and pet shops may feel the same way. It's a tough one to solve, and there's no silver bullet short of not buying them in the first place. Short term: medication and more frequent water changes, but long term... bigger tank or rehoming. Cheers, Neale.>>
RE: Iridescent shark with bleeding tail    /RMF     11/20/13

Hi Bob and Neale...
The fish is 14 in. long. I bought him when he was a baby, he's never been in a tank larger than a 55 gallon. I am one of many that thought they were the cutest things and allowed the pet store to sell me, not one, but four of these beautiful creatures. Two are 15 yrs old the other two are 8 yrs old and about 12-14 inches each. They use to be half the size of the older ones just 6 months ago. So to clarify, I have 2 IDs in each tank, 1 older and 1younger in each.
I would love to get them a larger tank but not doable in a 2nd floor apt with questionable floor strength.  I hope to still do this when I move.
My tanks are pretty clear but I know that this is not an indicator that all is well, although my water parameters are always good.  I recently upgraded the background to one of those 3D backgrounds. It has been a challenge to keep the tank clean though.  I am medicating to treat his tail which looks better today. The blood has burst open the wound.  So now I am hoping to heal the tail with good water quality and the recommended doses of both Maracyns. He's still not eating.
<Keep changing the water, using carbon...>
I'm doing my best to keep all of them alive and happy as long as I have them. I am educating anyone I know that is thinking of getting one on refraining from buying them.  Considering how long it's been, they are getting the best of care.  I just don't want to give them too much attention worrying and medicating them the wrong way, is all.  They are the sweetest fish I have and it's been a pleasure having them for all these years.
for your input.
Regards, AL
<And you; BobF>
RE: Iridescent shark with bleeding tail     /Neale     11/20/13

Hi Bob and Neale...
The fish is 14 in. long. I bought him when he was a baby, he's never been in a tank larger than a 55 gallon. I am one of many that thought they were the cutest things and allowed the pet store to sell me, not one, but four of these beautiful creatures.
<Oh dear... But I agree, they are lovely animals, and surprisingly peaceful for their size.>
Two are 15 yrs old the other two are 8 yrs old and about 12-14 inches each.
They use to be half the size of the older ones just 6 months ago. So to clarify, I have 2 IDs in each tank, 1 older and 1 younger in each.
I would love to get them a larger tank but not doable in a 2nd floor apt with questionable floor strength.  I hope to still do this when I move.
My tanks are pretty clear but I know that this is not an indicator that all is well, although my water parameters are always good.
<Good. But with these fish there are things you can't easily monitor that will affect health. Physical damage, for example (often the way eye damage starts) and the amount of stress they're exposed to by being unable to swim "properly" (and this weakens immunity, making Finrot more likely).>
I recently upgraded the background to one of those 3D backgrounds. It has been a challenge to keep the tank clean though.  I am medicating to treat his tail which looks better today. The blood has burst open the wound.  So now I am hoping to heal the tail with good water quality and the recommended doses of both Maracyns. He's still not eating.
<Would not worry about that too much. Concentrate on treating the Finrot.
As/when he's better, he'll eat.>
I'm doing my best to keep all of them alive and happy as long as I have them.
<I appreciate the bind you're in.>
I am educating anyone I know that is thinking of getting one on refraining from buying them.  Considering how long it's been, they are getting the best of care.
<I don't doubt. These fish were farmed for food, and presumably these youngsters were among the few that get into the aquarium trade and consequently have a chance of living a longer life than the farmed ones.
Still, it is like keeping a farm animal like a sheep as a pet. Doable, but not easy, even if it seems a nicer option for the animal itself.>
I just don't want to give them too much attention worrying and medicating them the wrong way, is all.  They are the sweetest fish I have and it's been a pleasure having them for all these years. Thanks for your input.
Regards, AL
<Welcome, Neale.>

Iridescent shark seizures  6/21/10
Hi There...
I searched your site, couldn't find an answer to my question. My 4 year old iridescent shark has been having seizures the last several days. At first I thought it was the lighting, so I've kept it off, no fix. The only thing I've changed in his environment lately is I started feeding his tank mates a different type of flakes. Can you tell me, is there anything I can do to help him stop having seizures? Should I go back to the old food?
Thanks in advance for your reply...
<It's unlikely to be seizures as such, and more a fright reaction. Unless your aquarium measures thousands of gallons, your aquarium is too small. Seriously. I'm not kidding. Pangasius hypophthalmus ARE NOT suitable for
home aquaria. They get to about 120 cm/4 feet long within a year or two, and they live in groups, and they migrate up and down rivers. Under home aquarium conditions they almost never adapt, and most specimens die
prematurely for one reason or another. At the very least, they end up damaging their eyes by throwing themselves into the glass walls of the tank. Stunting is common, and despite the common myth, doesn't mean the fish has "grown to the size of its tank" but instead means the fish has been chronically stressed for a long time. If yours is less than, say, 75 cm/30 inches, your catfish is stunted, and that means it is probably being kept badly. In short, you need to make sure the tank is very, very large, has an extremely strong filter [8-10 times turnover per hour] and that there are no aggressive tankmates likely to spook them. Do not EVER keep this species singly; it is just as social as a Neon tetra or Tiger barb, and will be just as stressed if kept alone. I honestly wish I could say something more helpful, but I really can't. These fish DON'T adapt to home aquaria, and usually end up damaging themselves precisely in the way you're describing. I doubt the change in food was the trigger, but possibly the tankmates are behaving differently and that's alarmed your catfish. Who knows. Without being told something about the size of the aquarium or its tankmates, I can't really say anything more detailed. I know I'm being super-negative here, but these are fish that shouldn't be in the aquarium trade, and there's really no excuse for shops to stock them or people to buy them. Every aquarium book ever written has something like "don't buy this fish" written down under the Pangasius catfish name! Cheers, Neale.>

Stress or not happy with food? Pangasiid incomp., FW stkg. period/hex tanks   1/24/10
I just revamped my tropical tank.
New (plastic) plants, new decorations and reintroduced all the fish at the same time in an effort to reduce stress. I have provided as many hiding places as possible for my fish.
<Sounds promising.>
It's a 55-gallon hex tank,
<Do be aware these are generally not good choices, and in terms of stocking a hexagonal aquarium of 55 gallons will only hold the same number of fish as, say, a 30 gallon rectangular one. Why? Because of surface are to volume ratio. A hexagonal tank this size has the same volume but lower surface area than a 55 gallon rectangular one. Less oxygen can dissolve into the water, and less CO2 can diffuse out. I don't recommend hexagonal, spherical or any other shaped aquarium other than a low, long rectangle. Sometimes, old school is the best!>
I keep the water at 78 degrees and have a Penguin filter that I keep two cartridges in at all times. (Done to increase the amount of carbon to help keep the water clear.)
<Actually, carbon only removes dissolved organic chemicals, the stuff that makes water tinted yellow over time. It has zero benefit in terms of removing solid particles such as silt that make water cloudy. Indeed, it's rather better to take out the carbon and replace with filter floss if silty water is a problem. In most freshwater tanks, carbon is redundant.
Manufacturers sell the stuff happily, given how massively overpriced it is, but me, I prefer to save my pennies.>
The water is still a little cloudy from the water change I did yesterday, but it's clearing up as expected.
In the tank we have a Plecostomus (about four to five inches in length - the giant one we traded in because I didn't need both of them in the tank),
<Has no place in a tank this size/shape.>
two small Cory catfish and an incandescent shark.
<Corydoras should be in groups of 5+ specimens of each species, and an Iridescent Shark (Pangasius hypophthalmus) has absolutely no place in this aquarium. Given its maximum length is well over 120 cm (more than 4 feet)
I'd strongly argue this fish shouldn't even be in the fish trade. Sure, most specimens in aquaria don't get that big. That's because they usually end up dead first. But the lucky survivors still get to a good 60 cm (2 feet) or more in length, and public aquaria really are fed up with taking unwanted specimens. On top of that, this is a schooling, riverine species that needs to be kept in groups in a spacious aquarium. In small tanks -- and yours is TINY by the standards of the species -- this fish ends up throwing itself against the glass, damaging its eyes. Many, MANY specimens are blind precisely because of this (and needless to say, with a beaten up head and cloudy eyes, pretty ugly looking as well).>
Obviously those are our cleaner fish.
<NO such beast. If you imagine any fish, ANY FISH, will make an aquarium cleaner, it's time to do some reading. Think about it. Adding fish adds the amount of food you need to add. That fish defecates, meaning there's more silt. That fish excretes ammonia, so there's more work for the biological filter. That ammonia becomes nitrite and then nitrate, feeding algae. So the tank becomes more algae-ridden. In every possible way, adding fish makes tanks dirtier. End of story.>
The rest of the tank holds two Mickey Mouse platys, two sunset platys, one female Betta, one Dalmatian molly and five tetras.
<Finally, some fish that make sense. I'd argue the Molly is better in a community where adding marine salt mix is an option, but I'll let that pass for now. These are small fish that would be happy in a tank your size and shape.>
So far it seems like everyone gets along,
<So far...>
though I admit my female Betta is a little ticked off since she used to rule the roost (it used to just be her, the Corys and the Pleco). But she's doing pretty well, she just sort of chases the others around checking them out, but I haven't noticed any aggressive behavior on her part.
I noticed today when I fed them, that the platys would take the food in their mouths and then immediately spit it back out. It's tropical flakes, it's what the people at the pet store said to feed them. (Which, from what I've seen on your site isn't the right thing to be feeding them.)
<Indeed. While flakes are fine up to a point, these are herbivores, and their diet should include as a staple Spirulina flake, plus things liked cooked peas and Sushi Nori. It won't kill them giving them flake, but offer them the green foods too. Usually, tetras ignore Spirulina flake, but catfish happily eat it. Indeed, Corydoras eat a lot of algae in the wild.>
Are they spitting it out because they don't like the food, or is it because they are still stressed after the water change I did yesterday?
<Unlikely because they're "unhappy" about the water change, but check water quality. If you have added a bunch of fish all at once, or were too aggressive when it came to cleaning the biological media in a mature filter, you could have higher than zero ammonia and nitrite levels. This would explain their odd behaviour. Also check the flake isn't stale. Open pots last about 6-8 weeks in a dry climate before they lose their savour.
Don't buy huge pots expecting them to last all year. If you must, decant small portions from a big tub into a small pot, and store the big tub in an airtight container somewhere cool and dry (just like you'd do with any dried human food, like cereal). Next up, offer a variety. Fish get as fed up with the same thing every day as you would. Once a week offer live brine shrimps or wet-frozen bloodworms. Finely chopped (raw) fish fillet or seafood is good too. Don't add anything from warm blooded animals though:
no meat, no chicken, and no dairy. While fish will often eat these things, with a very few exceptions, in the long term such foods cause problems.
Shredded beef heart and hard boiled egg yolk are the two main exceptions. On the other hand, all sorts of plants foods can be tried, including softened vegetables like courgette, spinach, lettuce and cucumber.>
Should I worry - or are they actually getting some of the food despite some of it coming back out?
<If it is still occurring within a couple days, yes, be concerned.
Certainly check water quality now. Platies need hard, basic water (10+ degrees dH, pH 7.5-8) with 0 ammonia and 0 nitrite. They actually prefer slightly cool water, around 22-25 C. Do review the needs of fish prior to purchase, and choose species with similar requirements.>
They all swim all over the tank (except for the molly, she hangs out near the top, and she's pregnant, so I'm not surprised by this behavior)
<Could be unhappy; review "the Shimmies" and be aware of the VERY specific needs Mollies have for long term health.
Most folks keep 'em wrong, and so end up with sick Mollies.>
- so I think they are all healthy. I'd just like to head off any potential problems to keep them from getting sick in the future. I'm an amateur, so I don't know everything, but I'm trying to do what's best for the fish ... I hate to see animals suffer, be they marine or not!
<Quite right! I applaud your philosophy here.>
Thanks for the help!
<Happy to be of help. Good luck, Neale.>
Re: Stress or not happy with food?
Neale, thanks for the advice.
Wow, I thought I was doing better ... but I guess I still have a lot to learn!!
<As do we all.>
I would prefer a rectangular tank, but I inherited the 55-gallon hex and you know, when we're talking a free setup, you take what you can get.
<Indeed. But it's also true that if you do inherit a tank like this, you understand the limitations, and choose fish accordingly.>
I would like to clarify one thing - the shark is an incandescent shark catfish. It's not the iridescent shark you referred to. :)
<Exactly the same fish. Pangasius hypophthalmus. Google the Latin name, and take a look. Indeed, Wikipedia has a photo of this fish alongside the common name you used.
I'm not a big fan of common names for precisely this problem. With a Latin name, you know where you stand. With common names, who knows what kind of fish is being sold!>
I'm not that inhumane!
<Most folks aren't inhumane deliberately... but the nature of the fishkeeping hobby is that the variety of species on sale far exceeds the abilities of most aquarists to keep them properly.>
But, as you so aptly pointed out, the catfish and Pleco aren't necessary...
Even so, thanks for the help. I'll cook up some peas with dinner and offer those to my patties and see if that helps.
<Hope this works. Cheers, Neale.>
Re: Stress or not happy with food?
Stupid petstore guy! ARGH :) I'm sure you hear that a lot.
<Unfortunately, yes. What can I say? I try my best, but there's just one of me, and fifteen million bozos out there. Cheers, Neale.>

Albino sharks not eating... Pangasiids  1/9/10
Hi Team,
I am new to this site. I have been discussing about my issue in several blogs, but have not got much help, but at least appreciate the time taken by the people to answer my queries.
Having read lots of solutions provided by you, I am hoping for a great help from you.
<We'll see won't we?>
I had a small tank with 25 gallons capacity and had the following fishes :
2 Albino rainbow sharks
2 Blood Parrots
4 Tinfoil Barbs
3 Sucker cats
<Mmm, you're going to need more room... the Tinfoils will be getting very skittish in time in such a small world>
All fishes were healthy and were feeding good. <well> The albino sharks grew very fast and one of them came to 16 inches while the other 9-11 inches.
<!? Inches...? And... what are we discussing here in the way of species? Is this the Pangasiid catfish... it's not the minnow shark (Cyprinid)>
The tank was too small for them. After some time the large of the two shark stopped having food. I thought they are stressed up as their house might be small.
In the mean time I got a large tank with 250 gallons capacity and 4ft tall.
I moved all the fishes to the new tank, while moving the larger shark hurt himself on the nose but not too much. It got healed in 2 days.
<Ah, good>
From the day I moved them to large tank, the sharks are not feeding at all.
Sometime ago at least the smaller of the two was coming to the surface to have food, but now even he has stopped eating.
<Am wondering what the difference/s in water quality are here. Do you have test results to relate?>
It has been over 2 months now, since they have not been eating. All other fishes are eating well and are healthy.
<Very strange... and what are you offering as food?>
These sharks are my favourites but I cant see them starving. They are losing
their weights badly.
Please please please help me know what might be wrong with them?
<Need more info... the species name, water quality results, and foods proffered>
I have added the following fishes in the tank :
2 Yellow Parrots
1 Giant Gourami
<Another "monster">
2 Green Terror
2 Malawi Blue Dolphin
I have plans to add the following fishes, please advice if they are ok:
2 Gold Severums / Green Severums
2 more Malawi Blue Dolphins
Thanks in Advance.
<Please write back with the requested information. Oh, and read here:
and the linked FAQs file above. Bob Fenner>
Re: Albino sharks not eating 1/9/2010

Thanks Bob, Appreciate your quick response.
<Welcome Ramesh>
Yu are correct, these are Pangasiid catfish species. The water quality is the same and I have checked the pH value, nitrites and nitrates. They are all fine.
I have been offering Taiyo Economy food.
<Ahh! Do switch to higher-protein fare... IF you can, do get Spectrum brand... Very nutritious and palatable. And do read where you were previously referred. BobF>
Hope this answers your queries.
Re: Albino sharks not eating 1/9/2010
Sorry for the confusion, here are the details of the fish:
It is from he species Pangasius, I also see that they call it as Iridescent sharks. Hope I am not confusing you.
<Thank you for your concern, consideration. I am not confused. BobF>
Re: Albino sharks not eating 1/10/2010
Thanks Bob. I will try them.
<Good. BobF>

Iridescent Shark, beh., sys.  10/27/09
Hi, was just wondering if you ever heard of a fish slapping its jaws together as if it was eating something but has nothing in its mouth.
<Nope, not seen this. Might be some sort of threat display? Or could be "gulping" water, a sign they aren't getting enough oxygen.>
This is not constant but happens probably once or twice an hour. Since they started doing this, they have been swimming really slow and kind of hovering about an inch or two off the ground. The fish are iridescent sharks,
<Pangasius hypophthalmus, I presume?>
one is about six to seven inches long and the other is about five to six inches long.
<Ah, well, these fish almost never do well in aquaria. You do realise how big they get? Easily 60 cm/24 inches, often 90 cm/36 inches and in the wild more than 120 cm/48 inches. These are food fish, and cannot be kept in home aquaria.>
They are in a 125 gallon tank,
<Too small.>
nitrate between 0 and 20, nitrite is at 0, hardness between 75 and 150, chlorine is 0, alkalinity is 120-180, and ph is about 7.2. temp is 78-79.
The eyes are clear on both of them, I can not see any skin problems to include the fins. The larger of the two damaged his nose when he was introduced to the new tank about a month ago as he was really quick to spook.
<All too common. These are riverine fish used to swimming freely. They almost never adapt properly to home aquaria.>
He is no longer so easy to spook and his nose looks like it healed well with no infection visible to the eye.
<Well that's good to hear.>
The fish seem to eat well only when we are a distance from the tank.
They never used to do that, it really didn't matter if I was standing right in front of it before.
<The bigger they get, the more space they need. In this teeny-tiny tank (by their standards) they're feeling horribly cramped and stressed.>
They also stopped taking food from the surface, they strictly eat from the bottom now. Also was wondering what the max amount of fish you would recommend for this tank as I keep reading how the groups are best around 3 but I'm sure you will tell me the tank is currently to small for 3 even at their current size.
Any opinions would be appreciated
<Time to buy a much bigger tank, or else do what 99.9% of the people who buy these fish end up doing, and that's finding a new home for them at a zoo or public aquarium. These fish simply shouldn't be in the trade, and I can't imagine why anyone would buy them. All the aquarium books state very clearly DO NOT BUY THIS FISH and yet people still do. Pangasius hypophthalmus are food fish, and no more suited to home aquaria than farmed food fish species like Atlantic Salmon, Channel Catfish, Common Carp, or Sea Bass. Cheers, Neale.>

Saprolegnia on shark (RMF, second opinion?) <<Nada to add>> 4/26/09
Hi crew! Please help me! I am trying desperately to save my iridescent shark.
<Yes, I can see from the photos he's in a bad way. A very difficult species to maintain, and I fear the problem here is more about his environment than anything else. Iridescent Sharks are food fish, and they simply don't do well in home aquaria. While they can be kept in aquaria if you have lots of space, 55 gallons isn't enough. Moreover, they are difficult fish to mix with other species. Despite their size, they are super-nervous, and perhaps surprisingly, should be kept in schools of 3 or more specimens.>
He is 5 years old. Was staying in an established 5 year old tank, 55 gallon, with two kissing Gourami and a Pleco. Don't exactly know how he got hurt, maybe fight with Pleco that is a foot long.
<Not so much a fight, but I do wonder if [a] the Iridescent Shark bruised himself or otherwise develop a light infection; and then [b] the Plec took advantage of this and started rasping away at the infected tissue. Plecs are notorious for "latching" onto injured, moribund or otherwise slow-moving fish that are exuding blood or mucous into the water. While I'm not 100% sure, this is my guess here.>
My shark is 10 inches.
<Way too big for this aquarium. Even if the Plec exacerbated the situation, the primary cause of the wound or infection was surely some combination of water quality and/or physical damage, e.g., jumping into the hood or bumping into ornaments. Heater burns are another common cause of mortality and injury among catfish.>
The next day noticed the patch of cottony fungus, identified as Saprolegnia. I set up a10 gallon hospital tank at 80 degrees.
<Can't possibly keep this fish in 10 gallons. I'm surprised it even FITS into a 10 gallon tank!>
I treated water with 1 tsp water conditioner (Jungle Start Right with Allantoin, a skin protectant), 1 tsp of Wardley Ick Away (malachite green), 1 tsp. of Melafix and 1 tsp of Jungle Fungus Clear Tank Buddies
(Nitrofurazone, Furazolidone, potassium dichromate).
<Random medicating is usually not a good idea. Remember, while Fungus isn't especially difficult to treat, it's a secondary infection that results from poor water conditions and injury. In a case like this, you need the fish to be in optimal water conditions, and even on his own, 55 gallons would barely provide that, let along 10. You also need to treat with something very specific for severe fungal infections; I'd recommend something along the lines of Seachem KanaPlex. Melafix is useless once fungal infections are established (I'll allow it might have some preventative value) and Ick medication is clearly irrelevant.>
The only other items in the tank are the heater and an air stone. I have been feeding him Jungle Anti-Bacteria Medicated Fish Food, but he does not seem to be eating anything.
<Don't feed him at all until he's in a tank offering optimal water conditions: 0 ammonia, 0 nitrite, low nitrate, pH stable around 6.5-7.5, and moderate hardness.>
I clean up the food that he does not eat each morning. His eyes are clouded over, maybe he can't find his food.
<Not a good sign; usually implies (if both eyes are cloudy) some type of secondary bacterial infection. Again, KanaPlex should help.>
He has been in this treatment for 5 days, with no improvement, seems worse.
His body is almost completely covered now.. I am sending you pictures.
When will this treatment start to help?
Or am I doing something wrong?
Please help me!
<Done my best. While I've seen fish come back from worse (they really are amazing sometimes) this does depend on optimal environmental conditions, which I fear you're not providing. Seriously, this is a fish that needs a tank twice the size of what you have, if not more, and a whopping filter with massive water turnover and plenty of supplemental aeration. Iridescent Sharks are classic riverine fish with little tolerance for stagnant water. Adults are routinely 60-70 cm long under aquarium conditions, and wild specimens twice that, weighing about the same as a family dog. Big fish.
Cheers, Neale.>

Can I put a Iridescent Shark and a Jack Dempsey together? <<BobF's go>> 3/28/09
For a while... I was searching the web and found your site and it seemed like you guys knew what you were talking about. So I wanted to ask you a question. I have a 75 gallon tank right now and I have a 4 inch Jack Dempsey and a 6 inch Iridescent Shark, and I was wondering if my Jack Dempsey would pick on my Iridescent Shark or if they would be fine. (I am aware that that Iridescent Sharks get quite big and once it grows too big for the tank I will get a larger one. I know that my Jack will get bigger too.)
<Mmm, in this sized volume, starting these two at the sizes you mention, I do think you won't have troubles for a while... the Jack Dempsey will likely leave the catfish alone... and depending on your foods, feeding, the "shark" may not grow so large as to ingest the cichlid for a year or more. Bob Fenner>
Can I put a Iridescent Shark and a Jack Dempsey together? <<Now Neale>> 3/28/09

I was searching the web and found your site and it seemed like you guys knew what you were talking about.
<Modesty forbids...>
So I wanted to ask you a question. I have a 75 gallon tank right now and I have a 4 inch Jack Dempsey and a 6 inch Iridescent Shark, and I was wondering if my Jack Dempsey would pick on my Iridescent Shark or if they would be fine.
<Wouldn't be my idea of a marriage made in heaven. JDs are territorial, and while they generally ignore open water schooling fish too big to eat, such as barbs, anything more threatening is likely to be eyed with suspicion.  Iridescent Shark by contrast are *schooling* fish and singletons are extremely nervous. As this fish matures it's going to feel steadily more skittish, and it's a sad fact most Iridescent Sharks bash their heads in at some point. You hardly ever see any specimens reared by home aquarists that have unmarked heads or eyes.>
(I am aware that that Iridescent Sharks get quite big and once it grows too big for the tank I will get a larger one. I know that my Jack will get bigger too.)
<Wild JDs will get to about 20 cm, though that's uncommon anymore given the amount of inbreeding. So unless you have a wild fish, 15, 18 cm seems to be typical. Iridescent Sharks by contrast do get massive. Even in aquaria they routinely top 60 cm, and 90 cm specimens are not uncommon. Wild fish supposedly get to well over a metre. Cheers, Neale.>

Bottom feeder suggestions for tanks (Oh no, Pangasianodon; run, run!) 2/11/09 Hello WWM crew, <Hi,> In my 30 gallon hexagon, I have 2 Kribensis cichlids. Id like to add maybe 2-3 fish that are middle to top level dwellers. <With Kribs? Most anything that stays at the top should work. Danios are the obvious option, but lack of swimming space may limit things. The problem here is that hexagon tanks are notoriously poor in terms of fish stocking capacity. They have a terrible surface area to volume ratio, meaning little oxygen diffuses in compared to the standard broad but shallow rectangle. You've also got less swimming space, so while Danios would be great in a 30 gal. rectangle, they're less happy in a deep but narrow hexagon. All things considered, I'd consider the smaller Danios like Zebras and Pearls, or alternatively White Cloud Mountain Minnows, in both cases assuming the temperature is no higher than 25 C (77 F), since neither likes super-hot water. (Nor do the Kribs, by the way.) Alternatively, you could go for surface swimmers that don't move about much, for example Silver Hatchets or even a single African Butterflyfish.> Can you recommend a bottom dweller that's tough enough to handle the cichlids but efficient in eating uneaten food? No matter how careful I am with trying not to overfeed, my cichlids are not interested in eating much. <Then feed less! Even if you add fish, that uneaten food gets turned into ammonia, and then into nitrite, and ultimately nitrate. Ammonia and nitrite are immediate killers, but your filter should remove them just fine. Nitrate is an insidious killer, and if you skip water changes for a couple of weeks, nitrate levels can easily get high enough to kill cichlids. Seriously, cichlids (including "hardy" Kribs) are sensitive to levels above 20 mg/l, so handling uneaten food isn't the goal, keeping excess food out is. Personally, I'd avoid catfish with Kribs: Kribs are pretty vicious when defending their territories, and can damage things like Corydoras (biting out there eyes!). Again, you have the problem of a poor surface to volume ratio, meaning that there's less "bottom" in this tank than would be the case with a 30 gal. rectangular tank. As should be apparent, while hexagonal tanks might look nifty, they're actually pretty seriously compromised in terms of keeping fish. My best suggestion would be to go with some of the snails, like Nerites or Tylomelania, that don't breed much/at all in aquaria, or even shrimps like Cherry Shrimps. These will all be ignored by the Kribs, and will help eat algae, uneaten food, etc., up to a point at least.> My 30 long tank has 20 assorted platys, swordtails and mollies. Id like to add a few Corydoras in this tank but I'm already overcrowded. I use a Penguin 350 filter and no salt in this tank so would this be okay? <I'd not add Corydoras to this system. I like the fact you've given these fish space, and by choosing livebearers, you reserve the option to add marine salt mix at, say, 3 grammes per litre, if the Mollies start getting sick (as they often do in busy freshwater tanks). If you really must add something, consider making the water slightly brackish and getting something like Knight Gobies. Not only are these attractive fish, they're very efficient predators that will keep the numbers of livebearer fry down!> I have 4 iridescent sharks, 2 parrot cichlids, 3 black skirt tetras, 1 kisser and 1 Danio in my 55 gallon tank. Can I add a small Pleco, which one? <You are MASSIVELY overstocked already. Do you have any idea how big those Iridescent Shark Catfish will get? Do take a look at the Fishbase page for Pangasianodon hypophthalmus, here: http://www.fishbase.org/Summary/SpeciesSummary.php?id=14154 http://www.fishbase.org/Photos/ThumbnailsSummary.php?ID=14154 See the fishes these chaps are holding in the photos? That's your catfish. While 130 cm (4 foot) specimens are not common in aquaria (!) they can and will reach about half that size, and astonishingly quickly. I simply cannot stress this strongly enough: these aren't fish for the home aquarium, and the majority of specimens end up having to be killed or given away to zoos (who don't really want them). For what it's worth, most any common Plec species, e.g., Pterygoplichthys multiradiatus, would be fine in a 55 gallon tank, assuming strong filtration and regular water changes. Do understand that the common Plecs of the hobby, Pterygoplichthys spp., get to at least 45 cm (18 inches) within 3-4 years, and are incredibly messy vegetarians. They need filters rated at not less than 6 times the volume of the tank per hour (i.e., at least 330 gallons per hour in your case) and big (50%) water changes every week or so. Otherwise your aquarium will end up looking extremely murky.> Thank in advance for your help. Audra <Happy to help. Neale.>

Re: Bottom feeder suggestions for tanks (Oh no, Pangasianodon; run, run!) 2/11/09 Hi Neale, <Audra,> I agree with you about the 30 hexagon, I only bought it because it looked good. It took me a long time to decide what to put in it and my Kribs are already spawning after being in the tank for a week. I'll consider the Zebra Danios. <Cool.> In the 30 long, my mollies have done well without salt, so I won't be venturing into brackish water for them at this time. <Fine. But I'd still recommend keeping them with tankmates that at least allow you the option of using a therapeutic dose of marine salt mix, even if you don't actually go fully brackish. Hence, salt-tolerant livebearers and killifish good, soft water catfish and tetras bad.> Thanks for the pictures on the sharks. I nearly had a coronary (kidding). But I've known about their size for a while now. Two of my iridescent sharks are about 10 yrs old now and 7 in. long, the other two about 5 yrs old and 4 in. long. <Hmm... still quite small. May well be one of the other Pangasiid species. None make great aquarium fish, though, even "tiddlers" like yours. Nervous, skittish animals prone to damaging their eyes, in my experience.> If I had done my research years ago, I would never have bought them, but they are my favorites. <They are certainly nice fish. Just difficult to house. Yours have done extremely well to have lived such a long time. By NO means the usual thing.> I plan to move the tetras, kisser and Danio out once the cichlids get bigger, so my sharks will have more room. My dream tank is a 110 gallon for them but this will have to wait. <Indeed.> I do 3-20% water changes a week on each tank so this helps keep things in order. I love Corys but I don't have an existing set-up where they could fit in. <Tell me about. My poor Peppered Catfish get attacked or nipped or chased wherever I seem to put them.> Thanks for all the suggestions Neale. Audra <Cheers, Neale.>

Re: Tank mates prob. (Oh no, not Pangasius hypophthalmus!)  12/25/08 Hello dear Neale, I hope you will be fine there. Neale I want your help that I have 2 iridescent sharks and 2 giant Gouramis in 90 gallon right now. <Hello Ali. I'd be a lot more "fine" if my time wasn't being wasted. I don't mind offering advice, but when it's ignored, and you come back for more advice, that isn't really very good for my ego! Let me be 100% crystal clear on this. You have NO BUSINESS at all keeping Iridescent Shark catfish (Pangasius hypophthalmus). Firstly, they are SCHOOLING fish. Two specimens is not a school; you need groups of 5 or more. Next, they get to 130 cm (over 4 feet) long and can weigh over 40 kilos (100 lb.). There is NO WAY you have the space to keep such large fish. Most specimens damage themselves in aquaria because they cannot handle things like glass walls. They become blind for example, because they bump their eyes into things. Giant Gouramis (Osphronemus spp.) are not much smaller, typically around 60 cm in length and a weight of 9 kg (about 20 lb.). Individuals can be very territorial towards others of their species, and I suspect the two specimens you have will not get along once mature.> But Neale I am very interested to keep 2 black ghost knife and 2 parrot fish with them. <Get rid of the Pangasius hypophthalmus first. Then worry about maintaining good water quality for six months. Understand Apteronotus albifrons will die at the first sniff of ammonia and nitrite, and will not tolerate pH changes. So keep testing water quality and chemistry in your tank, and if it is ABSOLUTELY perfect every single week from here to June, then maybe think about a Knifefish. Otherwise, leave them alone!> Can they live happy and calm with each other in one 90gallon tank? <No.> Thank you, Ali <Ali, please understand the best I can do is to prevent you making mistakes. In this case, I've said repeatedly that Pangasius hypophthalmus is NOT a fish you (or ANYONE ELSE) should keep as a pet. It is a food fish, not an aquarium fish! Merry Christmas, Neale.>

Re: Tank mates prob. (Oh no, not Pangasius hypophthalmus!)  12/25/08 Hello dear Neale, I am sorry I didn't mean to hurt you; I always listen to your advice and did whatever you said. <Ah, that's the best Christmas present!> I have returned the iridescent shark and giant Gourami back to the pet store. <Extremely WISE decision.> Now I am doing what you have said about maintaining the water condition. Please suggest me any fish that you think is best, ill introduce them when water condition become normal. My goldfish are fine now they are doing well. <I would start with a group of either Bronze or Peppered Corydoras (Corydoras aeneus or Corydoras paleatus). Get six or more specimens of each species. By all means keep both! These catfish work EXTREMELY well with Goldfish, and enjoy the same water temperature. Corydoras will do just fine at the 22-25 C that Goldfish enjoy. They stay relatively small, are completely peaceful, and being air-breathers, will not suffer in summer if the water gets too hot. Another great fish to keep with Goldfish is the Weather Loach (Misgurnis anguillicaudatus). It gets to about 20 cm, is great fun, and works well in groups of 3-4 specimens. Giant Danios (Devario aequipinnatus) are fun with Goldfish, but they are boisterous and may terrorise fancy Goldfish; they work best with standard (non-fantail) varieties such as Common Goldfish, Comets and Shubunkins. Perhaps surprisingly, the Variatus Platy (Xiphophorus variatus) can work well with Goldfish; it's a herbivore, so will do well on similar foods. Couple other choices include White Cloud Mountain minnows (Tanichthys albonubes) and the Green Barb (Barbus semifasciolatus).> Thank you, Merry Christmas, Ali <Likewise, and a happy new year to you, too! Cheers, Neale.>

Infected plant, a casualty, and a mis-diagnosis? Mmm, mis-mix of FW lvstk., disease period    2/26/08
Good afternoon crew! Hope it's warmer where you are than here! <Was about to wish you the same!> As requested before submissions, here are my tank parameters. -30 gal tank w/ side mounted 30-60 gal waterfall filter (carbon, filter sponge, ammonia) -Nitrate 0, <Mmm, none, zip?> Nitrite 0, Hardness approx. 120-150ppm, Chlorine 0, Alkalinity between 120&180ppm, pH 7.6, Ammonia 0.2-0.3 <Not good...> -tank temp avgas 76-78F -20W tank light for plant growth & vibrant fish color -25% water changes with gravel siphoned once weekly. Here is my stock. -2 fantail goldfish. One the size of a quarter, one the size of a nickel -3 golden wonder killifish about 1 1/2 long -3 red wag Platies size of a nickel -2 white skirt tetras quarter sized -1 iridescent shark 3 inches long <... quite a mix... am sure you've heard/read re Goldfish "like" for cooler (and harder, more alkaline) water than the tetras, Killies...> -tank has been established for a very successfully with only 2 deaths (I don't believe this is overstocking and there is sufficient dwelling spots like fake coral, rocks, caves. Please correct me if I'm wrong) Here is my situation. I reluctantly & recently purchased 2 plants (a very small bunch of Anubias, and what I believe is Fanworts) <The former are very tough... depending on what the latter are... not so much> for the purpose of providing more territory & safety for my recently turned aggressive killifish (only aggressive to the 3 of each other, not the other species). I read nightmare stories of people bringing in sick plants to their aquarium & all their livestock gets wiped out, <Rare, but happens. Much more often, the plants just die> but I felt it was necessary, and could provide some positive benefit. I think the negative side may be the case with me. I noticed 4 closely clumped white spots on the rear fin of my white skirt tetra. Over the course of 2 days the spots either all disappeared, were smaller, or on a different spot of the rear fin. No other fish were experiencing this. I treated the tank for Ich because the white spots were Ich sized, have had other Ich experience, and I know how Ich works & its life cycle. I used a Methylene Blue treatment for 3 days, 25% water change per day, removed carbon, and turned water temp to 80-82F. The problem did not get better with the treatment for the tetra, and in fact my 2 fantail goldfish seemed to have suffered from treatment, one gravely. <See above... don't like too-warm water... and the ammonia... trouble> Both goldfish developed frayed edges on their rear tails like a minor case of fin rot. The little guy seemed like he was "panting", and overnight he suddenly died. My waterfall filter provides plenty of oxygen bubbles, so I don't think it was from lack of oxygen. <Mmmm> The other goldfish still has a finely frayed rear tail, and the tips curl inward now like a woman's hair with rollers. His breathing looks normal. No other fish seem to be infected or reacting problematically at this time. My question is should I be treating for a fungus or parasite treatment instead of the Ich? What am I doing wrong, please lead me down the path of success! Tim P USA <... Really... need at least two systems here. One for the goldfish, maybe with the Platies... the other for the tropicals. IF this is a parasite, it may well be a trematode/fluke... Please see WWM re the System needs for all you list, how to treat for FW worm complaints... Bob Fenner> Re: Infected plant, a casualty, and a mis-diagnosis?   2/27/08 Thank you Bob for the info regarding the worm complaints. Just an update on my tank situation & to add to this distress, my iridescent shark now has something completely different than I've ever dealt with. The shark also has very white frayed edges on all his fins like fin rot. <Mmm, environmental... the treatment effects... perhaps the disruption of nitrification> Also his slime coat seems to be very over active, to the point where its making his black shiny body look like a velvety grayish to the point where it could look mossy (not to the extent of cotton fungus, and doesn't look like velvet disease). His gills seem to be a bit gasp. I will treat for flukes as you recommend but I don't see any worms. <The "spots" that keep recurring, moving... are "worms"... flukes/Trematodes... See the Net, WWM re> I suppose I will treat it as a parasite, not a fungus. <See... WWM... re> Though reading the articles on this site are very informative, I'm afraid to choose a wrong diagnosis. I will isolate the Goldfish & the Platies in a different tank, however do you recommend this after treatment since they have all co- existed for more than a year together, and may share the same diseases? Again, thank you for all your help, it makes a difference. Tim P <And send along some clear, well-resolved pix if you can. Cheers, Bob Fenner>

Re: Infected plant, a casualty, and a mis-diagnosis? Bob, As you've requested, here are a few photos of my iridescent shark. Notice the white slimy frayed fin edges, and he's also glazed over with the white-slimy kind of bumpy mucus which actually looks fleshy & torn-like. This isn't fungus is it? He's even has mucus hanging off his whiskers. Normally he would hang out under the rock at the bottom of the tank in the dark, but now I find him normally swimming around up top or near the top below the tank light. His swimming does not seem to look labored, and he is not breathing heavy. I treated the tank with Binox, hopefully I'm not fighting a cause that's already in the grave. Goldfish seems to not be getting any worse, maybe even better. No other fish seem to be infected at this time, with the exception of the killie with the 1 white spot on its rear tail. The original problem tetra has no spots. Is the anti parasite medication still the course of treatment needed? Again, thanks so much. P.S. Please feel free to use these photos on your site for educational purposes. It's the least I can do for you educating me, and hopefully this can help others. New water parameters . . NO3-0 NO2-0 Chlorine-0 Hardness 150ppm Alkalinity-180ppm pH-7.8 Ammonia- .1 to .2 Thanks Tim <Hello Tim. This fish has Finrot and/or Fungus. It's in terrible shape. Both these diseases are more environmental than anything else, and the fact you have Ammonia in the aquarium clinches the deal as far as I'm concerned. Let's make this crystal clear: Pangasius sp. catfish are NOT AQUARIUM FISH. Do please see the Planet Catfish page on this species to see how big they get: http://www.planetcatfish.com/catalog/species.php?species_id=172 Never have been, and never will be, worth keeping. They just don't do well in aquaria, even if you can handle the fact they reach upwards of 1 m in length. You need lots of water movement and good water quality, since these are riverine fish. They're also schooling fish and tend to be extremely nervous when kept alone, thrashing about the tank when the lights go out or whatever. Your tank is loaded to the gunwales with rocks and such, and these are utterly incompatible with Pangasius: when the catfish swim, they bump into the rocks, get damaged, and then infection sets in. They are riverine catfish that need a tank that is basically composed of two things: [1] a huge box filled with water and [2] a massively powerful filter producing 8-10 times the volume of the tank in turnover per hour. They don't want plants, rocks, seashells, bogwood... nothing! As if to underline this point some more, scientists recently established that at least one species of Pangasius (P. krempfi) actually swims out of rivers and into the sea once it grows up! Finally, you appear to be keeping a notorious fin-nipper, Gymnocorymbus ternetzi. This species is precisely the kind of fish you wouldn't combine with these nervous catfish. These characins will nip the Pangasius, damaging the fins and sending the poor animal into paroxysms of fear. So, short term: treat with a combination Finrot/Fungus medication. I have found eSHa 2000 works excellently well with catfish and other sensitive species. Daily salt water dips might also be useful, but I fear they'd be too stressful for a catfish this nervous. Long term: needs rehoming. Wrong tank, wrong tankmates. Hope this helps, Neale.>  

Please Help My Sick Iridescent Shark 1-11-2008 My Iridescent Shark was lying lifeless at the bottom of the tank this morning; I thought he was dead so I tried to move him. He began moving aggressively hitting his nose/mouth in the gravel and on the tank glass top so I could not move him. When I returned for work he was lying motionless again I tried to move him and the same thing happen. It took me three hours to get him out the tank to the hospital tank. He has busted his nose/mouth and is now not moving only breathing. Does he have a diseases, how can I treat him, will he die? <Pangasius hypophthalmus is unfortunately not an aquarium fish. These are schooling fish that reach a maximum size of 130 cm in the wild (though 60-100 cm is more typical in captivity). When kept in aquaria that are too small for them, or when kept singly, they often exhibit precisely the symptoms you describe. There's really no "fix" as such, beyond [a] getting it a couple of pals and [b] providing sufficient swimming space. Realistically, this means they need an aquarium 1000 l/250 gallons in size. Few people have this sort of tank! Long term, your fish will keep bashing its head on the glass or hood until it damages itself, and once that happens, Finrot and fungus set in the fish will die. The best case scenario is to contact your local public aquarium or zoo and see if they have space for your fish. But sadly many public aquaria are overwhelmed with these fish and can't house any more. Ultimately your fish probably doesn't have much of a future. Why, you ask, do people sell these fish -- because there are always people out there who buy these fish without researching them first. Cheers, Neale.>

Iridescent Shark Eye Problems  12/23/07 I'm glad to have found your website, but unfortunately I have not found any cases similar to that of my Iridescent shark. I live in Florida, and during the winter the temperatures of the aquarium do not drop below 20 degrees Celsius, currently the aquarium has that temperature. <Well, this is a little cool for Pangasius hypophthalmus, which is presumably what we're talking about here. Something closer to 24-25 C would be better, and would keep the immune system operating properly, reducing problems with secondary infections.> The first day that a cold front came through my area the temperatures lowered to the temperature it has now (20 degrees Celsius), this first day, though, the iridescent two sharks that I have, their skin ( I guess I could say since they seem to not have scales) seemed crack as if it were frozen, but they weren't frozen. <Not 100% sure what this is, though skin damage is entirely possible, and certainly some types of secondary infection can cause thread-like wounds on the skin, essentially blistering.> Anyways, the next day one of the sharks had one cloudy eye and the other had both of its eyes cloudy. <Extremely common with this species. Pangasius hypophthalmus is a hyperactive and nervous fish, and when alarmed thrashes about the tank. Following this, the delicate eye surfaces get damaged and infections set in. If not precisely what happened here, the result is the same: an opportunistic secondary infection that needs to be treated using an appropriate anti-Finrot/anti-Fungus treatment of your choice (though I'd counsel against "mild" treatments such as Melafix).> The shark with both cloudy eyes also had red streaks under at the base of the pelvic fins. All the fins of both fish (dorsal, caudal, pectoral, pelvic, etc.) also became torn, and are all stringy. <Definitely Finrot. Treat as above.> The worst part, I consider, is that the shark with both eyes cloudy seems to be blind and can't really find its food (flakes). <Eyesight won't cause starvation, since these catfish, like other catfish, hunt for food primarily by taste/smell. So if healthy, they will find suitable food easily enough. But given they are sick, not treating the infection will lead to more serious problems, and ultimately death.> As for the aquarium, I maintain it very clean and the treatments I use are Aqua Safe (neutralizer), algae destroyer weekly, and Easy Balance weekly (chemical balancer). I clean the aquarium yearly, with 25 to 50 % water changes every two or 1 and a half months and monthly filter clean/change as well. <Hmm... for these fish I suspect your water maintenance regime is inadequate. 50% water changes WEEKLY would be the minimum. These are riverine fish that grow to over 1.3 meters in length (over 4 feet) and produce enormous amounts of waste. In fact, I'd consider them utterly inappropriate for home aquaria. That said, lots of people keep them and enjoy them, and maximum size in aquaria tends to be around the 30 cm/12" mark, which isn't too bad. But it is an inescapable fact that most Pangasius hypophthalmus end up deformed, scarred, or dead from secondary infections due to maintenance in too-small an aquarium. They do need big tanks with minimum decoration (danger or scratches) but plenty of floating plants to give a sense of security.> The Aquarium is well-oxygenated and I feed them daily. Currently, the heater is on and it maintains a stable temperature of 20 degrees Celsius. I also vacuum the gravel monthly with the siphon. <Warmer water will be essential to proper immune response; but you will also have to add some sort of antibacterial (e.g., eSHa 2000) or antibiotic (e.g., Maracyn II).> I really hope you can help me in determining the disease of my iridescent shark, and informing me of any possible way to treat it. If you need any further explanation, pictures, videos, or description e-mail as soon as you can, this is very urgent and I've had these fish over seven years and I would greatly appreciate your help. Thank you for your time. <Hope this has helped, Neale.>

Can you Identify this fish for me?   8/28/07 I have searched and searched and Googled and Yahooed and still cannot find the identification of this fish. I was told it was a Black Shark Catfish, which it obviously is not. <Is a Pangasiid... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/pangasiids.htm and the linked files at top and bottom> So here is a physical description and I will send along a photo, if I can get one of it. Behavior: Likes to be solitary. Prefers to hide in a corner of the tank or under a log. Doesn't care if it is looked, doesn't mind a slight touch, but don't try to move it or net it or net anything close to it. <Good description... is a shoaling species that when alone is reclusive> Eats: Never seen it eat, but Goldfish, then guppies, then other fish disappear and there are only small mouth fish in the tank. <Ah, yes... and gets VERY big...> Physical Description: Barbels-4 under the chin, eyes on opposite sides of head- that looks similar to a whale shark. Two Pectoral, two pelvic and one long anal fin, one elongated dorsal fin. Black all around. Swim Behavior: Never 'rests', all fins (except dorsal) seem to be moving always. Slow moving, unless fleeing. Mouth: Doesn't gape. Never seen it open it's mouth come to think of it. Tank: 45 gal freshwater. <Will be much too small...> I am sorry the picture isn't much clearer. Not the easiest to get a picture of because it is always moving. I would really like to know what this is and the proper care and environment for it. FYI: I received this fish along with 2 Gourami's, a catfish, and I think it was a guppy, can't remember the other one now, from a lady who was taking care of a bed-ridden elder person, whose tank cracked and leaked all over. They decided it was time to find her something else to watch. Thanks for any help you can offer! <Be reading... and chatting! BobF... who has a friend JohnK with your family name...> 'Look deep into nature, and then you will understand everything better.' - Albert Einstein We still do not know one thousandth of one percent of what nature has revealed to us. - Albert Einstein <Strongly agreed>

2 very quick questions and then I have to join reality... JC Aquarium courses, degrees, Pangasiid ID, sick Echidna...  7/28/07 <Heeee! Definitions please> Thanks for your help! <Welcome> I have one more situation: I am very new to the marine world. I am taking a course in Aquarium Science at Oregon Coast Community College in Newport, Oregon (new program). <Neat! Have just perused this site... very exciting to realize such one and two year programs exist...> Question 1) Where do you get all your info? Do you all have years of experience, biology master degrees? <Mmm, many years of collecting aquarium literature, reading critically, writing (few processes make one learn better...), have an extensive pet-fish, fisheries, ichthyological library... Worked in the ornamental aquatics trade earnestly for decades... Do have many years of formal academic education, degrees in the life sciences... My brief bio. here: http://www.wetwebmedia.com/WWMAdminSubWebIndex/bobfbio.htm> A few select books you rely heavily on? <Yikes... there are many... Ed Noga, Fish Disease, Diagnosis and Treatment seems pertinent here... the Modern Coral Reef Aquarium tomes by Fossa and Nilsen... Debelius Atlas series...> Question 2) My snowflake eel is bloated. Yesterday it happened. I watch this dude every day. I have read all the info and I am saddened to think that it is going to die. Yes it was eating guppies, our lionfish died two days ago (in a different tank). I am afraid we got some 'bad' fish, however the Pangasiid is doing very well. <Mmm, I see... this group/family is tough...> Could this be a possibility-the 'bad' guppies? Or is there something else going on? <Might well be related to something in/on the "feeders"...> The ell is still alive this morning. Thanks ever so much! Really! <You have read here: http://www.wetwebmedia.com/snoflkeeldisfaqs.htm Bob Fenner>

Iridescent shark 7/21/07 hello, I have two iridescent sharks in my aquarium I had to empty my tank and clean it out. I got it second hand and I guess I should have taken the rocks out and replaced them first. I transferred the fish into a temporary tank, well to tell the truth it was an ice cream pail. but when I returned them to the aquarium they were both very red (as I am sure you know these are silvery and black normally). one of them instantly began to swim and carry on like normal and he got his color back in no time at all ,however the second one just stays laying at the bottom and swims around lazily along the floor he has not turned back to his normal color. did I shock them in the move and will he pull out of this? all the other fish in the aquarium have also resumed their own happy fishy lives. <Greetings. I hope that you work at a public aquarium or have a gigantic aquarium in your basement. Iridescent sharks -- Pangasius hypophthalmus -- are possibly the worst aquarium fish in the trade. In fact, practically all fishkeeping writers and experts consider them totally unsuitable for home aquaria. Here's why: maximum size is 1.3 m (over 4 feet). They are schooling fish. They grow extremely fast. They are extremely nervous and often damage themselves by swimming into things when alarmed. You have discovered this. As they mature, they will become more and more nervous as they feel confined. Yes, their colours will return once they recover from their state of alarm, but once frightened again, you'll have to go through the whole process again. Almost no useful information is provided by retailers when these fish are sold. In terms of basic care they are herbivores, and need lots of green foods. They live in huge river systems, and so expect a strong water current and lots of swimming space. Minimum aquarium size is something like 4000 litres/1000 gallons. Remember, these things can get to the size of small dolphins! To be fair, most specimens seem to stop growing around the 60 cm/2 foot mark, but even then, given their activity level and the fact they need to be in a school of 6 or more specimens, you still need a simply ginormous aquarium to keep them properly. It is really a food fish and widely farmed, and unfortunately a few specimens seem to find their way into the aquarium trade. Any retailer stocking these fish and not telling you what they turn into is being grossly irresponsible, in my opinion. On the plus side, they're not fussy about water chemistry and are harmless towards fish too big to eat. They also taste very good. Cheers, Neale>

Iridescent Shark in BW?     2/11/07 Hi there, first off I have gotten tons of excellent information from your site. Thank you for that. <Glad to hear it.  Pufferpunk here with you tonight.> My question is two part, I have 2 iridescent sharks and a Pleco, in a 175 (I know they get big and when they get bigger, I'll be moving 1 to another tank).  They are only 3" and 3 1/2" long right now. <It is highly unlikely you will ever be able to house even 1 iridescent shark properly.  Here's a pic of an adult: http://smg.photobucket.com/albums/v345/Pufferpunk/Other%20Fish/?action=view¤t=iridescentsharks.jpg > I would like to know the possibility of keeping them in a brackish tank setup? <No, these are strictly FW fish.> I would like to get a puffer that gets large but it would require brackish conditions. <The larger BW puffer (green spotted puffer, Tetraodon nigroviridis), actually will eventually need quite a lot of salt, even marine conditions as adult.  There are many FW puffers, some that can get quite large, like the Fahaka puffer but are much too aggressive for tank mates.> If that isn't possible for these fish, are they compatible to keep with an Oscar?  These 2 attacked some the four mollies that were in the tank when I brought them home. <They will eat whatever fish they can fit into their mouth.  If the Oscar is the same size or larger, they should be compatible.  You need to consider what you will do with these fish when they get larger.  It's almost impossible to find homes for them once they are large.  ~PP>   Thank you for all the info, Terry

Iridescent Shark... not feeding?   2/6/07 Hello again...2/5/07 <Mike> I have another dilemma; I purchased a 10" iridescent shark at my LFS and am keeping him in a 100 gallon tank for now. I hear that he will soon out grow it, I also hear that there <their> growth could get stunted and 12" could be there max size. <Possibly> Anyway I have had him now since 1/28/07 1 week 1 day and haven't got him to eat anything yet... should I be concerned? <Mmm, getting there> I have him housed with a Red Devil, 2-Jack Dempsey's, 1 Fire Eel, and 1 Texas cichlid. So it is hard to get food to him. <Are usually quite eager feeders> I have tried feeding at night using pellets, flake food, and night crawlers. As far as I can see he hasn't ate anything yet! I hear they are called "eat em up fish" and will eat anything and everything but no luck here.... I have called the pet store where I got it and she said she has had him for months and never saw him eat  she said that she used flakes. What should I do? <Mmm, best to place a divider in this tank... about half way... and make sure this fish is not getting bullied into non-feeding, assure yourself that it is taking food... I would continue with the (sinking) pellets offering. Bob Fenner>
Iridescent Shark... not feeding? - II - 02/09/2007

Do you think it could be internal parasites? I have read a lot about that. If so should I remove from tank or will it be too late and had already spread to other fish? Thank you, Mike Whitson <Very unlikely this is a parasite issue... just a matter of inter-species adjustment, the new fish settling in. Bob Fenner>

Iridescent Shark, Feeding, Cont'd - 02/11/2007
Should I attempt to force feed? Or just let him be? <I would NOT force-feed a Pangasiid... not necessary... I assure you, given enough space, a lack of harassment, this specimen will eat... and definitely NOT starve. BobF>

Holes in a Paroon shark. African Cichlid, Pangasiid incomp.  12/30/06 Hello! I have a Paroon shark <Pangasius sanitwongsei Smith, 1931... a REALLY big catfish> that has been in a tank with cichlids for about 5 months now. I had a Moray Eel <...> for about 3 days and after researching it (should have done that before I bought it) <Yes> I decided to give to my cousin's saltwater fish store. In the morning the day I gave him up, he was belly up in the tank, then when I came home, his head was by my sharks spot in the tank and it was obvious that they were bitten. I put medicine in the tank and tried to nurse them to health. It was apparent one shark would loose <lose> his eye because it was bloody then just turned black like his skin. It was almost like his skin grew over the eye.  Well my cichlids picked on the sharks and would bite his eye and his side fin (in front) <Incompatible...> so I put the shark into my 10 gal feeder fish <... dismal> tank with some medicine so he could heal in peace. He has been in the tank for 3 weeks and where his eye was started to turn pink. Silly me I thought it might be regenerating. Well, now there are holes where his eye and fin used to be. It appears like its rotting or something. I have no clue what is going on. Can you help and let me know what it is and how I can treat him? Thanks! Jennifer Mercer <What re water quality, testing... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwdis3setsfactors.htm and the linked files above. Bob Fenner>

Mystus leucophasis...?  10/24/06
Hello, <Hi there> I've search both your site & the web but find either very little or conflicting information on the Mystus leucophasis. I have 3, 4"- 6" in a 55 gal with 4 Oto catfish (moving soon). <Good. Incompatible> It's fully planted, and they love to tear up the green hedge. They eat everything including a slow Oto. <Yes> So I'm writing to get more information on them. I know I have both sexes in tank but not sure how to tell which is which, when are they sexually mature? what about breeding, what is their breeding ritual or habits, environment. How big do they actual get ? I've read any where from 6" to 12". Any recommended read? I'm looking for has much information has I can find on them. BTW- I saved them from the nasty tanks at Wal-mart. <Mmmm... as far as I'm aware this species is not handled by this mass-merchandiser... Is this what you have: http://images.google.com/images?as_q=Mystus+leucophasis&num=20&btnG= Goodle+Search&as_epq=&hl=&as_oq=&as_eq=&imgsz=&as_filetype =&imgc=&as_sitesearch=&imgsafe=active> I have 13 tanks 3 of which are 55 gal so If I need to put 1 per 55 I can do it or buy bigger if need be. <I suspect you have a much larger Pangasiid relative... do see Fishbase.org re identification here... Search for the genus> Thank you for all your help. Sheri <Glad to help. Bob Fenner>

Brooding ID "Shark" Catfish   9/1/06 I read about someone thinking his/her ID shark might be pregnant.  You responded it would be highly unlikely.  My male ID shark is brooding the female's eggs.  They are about 6 years old and approximately 12 inches long in a 55 gallon breeder size tank.  My husband and I caught him to look in his mouth thinking he swallowed some gravel.  There are about four or five creamy-yellow eggs the size of small marbles.  I do not expect that they will actually hatch, but who knows.  If you need any documentation I will do so.  Expectant fish grandma?   Kim B. 8/31/06 <Neat! I wonder what species of Pangasiid catfish you actually have... Please see here: http://fishbase.sinica.edu.tw/Summary/FamilySummary.cfm?ID=134 (the species links below) and: http://www.wetwebmedia.com/FWSubWebIndex/pangasiids.htm Bob Fenner>

FW Minnow Sharks, Pangasiid Catfish Shark... comp. mostly  6/5/06 Crew: <<Paula. Tom with you.>> I was reading your information on the different types of sharks/minnows. Under the Apollo shark it said "best kept singly." Does this mean only this fish in a small tank or only one of this type of fish along with others in a tank? <<These fish don't get along with others of their species or with similar types of fish. Not an uncommon situation with certain varieties.>> Also, will tri-color, iridescent, and Apollo sharks get along without fighting in one tank that holds about 40-50 gallons? <<The Tri-color (Bala) Shark will quickly outgrow this tank. It's active and fast requiring lots of swimming room. Scratch the Iridescent Shark from your list completely. It can reach over three feet in length and shouldn't be sold to hobbyists. The Apollo Shark will probably see the Tri-color Shark as an adversary due to the similarities in their appearances. A 50-gallon tank would probably suffice for the Apollo Shark, however.>> Thanks for the help. Paula <<Please continue your research, Paula. I commend you for doing your homework but there's still much to learn. My best. Tom>>

ID shark woe I have been doing some reading and it seems I should not have an id shark in a 33 gal tank. He is about 7 inches and I love him but should I give him away to someone with a larger tank? boo hoo? If I give him back to the fish store won't they just sell him to the next ill-informed hobbyist?  <I would move this fish... to a larger system... it will be "unhappy", too likely to jump out, harm itself dashing into the side of your 33> They told me my tank was fine when I suggested it may be too small. I think he may also have fin rot. What should I do about that? Melafix or Maracyn II. <Best to move it to a larger, clean system... allow it to self-heal, quick!> Anywho if you could set me up with a good list for a freshwater community tank which already houses 1 Pleco, some java fern and some corkscrew Val I would greatly appreciate it as the local fish store people seem to know squat ( they also told me 6 comets would be fine with my id shark, a school of neon tetra and two black Kuhlis in a 33 gal tank). <What? Goldfish in with tropicals? No... do take a look through the survey articles on freshwater posted on WetWebMedia.com> It is frustrating when the people I turn to give bad advice. You are now my knight in shining armor. <Not too shiny> I e-mailed you yesterday with some info if you recall but will do so again. 33 gal tank DynaFlo 3 filter 3 way cartridge filter temp mid 70's <Be chatting, Bob Fenner>

New Shark Dear Mr. Fenner, I purchased a new shark a day ago at the local pet store. They called it a "blue white fin shark" since it has horizontal blue and white stripes on it. I can't seem to find any information on this shark anywhere and I need to know how to care for it.  <please resist buying an animal before you know its needs, my friend... at any rate, by the description it is still unclear what species you have. Please browse our archives from the index page at WetWebMedia.com. AS just a guess... does the body shape of your fish resemble the iridescent shark here: http://kingsoftheaquarium.tripod.com/iridescentshark.htm> It doesn't seem to eat anything right now. At this time I am not sure as to how large this shark grows, if it will get along with the other fish, or any general information on it.  <if it is the above species... it is peaceful but grows enormous (18+")> The shark, which is about 2" in length, is in a 10 gallon fish tank with 2 zebra Danios (I'm not positive about the name, but they are zebra fish), 1 cat fish, 2 Gouramis, 1 painted glass fish, 2 Neon Orange Mickey Mouse Platies, 2 tetras (whose type of tetra is unknown). The pet store employees weren't very helpful, as they didn't know much about the shark. Please help me A.S.A.P. by sending me information about the shark (how to care for it, if it gets along with other fish, and how large it grows).  This will be greatly appreciated. Thanks for your time and help, <best regards, Anthony>
Re: New Shark
Dear Mr. Fenner, <The previous reply was from Anthony Calfo. Steven Pro here with the follow up.> Thanks for your help before. I think I have the iridescent shark you mentioned. Do you have any advice as to what to do now? <My best advice is to return the fish.> We didn't know any information on it because the store gave the improper name for the shark and they never provided us with any information about it. <And yet you still elected to purchase it anyway knowing nothing about its adult size or captive care requirements. Do not get me wrong. I understand how easy it is to just get whatever your store recommends, but these are live animals. And with their purchase, we assume responsibility for their lives. The live or die dependent completely on us. It is therefore our duty to fully understand what our pets need and to sincerely determine whether we can meet their requirements before we buy them. I will climb down off of my soap box now.> We only have a 10 gallon with 10 other tropical fish (as mentioned in the previous message). <From your previous listing, I would stick with peaceful Barbs (such as the Rosy or Cherry Barbs) and different types of Tetras.> Thanks again, Brittany Simmons <You are welcome. -Steven Pro>

INFECTED IRIDESCENT SHARK I have an Iridescent Shark that is 3 to 4 inches long. Last week a "bubble" appeared on his side. It really looked more like a blister. When I came home from work, it had "popped" and now he has a hole in his side. This doesn't look like any of the ulcerative type pictures on your site, it is literally a hole. I watched him, and noticed a small bit of air inside the hole that slowly gets larger until a line of bubbles comes from his side. He isn't acting different, but surely this isn't normal. I can get some pictures. Do you have any suggestions? Thanks, Audra < You shark has a bacterial infection that sounds like it needs to be treated. Make sure the tank is clean by doing a 30% water change and vacuum the gravel. Clean the filter too. Check the water. Ammonia and nitrites should be zero. Nitrates should be under 25 ppm. Treat the tank with Nitrofuranace as per the directions on the box. It may affect the good bacteria that break down the fish waste so check for ammonia spikes. You may need to add Bio-Spira after treating to establish the good bacteria back in your tank.-Chuck>

A black iridescent shark question I have a black iridescent shark approximately 6 inches long. I noticed yesterday that it looked like he had a festering sore right behind his left-sided fin; now today it looks like an actual hole. I called the local pet store, but they weren't sure and would do some checking - any ideas what it is and what to do for it???  I did a water check and everything is right on where it should be.  He's in a 55-gal tank with another iridescent black shark, platys, Dragonfish, Dojos, clown loaches, and has been since May of this year.  Thanks in advance. <Hi Cheryl, Can you give us the actual readings on your water? Ammonia, nitrite, nitrate and pH. Also, what is your water change schedule? Your sharks problem may have to do with high nitrates. That's a lot of "soon to be large" fish in a 55 gallon. As adults the sharks will reach over four feet! You'll need to plan for there long term care. The clown loaches will hit eight inches or more. With this many growing fish it's common to have your nitrates spike quickly. Long term high nitrates can cause skin problems.   Also, I'm not sure what you mean by "Dragonfish", common names being what they are. Do you have a link to a picture? Don>

Iridescent shark We have an iridescent shark that has out grown our 55 gallon tank. It was 3-4 inches long when we got it, and is now 14-15 inches long.  It kept running into the sides and was not able to turn around with out getting skittish.  Had made several jumps to the top and scraped chunks out of the skin.  One night it actually jumped out of the tank onto the floor.   We bought a 125 and that was very hard on the shark to move it.  The fins got caught in the net, but everything has healed.  
<<Better by far to "scoop out" such fishes w/ large (doubled) plastic bags... you can get used from a fish store or use thick trash bags... Do dump out most of the water before lifting! RMF>>
Our problem is, since we have moved the shark, it has not eaten.  It has been about a month now.  We have fed tetra flake food, sinking pellet food, which is what it ate all of the time, krill, Tubifex worms.  Temp is about 75, changed the water last night and the nitrate was a little high, but still not eating.  Have platys and Cory cats, which was in the other tank with it also. Any suggestions  -  HELP  we have put a lot of money and effort into this shark and do not want anything to happen to it. < Try raising the water temp to 80 degrees F. They come from fast moving waters so make sure the filter is adequate for the tank and pumping at least 400 gallons per hour. Make sure that the water has zero ammonia and nitrites and that the nitrates stay below 25 ppm. I think I would add an airstone to increase the aeration of the water too. Try keeping the light off for awhile and let him get use to the new tank. You fish may have sustained some internal injuries during the move. If the above suggestions don't improve things in about a week then I would recommend treating the tank with Metronidazole. This will be expensive in a big tank but I don't think I would risk moving him again.-Chuck> Thanks SSimpson

Burned ID Sharks No one seems to be able to help me answer my question. I have two small ID sharks in a 10 gallon tank. They have both had Ich before but it is long gone. In the past week I noticed red marks on the back side of them. They are starting to go away, but now my one shark is covered on one side and all along his tummy and underside with clear bubbles, that almost look like boils?! He is still active and is still eating but I am concerned with how quickly it spread and that my other shark might get it. What is it, how do I get rid of it, and will my sharks die? <Sounds like either the medicine itself burned the fish or that it killed off your biofilter... I would add a teaspoon of salt to the water, test for ammonia and nitrite and be careful about not over-feeding till it recycles. Bob Fenner> 

Re: Burned ID Sharks Well, now the shark still has the boils but they have filled up with blood. There are no red marks left. Just the boils that are now full of blood? Any idea what the boils are or how to get rid of them. One is right in his gill and worries me?! <Mmm, sorry for the delayed reply (have been on a liveaboard out of the country)... only time and improved, steady water quality, decent nutrition will show if your minnow sharks will recover. Bob Fenner>

INFECTED IRIDESCENT SHARK I have an Iridescent Shark that is 3 to 4 inches long. Last week a "bubble" appeared on his side. It really looked more like a blister. When I came home from work, it had "popped" and now he has a hole in his side. This doesn't look like any of the ulcerative type pictures on your site, it is literally a hole. I watched him, and noticed a small bit of air inside the hole that slowly gets larger until a line of bubbles comes from his side. He isn't acting different, but surely this isn't normal. I can get some pictures. Do you have any suggestions? Thanks, Audra < You shark has a bacterial infection that sounds like it needs to be treated. Make sure the tank is clean by doing a 30% water change and vacuum the gravel. Clean the filter too. Check the water. Ammonia and nitrites should be zero. Nitrates should be under 25 ppm. Treat the tank with Nitrofuranace as per the directions on the box. It may affect the good bacteria that break down the fish waste so check for ammonia spikes. You may need to add Bio-Spira after treating to establish the good bacteria back in your tank.-Chuck>

FW minnow shark disease Hello- I need a little help here. We have a 75 gallon freshwater tank. We have had what I think is an ongoing problem of some sort of disease. I have already had 2 Iridescent Sharks die. They begin to stop eating get really skinny and then just swimming all weird. Top of the tank bottom and middle. I'm a little confused I just don't see why its only the Iridescent Sharks, no one else seems to be showing any signs of disease. The first 2 died within a few days of each other,  now it has been about 3 weeks since we have had any problem and now we have it starting all over again. The tank includes 2 Bala sharks, 1 gold shark, 1 silver shark, 1 cigar shark, 2 glass cats, 1 ghost knife, 1 coolie loach, and 2 iridescent. We are running a Aqua Clear 500 and a Aqua tech 20-40. plus 2 Aqua clear 4000 power heads, for under gravel filtration. The tank has been running since June 25th of this year. When we set up the tank we started it with A miracle and a 700 gph pump (little giant). In about September we noticed a crack in the sump and immediately replaced it with the filtration that is on it now. About 3 weeks the filter crashed we first noticed the first iridescent swimming disoriented, and then he stopped eating, then died, The 2nd one followed shortly there after. We suspect the tank recycled causing stress to induce these deaths. It has now been about a month and we seem to be having the same problem again with another iridescent only this time there seems to be damage and some sort of spot on the top fin. If there is anything you can do to help or maybe give us an idea of what this might be please contact me by e-mail. < First of all we need to evaluate the overall health of the tank. For that you need to get some testing done. Measure the ammonia and nitrites. They should be zero all the time. Any readings mean that the nitrogenous wastes are not being completely being broken down by the bacteria and you will need to address that. Secondly is get a reading on the total nitrates . They should be less than 25 ppm but some fish may not be able to handle even that high of a reading and you iridescent sharks may fall into that category. They may not die out right but instead succumb to diseases for which they never recover from. The nitrates can be reduced by servicing the filter regularly and by doing weekly water changes. The amount of water is determined by the fish and how they are being kept. For general purposes we usually recommend about 25% per week.-Chuck> Jamie Iridescent Shark Question I have had my Iridescent shark about 2 months.  He recently got a infection (tail and fin rot) and I treated the tank and I think I have got rid of the parasite; overall, his appearance looks good, but he is acting depressed.  My fish will not eat, or hardly even move.  I even got him some other fish friends and he won't do anything.  The new fish are not acting the same as him.  Does he still have a parasite?  I use a water neutralizer and stress coat because he is such a nervous fish. < Try a 30% water change and service the filter. Check the water temp. and make sure it is around 80 F. Try some live or frozen food to get him interested in feeding again.-Chuck>

Iridescent Shark Patchy  I have an iridescent shark and approximately one week ago, he developed a white raised pimple-like bump surrounded by a small white patch on his right side just below his head. I have seen Ich before and this does not look like it. He is the only fish in the tank at this time. Over the past few days, the bump seems to have gone down slightly but the white patch underneath seems to be getter larger. He does not seem as active as he usually is. Any ideas on what this could be; could he have injured himself somehow? Any help would be appreciated. R. MoDavis  <<Dear R; It's hard to say. First I will ask you to test your water, this is always the first step when problems arise. Make sure ammonia and nitrites are zero, and nitrates are low, say 20 to 60ppm, give or take. Next, temperature must be stable, around 78F is fine. How big is the shark, and how big is the tank? How often do you do water changes? Why is he the only fish in there? Curing the problem could be as simple as adding some Melafix. But if other fish have died in that tank recently due to water quality problems, Ich, or bacterial infections, you will need to do some work to save this shark. Let me know. -Gwen>>

Salinity & Fuzzy Skinned Sharks Hello and thank you in advance.   <Good morning!> In February I purchased a 35 gallon hex freshwater tank. It is populated with the following:  3 tiger barbs, 2 rosy barbs, 2 Gouramis, 2 iridescent shark catfish, 1 Pleco, and 1 glass fish (the other 3 died yesterday and today).  All fish except for the glass fish are 'original' members.  When setting up my tank, I was told 1 tablespoon of salt per gallon but on your site I read that it should be 1 tablespoon per 5 gallons. Which is correct?  I also have a salt hydrometer, what is an acceptable salinity level for a freshwater tank? <It should be one Tbsp per 5 gallons or even less. 1 per gallon is way too salty!> In addition, last week (prior to introducing the 4 glass fish) I noticed that the 'sharks' looked fuzzy and it has gotten worse.   <You added new fish when the current ones were looking ill? Never a good idea my friend.> Last night I ran to Petco and read about different diseases and determined that the 'sharks' have a fungus.  I treated the tank last night with fungus medicine.  I don't remember the name but I had to open up the capsules and release the contents into the tank, turning the water green.  I am suppose to wait 48 hours and repeat the medicine then wait another 48 hours and put the carbon back in and change 25% of the water.  Prior to putting in the medicine, I removed the carbon as directed.  Within a few hours of medicating the fish, 2 of the glass fish died and another this afternoon.  They (glass fish) have only been in the tank since Saturday, could they have been ill prior to putting in my tank or could the medicine kill them? <The Glass Fish probably died from medication overdose. Fish that have small or no scales are extremely sensitive to medication and should only be given half doses.> How deadly is a fungus and why aren't the other fish affected?  Any help you can give would be appreciated, my daughter is distraught that her fish are dying and I don't think the 'sharks' are going to make it. <The deadliness will depend on exactly what it is. Check here: http://www.wetwebmedia.com/FWSubWebIndex/fwfshparasites.htm to see if you can find out exactly what it is and treat accordingly.> FYI, I have a Fluval 300 and keep the temp around 78 degrees.  Every 3 weeks I change approximately 6-10 gallons.  I check the PH level every other day and keep the tank at 7.0 (neutral).  What am I doing wrong if I even am? <This all sounds good. Ronni> Jennifer

Re: Salinity & Fuzzy Skinned Sharks Ronni: <Hi Jennifer> Well, I no longer have the fungus in my tank and my shark's body has cleared up BUT we now have another issue.  The tiger barbs and Gouramis are now picking on the shark b/c he is on his own.  He now has some missing scales and I am afraid of infection setting in causing his demise.  Unfortunately, I am unable to remove him into a separate tank.  He has been hiding under an archway to protect his back and he is eating well.  Would a salt dip help? If so, what should be the water/salt ratio? Thanks in advance. Jennifer <A salt dip may help heal his wounds but he's still going to get picked on which will cause more wounds. You really need to isolate him, provide more cover and more shark-mates, or get rid of him. Ronni>

Re: Salinity & Fuzzy Skinned Sharks Ronni: The link you gave me I had already checked and the fungus symptoms are exactly what the sharks have.  Unfortunately, we lost a shark this morning and I expect the other shark to expire before evening unless I am extremely lucky.   <I'm sorry> I noticed this morning that my 2 rosy barbs have one eye that is puffy (with the sharks that was the last thing to be affected).  Should I continue the medicine for the remaining fish to eliminate this disease???? <The best thing to do is isolate the fish that are showing symptoms into a separate quarantine tank and medicate them in there. If that isn't possible, treat your main tank with a half dose of the medication.> Thanks, Jennifer <You're welcome! Ronni>

Iridescent shark breeding? Hi, <Hello> We have two Iridescent sharks in a 125 gallon tank along with a few other fishes. The sharks are about 6 years old and are approximately 18" long each. One of them appears to be pregnant. Her middle has gotten very round recently and she seems to be swimming a little more slowly than usual. I've read that Iridescent sharks don't reproduce in a home aquarium so I'm wondering if there's just something wrong with her. <Mm.  I very, very much doubt that they'll spawn.  For one, they're still quite small (yup, small....), and for two, you got it, they don't seem to spawn in aquaria.  They do, however, spawn commercially in enormous ponds and such.  But it could be that she is egg-laden, which would certainly make her rounded, and would not necessarily lead to breeding.  If it is an illness/condition, it's most likely constipation - what are you feeding them?  Also, what are your water parameters (ammonia, nitrite, nitrate, pH)?> If she is pregnant what is the gestation period and what should we do about quarantining the babies or if she's ill what should we do about it? <Well, I doubt if you'll be dealing with babies - but if you do, most definitely do keep good notes and keep us informed!  If she's constipated, you might try feeding her chopped earthworms.  She should accept them, and they have a good roughage content, so might help her clear any blockage.> Please advise as soon as possible. If she may be ill we want to remove her from the tank. <My apologies for any tardiness....  I don't think you'll need to remove her from the tank, at least, not yet; but please do keep in mind, these guys can potentially reach a staggering fifty-two inches!!  Now, if only I could glass in the house, and have a tank for myself to live in in the middle of it....  ;)  -Sabrina> Thanks for your help. Beth Domanski

Novice-need help!!!! Learn before you burn... FW induced troubles   3/23/06 Hi I have been reading and I think your website is amazing, probably the best out there!!! Thanks for all your help!!!! You are all great!!! Anyhow, I am so new at this and this is probably the most ridiculous questions but I need some answers: 1- Today I've been seeing one of my ID sharks just sort of laying around the plants (plastic) not being his active self, at one point I thought he was dead cause he was just laying on it not moving, then he rapidly moves across the tank and does the same thing on the other plants? I have also noticed that he looks a bit swollen around his belly, he wasn't like this before, my husband thinks it may be pregnant but it's so tiny, I doubt that!!!?HELP!!!! I hope he is ok!!! what should I do???? <When, where in doubt, a partial water change... What do your water quality test kits show?> 2-I don't know how big my tank is it looked pretty big to me when I bought it it was a complete tank with all access: heater, filter, food, etc..) The filter it came with says it's for a 5 to 15 gal tank so I guess that's it???!!!! <There are about 231 cubic inches in a U.S. gallon... calculate> Anyway the question is, I don't know if this tank is big enough -- for now-- <Maybe not... could be these shark catfishes are just suffering from low dissolved oxygen... The real root issue here is highly environmental...> I know I have to upgrade eventually cause my fish will grow big but for now is it ok to have 2 baby iridescent sharks(<2 inches each), 2 tiny upside-down catfishes(<1/2 inch), 1 Pleco (about 2 inches) and 4 tiny neon tetras? <Mis mixed> 3-How often does my tank need water change? some say every wk. others say every 4 wks.? But just recently (3 wks. after getting tank and fishes) I have noticed that the water is starting to cloud up, should I change the water? 4-How often do I feed my fishes? Food says 2-3 times a day, people at the pet store say 1-2x daily and I had someone tell me that he feeds his fishes every other day?????? So I've been feeding 1/daily???? <Posted... on WWM> 5- Should I feed my Pleco peas? Zucchini? will the other fish eat these??? Is that OK? 6- and the most stupid question of all is:::::: When I clean my tank should I take my fish out and put them in another small tank until I'm done cleaning or do I do this with the fish in the tank???? Doing it while they are in there doesn't sound right, but won't taking them out of the tank and then putting them back in stress then out????? Sorry for  all the questions but the people at the pet store don't seem to know what they are talking about, and already I'm attached to my fishes so I want to take very good care of them, plus I'm excited to see them grow!!! Thank you for your time and for answering all these crazy questions!!!! <These issues are detailed on our site. Read, learn to use the indices, search tool... Much for you to be aware of related to these issues. Bob Fenner>

Iridescent shark starved itself to death... Mmm, not likely  3/18/06 I have a 20 gallon tank, well cycled and up and running for about 2 months. I have had a couple of Iridescent sharks ( 2 inches long) since the beginning. <You do realize how large this fish gets?> For over a month and observed that one of the sharks "ate up" all the food and didn't allow the other shark any chance to feed. <They are voracious feeders, yes> I saw that, the shark that ate everything only ate the floating food and didn't touch the once that sunk to the bottom. I read somewhere that some sharks may eat the sunken food and this should not be a issue. So, I put in sinking food, but never saw the other shark eat. <Mmm, beware, or be aware that such common name, labels as "shark" have nothing other than external appearances in common... most FW "Minnow Sharks" are cyprinids... the Iridescent Shark is a Pangasiid catfish...> Its been 2 months, and I thought everything was okay. Then, I introduced 3 swordtails, 2 guppies over a period of one month. <Yikes... would be eaten in the not-so-long term> Now, the guppies and swordtails did compete for the floating food with the shark. (I do put enough quantity to suffice everybody !!). After a month, I see that the shark that did not compete for food passed away. I guess, the sunken food was ate by the guppies and swordtail starving the shark to death. am I right ?! <Not likely, but possible> the water chemistry is fine and all the other fish are active and happily swimming around. How do I make sure that all my fishes get enough quantity of food ?! <Mmm, first and best by investigating their individual species "needs"... for environment, water quality, foods/feeding, compatibility. The "shark" mentioned is way out of line with what you list here> I would like to add more fish. I would like to have fish that swim around actively and the water from the tap is pretty hard. <Ahh! A good start> A Betta or tetras, which one is a better option for my tank inmates ?! <Read my friend... on WWM, books, the Net at large...> Thanks in advance for the help. -- ~Sunil <Please read here: http://wetwebmedia.com/FWSubWebIndex/pangasiidcatfaqs.htm and the links you'll find... yes, this fish grows to a few feet in length... quickly! Bob Fenner> Re: iridescent shark starved itself to death...  3/20/06 Thank you for the quick response !!! <Welcome> Yes, I realized a bit late about the size my iridescent shark will get to (yeah .. its a "catfish"... but, I still love to call it a "shark" just because he looks like one !!). I have decided to give him back and get some fishes suited for my tank. <Good>     As I mentioned below, one of my sharks passed away and two days later, the other shark is  also showing the same behaviour. It was eating properly until the other shark died and now, it is swimming slowly at the bottom of the tank and hasn't eaten anything for the past two days. There are no visible signs of sickness or injury. The water chemistry is okay.     I just wanted to make it healthier before I gave it back. But, tonight, it seems to have lost all energy (he had a stomach full two days ago, and I don't think the fishes go that weak if they go without food for two days), all that he does is lie low and motionless and almost dead. <Such "high energy" animals have to be fed very often... at least twice daily... high protein foods are better...>     All I can do now, is look at him, helpless and unable to do anything to make him feel better. I did a 30% water change. What else can I do ?! <More animal make-up food, more often> sad and heart broken, Sunil <Do what you can and be satisfied. Bob Fenner>

i.d. Shark   3/2/06 Hi there I just emailed you but I just thought of another question sorry about that! My i.d. shark does not seem to like to come out during the day but when I shut the light off he comes out. It seems to me like he is just playing shy but we have had him for3-4 months now. Why is he doing this? We have taken him out a couple times and changed the tank around to see if that would help because we were told that it could be a territorial thing but he still just lies on the bottom of the tank and if he sees us looking in the tank then he hides behind something. Can you explain to me what Ich looks like please and what I can do if I get it in my tank? I have 2 fish I believe are pregnant and I do not want to take any chances with Ich and just want to have a heads up about it. Thank you very much I love your site it is so helpful. I have spend the last 3-4 months looking for good information but I have not yet been able to find anything. A lot of websites contradict themselves. Amy <Please see WWM (use the Google search tool on the site) and Fishbase.org re this fish... You will soon know its ultimate size and water quality requirements make it incompatible here. Bob Fenner> <<http://fishbase.sinica.edu.tw/Summary/SpeciesSummary.php?id=14154>>... yes... five feet long... needs a six foot long tank, others of its own kind... will eat all else you presently have>>

The Great White Shark of FW Aquariums  2/1/06 Hi, <Hi, Pufferpunk here> My son received a ID Shark for Christmas in a 5 gallon tank. As you do, we added a few things: stones, plastic water plants and a kissing fish along with a heater and small charcoal filter. <Woah!  That kissing Gourami will grow as large as a foot & your iridescent shark, 4 feet!  Here's a pic of an adult: http://www.planetcatfish.com/catelog/pangasii/pangasiu/172_12.PHP  There aren't too many fish that live out their life in a 5g tank, other than a Betta or a few tetras.>   It is now a month later and today we have notice that the ID shark is acting rather frantic, with pauses of lying on his side. The other fish is chasing him, which is new as of today. <Kissing Gouramis can get quite aggressive.> The food and the water purifier are all recommended by the pet shop. The only thing we can think of is that maybe the tank has become too small for the two fish. <Correct in your assumption.> He isn't that large (2 inches) but we were in a pet shop this past weekend looking to add another fish when we were informed that ID sharks can grow quite large (8 inches) and that our tank would be too small for a third fish. <Correct again, except for the 8" part.> Do you think it could be the size of the tank at this point? <Exactly!  I'd return them both & buy fish more suitable for such a tiny tank.  Maybe a beautiful Betta or 3 small tetras.  ~PP> Janice P.S. The food is Nutrafin max for tropical fish.

Baby Iridescent Shark, Not Much Info, We Need More 11/2/05 One of my tank houses a 10" iridescent shark, he is rather big <Uhh, actually, at 10 inches, he's still *tiny*. See here: http://www.fishbase.com/Summary/SpeciesSummary.php?id=14154 .> and usually eats very well, but as of lately he has not been eating. All of my ammonia and nitrites are at 0, and nitrates are a little over 10. Is there anyway possible to get him eating again? <Really, not enough information here to go off.... I would try offering meaty foods of aquatic origin - shrimp, squid.... or frozen meaty fish foods. Wishing you well, -Sabrina> 

Miniature Iridescent Shark Cats - 10/10/2005 Hi, I have had two iridescent sharks for approximately 4 years now. The bigger of the 2 is approximately 6 or 7 inches long. <Still very, very tiny.... Please read here: http://www.fishbase.org/Summary/SpeciesSummary.php?id=14154. For some reason (aquarium conditions, food, others....) your fish are quite stunted in growth. This is not necessarily a good thing.> Over the past few days it has developed a rather large very noticeable oversized abdomen as if it were pregnant. Its activity and movement have not changed, what could this be? <At this size, it is not pregnant. My first guess would be that the animal is constipated..... but there's just not enough information here for me to go off.> Please help me....... <Wishing you well, -Sabrina>

I was just wondering, can I keep an Iridescent shark( Pangasius hypophthalmus) in a pond of about 2 feet deep?  9/1/05 <That is not really a question of depth, but of the temperature in your pond, and the filtration. You would need consistent temperatures above 75 F, and a good strong filtration. This species is also a bit sensitive to Ick and I would be concerned in a pond where it will be difficult to examine. Good Luck, Oliver >

The Pangasius sutchii - Next time, Please Refer to the Corrections FIRST link! Dear ????, <Mike G with you this afternoon> ill introduce myself: I'm Bennie Tuil from Holland and found your email on the internet. id like to know if you really got the Pangasius sutchii. <I don't quite follow what you are asking. I myself do not have any Pangasius as they grow too large for the aquaria I maintain.> because I do have the Pangasius sutchii but id like some info. about them. <Pangasius sutchii are fish that are, for the most part, unsuitable for home aquaria. They attain very large sizes, and are actually a food fish in their native land. Please refer to the following links for more information on this fish: http://www.wetwebmedia.com/FWSubWebIndex/pangasiids.htm http://www.wetwebmedia.com/FWSubWebIndex/pangasiidcatfaqs.htm Best of luck, Mike G> sincerely yours: Bennie Tuil Holland

Monster Tank I just purchased a 36 gallon tank after I had a very bad week with my 5 gallon tank. I had an iridescent shark & 4 goldfish. All the goldfish died one day at a time. The shark barely survived. We had to do an emergency 1/2 water change, change the filter, clean the bio wheel & he still appeared dead. He was literally vertical head up, tail down, I finally got him back with holding him horizontal with the net. A few days later, he is alive & well, although very lonely. I stick tested the water & there were extremely high levels of nitrate (before the water change). Now that I bought the 36 gallon corner unit fish tank I need help deciding what the best filtration system would be. As a kid I had a 20 gallon tank with an UG filter along with a regular filter. That seem to work great, but with such a large tank I'm not sure what would be best. Now they have those canister filters, the filters that hang inside the tank, the UG filters & probably more. We purchased an UG filtration & a Tetra Whisper Power Filter 40. The instructions actually suggest the Tetra Whisper Power Filter 40i which sits inside the tank (better for corner units). So before I start taking these back to the store & purchasing new ones, I was hoping for some good advise. Should I use 2 filters or just a canister filter or just one that sits inside the aquarium? I am hoping to transfer our survivor to the new tank & use the 5 gallon tank for 1 or 2 goldfish for my daughter. I also hope to add another shark & some other fresh water fish to the new tank. Should I also put live plants in the new tank? I have never experienced that either. Please help me have a healthy aquarium. Thank you, Amanda <Amanda, you have a monster in your tank. You need to return the shark. An Iridescent will grow to over four feet! Please see here: http://www.planetcatfish.com/catelog/pangasii/pangasiu/172_f.php Even a single Goldfish is to many for a five gallon. If it has a filter and heater a Betta and a few Corys would work. Without a heater try about 5 White Clouds. Never clean a Bio Wheel. It's function is to grow a bacterial colony that removes ammonia from your water. It takes weeks to recover once lost. I hate UGFs, I wouldn't put it in. If you already did, I suggest you remove it. So, you need to go to the pet store. Take back the shark. No way around that unless you want to flood your basement for him. Pick up a test kit for ammonia, nitrite and nitrate with a new filter. Many fine brands/styles on the market. I like the Marineland Power Filters with the Bio Wheel. Get one that will pump around 225 to 275 gallon per hour. Do not bring home any fish. Get the filter running and the temp around 78. Throw in a small raw shrimp. First ammonia, and later nitrite will spike and crash. When they stay at zero and nitrates are on the rise you are "cycled" and can start to slowly stock your tanks. No water changes needed until there are fish in there. Expect this to take about 6 weeks. Don>  

Black fin FW shark I supposedly have a black fin shark. I have read on a website that it is called a Tetra Catfish. Is this true? < I can only find them listed as Black Finned sharks, but common names are often different in different areas of the country.> I also need a way too sex it. It is fully black except all around its fins is white, and one or two of its whiskers is white. (WHISKERS!) < Your catfish (Pangasius pangasius ) gets huge, around 4 feet long. This fish probably is not sexually mature until it gets at least 2 to 3 feet long.> Also I have a mud turtle, 5 minnows, and this shark all in a twenty gallon tank, but is only filled about five inches high in water for the turtle. I plan to buy more black fin sharks (AKA Tetra Catfish) so I need a way to tell male from female! Thanks in advance! < Nothing is known about their sexing or reproductive behavior in the  <<?>>

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