I am new to iridescent sharks. I have a 20g tank and just got 2 about 3in long. One is fine, it swims around a lot, normally towards the top, and is getting used to me mulling around so it is not too scarred. The other one has been laying on the bottom and does not move at all. Is there something wrong with the water? Should I do something? Or is this totally normal for one to be energetic and one to be dull and sleeping on the bottom all the time.

Thanks
Matt

you are joking right???

id sharks, a google search says, can grow up to more than 1 meter, and are schooling fish needing to be kept in 5's or more. humm 20gallons for 2???

Dont worry man, they wont grow more than about 12-18 (after a looong time)inches, im not worried about that. I just wanna know if my fish is ok, since it hasnt really moved from the bottom. I know they get scared and lay on the bottom or hide, but he doesnt move really at all.

Probably not enough room for him and he feels stressed not having the needed number to school with..

I am not sure if you cycled at all or what not. If not, it could be they are getting poisoned form the water.

If not it could be getting stressed from not having enough room. Or not enough hiding places. Also they tend to turn into nocturnal animals. So maybe it is sleeping.

Besides all this. These sharks will get to 3-4 feet normally, probally within 2-3 years I would think, so though you think you have enough space now, it can easily get to 6-8 inches pretty quickly, and soon you will not have enough room. I have not seen any of these not get larger than at least a foot before they had to get rid of them.

Some fishermen disagree with you on their final size:

http://www.fishforums.net/content/New-to-the-hobby/11418/http-www-fishforums-net-index-php-showtopic-11418/

kinda makes me point. and it could all have been avoided by a google search. 20 seconds!

id sharks aka pangasius (sp?) have a few different species, but the ones you find in the shop can easily push 2ft long.
they need a super long tank because they're so skittish, about 7ft long or more is best! i've seen one of these in a 5ft tank (temporarily) that was 1ft long, it would crash into the sides and panic if you looked at it..

it sounds like your tank isn't cycled properly, what are your water parameters?

Its a 7 month tank, 0.5 ammonia and pH of 7.3. temp 79F. Ive read that they grow according to their tank, and if the tank is small, they are small. correct?

sounds like hes being poisoned you shouldn't have ammonia in the water. yes he will grow to the tank size kind of, he will suffer major problems internaly tho due to his growth being stunted. dont want to sound mean either get a bigger tank to re-home or take back to the LFS its pretty crule on the fish

This post has been edited by beesnees: Jan 25 2007, 04:59 PM

Yeah- 20g tank, 30" (I think) long, 30" long pangasius. 'Snug' is the right word, methinks.

c'mon man you cant really believe that, can you? you may well stunt the growth of the fish, but it will not stop growing. if that worked you could catch a baby great white and keep it in a 2 foot tank and it would never grow!!! sounds silly when you say it like that! but that's what you are saying.

also, the tip of his nose is white, is it from bumping into the glass? will he get sick?

Your best bet is to take them back to the store, and let your tank cycle longer. After you've cycled you can put some smaller fish in your tank. If you really love these fish though, take your current ones back and buy a much bigger tank. Cycle it, then you'll be ready to keep this type of fish.

It's an old wives tale that they grow to the size of their tank.

They grow very big very quickly.

They also play dead when scared which may be the reason why one of yours is acting strange.

...

pangasius sutchi is the most common one sold in pet stores apparently. though in new zealand, there is only 3 left in the country that we know off. i just bought two of them

its been aroudn in the country for years and years! the big one is 80 cms long, the other is about 50 cms long.
they eat lots, they need s*it loads of filtration.
i mean twice to three times recommendd on filters.
you should return your fish, and stick to smaller cichlids in that 20 g of yours. sorry to say, that monsters cant be kept in cages like that, they will die.

pangasius sutchi may grow to 10 metre max in captivity, its unusual to hear of them growing larger, fish do not grow to the tank size, thats a myth, fish will keep growing untill they have no room and they will kill themselves.

i have seen arowanas in small tanks, and alive, but they dont look happy, with destroyed fins and really bad colour.
imagine if someone kept you in a cage where you cant even turn around, you just standing there, its the same.

i am planning on keeping a 50to60cm pangasius sutchi in a 8foot tank.
here is one rule someone told me once, its worked for me so far.

the depth of your tank, front to back, should be 25% to 30% longer than the total fish length, so they will be comfortable, any less could be ok, depending on the fish. but when they reach close to that length, think of upgrading.
your small sutchi catfish will get to 5 inches in a year or less.
when they reach 15 inches or so, the growth is slowed somewhat. in a large aquarium, 1200litres minimum i think to keep one. there are multiple spiecies of pangasius, most are not sold in pet shops......

You can get dwarf versions of this shark (idk how many times ive said that on this forum and am ignored), idk if its only in NA or what, but they are available, and those ones do grow to a max size of 12-18 inches.. personal experience here idc what a website sais.

With that said, your tank is still too small and fish dont grow to the size of their tank like people believe, they will be stopped from growing to their max compacity and die at a much earlier age. go with a 50 gallon MINIMUM id recommend.

As for your problems with them, listen to the otehrs cuz i have no clue.

Murph

This post has been edited by murphyk32: Apr 1 2008, 10:16 AM

Speaking from experience with these fish, keeping two stunted 12 and 14 1/2" inch ones in a 40gal, they will definetely NOT grow to the size of the tank.One of them, the larger one, was about 5-10 years old when I got it. It was kept in a 30gal, with silver dollars, 2 different 10-12inch catfish and others, the tank was seriously neglected.They were underfed and overcrowded, along with this the tank maybe got a water change every month at max, so as you can imagine it would grow and die right?
No, it reached 14 1/2 inches in length and in doing so it got veryyy 'stunted'.
My point is if you actually care for these fish properly, they will grow huge.

*feels ignored**

yes if u take care of the normal id sharks they will grow massive,, BUT he is stating that they only grow to 12-14 inches, and my point jsut made and ignored above is that he may very well be right Because a dwarf id shark is available... that dwarf id shark is known for growing 12 inches, not the 2-3 feet.

The matter of size can be solved by people letting off a bit cuz that wasnt really his problem and him just going to the place he bought them and asking if they are dwarf or what....

really simple.

Murph