Shark Catfish... beh., fdg.   
Hello,
<Ave!>
I just bought two shark catfish, they are completely silvery with lots of black spots.
<Sounds like these are in fact the Pictus Catfish -- Pimelodus pictus -- a South American freshwater catfish. Check the pictures here:
http://www.planetcatfish.com/catelog/species.php?species_id=276
The usual "Shark Catfish" of the hobby is Sciades seemanni, an estuarine species.>
I put them in my tank and fed them some bloodworms, about half a cube. Then when I came to look at the tank I noticed that both of them had large stomachs, it seemed like it was bulging out. Is this normal?
<Sounds like they just ate a lot. So long as the bulge goes away in a couple of hours, don't worry about it.>
I have read so many articles on bladder problems in fishes that I am getting worried in case something like that has happened to them. The lady in the LFS did say they eat bloodworms, so I that's why I fed it to them. What have I done wrong?
<Likely nothing wrong.>
Also, could you please tell me how to care for them properly, as I am not too sure if I have got my facts right.
<Do read here:
http://www.wetwebmedia.com/FWSubWebIndex/pimelodids.htm
Basically easy to keep, but hyperactive and predatory, as well as fairly big, so bear that in mind.>
I bought some bloodworms, tropical flakes (tetra) and some catfish pellets (tetra) and some other protein pellets as well which are JMC I think. In a plastic container, transparent with an orange top.
<All sounds fine. They eat pretty much anything (including small tankmates!).>
Thanks a lot for any help you could give me.
Neervana.
<Cheers, Neale.>

Re: Columbian Cat Shark  - 6/3/08
Thanks Neale,
They look completely stunning in a Reef Aquarium, no one believes me when I tell then they are not actually real sharks and will not grow 6ft. The way they move and cruse the aquarium mid level and explore the caves makes them look remarkably like Reef Sharks.
<Have seen them thus, and yes, the likeness is amazingly close, right down to the way they swim. One ichthyology text book I have begins the chapter on catfish by saying simply "Catfish do everything". Bold stuff from a scientist, but really very true. An amazing group of fish, and the more species you keep, the more impressed you become with their adaptability.>
Theirs colours have changed from washed out silver to dark metallic steel grey, with a brownish dorsal fin, the rest of the fins are black with white tips. They have great appetites and are growing by the day.
<Juveniles grow very rapidly. They level off around about 15-20 cm, and only very infrequently do aquarium specimens reach their maximum size in the wild of 35 cm. Some experienced aquarists have opined that there may be more than one species in the trade offered under the Colombian Shark Catfish moniker, and hence the variability in maximum size.>
I have a very strong current in the tank from 4 power heads and they love the current. Not seen them sit on the tank bottom once... but then they even sleep on the wing...whoops...fin! Never stop!
<Indeed so! They are migratory in the wild, moving up and down estuaries all the time.>
Feeding them enough to maintain there activity level will be the challenge in a Reef tank without upsetting the water quality !
<Adults do need rather less food per unit body mass than the juveniles; it's generally recommended that big catfish be fed only every other day. I tend to prefer to simply offer small daily meals, ideally things that are high in fibre (like unshelled crustaceans) so that the fish feel full without too much protein (i.e., nitrogen) getting into the system.>
Thanks again.
<Cheers, Neale.>

Re: Shark Catfish 1/23/08
Hi Neale,
<Neervana,>
Thanks so much for your quick reply, was getting a bit panicky! So if they are swimming around really fast it doesn't matter?
<Depends how you define "does it matter". Obviously these are active, river fish that need lots of space. In a small tank they will never do well, and will likely jump out or simply become nervous or sluggish. For Pimelodus pictus, the tank should be at least 1 m long from side to side, and should also have lots of water current, so the fish can enjoy swimming into the stream.>
I forgot to mention that, they are going crazy, they are swimming REALLY fast and going crazy in the tank.
<Typical for the species.>
Do I need to add some stress zyme to calm them down a bit?
<No. [a] That isn't what StressZyme does and [b] you can't calm them down -- they are river catfish and WANT to swim about.>
Also if I have fed them bloodworms today, should I feel them those pellets tomorrow?
<Always a good idea to rotate food items. You wouldn't eat the same thing every single day, would you? Mixing things up ensures the fish don't get bored and get a nice balance of nutrients.>
Thanks, Neervana.
<Cheers, Neale.>

Advice please. Re: Shark catfish, beh.  - 1/24/08
Hi Neale, (or if it's someone else)
<It is indeed me.>
I just wanted to say that my two shark catfish are doing very well now, they have calmed down a lot and are swimming peacefully but are trying to hide in a place where they can't be seen! The bulges in their stomachs have now disappeared (due to feeding them bloodworms yesterday) and I'm going to feed them tonight with a Tetra pellet each. I will take your advice on feeding them sparingly, with food each day other than big meals.
<Cool.>
When do you think I should do a water change?
<Same as ever: once a week, 25-50%.>
Because I just got them yesterday and I bought a tank for them so they could be alone, I don't know when I should change the water. I'm going to try and buy a vacuum gravel tomorrow with a water tester. The tank is fully cycled, but because they are new fish I don't know when I should start doing water changes. I know it should be once a week, but if I change it this Sunday is that too soon? They are very active and seem to be very healthy, breathing normally, have bright and have not lost any colour at all. They aren't stressed but sometimes they start swimming around crazily (which I take is normal from your previous answer to my email).
<Don't worry about it. They're riverine fish, and swimming rapidly is what they do. Sometimes people turn the lights off just before doing water changes, so that the fish calm down a bit. Worth a shot I suppose, but since they're catfish I doubt they care whether the lights are on or not. Just don't chase the fish about with the hose pipe! Be gentle, and pour the new water in gently too.>
Would appreciate it if you could advise me when to make the first water change. Is there anything else I should be doing?
<Sounds like you have everything covered. Good luck!>
Thanks, Neervana.
<Cheers, Neale.>

Arius seemanni, strange behavior   4/2/07
Hello,
I have two Arius seemanni in a 120-gallon tank. They are about 5 inches. Before they where very active, swimming constantly around using the whole aquarium. Now they stay in the bottom of the one end corner most of the time. Especially the leader seems sick (or not him/her self), swimming in small circles up and down, some times fast and some times slow, or just stay at the same place with its tail towards the ground and the head towards the glass and almost laying on the side.
<Listlessness in shark catfish, Hexanematichthys seemanni, is not uncommon. The main problem is that these are migratory fish: they spend all but the first few months of their lives constantly swimming up and down estuaries between freshwater and the sea. They don't stay in any one set of conditions for very long. They are also intensely sociable, and when kept singly or in pairs tend to be far less settled than when in groups of three or more. Since they are totally non-aggressive towards their own species, it is even possible to add juveniles to a tank containing adults -- they will all happily swim together!>
If I turn off the circulation pump and the light, this seems to help a little bit getting it to move a bit more around. They have no problems moving around when eating - I feed them more or less every day with bloodworms.
<Provided they are eating, their health is probably sound, so I'd diagnose a psychological rather than a physiological problem here.>
Some history: About one and half month ago I got problems with nitrite. It took me until a week ago to get the problem fixed. The strange behavior began about fourteen days ago. In the process of getting the nitrite right again, I slowly cut down salt to zero. When nitrite became all right again, I raised the salt in four days from 0 to 9 PPT (0.09 %). But the situation is still the same.
<Why did you reduce the salinity when the nitrites went bad? Regardless of the situation, you need to adapt the filter to the salinity you want to keep the tank at. For shark catfish, around SG 1.010 is ideal, though they do well in seawater too.> By my reckoning, a salinity of 9 ppt is about SG 1.005, ~25% seawater -- far too low for long term care of shark catfish. When kept in low or zero salinity conditions, shark catfish seem to develop a very strong "migration" instinct, a desire to find different conditions closer to those that they'd inhabit in the wild.>
Do you know what’s wrong with them?
<Likely the group is too small and the salinity too low.>
Will they ever get back to normal?
<As things stand now, no, probably not.>
Can I do anything to help them?
<Yes, buy at least one more catfish for the group, and then raise the SG to around 1.010.>
Nitrite is all most zero, Nitrate is about 75, pH is about 8.3, total hardness is about 21 and carbonate hardness is about 8.
<All fine for these catfish. They are very, very adaptable physiologically, but in terms of what conditions they "feel" happy in, they are picky. They are superb animals, in my opinion the most shark-like of all the "sharks" sold in the aquarium trade (except of course actual sharks!). But they aren't always the easiest fish to keep.>
Best regards, Glenn
<No problems. Neale>

Columbian Shark help!!   3/14/07
Hi guys:
<<Hey, Andy. Tom with you this time.>>
I have some issues with Columbian Sharks I need assistance with.  I've had 2 of these guys in a 20gal freshwater tank for about 2 months (I bought them when they were juveniles).  I just transferred them over to a 55gal tank that I'm slowly transitioning into brackish water as I know these guys need it.  
<<Andy, you must be one of the people that actually read. Very refreshing! :) >>
However, ever since I put them in the 55gal tank, they literally just swim facing directly up in the front left corner of the tank.  They do this together (right next to each other) and RARELY leave this spot.  
<<Acclimation here, Andy. New surroundings, etc. How tall is the 55-gallon as compared to the 20-gallon? You might not think it but deeper water affects some fish more than others. Most of these would fall into the “labyrinth” category where getting to the surface is critical to their survival but “low-runners” like your Columbians might be wondering what the heck is going on.>>
I feed them bloodworms, flakes, krill, brine shrimp, etc. but they ignore all food it seems.  It is very strange because they were acting COMPLETELY normal with huge appetites in the 20gal tank before I moved them.  They also used to stay on the bottom, never the top corner like this.  Any idea what this is?  
<<My guess would be that that they aren’t at all “fazed” by the additional swimming room, just the additional depth. Try dropping the water level in the tank. Give them the depth that they were accustomed to in the 20-gallon tank. Going to take some patience and calculating on your part where converting to brackish is involved but you can do it.>>
I'm worried about them and want to prevent stress/illnesses in them so any advice would be appreciated!!
<<These guys aren’t “deep-water” fish, per se, Andy. Of course, in the wild the depths are greater than in our aquariums but you need to think in terms of “longitude” rather than “latitude” in your tank. Look at how your fish are “built”. They can adjust, with time, to a “full” tank but you might be hurrying them along a little too soon. Lower the water level and see whether, or not, this gets them acting more normally.>>
Thanks again,
Andy <Mmm, are social animals... likely are "schooling" with their reflection. I would try temporarily (for a few weeks) taping a piece of newspaper or such over the pane they're stuck at. RMF>

Re: Columbian Shark help!! (follow-up question)  3/16/2007
<<Hi, again, Andy.>>
Great idea, thank you for your assistance!  I did as you suggested last night and it already appears to be helping. They ate last night for the first time in 3 days!!  
<<Glad to hear it, Andy.>>
One more question for you.  In this tank (55gal in the process of being transferred to brackish), there are also 2 spotted puffers, 2 Dalmatian mollies, and one ropefish (Yes, they all get along!).  
<<Still a good idea to keep a watchful eye here.>>
The sharks, mollies, and puffers gobble EVERYTHING I put in there for food rather quickly.  I'm afraid the ropefish won't be able to get any food and will eventually starve as he doesn't seem to come out at all during feeding (I know he's nocturnal).  My question is this: Is there any foods that are specific to ropefish or anything I can put on the bottom that he'll find when he comes out at night?
<<Unfortunately, Andy, the Columbians are going to be every bit as interested in whatever foods you select as your Ropefish would be so, it might be more a matter of “when” than “what”. Live foods are preferred by both but I would offer that you should stay away from small feeder fish of any description with your current stocking arrangement. (We almost universally advise against this anyway from a nutritional standpoint, however, it can/will “trigger” predatory responses in both of these fish that the other fish, particularly the Mollies, don’t need awakened.) You might try a food like sinking shrimp pellets later in the evening. These make it to the bottom rather quickly and might not get “picked off” on the way down by the others. The Sharks, as you know, are scavengers but changing up feeding times may give the Ropefish a chance to feed while the others are less active.>>
Thank you again for your assistance, I love this website and you guys are a HUGE help!
Andy
<<Thanks, Andy. We certainly appreciate that. If I may, while you’ve just recently “upgraded” your tank, you’ll need to keep in mind that your Columbians will need even more room down the road. These guys grow very large and the typical recommendation is about 50 gallons per fish. I suspect you are already aware of this but I like to point this out when the opportunity presents itself for our other readers. Keep up the good work and good luck with your new tank. Tom>>

Arius seemanni dis./injury, beh.   8/1/06
Hey Guys,
   I think your web site is great and I have learned a lot from you guys. Anyway I have a Arius seemanni he is about 6.5in and mostly just swims around the top of my tank.
<Is a social species... should be kept in a small grouping>
The other day he jumped out I was luckily there and put him back into the tank, he immediately started swimming like nothing happened. I did notice that his eyes where kind of foggy and he seemed to bump into stuff more often.
<Likely "rubbed" its eyes... damaging them>
But as of today 6/28 his eyes look good and I was told he had an infection.  What do you think?
<I would do nothing in the way of chemical additions here... Likely will self-cure...>
Also he is in full saltwater and all the water parameters are perfect.  He has no other catfish friends and I was wondering if he would be happy and school with coral catfish?
<Mmm, no... Birds/catfishes of a feather/fin flock/school together... Better to have others of the same species... even if they start off considerably smaller in size>
If so how many should I get?
thank you for your and knowledge
Joe
<Bob Fenner>

Lonely Schooling Columbian Shark  7/28/06
Hey Guys,
<Hi Joe, Pufferpunk here>
I think your web site is great and I have learned a lot from you guys.
<Glad to hear it!>
Anyway I have a Arius seemanni he is about 6.5in and mostly just swims around the top of my tank. The other day he jumped out I was luckily there and put him back into the tank, he immediately started swimming like nothing happened.
<I hope you add a nice, sturdy cover to that tank after that!>
I did notice that his eyes where kind of foggy and he seemed to bump into stuff more often.  But as of today 6/28 his eyes look good and I was told he had an infection.  What do you think?
<Whatever it was, seems to be gone now.>
Also he is in full saltwater and all the water parameters are perfect.  He has no other catfish friends and I was wondering if he would be happy and school with coral catfish? If so how many should I get?
<Since this is a schooling species, he would definitely like some friends like himself.  The fact that they can reach sizes of around 18" though, means a HUGE tank in their future, for a school of 5-6.  ~PP>
Thank you for your and knowledge, Joe

Columbian Catfish & Brackish Water  6/25/06
Hello!
<Hi Lou, Pufferpunk here>
I have a few questions for you!  First--a little  history.  We set up a 10 gallon community tank for our 7 year old last  fall.  All was well--he does a great job testing the water and caring for  his fish.  
<Good for him, at 7!  I bet he had a little help...>
Anyway, Christmas Eve, my sister-in-law bought him two silver-tipped sharks and an algae eater. (Even after I told her that his  tank was at capacity and a PEACEFUL tank.)  
<Bad, bad, bad idea to ever give pets as gifts!  I hope she was well scolded!>
She gave them to him at 9 pm  Christmas Eve, so we had no choice but to put them in the 10 gallon tank.  They did very well but got fairly large.  
<No surprise there--they can get to 18" if housed properly.>
All three are at least 6 inches  long.  
<Ummm... do you have 2 or 3?>
We started to have water trouble and one of our zebra danios mysteriously, completely disappeared.  
<Gulp!  Large water changes are in order for these fish, with voracious appetites & lots of waste in return.>
We moved the sharks and algae eater into a 55 gallon 3 weeks ago.  (We do keep the water brackish for  them).  
<The other fish you have will not appreciate any salt.  As far as "brackish" what do you mean?  Even for very low-end BW (a specific gravity of 1.005), it would require roughly around a cup of marine salt/5gallons.  At the size your Columbian sharks are now, they should be around mid-range BW, 1.010 (you'll need a hydrometer to measure SG).  They will require marine conditions as adults (at least 1.020).  They are also schooling fish.  So for a school of 18" fish, you're going to need a really HUGE tank!  (Time to go back to the sis-in-law for more scolding!)>
My first questions are about the sharks.  They have always swam together.  Now that they're in the bigger tank, we can see them  better.  They swim almost vertical and push their whiskers out of the water near the filter.  Is this normal?  
<Is there enough current or air-flow in there?  Check the water parameters (ammonia, nitrIte, nitrAte, pH)>
They are very skittish and when startled, shoot back and forth across the tank at lightening speed.  
<They might need more decor to feel safe.  Even some floating plastic plants might help (live plants don't do well in BW)>
They  appear healthy and are growing like crazy but seeing their bellies constantly seems strange.  I thought they were bottom feeders?  
<Generally anything with whiskers are.>
Today they are actually swimming separate more, which is shocking and not constantly at the  top but still going up the sides.  Also, could they mate?  What would  we look for?  (Just baby sharks?)
<Possibly but not in those conditions & tank size.  They will probably stunt in there.>
We also have 3 tiger barbs and a gourami in the 55 gallon tank.
<Opps!  Not BW fish.>
The  barbs seem to nip each other and chase around in circles a lot.  Is this  normal?  Are they being "playful" or trying to harm each other?  It  seems like the same two going at it while the third darts in and out between  them.
<Typical barb behaviour.>
In a couple weeks, we were going to add another gourami.  
<Not a BW fish.>
Any other  suggestions?  We'd like a colorful tank but don't want to load up on any  more fish that will get so big!  What about a Bala?
<Balas grow huge and again are not BW fish.  I think you should stick with these 2 (or 3?) & start saving for a larger tank & bags of salt.  They are fast-moving, active fish that may be disturbing to peaceful fish.  Do more research on BW fish.  ~PP>
Thank you very much for your help!!
Lou