Shark cat acting a bit odd

[Paulcdr]

Hi

I'm new to the forum, so hello to everyone first of all. my name is Paul from northern Ireland.

i have a 4 foot tank with about 15 fish running for about 3 years now. i recently added a pair of shark cats. I have had one in the tank for about 18 months and is about 6-7 inches in size. I am having an issue with one of the new one's. it is only about 3 inches long, but he just floats vertically at the top of the water. he flows around the tank with the water movements. he only really moves him self when he gets to an obstacal or is hungry. the water quality is fine and I run an external filter which is cleaned once a week. The one I got him with is doing just fine.

Any info that anyone has on this will be grateful.

Cheers
Paul

[Poofaye C.]

Had my silver cat shark for about 5-6 years. It happened every time I introduce a new fish buddy. As vicious an eater they are, they're supprisingly timid towards other fish they can't eat!! My opinion, he's stressed! Try to find out what could be causing it, besides him being new. Hate to say it, could be a little crowded in there.

[teach]

what other fish do you have in there.