Black fin shark catfish

[ger87410]

They will swim along the glass upwards fromt he bottom of the tank facing the top, swim a few inches, turn sideways and what looks like hit their belly against the glass. I've had them for almost a month now and they've always done this. Anyone know what's going on?

 

[Clare]

I assume by your post that you are referring to Columbian sharks, Aerius seemanni (not sure how to spell that). As they get bigger they need brackish water. They start to act strange when they turn from being fine in freshwater, to needing this salt. Ours are in a 7ft tank yet remain together in a corner swimming around using less than half the tank!! Best kept in groups of 4 or more.
Good luck.

Oh, we feed ours very finely chopped prawn cockle and mussel which they love!!!

 

[Vip]

Or is it a Salmontail catfish?

 

[ger87410]

The exact name of the fish is "black fin shark catfish". The only other thing it's known as is a columbian shark. I'll try increasing the sg.