what fish are similar to the columbian shark catfish that don't need brackish waters?

[Stanley Z]

I'm looking for a fish that looks at least a little bit similar to the columbian shark catfish and gets just as big but doesn't need brackish water or any salt.

[mickey p]

I like pictus catfish, they only get about 6 in and they look more like regular catfish but they still look really cool I think.