S.A. Blackfin Shark Regular Arius seemani Also known as the Shark Catfish, these are very beautiful fish to be kept in a brackish tank. Keep plenty of room for these fish, and keep the groups with at least 4. You can tell what kind of a Shark Catfish looks like, because they have beautiful silver bodies, and a white belly. Their fins are tipped with black/white, depending on the breed. *BE CAREFUL* They have venomous dorsal spines, so be careful when handling! Keep their diet at twice a day. They are carnivorous, and prefer chunky food. That being said, they won't bother fish that are bigger than it, but may pick on smaller ones.