Shark fish January 3, 2023 by Jason Roberts All of the “shark fish” in the freshwater aquarium trade are from one of two groups: active Cyprinids (Carp and Minnows) and predatory Catfish. None of them are true sharks, which are saltwater fish. It’s easy to see why they are called fish tank sharks, though. All are active bottom to midwater swimming fish with pointed dorsal fins and forked tails. Each freshwater shark is easy to keep. Most are common fish in their home regions. And all will breed in captivity when given lots of space. Every fish store in the country will carry at least one of these Sharks and possibly several. But every single one of these Sharks (except for the Roseline Torpedo Shark) is a terrible choice for a beginner aquarist with a small tank.