Knife Fish

Knife Fish (Knifefish)
Knife fish have a long, tapered body that is laterally compressed. They have a continuously moving fin on their underside. This fin allows them to move backwards. They move in a smooth, rippling motion. Their motion makes them fascinating to watch. Knife fish come in two groups and approximately 150 species.

They prefer a tank with hiding places. They can be shy and prefer to ignore light. Most are nocturnal and become more active at night. They are usually peaceful but can be aggressive eaters or territorial.