Black Shark Medium Labeo chrysophekadion These are very popular freshwater fish. They have other names involving the terms black sharkminnow or black labeo. Black sharks are bottom feeders and aquarium surface cleaners. Their colors are a brown and black. Their diet consists of algae, in either tablet or flake form. But, being bottom feeders they can pick up the leftover food. They have been known to be territorial, and violent behavior may occur if they are kept with their own species or relatives (It is best if they aren't kept with their relatives.) Very compatible with barbs, because they will stay more towards the top of the tank. Danios and plecos are also stable fish to cohabitate with. Make sure to keep plenty of hiding spaces in the tank, and also allow ample swimming room. The max length of these Black Sharks is usually 80 cm for both male and female..