The red-tailed black shark (Epalzeorhynchos bicolor; syn. Labeo bicolor), also known as the redtail shark and redtail sharkminnow, is a species of freshwater fish in the carp family, Cyprinidae. It is endemic to Thailand and currently critically endangered, but common in aquaria, where it is prized for its deep black body and vivid red or orange tail. The red-tailed black sharks seen in the aquarium trade today are all captive bred. It is not closely related to sharks.