The red-tailed black sharkminnow (Epalzeorhynchos bicolor) also known as the red-tail shark and red-tailed labeo, is a bottom dwelling species of freshwater fish in the family Cyprinidae (carps and minnows) native to Thailand. Listed on the IUCN red list of threatened species, E. bicolor is critically endangered in the wild and thought extinct until recently confirmed extant in one very local (10 square km) region of the Chao Phraya basin. The threatened status of the red-tailed shark is thought to be due to heavy collection from the wild for the aquarium trade, combined with habitat destruction caused by human development, including building of dams and wet-land draining. Now the aquarium industry exclusively breeds red-tailed black shark in captivity rather than harvesting them, and agricultural and other pollution is cited the main threat to its existence in the wild. The IUCN recommends development of program for reintroducing E. biocolor back to its native environments. Red-tailed sharks remain common in the aquarium trade. They tend to be territorial and aggressive when cohabiting in the same tank, and also chase other less-aggressive fish types, so need enough space that they can maintain a territory.

(Froese and Pauly 2011; Vidthayanon 2011; Wikipedia 2011)