The Black Pacu (Colossoma macropomum) is a large species of freshwater fish in the family Serrasalmidae. The Black Pacu is the heaviest characin in the Americas (the lighter Salminus can grow longer) and the second heaviest scaled freshwater fish in South America (after the arapaima) It is similar in shape to the piranha and juveniles are sometimes confused with the carnivorous fish; the Black Pacu is tall and laterally compressed with large eyes and a slightly arched back.
