Ctenocheirodon pristis is a species of characin native to South America that can grow up to 3.4 cm long (only 3.3 for males).[1] It is the only known member of its genus.[2] Its specific name comes from the Greek word pristis, which means saw. This refers to the projected fins on the underside of the fish.
C. pristis is a freshwater fish and it lives in the drainage basin of the Rio Tocantins in South America. It lives in areas of slow-moving water over river bottoms with little vegetation. As a result of the location, C. pristis lives exclusively in tropical areas.