Pupfish are a group of small killifish belonging to ten genera of the family Cyprinodontidae of ray-finned fish. Pupfish are especially noted for being found in extreme and isolated situations. They are primarily found in North America, South America, and the Caribbean region, but Aphanius are from southwestern Asia, northern Africa and southern Europe. As of August 2006 there were 120 known nominal species, and 9 subspecies.