Gambusia is a large genus of fish in family Poeciliidae (order Cyprinodontiformes). Gambusia contains over 40 species, most of which are principally found in freshwater habitats, though some species may also be found in brackish or saltwater habitats. The type species is the Cuban gambusia, G. punctata. The greatest species richness is in Mexico, Texas and the Greater Antilles, but there are also species elsewhere in eastern and southern United States, The Bahamas, Central America and...