Gambusia affinis 2009-06-09T01:27:54Z IDOMAL:0001276 IDOMAL:0001276 The mosquitofish (Gambusia affinis) is a species of freshwater fish, also commonly known simply by its generic name, gambusia, although such usage is ambiguous. It is sometimes called the western mosquitofish, to distinguish it from the eastern mosquitofish (G. holbrooki). It is a member of the family Poeciliidae of order Cyprinodontiformes. The genus name 'gambusia' is derived from the Cuban Spanish term 'gambusino', meaning useless. idomal_namespace louis larvivorous fish larvivorous fish