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 calle the western mosquitofish, to distinguish it from the eastern mosquitofish (G. holbrooki). In Hong Kong, it is also known as the live-bearing tooth-carp. It is a member of the family Poeciliidae of order Cyprinodontiformes.