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 species are also found elsewhere in eastern and southern United States,
The Bahamas, Central America, and
Colombia.
Gambusia species are often called topminnows or simply gambusias; they are also known as mosquitofish, which, however, refers more specifically to two species,
G. affinis and
G. holbrooki. These can be introduced into ponds to eat
mosquito larvae. As a consequence, they have been introduced widely outside their native range, and sometimes become
invasive, threatening the local species. They are very important in aquarium trade, desired for small size, ease of breeding, and charming gracefulness. They are viviparous—they have
live young.
