What is "mosquitofish"

mosquitofish \mosquitofish\ n. A silvery topminnow ( Gambusia affinis) with rows of black spots of tropical North America and West Indies; important in mosquito control.

Syn: Gambusia affinis.

n. Any of several small fish that feed on mosquitoes, but especially those of the genus (taxlink Gambusia genus noshow=1).

n. silvery topminnow with rows of black spots of tropical North America and West Indies; important in mosquito control [syn: Gambusia affinis]

The western mosquitofish (Gambusia affinis) is a species of freshwater fish, also known commonly, if ambiguously, as simply mosquitofish or by its generic name, Gambusia, or by the common name gambezi. There is also an eastern mosquitofish (G. holbrooki).

Mosquitofish are small in comparison to many other freshwater fish, with females reaching an overall length of and males at a length of . The female can be distinguished from the male by her larger size and a gravid spot at the posterior of her abdomen. The name "mosquitofish" was given because the diet of this fish sometimes consists of large numbers of mosquito larvae, relative to body size. Gambusia typically eat zooplankton, beetles, mayflies, caddisflies, mites, and other invertebrates; mosquito larvae make up only a small portion of their diet.

Mosquitofish were introduced directly into ecosystems in many parts of the world as a biocontrol to lower mosquito populations which in turn negatively affected many other species in each distinct bioregion. Mosquitofish in Australia are classified as a noxious pest and may have exacerbated the mosquito problem in many areas by outcompeting native invertebrate predators of mosquito larvae. Several counties in California distribute mosquitofish at no charge to residents with manmade fish ponds and pools as part of their mosquito abatement programs. The fish are made available to residents only and are intended to be used solely on their own property, not introduced into natural habitat. On 24 February 2014, Chennai Corporation in India introduced western mosquitofish in 660 ponds to control the mosquito population in freshwater bodies.

Fertilization is internal; the male secretes milt into the genital aperture of the female through his gonopodium. Within 16 to 28 days after mating, the female gives birth to about 60 young. The males reach sexual maturity within 43 to 62 days. The females, if born early in the reproductive season, reach sexual maturity within 21 to 28 days; females born later in the season reach sexual maturity in six to seven months.