Gambusia affinis affinis
The male anal fin is modified and is an intermittent organ for introducing sperm into the female. Adult females can produce three or four broods per season, sometimes producing 200 or more young at a time. This fish is easy to breed in aquariums and is not sensitive to temperature changes, but it does not adapt well to living with other fish.
Native to the southeastern United States, mosquitofish have been introduced to suitable warm waters around the world since 1905, when they were experimentally introduced to Hawaii and virtually eradicated mosquitoes. As a result, Gambusia affinis affinis is the most widely distributed freshwater fish on earth (other mosquitofish species have not been as successfully introduced). More recently, it has been bred in many places to control West Nile virus.
Female mosquitofish are about 2 inches long, while males are about half that length.
Life history and Behavior
Food and feeding habits
Also known as the North American topminnow or western mosquitofish, this species is known as the ultimate scourge of mosquito larvae. Although there are other species of fish that feed on the larvae, the mosquitofish tolerates levels of salinity and pollution that would kill most other species and produces up to 1,500 young in a lifetime. Although highly effective at controlling malaria mosquitoes, the mosquitofish is not a panacea. Mosquitofish larvae cannot survive without water (like mosquito larvae), they do not control mosquitoes in areas with abundant surface vegetation that hides mosquito larvae, they can consume young food and commercial species, and they can have negative impacts on native fish species.
|Conservation status||Least Concern|
|Life span, years||3|
|Maximum body weight, kg||No information|
|Maximum length, cm||7|
|Sailing speed, m/s||No information|
|Threat to people||No information|
|Way of eating||Planktonophage|