Mosquito-fish (Gambusia affinis) are small, guppy-like fish, which are expansively used in modern mosquito control programs. They feed primarily on aquatic insects and prefer mosquito larvae. Gambusia are able to mature, reproduce and survive quite well in a variety of water conditions, which makes them perfect to stock in permanent mosquito breeding sources. They are capable to tolerate moderately high levels of salts, algae, pollutants, and a temperature range from nearly freezing to above 100°F. Mosquito-fish are compatible with most ornamental pond fish, including Goldfish, Koi and Carp. This makes them an excellent addition to any fish pond with shallow areas and vegetation, that the bigger fish cannot penetrate to eat the mosquito larvae.

 Female mosquito-fish produce eggs that hatch within their bodies, releasing 30 to 100 well developed young, called "fry" into the water. Young mosquito-fish are about one-half inch in length when born and immediately begin eating mosquito larvae. They grow rapidly in the summer and reach a maximum size of 1-11/2 inches in males and 21/2 -3 inches in female. Gambusia breed throughout the summer and a new brood is produced at intervals of 4-6 weeks. The young fish reach maturity in about 4-5 months.

 The Antelope Valley Mosquito & Vector Control District stocks thousands of these fish each year in artificial ponds, reservoirs, retention/detention basins, wastewater lagoons, natural creeks, and drainage channels to eliminate the need for frequent treatments with mosquito larvicides. Residents of the District can get mosquito-fish at no cost for stocking their ornamental ponds, animal watering troughs, and unused swimming pools. Please call ahead to make sure there are enough fish available.