Mosquito Fish

(Gambusia affinis holbrooki), a fish of the family Poecilidae, order of cyprodonts. In the male the front spines of the anal fin have become a copulatory organ, the gonopodium. Length of the male, up to 4 cm; weight, up to 0.4 gm. Length of the female, up to 7 cm; weight, up to 3.5 gm.

The mosquito fish is viviparous; there may be up to six broods annually at one month intervals. The number of young per brood ranges from 15 to over 100; their body length is 7-8 mm. Sexual maturity is reached at one month. The mosquito fish lives in small bodies of stagnant water and feeds on the larvae and nymphs of mosquitoes, small water animals, roe, and even its own offspring. Its natural habitat is North America.

The mosquito fish was introduced into the USSR in 1925 by the physician N. P. Rukhadze. After successful acclimatization, it was used extensively and with great success in the battle against malaria in the 1930’s and 1940’s in the Central Asian Republics, the southern RSFSR, and the Ukraine. The mosquito fish can cause damage in fishing grounds.