Mosquitofish are small in comparison to many other freshwater fish, with females reaching an overall length of 7 cm (2.8 in) and males at a length of 4 cm (1.6 in). 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 eats zooplankton, beetles, mayflies, caddisflies, mites, and other invertebrates. Mosquitofish were introduced directly into ecosystems in many parts of the world as a biocontrol to lower mosquito populations.