They are widely distributed in fresh and brackish water in South and Southeast Asia, ranging from India to the Philippines and Greater Sundas.

They are all viviparous, producing small clutches of up to 30 fry that closely resemble the adults, except they are much smaller, around 1–1.5 cm (0.4–0.6 in) in length.

They are important predators on insects such as mosquitoes, so play a role in controlling malaria.

The male is equipped with a gonopodium-like anal fin known as an andropodium that delivers sperm into the female.

About ten embryos are developed at any one time, but at birth, these are fairly large (around 1 cm or 0.4 in) compared with other fish of this size.