20, see text Nomorhamphus is a southeast Asian genus of viviparous halfbeaks from streams, rivers and lakes in Sulawesi (Indonesia) and the Philippines.

They are all viviparous, producing small clutches of around a dozen fry about 10 to 15 mm (0.39 to 0.59 in) long at birth.

Males are also more brightly coloured than the females (often having red, black, or blue patches on their fins).

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 a gonopodium that delivers sperm into the female.