Tilapia, genus of tropical fishes, belonging to the cichlid family. The genus is thought to have existed for about 24 million years. There are 14 species of tilapias, all native to tropical fresh waters of Africa, but some commercially important species have been introduced and cultivated in Israel and in several Asian countries, including Indonesia, Malaysia, Thailand, and the Philippines. Several species are popular aquarium fishes because of their interesting behavior and attractive coloration. The larger species are important as a source of food and are cultivated extensively. Fresh and smoked tilapia are now readily available all over the world.

Tilapias have laterally flattened bodies that range from about 10 to 30 cm (about 4 to 12 in) in length. They feed on a wide variety of food, including insect larvae, crustaceans, juvenile fish, worms, various plants, and detritus. Some species can survive in waters with oxygen concentrations as low as 0.1 parts per million, and one species inhabits hot springs with water temperatures as high as 40° C (104° F). However, most species of tilapia are not so tolerant.

Before spawning, male tilapias engage in elaborate courtship displays involving an intensification of their vivid coloration as well as various fin and body movements. Most tilapias are highly territorial and engage in intense aggressive behavior toward males of the same species and toward members of other species. All species of tilapia care for their offspring. Some build nests, in which they deposit their eggs. They guard these nests vigorously, chasing away any intruders. Others collect their young in their mouths and brood their offspring orally. One or both parents may engage in mouth brooding. The young are released at intervals but are gathered back into the mouth when danger threatens.

In Africa the tilapia harvest is an important component of subsistence fisheries. Tilapias are widely used in aquaculture, especially in Israel, Indonesia, and Malaysia. However, in Asia, the introduction of tilapias for fisheries development has threatened many of the native fishes. The smallest known tilapia species is listed as an endangered species.

Scientific classification: Tilapias make up the genus Tilapia in the family Cichlidae, order Perciformes. The smallest known species is classified as Tilapia guinasana.