Any of numerous, mostly freshwater, fish species (genus Tilapia, family Cichlidae), native to Africa. They resemble North American sunfishes; one species grows to 20 lbs (9 kg). Tilapia species are easy to raise and harvest for food; they grow rapidly, resist disease, and eat readily abundant algae and zooplankton. They have been used in warm-water aquaculture systems since the early Egyptian civilization and have been introduced into many freshwater habitats. See alsocichlid.