Africa: widespread throughout the Nilo-Sudan region of Africa, occurring commonly in all major river basins including the Senegal, Niger, Volta, Chad (Ref. 81285) and Nile (Ref. 3636). Found almost everywhere in West Africa, except in Gambia (Ref. 81285). Also present in the Congo basin and lakes Albert, Turkana/Rudolph and Tana (Ref. 3636). Several countries report adverse ecological impact after introduction.