Niger River Niger River The Niger River (; , ) is the principal river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in southeastern Guinea. It runs in a crescent through Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Niger Delta or the Oil Rivers, into the Gulf of Guinea in the Atlantic Ocean. The Niger is the third-longest river in Africa, exceeded only by the Nile and the Congo River (also known as the Zaïre River). Its main tributary
Nile tilapia to this species, too. An undescribed population found at, for example, Wami River, Lake Manyara, and Tingaylanda seems to be a close relative. Nile tilapia The Nile tilapia ("Oreochromis niloticus") is a species of tilapia, a cichlid fish native to Africa from Egypt south to east and central Africa, and as far west as Gambia. It is also native to Israel, and numerous introduced populations exist outside its natural range (e.g., Brazil). It is also commercially known as mango fish, "nilotica", or "boulti". The first name leads to easy confusion with another tilapia traded commercially, the mango tilapia ("Sarotherodon galilaeus").