The creation of lacustrine systems in artificial reservoirs provides a survival challenge to riverine species some of which fail to adapt, being unable to utilize organisms of the pelagic zone and to reproductive in new habitats. Clupeids have successfully occupied the pelagic zone and become the dominant group, whether through natural colonization as in Lake Volta or as introductions as in Lake Kariba and Cabora Bassa. Cichlidae have also been successful and so have Cyprinidae, Bagridae, Claridae, Citharinidae, Centropomidae, Mochokidae, Mor-myridae, Osteoglossidae, Polyteridae, Schilbeidae, and Characidae, depending on their occurrence in the catchment area. The introduction of Limnothrissa miodon and Stolothrissa tanganyikae into Lakes Kariba and Cabora Bassa is generally hailed as a success story. On the contrary, the introduction of Lates nilo-ticus and Oreochromis niloticus into Lake Victoria has had adverse impacts on native fish species and has received bad publicity.
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