Introductions and extinction of fish in the African great lakes.

The great lakes of Africa contain one of the most remarkable known examples of rapid evolution and speciation of a vertebrate group. The three major lakes - Lake Victoria, Lake Malawi and Lake Tanganyika - each contain a unique radiation of fish belonging to the family Cichlidae. This has produced species 'flocks' that are unique to each lake in species numbers and diversity. At present most of the cichlid species in Lake Victoria are facing extinction as a result of the introduction of an exotic fish species. There are many other examples of introductions or invasions of non-native fish that have had severe effects on the native fish populations and regional economics. These examples should provide a clear warning against the proposed introductions of exotic fish into Lake Malawi.