Generic term for any lake formed in a rift valley, but often used in specific reference to a group located in the East African rift, particularly those lying in its western and southern sections, i.e., the African Great Lakes. In the aquarium hobby the meaning of the term is typically restricted even further to include just lakes Malawi, Tanganyika, and Victoria, the latter of which is not in fact a rift lake and is located in a  shallow depression between the eastern and western branches of the main rift. These three lakes are famous for the high number of endemic fish species inhabiting them, especially members of the family Cichlidae.