What is "diplotaxodon"

Diplotaxodon is a small genus of seven formally described, as well as a number of undescribed, deep-water species of cichlid fish endemic to Lake Malawi in east Africa. These fishes represent a remarkable adaptive radiation of offshore and deep-water adapted fish descended from ancestral shallow water forms. They include the dominant zooplankton-feeding fish of the offshore and deep-water regions of the lake, as well as a number of larger species that appear to feed on small pelagic fishes. Adult sizes range from 10 to 30 cm in total length, depending on species.