Hemichromis exsul has been described scientifically already in 1933 under the name of Pelmatochromis exsul. Type locality was lake Rudolf (now lake Turkana) in Kenya. Later researchers considered H. exsul to be a synonym of Hemichromis letourneauxi.
This point of view became doubted when Lothar Seegers in 1998 published a photo of a Hemichromis that he had collected in lake Turkana. That fish looked totally different from all Hemichromis letourneauxi known so far. Sadly almost never any freshwater fish from Kenya become exported, so H. exsul stayed a phantom.
Only in summer 2017 some specimens could be brought to Germany by private persons. Once more we can offer German bred ones currently.
Hemichromis exsul differs from all other Hemichromis known so far by the dark, blackish rims of the fins. Moreover the typical lateral blotch exhibited by most red jewel cichlids is missing in most animals. The fish stays rather small and are very peaceful - at least for a red jewel cichlid.