A study of the Lake Tanganyika cichlids Trematochromis schreyeni and Ctenochromis benthicola has found that the two species are actually the same fish.
Trematochromis schreyeni was described in Poll in 1987 from Luhanga on the western coast of Lake Tanganyika, but Poll failed to spot that the fish was identical to Ctenochromis benthicola that Matthes had described from the Lake in 1962.
Scientists examined the single type specimen Poll used to describe Trematochromis schreyeni and the type material for Ctenochromis (Haplochromis) benthicola, along with new material and found that the fish all belonged to a single species using sophisticated statistical analyses."The fish all belonged to a single species..."The finding means that Trematochromis schreyeni Poll 1987 is now a junior synonym of Ctenochromis benthicola, as it was described latest.
Consequently, the scientists have produced a new description for Ctenochromis benthicola to take the specimens from Poll's 1987 study into account.
C. benthicola reaches an adult size of around 20cm/10" and is endemic to Lake Tanganyika. Existing literature on T. schreyeni states an adult size of 7cm/3" based on Poll's type specimen.
The study was undertaken by cichlid biologist Jos Snoeks, and collaborators Takahashi and Nakaya, who are best known for splitting Cyphotilapia frontosa into two species, frontosa and gibberosa.
For more information see the paper: Takahashi, T, J Snoeks & K Nakaya (2006) - Trematochromis schreyeni Poll, 1987, a junior synonym of 'Ctenochromis' benthicola (Matthes, 1962)(Perciformes: Cichlidae) from Lake Tanganyika. Journal of Fish Biology 68 (s1): 56-67.