Three new killifish species (Cyprinodontiformes: Nothobranchiidae) from Equatorial Guinea

Two new Mesoaphyosemion species and one new species of the ’Aphyosemion’ herzogi group are described from the inland of Equatorial Guinea. The results of mtDNA analyses of most of the known phenotypes of the genus Mesoaphyosemion and the ‘Aphyosemion’ herzogi species group, respectively, are presented. Both new Mesoaphyosemion species have dark blotches on the posterior flanks and resemble M. maculatum from Gabon, yet they are not closely related to that species. Although the two new species occur in very close proximity, DNA results suggest no close relationship. The ‘Aphyosemion’ herzogi species group has a similar distribution as the genus Mesoaphyosemion, but with its northern boundary in southern Cameroon. Based on mtDNA the new ‘Aphyosemion’ from the Mitemele drainage in south west Equatorial Guinea is basal species to the remaining species group. It is distinguished from the two described congeners, ‘A.’ bochtleri and ‘A.’ herzogi by a diagnostic combination of colouration characters. Unpaired fins and flanks have a green background and caudal peduncle is often yellow to golden with dark red irregular dark red bars. The genetic data indicate that the species group contains several additional, genetically and by colour pattern well separated, potentially undescribed species.