ABSTRACT
In the present response paper, the article entitled "Morphometric variation of the Herichthys bartoni (Bean, 1892) species group (Teleostei: Cichlidae): How many species comprise H. labridens (Pellegrin, 1903)?" by Mejía et al . 2015 is critically reviewed. The current review pinpoints some of the more conspicuous conceptual inconsistencies and fundamental errors found in the study by Mejía et al . (2015), It is contended that the authors fail to provide any new insights into the complex biogeography and evolutionary history of the Nosferatu and Herichthys genus groups, and that while results of their Cox1 molecular analysis are comparable to those by De la Maza-Benignos et al . (2015), the conclusions of the two studies are not comparable. In addition, it is contested that, whereas the designation of genus Nosferatu by De la Maza-Benignos et al . (2015) was found on the principles of the biological and phylogenetic species concepts, the rejection of the genus by Mejía et al . (2015) is solely based "on the presence of (overlapping) morphometric characters" between genera. The assumption by Mejía et al . (2015),that because their geometric morphometrics analysis failed to provide separation of species, then Nosferatu genus does not correspond to a valid taxon; and their suggesting geometric morphometrics "as useful tool to discriminate species, because it allows to propose diagnostic characters" were not supported by their results. While Mejía et al . present some interesting thoughts on the systematics of Nosferatu , they unfortunately fail to provide any data that can be objectively assessed as relevant to motivate any changes in the current taxonomy.
Keywords:
Cox 1; Genera; Geometric morphometrics; Monophyly requirement; Paraphyletic; Species concepts