Materials for Revision of the Genus Photonectes (Melanostomiidae)

Abstract

Characters of external morphology of Melanostomiidae fishes of genus Photonectes are critically analyzed. The features previously used to distinguish the subgenera are shown to be unfit for these purposes. Existence of only two decisively diagnosed subgenera is proven within the genus, Trachinostomias and Photonectes s. str., for which the revised diagnoses are given based on the new set of characters. Species P. uncinatus is moved from subgenus Trachinostomias to the nominative subgenus. Reasons for the separation of groups of species within the nominative subgenus and the phylogenetic relationships between these groups are briefly discussed. Three new species are described: P. distichodon, P. filipendulus, and P. xenopogon spp. n. Distinguishing features of another new species that is not yet described due to the lack of data are presented. The key for identification of all known species of the genus is presented.