New data on the morphology of the Mekong blind sole (Typhlachirus elongatus) indicating the need for a revision of the genus

The results of analysis of 88 specimens of the Mekong blind sole (Typhlachirus elongatus) from the Mekong River delta in Vietnam indicate that the range of variability in meristic diagnostic characters of this species is broader than previously documented. Comparison of the new morphological data for T. elongatus from our analysis with data from the available literature for T. lipophthalmus and T. caecus reveals no differences between species. This fact confirms Chabanaud's conclusions about the monotypy of the genus Typhlachirus and indicates the need for further revision of the genus. Here, molecular data from the genes cytochrome c oxidase subunit 1 and 16S rRNA are presented for the first time for the genus Typhlachirus.