Evidence of two species currently under the name of Eleotris fusca (Gobioidei: Eleotridae) in the Indian Ocean

The observation of the cephalic free neuromast pattern of the genus Eleotris allows to classify the specimens in different groups of species but, as diagnostic characters without overlap are scarce, the morphological identification of the species is difficult. However, genetic analyses, particularly with barcoding (COP, facilitate the discrimination between species. In a recent study on the phylogeography of Eleotris fusca Bloch & Schneider, 1801 in the Indo-Pacific area, two species have been revealed although they present the same cephalic free neuromast pattern. The first one included specimens mainly from the Pacific Ocean and the second one, specimens from the Indian Ocean. They are separated with a mean pairwise divergence of 5.6% and present 32 diagnostic nucleotide substitutions in the 585 bp of COI sequenced. After the examination of all the available types of the synonym of E. fusca from the Indian Ocean, we revalidated the name of Eleotris klunzingerii Pfeffer, 1893.