title: Morphological Variability and Species Structure of Tubenose Gobies of Genus Proterorhinus (Gobiidae) of the Black Sea, Their Diagnostic Characters, and Distribution Patterns within the Basin
abstract: Abstract — On the basis of morphological studies of museum collections based on preliminary analysis of genetically identified samples, a system of species diagnostic characters and a key for identification of three Black Sea species of tubenose gobies (genus Proterorhinus ) were developed. These species, the validity of which is confirmed by the data of molecular genetic analysis, are very similar in external morphology and are differentiated by a set of characters, the most important of which 
journal: Journal of Ichthyology