ИСТИНА

The family Gobiidae includes about 2000 described species and is accepted as the second largest vertebrate families. However, the vast majority of its species distributed worldwide in both tropical and temperate habitats were not genetically studied, and until today some species are described based on external features from a few specimens or even in individual. At the same time, a number of genetic studies prove the conspecificity of some morphological or color morphs, as well as significant genetic differences between morphologically similar populations. The first cryptic goby species were discovered in the Ponto-Caspian basin by karyological studies among “freshwater Caucasian gobies” (Vasil’eva, Vasil’ev, 1994) which for a long time have been attributed to the same subspecies Neogobius platyrostris constructor. Recently, this group of morphologically and ecologically similar Ponto-Caspian gobies includes six species: Ponticola constructor, P. cyrius, P. rhodioni, P. iranicus, P. rizensis, and P. turani; the first four species demonstrate distinct karyological differences and are confirmed by molecular phylogeny. The mtDNA cytochrome b gene analysis revealed four phyletic lineages in the genus Proterorhinus, external diagnostic features of these cryptic species are not found yet. And the last discovered Ponto-Caspian cryptic species are widely distributed Ponticola gorlap and P. iljini from the Mangyshlak Peninsula distinguished by both karyological and cytochrome b gene analyses. Recent genetic studies revealed cryptic species among several groups of Atlantic gobies, for example, in coral-reef Elacatinus, Tigrigobius, and Risor (Victor, 2010, 2014), and in widely distributed euryhaline frillfin goby Bathygobius soporator (Lima et al., 2005). Compared with aforementioned investigations, the number of genetic studies, resulted in the discovery of cryptic species in the Indo-Pacific, looks very scarce with respect to the greatest taxonomic diversity of gobiids in this area. Indeed, the alleged Indo-West-Pacific origin of Gobiiformes, the striking level of observed ecological and physiological adaptations in different species, the high habitat fragmentation, the isolation of small lagoon populations of coastal widespread species, and numerous freshwater insular populations suggest that species diversity is underestimated. In this respect, the most interesting for genetic studies are inshore gobies distributed throughout the Indo-Pacific in brackish and fresh waters, and coral-dwellers.