Phylogeny, phylogeography and hybridization of Caucasian barbels of the genus Barbus (Actinopterygii, Cyprinidae)

Phylogenetic relationships and phylogeography of six species of Caucasian barbels, the genus Barbus s. str., were studied based on extended geographic coverage and using mtDNA and nDNA markers. Based on 27 species studied, matrilineal phylogeny of the genus Barbus is composed of two clades ¿ (a) West European clade, (b) Central and East European clade. The latter comprises two subclades: (b1) Balkanian subclade, and (b2) Ponto-Caspian one that includes 11 lineages mainly from Black and Caspian Sea drainages. Caucasian barbels are not monophyletic and subdivided for two groups. The Black Sea group encompasses species from tributaries of Black Sea including re-erected B. rionicus and excluding B. kubanicus. The Caspian group includes B. ciscaucasicus, B. cyri (with B. goktschaicus that might be synonymized with B. cyri), B. lacerta from the Tigris-Euphrates basin and B. kubanicus from the Kuban basin. Genetic structure of Black Sea barbels was influenced by glaciation-deglaciation periods accompanying by freshwater phases, periods of migration and colonization of Black Sea tributaries. Intra- and intergeneric hybridization among Caucasian barbines was revealed. In the present study, we report about finding of B. tauricus in the Kuban basin, where only B. kubanicus was thought to inhabit. Hybrids between these species were detected based on both mtDNA and nDNA markers. Remarkably, Kuban population of B. tauricus is distant to closely located conspecific populations and we consider it as relic. We highlight revealing the intergeneric hybridization between evolutionary tetraploid (2n=100) B. goktschaicus and evolutionary hexaploid (2n=150) Capoeta sevangi in Lake Sevan.The study was supported by Russian Science Foundation (grant no. 15-14-10020); final stage of the study was supported by Russian Foundation for Basic Research (grants nos. 18-54-05003 and 19-04-00719)

DNA barcoding of the fishes of the genus <i>Alburnoides</i> (Actinopterygii, Cyprinidae) from Caucasus

<p>Spirlins of the genus <i>Alburnoides</i> are widespread fishes, which taxonomy has been rapidly developing in recent years. Mitochondrial cytochrome c oxidase subunit I (COI) was used as DNA barcode marker to create a reference dataset of Caucasian <i>Alburnoides</i> and to test its barcoding efficiency. All four previously known Caucasian species of <i>Alburnoides</i> were confirmed as valid species with high genetic distances to sister species as well confirmed as Caucasian endemics. <i>Alburnoides samiii,</i> previously known from Sefidroud basin (Iran), was discovered in Transcaucasia. The accuracy of species identification of Ponto-Caspian <i>Alburnoides</i> by DNA barcodes was 100%. In addition, one potentially new species within <i>A. gmelini</i> was revealed. Despite the limited ability of COI to infer phylogenetic relationships, study provided evidence that Ponto-Caspian lineage of <i>Alburnoides</i> includes significantly larger number of species from Caspian Sea basin and inland basins of Central Asia.</p