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

Abstract

The phylogenetic relationships and the phylogeography of seven species of Caucasian barbels of the genus Barbus s. str. were studied based on extended geographic coverage and the use of mtDNA and nDNA markers. Based on the 26 species studied, matrilineal phylogeny of the genus Barbus is composed of two clades: a) West European clade, and b) Central and East European clade. The latter comprises two subclades: b1) Balkanian subclade, and b2) Ponto-Caspian subclade, which includes 11 lineages mainly from Black and Caspian Sea drainages. Caucasian barbels are not monophyletic and are subdivided into two groups. The Black Sea group encompasses species from tributaries of the Black Sea, including the reinstalled B. rionicus, except for B. kubanicus. The Caspian group includes B. ciscaucasicus, B. cyri (with B. goktschaicus, which might be synonymized with B. cyri), B. lacerta from the Tigris-Euphrates basin and B. kubanicus from the Kuban basin. The genetic structure of Black Sea barbels was influenced by glaciation-deglaciation periods accompanied by freshwater phases, periods of migration and the colonization of Black Sea tributaries. Intra-and intergeneric hybridization among Caucasian barbines was revealed for the first time. In the present study, we report the discovery of B. escherichii in the Kuban basin, where only B. kubanicus was known to inhabit.Hybrids of these two species were detected based on both mtDNA and nDNA markers. Remarkably, the Kuban population of B. escherichii is distant to closely located conspecific populations, and we consider it as a relic. We reveal the intergeneric hybridization between evolutionary tetraploid (2n=100) B. goktschaicus and evolutionary hexaploid (2n=150) Capoeta sevangi in Lake Sevan.

Evidence for Plio-Pleistocene Duck Mussel Refugia in the Azov Sea River Basins

“…At the same time, spreading of freshwater and brackish water animals happened by changing environmental conditions. As a consequence, isolated populations of these animals evolved, in particular among amphipods, freshwater fishes [9,10], and freshwater mussels (this study). Our phylogeographic study revealed the presence of a separate, well-diverged subclade of Anodonta anatina in Southeastern Europe.…”

“…The mean genetic distances between the IBER, ITAL, and EUR lineages and the AZOV lineages varied from 2.35% to 3.08%, which indicated the long-term isolation of freshwater basins in the Azov-Prikubanskaya Lowland and A. anatina populations inhabiting those water bodies. Previously, it has been shown that several other aquatic taxa, e.g., the freshwater fish genus Barbus and the amphipod genus Pontogammarus, had survived in the Ponto-Caspian refugia during the Neogene-Quaternary epoch [9,10].…”

“…This process was accompanied by emergence of isolated populations. For example, genetic studies of Barbus fish (Teleostei: Cyprinidae: Barbus) in Europe made it possible to identify the Ponto-Caspian subclade within this genus and corresponding refugium for freshwater fauna [9]. Connections between parts of the Ponto-Caspian basin were also studied on the basis of the phylogeny of marine invertebrates, i.e., amphipods [10].…”

Barbus xanthos, a new barbel from the Southern Aegean basin (Teleostei: Cyprinidae)

“…A total of 10 species has been reported from Turkish inland waters: B. anatolicus Turan, Kaya, Geiger & Freyhof, 2018 from the Yeşilırmak and Kızılırmak rivers, B. cyclolepis Heckel, 1837 from the Ergene River, B. cyri De, 1865 from the Kura and Aras rivers, B. escherichii Steindachner, 1897 from the Sakarya River, B. lacerta Heckel, 1843 from the Tigris, Euphrates and Van Lake basin, B. rionicus Kamensky, 1899 from the Çoruh River, B. niluferensis Turan et al ., from the Susurluk River, B. oligolepis Battalgil, 1941 from the streams and rivers in the Biga Peninsula, B. pergamonensis Karaman, 1971 from the streams and rivers in the Aegean Sea basin, and B. tauricus Kessler, 1877 from small streams in the south‐eastern and western Black Sea (Geiger et al ., ; Kottelat & Freyhof, ; Levin et al ., ; Turan et al ., ).…”

Distribution of host-specific parasites in hybrids of phylogenetically related fish: the effects of genotype frequency and maternal ancestry?

“…Such hybridization very often results from the introduction or invasion of non-native fish species [12][13][14][15][16] caused by direct anthropogenic activities (agriculture, fish farming and waterbodies transformation) or human-mediated disturbances of nature (climate change, interspecies competition or limited living resources). Generally, the presence of F1 hybrids is documented in many wild-living cyprinids even when the frequency of hybrids is rather low [6,[16][17][18][19][20][21][22]. Cyprinid hybrids exhibit high larval resistance to environmental disturbances (osmotic and thermal conditions), wider ecological plasticity, greater fasting abilities in comparison to their parents, and limited susceptibility to parasite infection [7,[23][24][25].…”