Cobitis nalbanti, a new species of spined loach from South Korea, and redescription of Cobitis lutheri (Teleostei: Cobitidae).

Cobitis nalbanti, new species, is described from the South Korean Han and Geum Rivers, draining to the Yellow Sea. It differs from its congeners by having a wide, ovoid lamina circularis; rounded scales with a large, slightly-displaced focal zone; a relatively long, protruded snout; the suborbital spine not reaching the center of the eye; the mandibular barbel not reaching the anterior edge of the eye; usually 12-14 dark brown blotches in the fourth Gambetta's zone; a single elongated black spot on the upper part of the caudal-fin base; the only streak on the head running from the tip of the snout to the nape, across the eye; 2n=48-51 and NF=66. Cobitis nalbanti was previously identified as C. lutheri. Morphological analysis of C. lutheri shows that it is distinct in having a short obtuse snout, the suborbital spine reaching the center of the eye, the mandibular barbel reaching the anterior edge of the eye, usually less than 12 dark brown blotches in the fourth Gambetta's zone, two spots at the caudal-fin base, several dark streaks on the head, and 2n=50, NF=70. A lectotype is selected for C. lutheri. Cobitis lutheri has a wide distribution in the Amur River basin, several rivers flowing into the Sea of Japan (East Sea), and in the northern part of Sakhalin Island.

Molecular phylogeny of the genus Gobio Cuvier, 1816 (Teleostei: Cyprinidae) and its contribution to taxonomy.

The phylogenetic relationships among gudgeons that represent most nominal taxa within Gobio gobio sensu lato were examined by mitochondrial and nuclear genome sequencing. The molecular analyses confirmed the separate generic status of Gobio as a monophyletic group and revealed 15 Eurasian lineages divided into two main clades, the Northern European and the Ponto-Caspian. The validity of eleven nominal taxa as distinct species was confirmed, gudgeons from the Volga River basin were described as a new species G. volgensis, and three revealed phylogenetic lineages were submitted for a comprehensive revision as "species-in-waiting". The species G. gobio showed a wide range extending from the British Isles to the Black Sea coast and overlapped the areas of several other species. Four pure lineages were detected in the middle Danube River basin. The Crimean Peninsula was found to be a region with the occurrence of individuals of hybrid origin. This region will require special investigation to define species participating in hybridization events, and to establish further steps for the conservation of endemic native gudgeon species. A simple diagnostic method, based on different lengths of the PCR products, called "S7indel diagnostics" is presented for further taxonomic investigations in the genus Gobio.

European colonization by the spined loach (Cobitis taenia) from Ponto-Caspian refugia based on mitochondrial DNA variation.

In the last 20 years, new species, asexual reproduction, polyploidy and hybridization have all been reported within the genus Cobitis. An understanding of the current distribution and baseline phylogeographical history of 'true' nonhybrid Cobitis species is crucial in order to unravel these discoveries. In the present work, we investigated the phylogeography of the spined loach, Cobitis taenia, using 1126 bp of the mitochondrial cytochrome b gene from 174 individuals collected at 47 sites. In total, 51 haplotypes that differed at 49 positions (4.35%) were detected. We deduce that C. taenia survived European glaciations in at least three refugees in the Ponto-Caspian area. Two of these refugees each provided a major lineage that recolonized Europe in separate directions: one westward to England and the other spreading north into Russia before moving west. A third (minor) lineage that contributed little to the recolonization of Europe was also revealed--remaining near its Black Sea refuge. However, more recent history was difficult to resolve with colonization from a more western refugium during the last glacial maximum (LGM) a distinct possibility. Nested clade analysis indicates a pattern of restricted gene flow with isolation by distance at the first two levels and overall. Unlike many other European freshwater fish species, the Danube is not part of the current distribution of C. taenia, nor was it used as either a refuge or a source of colonization of Europe. Low genetic diversity within C. taenia suggests that its colonization of Europe is relatively recent. Demographic analyses revealed a history of recent expansion and isolation by distance.

Reproductive capacities in the polyploid males of spined loaches from the unisexual-bisexual complex, occurred in the Moscow River.

The unisexusal-bisexual complex of spined loaches from genus Cobitis, occurred in the Moscow River, includes two tetraploid forms. One of them consists of males and females. The studies of spermatogenesis as well as spermatozoa mobility and ultrastructure, of these males were performed simultaneously with experimental crosses to define their reproductive capacities. The testis visually looked undeveloped in the most of cases. The study of spermatogenesis revealed that they reached the stage of starting spermatogenesis wave. The most cells were spermatocytes I or II. In some males, several seminal tubules were filled with connective tissue, displaced germ cells. Spermatozoa of tetraploid males looked unmoved under the light microscopy. The study of male gonads by electron microscopy revealed that the most of germ cells were destroyed. Normal spermatozoa were absent. Experimental crosses between gynogenetic triploid females and tetraploid males revealed that these males were capable to stimulate gynogenetic development, but not effective: only 4.7 % oftriploid eggs inseminated with sperm from tetraploid males survived up to hatching. But 56.6 % of obtained hatchlings normally developed and survived up to 58-days age.