Oxynoemacheilus fatmae, a new species from the Güzelhisar Stream in the Aegean Sea basin, Türkiye (Teleostei: Nemacheilidae).

Oxynoemacheilus fatmae, a new species, is found in the Güzelhisar Stream in the northern Aegean Sea basin. It is differentiated from all other species of Oxynoemacheilus in the northern Aegean Sea and adjacent basins by having four to eight irregularly shaped narrow black bars on the posterior part of flank, and anterior parts of the flank with a marbled pattern. O. fatmae is differentiated from the closest species Oxynoemacheilus theophilii by having 14 fixed diagnostic nucleotide substitution sites, and the pair-wise genetic distance is 2.22%. It further differs from O. theophilii by having a slenderer body (body at dorsal-fin origin: 15%-17% standard length [SL] vs. 17%-18%), a slenderer caudal peduncle (10%-12% SL vs. 12%-13%), a more forked caudal fin (length of middle caudal-fin lope: 16%-19% SL vs. 19%-23%), and the absence the dorsal and ventral adipose crests on the caudal peduncle behind the vertical of the posterior anal-fin base (vs. present). Three species delimitation tests (assemble species by automatic partitioning (ASAP), automatic barcode gap discovery (ABGD) and generalized mixed yule-coalescent (GMYC)) and phylogenetic analyses reinforce the validity of O. fatmae as a distinct species.

Oxynoemacheilus marmaraensis, a new species from the Susurluk River, Türkiye (Teleostei: Nemacheilidae).

Oxynoemacheilus marmaraensis, new species, is restricted to the Susurluk River. It is distinguished from all the named species of Oxynoemacheilus in the northwestern Anatolian by the flank with a vermiculate pattern and the presence of a suborbital groove in males, and no axillary lobe at the base of the pelvic fin. It also differs from the closest species, Oxynoemacheilus kentritensis, by having 58 nucleotide substitution sites. The genetic distance is 10.49% between O. marmaraensis and O. kentritensis. Phylogenetic analyses and species delimitation tests (Poisson tree processes and assemble species by automatic partitioning) support the validity of O. marmaraensis as a distinct species.

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

Barbus xanthos, a new species, is described from the Esen, Dalaman, Tersakan and Büyük Menderes rivers in south-western Anatolia. It differs from other Barbus species in the adjacent basins by having 53-60 lateral line scales, a weakly ossified last unbranched dorsal-fin ray (about 33-50%), numerous small irregular-shaped black or dark-brown spots smaller than scales, often forming large, black or dark-brown blotches on back and flank in juveniles and adults, and a straight or slightly convex posterior dorsal-fin margin. B. xanthos differs from its most closely related congener, B. pergamonensis, by nine nucleotide substitution sites in the mitochondrial DNA cytochrome oxidase I barcode region.

Oxynoemacheilus cemali, a new species of stone loach (Teleostei: Nemacheilidae) from the Çoruh River drainage, Turkey.

Oxynoemacheilus cemali sp. nov. is described from the Çoruh River drainage in the eastern Black Sea basin. One molecular marker (coI), 25 morphometric and four meristic characters were analysed. Oxynoemacheilus cemali is distinguished from O. kosswigi, O. banarescui, O. samanticus and O. angorae in the Black Sea basin by having a suborbital groove in males, an axillary lobe at the pelvic-fin base, no dorsal adipose crest on the caudal peduncle, a slightly-forked caudal fin and 7-15 dark grey dorsal saddles. Morever, Oxynoemacheilus cemali is distinguished by commonly having 9-15 irregularly-shaped dark-grey bars on the flank posterior to the dorsal-fin origin or, rarely having a mottled pattern or 4-6 irregularly shaped dark-grey bars on the flank posterior to the dorsal-fin origin. Oxynoemacheilus cemali is also distinguished from the closely related species O. araxensis and O. cyri, distributed outside the Black Sea basin, by having 15 and 31 diagnostic nucleotide substitutions in the coI barcode region, respectively.

Genetic and molecular evidence that brown trout Salmo trutta belonging to the Danubian lineage are a single biological species.

We tested for reproductive isolation between Salmo trutta abanticus, S.t. labrax, S.t. caspius and S.t. fario by conducting crosses to produce F1 and F2 offspring. We also estimated the extent of genetic divergence between all three entities by examining sequence variation across the coI, d-loop and cytb mitochondrial genes. All of the F1 cross-types were successfully produced. After 2 years of culturing, F2 generation were produced as well. Fertilization, hatching and survival rates and hatching performance of F1 and F2 generations were evaluated. F2 generation had similar performance to their parent. Fertilization, hatching, larval survival rate and hatchery performance of F1 and F2 generation were similar except pure bred F2 S.t. abanticus. Purebred F1 individuals shared similar coloration patterns and spots with their parents but direction of the hybridization appeared to be decisive on morphology of hybrids. Some of the hybrids exhibit different morphological characters than their parents. Based on partial alignments of the three genes, phylogenetic analysis showed that these S. trutta are gathering within the same clade and appeared as monophyletic group. We found that there were some morphologic and genetic variation among S. trutta subspecies but the degree of variation does not warrant species level recognition. These findings indicate that the four subspecies constitute a single biological entity, corresponding to different morphs of the Danubian lineage. We therefore recommend that S. trutta belonging to Danubian lineage in Turkey be referred to as Salmo trutta and that strains be named according to location, such as Abant, Caspian, Black Sea and Anatolian.

Population structure and genetic analysis of narrow-clawed crayfish (Astacus leptodactylus) populations in Turkey.

The genetic differentiation among Turkish populations of the narrow-clawed crayfish was investigated using a partial sequence of cytochrome oxidase subunit I gene (585 bp) of 183 specimens from 17 different crayfish populations. Median joining network and all phylogenetic analyses disclosed a strong haplotype structure with three prominent clades diverged by a range between 20 and 50 mutations and substantial inter-group pairwise sequence divergence (5.19-6.95 %), suggesting the presence of three distinct clades within the Anatolian populations of Astacus leptodactylus. The divergence times among the three clades of Turkish A. leptodactylus are estimated to be 4.96-3.70 Mya using a molecular clock of 1.4 % sequence divergence per million years, pointing to a lower Pliocene separation. The high level of genetic variability (H d = 95.8 %, π = 4.17 %) and numerous private haplotypes suggest the presence of refugial populations in Anatolia unaffected by Pleistocene habitat restrictions. The pattern of genetic variation among Turkish A. leptodactylus populations, therefore, suggests that the unrevealed intraspecific genetic structure is independent of geographic tendency and congruent with the previously reported geographic distribution and number of subspecies (A. l. leptodactylus and A. l. salinus) of A. leptodactylus.

Oxynoemacheilus cilicicus, a new nemacheilid loach from the Göksu River in southern Anatolia (Teleostei: Nemacheilidae).

Oxynoemacheilus cilicicus, new species, is described from the Göksu, Seyhan and Ceyhan rivers in southern Turkey. It is distinguished from other Oxynoemacheilus species in the Eastern Mediterranean Sea basin by possession of an incomplete lateral line, terminating before the vertical of the dorsal-fin origin or slightly behind the dorsal-fin base, a deeply emarginate caudal fin, no suborbital groove in male individuals, and a series of dark-brown bars on the flank not interrupted along the lateral line. Molecular data suggest that Oxynoemacheilus cilicicus is characterised by 22 variable nucleotide substitutions and a minimum K2P distance of 4.09% with O. panthera in the mtDNA COI barcode region.

The westernmost known population of Paracobitis (Teleostei, Nemacheilidae), with the description of a new species from the Euphrates River in southern Anatolia.

Paracobitis salihae, new species, from the Göksu River in the western upper Euphrates drainage, is distinguished from other Paracobitis species by possessing a truncate caudal-fin, and a dark-brown vermiculate or marbled colour pattern. It is also characterised by 19 variable nucleotide substitutions, three diagnostic nucleotides and 3.6% minimum K2P distance compared to geographically adjacent and related P. zabgawraensis. Paracobitis salihae might be Critically Endangered and is threatened by dam constructions.