Genetic identification and phylogenetic relations of Oxynoemacheilus species (Teleostei: Nemacheilidae) from drainage of Euphrates in Turkey based on COI-barcode region

The present study investigated the ability of DNA barcoding to reliably identify Oxynoemacheilus species in Euphrates River basin of Turkey, known as biodiversity hotspots. The barcode region (627 bp) of the mitochondrial cytochrome c oxidase I (COI) were used to barcode 167 individuals belonging to six Oxynoemacheilus species. Based on Kimura two-parameter (K2P), the intraspecific diversity and minimum interspecific genetic distance were % 0.59 and % 1.62 respectively. Nearest neighbor distance was 7-fold higher than maximum intra-specific distance on average and a distinct DNA barcoding gap was observed. According to the phylogeny-based succes test neighbour-joining phenograms were generated with 1000 bootstrap replications using the K2P model and all the specimens clustered in concurrence with the taxonomic status of the species. The MP and ML phylogenies indicated a consensus tree topology containing two clades corresponding to the geographical origins: Western and Eastern Anatolia groups. The results of present study indicated that the COI gene could be a suitable DNA barcode marker for the Oxynoemacheilus species identification and delimitation with approximately 81% success rate.