Molecular identification of stone loaches of Choman River system, Tigris Basin, based on the Cytochrome b gene with an overview of the Cobitoidea Superfamily

Molecular data and phylogenetic relationships of four Choman loaches species (Oxynoemacheilus chomanicus, O. zagrosensis, O. kurdistanicus and Turcinoemacheilus kosswigi) recently morphologically described from western Iran were evaluated with 64 species from the Cobitoidea superfamily based on their cytochrome b sequences to exhibit the placement of the Choman loaches species within the Cobitoidea superfamily. A comparative analysis of Kimura-2-parameter (K2P) distances was accomplished using sequence divergences of Cobitoidea to calculate intra and interspecific in superfamily, family and genus taxa. The average intraspecific K2P genetic distances of Choman loaches species was 0.005 whereas this value was 0.016 for the Cobitoidea superfamily. Molecular phylogenetic relationships were assessed using Maximum likelihood and Bayesian methods. Dendrograms obtained by these methods revealed all four Choman loaches species as distinct species among other reported Nemacheilidae Spp. These species were clustered with Oxynoemacheilus and Turcinoemacheilus genera within other species in the Nemacheilidae family. The phylogenetic analysis revealed that Cobitoidea superfamily consists of nine families ((Gyrinocheilidae + Botiidae) + ((Catostomidae + Vaillentellidae) + ((Nemacheilidae + Cobitidae) + ((Ellopostomidae + Gastromyzontidae) + Balitoridae)))) and indicated Nemacheilidae is a valid and distinct family from Balitoridae.