Elham Boroumandi - Department of Fisheries and Environmental Sciences, Faculty of Natural Resources and Earth Sciences, ShahreKord University, Shahre Kord, Iran.
Iraj Hashemzadeh Segherloo - Department of Fisheries and Environmental Sciences, Faculty of Natural Resources and Earth Sciences, ShahreKord University, Shahre Kord, Iran.
MohammadReza Ashrafzadeh, - Department of Fisheries and Environmental Sciences, Faculty of Natural Resources and Earth Sciences, ShahreKord University, Shahre Kord, Iran.
Rouhallah Rahimi - Department of Fisheries and Environmental Sciences, Faculty of Natural Resources and Earth Sciences, ShahreKord University, Shahre Kord, Iran.

Spiny loaches Cobitis are found in Eurasia, North Africa, and South Asia. This genus is represented by four valid species including Cobitis linea (Kor drainage), C. faridpaki and C. saniae (Caspian basin), and Cobitis avicennae (Tigris basin) in Iran. Cobitis faridpaki and C. keyvani have many populations in southern Caspian Sea basin that due to their morphological variability it is difficult to assign them either of the noted species. Fish used in this study were collected in 2016 using a back pack electrofishing device in Barkilirud and Chalkeh rivers (Caspian Sea basin). In this study, sequences of Cytochrome Oxidase subunit one (COI) were used. To find related COI sequences a BLAST search was performed in NCBI. Phylograms reconstructed using Maximum Parsimony (MP), Neighbour-Joining (NJ) and Maximum Likelihood (ML) approaches with 500 bootstrap replicates had similar topologies. Cobitis faridpaki, C. saniae, and C. avicennae nested in a monophyletic cluster with a bootstrap support of 64% and the two Caspian Cobitids were nested in a highly supported group (BS = 99%). Among Iranian species the highest K2P genetic distance was between C. avicennae and C. saniae (6.5%) and the least genetic distance was between C. faridpaki and C. saniae (2.5%). Genetic distances among Cobitis spp. from GenBank were 0.8-9.06%.

Caspian Sea. Barkili and Chalkeh rivers, COI gene, Genetic distance