Morphological and Molecular Perspective on Geographical Differentiation of Barbus Populations (Actinopterygii; Cyprinidae) within Iranian Freshwater Drainages

摘要

Geographically isolated populations of Barbus present remarkable variation with regard to morphometric and meristic characters within Iranian drainage systems; while they are relatively similar in external morphology such as coloration. Present study is the first report on geographical differentiation of Barbus populations in Iran from both morphological and molecular point of views. The morphometric and meristic characters as well as phylogenetic relationships (using sequence data of mtDNA cytochrome b gene) of twelve populations from three drainages (i.e. South Caspian Sea, Orumyieh and Tigris-Karoun) were analyzed. The univariate analysis reveals significant morphological differentiation among the populations from the three drainages. The phylogenetic analyses indicate relatively high genetic differentiation among the populations from the mentioned drainages, which are consistent with the observed morphological variation, and correspond well with their biogeographic distribution. However, the result of Automatic Barcode Gap Discovery (ABGD) analysis shows intra-specific differentiation for the sequences from South Caspian Sea drainage, while support the distinction of the specimens from Tigris-Karoun drainage as B. lacerta. Since the sequence data of Barbus cyri from Armenia is clustered with individuals from the South Caspian Sea and the morphological comparison, the specimens from that basin are considered as B. cyri and the Orumyieh basin as Barbus sp.