Morphological variation in a common Turkish cyprinid, Squalius cephalus , across Turkish water catchment areas

Abstract

Morphometric variability and differentiation in the common Turkish cyprinid Squalius cephalus was investigated across the water catchment areas of the Rivers Istranca (SW Black Sea), Kura (Caspian Sea), Koca (Sea of Marmara), Sakarya (S Black Sea), Çoruh (Black Sea coast in NE Turkey), Gediz (Aegean Sea), Seyhan (Mediterranean Sea) and Mimikhan (River Euphrates basin). Results of multivariate analyses of morphometric and meristic data confirmed a stable geographic differentiation. Analysed samples of S. cephalus from Turkey are separated into three groups with considerable gaps between some of the analysed samples. Contrary to previous results, multivariate analyses of standard morphometric indexes showed no morphological differentiation of analysed samples from Turkey, and hence, complete lack of clearly-defined, discrete taxa within S. cephalus from this region.