A study of morphological characteristics of Paracobitis Bleeker 1863 complex in Sistan basin

We conducted this study during the Summer, 2013 to evaluate morphological features of the species of the genus Paracobitis in Sistan basin. For this purpose, 60 specimens randomly were caught by a gill-net from different parts of Lake Chah Nime (Zabol, Sistan and Baluchistan), fixed in formalin solution and transferred to a laboratory for further examination. We measured 37 absolute morphological characteristics by a digital caliper and 6 meristic analyses using a stereomicroscope. We calculated 34 relative morphological characteristics with a division of absolute morphological characteristics by standard length and head length. In order to compare the morphological samples, the obtained morphological characteristics (absolute and relative) and meristic analyses were analyzed by principal component analysis and canonical variables. According to the results, we confirmed the existence of two species, P. vignai and P. rhadinaea, in the studied areas and appropriate geomorphic features were provided for their separation - barbel length, presence or absence of scales, mouth width and number of pectoral fin rays as morphological characteristics to distinguish the two species. In addition to the two species, different morphological forms were present in the sample. We proposed the use of molecular markers for better, more accurate results.