and condition factor of autumn and spring populations of Alburnus chalcoides (Gueldenstaedt, 1772) from Sefid and Siahdarvishan rivers in the southern Caspian Sea basin

Morphological variations (morphometric and meristic traits), length-weight relationship parameters and condition factor were studied in autumn and spring populations of Alburnus chalcoides, collected from Sefid River (45 autumn and 113 spring) and Siahdarvishan (22 autumn and 28 spring) in the southern Caspian Sea basin. After anesthesia and fixation into the 4% buffered formalin, the samples were transferred to the laboratory and a total of 22 morphometric and 8 meristic characters were measured and counted using caliper and stereo-microscope, respectively. The results showed that the autumn and spring migratory populations of the studied species in the Sefid and Siahdarvishan rivers have significant differences in 7 and 2 morphometric traits (P<0.05), respectively, but not different in meristic characters (P>0.05). The results of the length-weight relationship parameters revealed that the Sefid River populations has an isometric growth pattern and the autumn and spring populations of the Siahdarvishan River showed positive allometric and isometric growth patterns, respectively.