Length-weight, length-length relationships and condition factor of Rutilus kutum (Kamensky, 1901) from different parts of the Caspian Sea basin

During 2019, the length-weight, length-length relationships and condition factor of Caspian kutum, Rutilus kutum  (Kamensky, 1901) were studied by catching a total of 339 specimens were collected from Chelvand, Khalehsara, Sefid, Khoshk and Shir rivers, Anzali Wetland and Turkmen Shores of the Caspian Sea basin. The equation W =aTLb was used to calculate the length-weight relationship, FL=a + bTL for the length-weight relationship, and K= (W / L3) × 100 to calculate condition factor. The b-value were estimated from 2.47 to 3.17 and condition factor from 0.85 to 1.01. Maximum and minimum parameter of b-value and condition factor were related to the Khoshk River, Torkman shore and Anzali wetland and Sefid River, respectively. In addition, the growth pattern was positive allometric for the Chelvand, Khoshk and Shir populations, isometric for the Khalesara population and negative allometric for others.