Population dynamic of Gasterosteuse aculateus Linnaeus, 1758 from Sothern Caspian Sea

This study was aimed to estimate growth parameters and mortality rate of stickleback caught from the southern Caspian Sea. Fish sampling was conducted from February 2018 until June 2018. To do so, 247 fish were sampled, weighted and biometric assays were done, among which 237 samples were sex-determined. The numbers of male and female fish samples were 106 and 131, respectively. Kolmogrove-Smirnov test showed a significant difference in length-frequency distribution between sexes. Randomization test was applied to compare mean length of male and female samples which indicated a significant difference between sexes. Results indicated that the shortest and the longest fish recorded in the Caspian Sea were 1.55 and 6.93 cm, respectively. Vonbertalanfi Growth factors in the Caspian Sea was obtained (L∞= 8.797 cm, k=0.356 per year and t0= -0.699 year). Mean natural mortality for male, female and total were 1.86 year-1, 1.76 year-1, and 1.64 year-1, respectively. Mean relative weight of the female, male and total fish were 85.2%, 83.02% and 85.16%, respectively, implicating inadequate condition of the fish weight. The present findings help better understanding of biological status of stickleback stock in southeastern part of the Caspian Sea.