Estimation of biological parameters of anchovy kilka Clupeonella engrauliformis (Borodin, 1904) in the south Caspian basin

Kilka as pelagic fish feeds the planktons, has an important role in the food chain of the Caspian Sea. Since the population parameters, are important to set sustainable fisheries. Sampling on the southern coast of the Caspian Sea was carried out from October 2006 to September 2007 in Bandar Anzali and Babolsar. During the study period, 546 samples were measured and weighed and 221 fish were aged by using sagitta otoliths. The results showed that the mean length and age of anchovy kilka were 117.8±6.9mm and 4.5 years respectively and over 80 percent of the samples were composed of 4 and 5 years old classes. Infinity length (L∞) calculated. 147.45mm and age at zero length (to) equaled -1.73. b parameter in length–weight relationship was estimated 2.56 which showed negative alometric growth pattern (P<0.05). Growth coefficient (K) using the Ford–Walford plot was 0.245 per year and total mortality coefficient (Z) was estimated 1.067 per year. Natural mortality rate was M=0.503 per year and fishing mortality equaled to F=0.564 per years.Continuously monitoring the stocks of anchovy in the Caspian Sea could be effective step in understanding their condition.