تعيين برخي از شاخص هاي هم آوري شاه كولي( Alburnus chalcoides, Guldenstaedt 1772) مهاجر به تالاب انزلي

Determine of some of fecundity indicators in Shemaya (Alburnus chalcoides, Guldenstaedt 1772) immigrant to the Anzali Wetland

Shemaya (Alburnus chalcoides, Guldenstaedt 1772) is one of the economically valuable fishes in the Caspian Sea. This fish enters rivers and wetlands flowing into the Caspian Sea for spawning. The study of fecundity is one of the important indicators of reproduction biology in fishes. The present study was conducted in the spring of 2008 on 66 shemaya specimens caught from each of 2 and 3 years, the Anzali wetland to investigate fecundity in this immigrant species. According to the results obtained highest average fork length (19.27 cm), average weight (82.79 g), ovary weight (9.64 g), absolute fecundity (8301.21 eggs ) and average number of ovules in each gram of body weight (821.79) belonged to 3 year old shemaya specimens, while lowest average fork length (15.83 cm), average weight (42.3 g), ovary weight (5.54 g), absolute fecundity (4447.84 eggs) and average number of ovules in each gram of body weight (820.47) belonged to 2 year old shemaya specimens. Maximum average relative fecundity (109.89) and gonadosomatic index (GSI) (14.49%) were recorded in 2 year old shemaya and minimum average relative fecundity (99.21) and gonadosomatic index (GSI) (13.61%) were recorded in 3 year old shemaya. On the basis of nonparametric Mann Whitney and T-test, significant differences were detected in the biometry parameters and fecundity of shemaya specimens in different age groups.