Length and Weight Ratio, Gonadosomatic and Hepatosomatic Indexes, Growth Patterns and Condition Factor of Alburnus chalcoides in the Southwest Coastlines of the Caspian Sea (Guilan Province)

Length-weight relationship, growth pattern, condition factor and age composition of Alburnus chalcoides in the southwest coasts of the Caspian Sea (Astara, Anzali and Kiashar) were examined from September 2017 to October 2018. A total of 77 fish were caught using beach seine. The mean length and weight of fish were 19.25±5.17 cm and 76.78±83.92 g, respectively. Fish age ranged from 0-4 years and age class 0-1 accounted for 81.8% of the examined specimens. Considering the growth pattern, the regression coefficient (b) was bigger than 3. The figure obtained from Pauly equation was 5.28 which is larger than the t value of Pauly table (1.66), suggesting a heterogeneous or alometric growth pattern for the species under question. The CF values were 0.83±0.14 and 0.82±0.11 in males and females, respectively. Mean gonadosomatic index was higher in females and significantly varied in females (8.04±4.82) as compared to males (3.05±1.47). Mean hepatosomatic index was 0.79±0.49 in males and 0.75±0.44 in females.