A comparative study of some blood factors in male and female Caspian kutum (Rutilus frisii kutum) broodstock from the southern basin of the Caspian Sea

In this study, some serum factors in male and female Caspian kutum (Rutilus frisii kutum) broodstocks were investigated. The estimated values were compared between male and female fish of various age groups. A total of 80 mature fish (40 males and 40 females) were randomly caught from the Shirood and Tajen rivers (southern Caspian Sea) during spawning season. Blood samples were then taken from the caudal peduncles and the serum biochemical parameters were measured according to common laboratory methods. Cholesterol levels showed significant differences (P < 0.05) between male and female broodstocks from the Tajen River, as well as between male and female kutum of the Tajen and Shirood rivers. Comparison of the estimated serum factors with the fish ages revealed no significant changes (P > 0.05). A high correlation was found between total protein and weight in fish from both rivers based on Pearson's correlation. This study suggests that male and female variations in blood factors should be taken into account when these parameters are used to assess sex, age, and spawning sites.