Evaluation of the effects of ages and sexes on hormonal factors of Alosa braschnikowi in the Caspian Sea

Alosa braschnikowi has an opportunistic nutritional behavior in the southern Caspian Sea. Due to its good weight and length, this fish is an economical and valuable species and has commercial value in the western part of the Caspian Sea. Also, it is caught by other fish such as sturgeon. The aim of this study was to measure the hormonal factors of Alosa braschnikowi in both males and females and at different ages to the amount of these hormones is detected. This study was performed on ۳۷ fish on Rudsar beach (Guilan). In order to carry out this research, the fish were caught at different ages and in both males and females in February and March, April, May and November ۲۰۱۸. Samples were randomly selected and immediately after sampling, blood was taken from the fish and the fish were divided into two sexes, male and female, and in ۳ age groups (۳, ۴ and ۵). Testosterone, ۱۷-beta-estradiol and ۱۷-alpha-hydroxyprogesterone were measured using ELISA and by the Monobind Inc (American-made) ELISA kit. Laboratory results showed that ۱۷-beta-estradiol and ۱۷-alpha-hydroxyprogesterone did not have statistical significant difference between the sexes (P <۰.۰۵). However, testosterone levels were statistically significant between the sexes (P <۰.۰۵) and the amount of testosterone in male fish was higher than female. Also, testosterone, ۱۷-beta-estradiol and ۱۷-alpha-hydroxyprogesterone at different ages did not have statistical significant difference (P <۰.۰۵). In general, it can be said that the hormonal characteristics of this fish are not affected by age and only to some extent, sex affects these factores. It seems that the possible reason for hormonal differences in this research is impact of factors such as reproductive stages on these hormones that these stages have much more ineffectiveness compared to age and sex factors.

کلیدواژه ها:

Alosa braschnikowi ، Testosterone ، ۱۷-beta-estradiol ، ۱۷-alpha-hydroxyprogesterone