study of sex steroid hormones and ovarian histology in female shemaya (alburnus chalcoides) migratory to anzali wetland

abstract reproductive biology of female shemaya (alburnus chalcoides) studied with examination of histology, egg diameter and value of sex steroid hormones during spawning phase in the anzali wetland from march 2013 to jun 2014. finally 42 numbers of female fish were examined. the result of sex steroid hormones showed the rate of testosterone hormone in gravid fish was 7.93±1.18 ng/ml; but in ripe females, its value was 3.88±1.12 ng/ml (p<0.05). level of 17β- estradiol during spawning phase were examined and its value in gravid fish and ripe fish respectively was 2.98±0.18 and 2.55±0.09 ng/ml. also level of progesterone hormone in ripe fish was 0.36±0.04 ng/ml, that its value in ripe fish and its value in gravid fish was 0.25±0.03 ng/ml (p<0.05). egg diameter in gravid fish and ripe fish respectively was 655.12±13.29 and 792.4±13.96 micron. microscopic study of ovarian histology in female fish showed ovarian contain eggs in primary growth stage, cortical alveoli, early vitellogenic oocyte, advanced vitellogenic oocyte, hydrated oocyte, germinal visicol break down oocyte. according to value of 17β-estradiol during spawning phase and result of other study, probably eggs are growing during spawning phase. the process of oocyte growth in these fishes is asynchronous.