Reproductive maturation of sub adult Indian carps in earthen ponds

Carp culture in extensive and semi-extensive systems: i.e., earthen ponds, natural and semi-natural water resources, reservoirs and the paddy field has widspred distribution. Indian major carps including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) which have faster growth and good feed value than other warm water fishes introduced to many countries including India, Thailand, Burma, Philippines, Japan and the former Soviet Union are also considered and are reared. Sex steroids are important in the control of reproduction in fish. Development of methods for Indian education programs for proliferation requires knowledge of the hormonal changes during sexual maturation and spawning is. Testosterone, progesterone and 17 ϐ-estradiol are steroid hormones that play an important role in controlling Tuesday reproduction and sexual maturity of the fish are. This study aimed to investigate the changes in steroid hormones testosterone and 17 beta-estradiol including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) were conducted in different seasons. 40 specimen of carps breeders were investigated in southern (Aquaculture Research Institute) and north (North Aquaculture Research Institute) of Iran and maintained in different seasons (spring, summer, autumn, winter). Fish were caught by netting vetch and spring 1 cm. Blood samples were collected from the fish caudal blood serum by centrifugal separation model Labofuga 200 was made in Germany. Testosterone, and estradiol RIA (Radioimmunoassy) using an automatic gamma counter LKB model made in Finland made in France using the Immunotech kit hormone were measured. The results showed that the average level of 17 betaestradiol in the female in the spring, summer, autumn and winter, respectively, 82/12 ± 75/107, 66/13 ± 2/80, 73/17 ± 8/122 and 72/17 ± 25/104 ml, respectively. Mean testosterone levels in the female in the spring, summer, autumn and winter, respectively, 004/0 ± 092/0, 002/0 ± 05/0, 003/0 ± 11/0 and 006/0 ± 1/0 ng ml, respectively. Overall, the highest levels of 17 beta-estradiol and testosterone in female Roho were recorded in autumn. Also, low levels of 17 beta-estradiol and testosterone in female Roho was observed in summer. Highest and lowest levels of the male hormone, respectively, were recorded in winter and spring. The relationship between the hormone 17 beta-estradiol and testosterone with environmental factors such as pH and dissolved oxygen were discussed. there was a positive correlation between testosterone levels in males only the amount of dissolved oxygen .results revieled that sex hormone levels were increased during winter and autumn would be the signe for reproductive performance and spawning seasone in three species