The Effects of 17 beta-Estradiol on Growth, Survival and Feminization of Green Tiger Shrimp, P. semisulcatus (Decapoda: Penaeidae)

The effects of 17 beta-estradiol were investigated on survival, feminization and growth of green tiger shrimp, Penaeus semisulcatus in different life stages. Egg, nauplius, protozoea, mysis and postlarvae were immersed in water containing 50 mu L-1 17 beta-estradiol from the beginning of the each stage to the end of the stage. The grow out were carried out about 4 months to emerging the secondary sexual characters in ventral side of shrimp in this ponds. The results of the experiment showed that the method of immersion 50 mu g L-1 17 beta-estradiol in eggs, nauplius, protozoea stages decreases the survival rate. The best feminization rate (71.88%) were observed in naupli group and this result was important statistically than control and other groups (p<0.001). Respect of the growth rate, the highest mean weight was 14.15+/-2.41 g in nauplii group and this followed by control (13.66+/-2.48 g) and egg groups (12.04+/-0.68 g) and were significantly different from the other groups (p<0.05).