Effects of different feed additives on the development of ovaries and testicles in the ridgetail white shrimp Exopalaemon carinicauda (Decapoda, Caridea, Palaemonidae)

Abstract To solve the problem of unsynchronized gonadal development in Exopalaemon carinicauda , different feed additives were evaluated for their effect on gonadal development among female and male individuals. Different concentrations of Schizochytrium (0%, 3%, 6%, and 9%), Porphyridium cruentum (0, 0.5, 1 and 2%) and 5-hydroxytryptamine (5-HT) creatinine sulfate (0, 0.0025, 0.005 and 0.01%) were used. For females, the gonadal index of E. carinicauda was significantly higher with the addition of 6% Schizochytrium , 1% P. cruentum , and 0.0025% 5-HT creatinine sulfate ( ). The ovarian development rate reached its highest at 79.30 ± 2.64%, and the final contents of blood ovarian vitellogen and oestradiol were significantly higher, compared to the other groups ( ). For males, the gonadal index was higher with the addition of 9% Schizochytrium , 0% P. cruentum and 0.01% 5-HT creatinine sulfate, although the difference was not significant ( ). No significant difference was found in the sperm survival rate ( ), but the activities of sperm total ATPase and lactate dehydrogenase showed significant differences in each group ( ). Overall, we report the effects of the three additives on gonadal development in E. carinicauda , with females showing the more significant effects.