Influence of bilateral eyestalk ablation on gonads of fresh water prawn, Macrobrachium dayanum.

: The study was carried out in laboratory for one month to know the effect of bilateral eyestalk ablation on gonads of Macrobrachium dayanum. Healthy specimens of Macrobrachium dayanum in the size group of (4-6 cm in length) were taken for the experiment. The eyestalk ablation was done by cutting away the eyestalks from their bases with sterilized scissor. The results here obtained indicated positive effects of eyestalk ablation on ovary and testes of Macrobrachium dayanum. The histological details of the female prawns which were ablated showed post-vitellogenic oocytes; where as unablated females prawn never developed beyond pre-vitellogenic oocytes. Similarly in males, testes showed pronounced development of different cells as compared to unablated ones. Fully developed spermatozoa were seen in ablated ones. Gonadosomatic studies also showed that ovarian and testicular cells developed better as compared to control and these findings suggest the fact that the eyestalks of M. dayanum contain ovary and testis inhibiting factors.