Studies on the Effect of Unilateral Eyestalk Ablation in Maturation of Gonads of a Freshwater Prawn Macrobrachium dayanum

2 Abstract: The effect of unilateral eyestalk ablation in freshwater prawn Macrobrachium dayanum was investigated in the laboratory for 15 days. Healthy specimens of M. dayanum were taken (3.5-7.0 cm in length). Specimens with uniform ovarian and testes conditions (immature) were selected for the experiment. The eye stalk ablation was done by cutting the eyestalk from their bases with the help of fine sterilized scissors. The results obtained indicated that the removal of the eyestalk has accelerated the gonad development. In males we observed an increase in the testicular index in M. dayanum after the eye-stalk ablation, increase in the size of testis, follicle diameter and the number of the follicles and the mature follicles/Spermatocytes, after the eye-stalk ablation, is the testimony of the fact that the removal of eye-stalk of M. dayanum contains testis inhibiting factors. In female animals also there is an increase in the ovarian index in eyestalk ablated prawns as compared to normal animals. The study indicated a positive effect, incorporating unilateral eyestalk ablation is sufficient to induce gonadal development in Macrobrachium dayanum.