Effects of unilateral eyestalk ablation on growth and reproductive parameters in wild and pond-reared Penaeus monodon (Fabricius) broodstock.

Abstract

Effects of unilateral eyestalk ablation on wild and pond-reared Penaeus monodon during ovarian maturation were determined by examining the growth (e.g., carapace length, body length, body weight) and reproductive (e.g., gonad weight, gonadosomatic index (GSI), average and maximum oocyte diameter) parameters to compare their reproductive potential. Growth parameters were similar in the wild unablated and wild ablated prawns from the immature or previtellogenic (P) to mature or cortical rod (C) stages but increased during the immature (P) to maturing or vitellogenic (V) stages in the pond ablated prawns. During stage C, gonad weight was highest in the wild unablated group while GSI, average and maximum oocyte diameter was similar in the three groups. After spawning (stage S), gonad weight was similar in all groups but GSI, average and maximum oocyte diameter were higher in the pond ablated prawns than in the wild unablated and wild ablated groups. Changes in growth and reproductive parameters at various stages of maturation suggest that reproductive performance successively decreased in the wild unablated, wild ablated and pond ablated P. monodon.