Rematuration of Spent Macrobrachium rosenbergii Female Broodstock through Dietary Manipulation and Eyestalk Ablation

Abstract

The single or combined effects of artificial feed and eyestalk ablation on gonadal maturation of spent Macrobrachium rosenbergii female brooders was studied in 48 females. Significant differ- ences in percent weight gain, food conversion ratio, specific growth rate, gonado-somatic index, number of molts, molting interval, and ovarian development stages were observed. The highest numbers of molts and shortest molting intervals were found in eyestalk-ablated groups while higher percent weight gains were obtained in non-ablated groups. Groups fed formulated feed registered lower percent weight gains and higher FCRs than groups fed natural feed (clam and squid meat). Females in immature stages were found only in non-ablated groups while the only ovigerous females were found in the ablated group fed formulated feed. In short, unilateral eye- stalk ablation together with properly formulated feed (46.1% crude protein) could induce gonad maturation of spent female Macrobrachium rosenbergii brooders during the non-monsoon sea- son.