Reproductive Performance and Larval quality of Freshwater Prawn Broodstock of different water resources

Abstract

The present study was conducted to compare the reproductive performance and offspring quality of adults of the giant freshwater prawn, Macrobrachium rosenbergii broodstock from four different sites (1) Ganga riverine wild breeders (GW) (2) Ganga riverine pond-reared (GP) breeders (3) Gandak riverine wild breeders (gp); and (4) Gandak riverine pond-reared breeders (gw) were grown out in culture ponds and collected as broodstock at the end of grow-out culture period. M. rosenbergii females were individually stocked for 120 days in three 1500L freshwater recirculation system tanks and fed a commercial diet. Ovarian development, molting and spawning events were checked daily. In addition a number of egg and larval quality parameters were determined. The breeding frequency, fecundity, egg laying success rate, egg dimensions and egg hatchability were not significantly different between animals from the four different sources. However, there were significant differences in terms of offspring quality between the different broodstock sources. Individual dry weight, larval development rate, time to reach the post-larval stage, post-larval survival and tolerance to ammonia toxicity were all better in offspring originating from all broods did not significantly differ in terms of breeding frequency, fecundity and egg dimensions. However, larval quality of Ganga riverine wild and Ganga riverine pond-reared breeders was markedly better than that of Gandak riverine wild reared stock and Gandak riverine pond-reared stock in terms of larval development, survival and post larval production. These results indicate that broodstock sourcing deserves proper attention in hatchery operations of M. rosenbergii. It furthermore proves that domesticated (pond-reared) animals are not necessarily inferior as breeders as compared to wild-sourced animals. The results may also point out the potential to selectively breed stocks with improved characteristics adapted to the local culture environment.