Effects of Stocking Density of All-male Macrobrachium rosenbergii (De Man, 1879) in Polyculture Ponds on Production and Economics (original) (raw)

2012, Asian fisheries science

A study was conducted to evaluate the effects of stocking density of all-male freshwater prawn Macrobrachium rosenbergii (De Man, 1879) on water quality, production and economic return in polyculture ponds. Trials involving three stocking densities of all-male prawn viz., 15,000, 20,000 and 25,000 ha-1 were carried out in replicates, combined in polyculture with fixed densities of silver carp, catla and small fish mola at 1,500, 1,000 and 20,000 ha-1 , respectively. Commercial prawn feed and fertilisers were applied routinely to all ponds. Blue-clawed males were harvested periodically at 15-day intervals over a 5-month culture cycle before final harvest. Differences in prawn density (treatments) did not significantly (P>0.05) affect any water quality parameters. Mean weight of prawn at harvest decreased significantly (P<0.05) with increasing stocking density. Net production of prawns however, was significantly higher at prawn densities of 25,000 and 20,000 ha-1 (661 kg. and 640 kg. ha-1 , respectively) compared with 15,000 ha-1 (535 kg. ha-1). Silver carp and catla production did not differ significantly among density treatments, while production of mola was higher at 20,000 prawn. ha-1. This treatment also resulted in higher net production of all species combined (1,688 kg. ha-1) as well as the highest return (US$ 2,597 ha-1).