Economic analysis of monosex culture of giant freshwater prawn (Macrobrachium rosenbergii De Man): a case study

All-male monosex culture of Macrobrachium rosenbergii (De Man) has emerged as a popular practice in India, especially in the state of Andhra Pradesh. A study was conducted to compare the economics of all-male, mixed and all-female culture in 15 adjacent, rectangular ponds of 4000 m2 each by stocking juveniles previously reared in a nursery for 60 days. The experiment was conducted using a completely randomized design with three treatments; T1 (all male), T2 (mixed) and T3 (all female), and five replicates for a period of 5 months after the nursery phase. Statistical analysis showed highly significant (P<0.01) differences among the three types of culture. The cost of production was estimated and the economic feasibility of the culture methods was evaluated by cost-return and partial budgeting analysis. The average weight, productivity and specific growth rate were the highest for all male culture, being 80.92±2.41 g, 1532 kg ha−1 and 1.97±0.02 respectively. All-female culture registered significantly higher survival (89.16±0.77%) and the best apparent feed conversion ratio of 1.26±0.02. The economic analysis revealed that all-male monosex culture of M. rosenbergii was 63.13% and 60.20% more profitable than mixed and all-female cultures respectively.