Evaluation of freshwater prawn-small fish culture concurrently with rice in Bangladesh

An integrated aquaculture of freshwater prawn (Macrobrachium rosenbergii) and self-recruiting small fish mola (Amblypharyngodon mola) was conducted in farmers' rice fields at Mymensingh, Bangladesh. There were four treatments with three replications. Four stocking densities, 10 000, 15 000, 20 000 and 25 000 ha(-1), of freshwater prawn were applied. The stocking density of mola was the same (20 000 ha(-1)) in all treatments. During land preparation, triple super phosphate (TSP) and murate of potash (MP) were applied at the rate of 150 and 75 kg ha(-1) respectively. Urea was applied at the rate of 200 kg ha(-1) in equally distributed three installments after 16, 45 and 65 days of rice plantation. Prawns were fed with commercial pelleted feed at 3-8% body weight. All water quality parameters were found to be within the suitable range for freshwater prawn culture. There was a homogenous abundance of plankton communities in all treatments. The results of a 4-month culture period showed that the average production of prawn ranged from 222 to 388 kg ha(-1), mola 51 to 68 kg ha(-1) and rice 2 880 to 3 710 kg ha(-1). Significantly higher production of both prawn and mola was recorded in the plots where the freshwater prawn stocking density was 15 000 ha(-1). This treatment resulted in a net profit of USD 1100 ha(-1).