IMPACT OF STOCKING DENSITY OF BRACKISHWATER CATFISH ON GROWTH AND PRODUCTION OF SHRIMP AND PRAWN IN POLY CULTURE
The study was conducted to optimize stocking density of Mystus gulio in polyculture with shrimp (Penaeus monodon) and prawn (Macrobrachium rosenbergii) during year 2015-2016 in the pond of Bangladesh Fisheries Research Institute, Brackishwater Station, Paikgacha, Khulna. Three different stocking density such as 40000, 50000 and 60000 per hector were maintained, where catfish density was 10000, 20000 and 30000/ha in T1 T2 and T3 treatments, respectively. Total production was 750.6, 895.8 and 756.42 kg/ha in T1 T2 and T3, respectively. Total production was 895.8 kg/ha in T2 was significantly higher than T1 and T3. Catfish production was 104.3, 184.8 and 168.8 kg in T1 T2 and T3, respectively. However production of catfish in T2 was significantly higher than T1. Net benefit was Tk. 314862.5, Tk. 376275.0 and Tk. 268255.0 with the corresponding cost benefit ratio of 1.76, 1.94 and 1.33 in T1 T2 and T3, respectively. Net benefit and BCR value in T2 was significantly higher than T1 and T3 which implies that percentage of net economic return is higher in 50000/ha densities where catfish was 20000/ha. So it is understood that polyculture of shrimp, prawn and catfish with a stocking density of catfish was 20000/ha would be environment friendly and economically viable for coastal areas of Bangladesh.