ALL-MALE AND MIXED SEX PRAWN (MACROBRACHIUM ROSENBERGII) PRODUCTION UNDER POLYCULTURE WITH CARPS

Abstract

An experiment was conducted at Dumurpota of Satkhira district for six months to compare the production performance of prawn (Macrobrachium rosenbergii) under all-male and mixed sex culture systems with carps (Labeo rohita and Catla catla). A total of six experimental ghers were used for two treatments in triplicates: carps with all-male prawn (T1) and carps with mixed sex prawn (T2). In both treatments, prawns were stocked at a rate of 10,000 PL/ha while C. catla and L. rohita were stocked each at a rate of 650 fingerlings ha-1. In T1, the initial average body weight of M. rosenbergii, L. rohita and C. catla was 7.33, 54.83 and 54.5 g respectively, whereas after 180 days of culture period the final average weights became 79.33, 256.5 and 253.47 g, respectively. In T2, the initial average body weight of M. rosenbergii, L. rohita and C. catla were 7.33, 55.07 and 54.17 g respectively, which resulted in the final average weights of 58.67, 258.87 and 252.57 g, respectively. The average production of prawn, L. rohita and C. catla in T1 was 745.97, 160.89 and 170.17 kg ha-1, respectively, while that in T2 was 540.81, 159.34 and 162.98 kg ha-1, respectively. The survival rates of M. rosenbergii, L. rohita and C. catla in T1 were found to be 91.28%, 89.93% and 87.93% respectively, whereas those in T2 were 87.56%, 90.3% and 88.3%, respectively. It was found that the production of carps was similar in both the treatments, but the production of prawn in T1 was substantially higher than that of T2 resulting in a net income difference of 77429.40 Tk ha-1. These results indicate that in polyculture with carps, the sex composition of prawn has no effect on the production of carp species but stocking of all male prawn can significantly increase the production of prawn and the economic return in such type of farming.