Assessment of growth and production potential of Indian butter catfish Ompok bimaculatus as a substitute for mrigal Cirrhinus mrigala in polyculture of Indian major carps

The growth and production of Indian butter catfish Ompok bimaculatus, popularly known as ‘pabda’ with Indian major carps (IMCs, catla, rohu and mrigal) was evaluated with an aim to introduce this fish into carp-based polyculture systems. Nine earthen ponds of similar dimensions were used for this study. The duration of culture was eight months and three species compositions, viz., catla, rohu and mrigal (4:3:3) (T1), with 100% replacement of mrigal with pabda (T2) and 50% replacement of mrigal with pabda (T3) were used. The overall fish stocking density was 7500 fingerlings per ha. The fish were fed with farm-made feed (21.8% CP) @ 2-4% of their body weight. Pabda attained highest growth and survival in T2 and the introduction of pabda did not affect the overall survival, growth and production of catla and rohu. It also did not affect the overall fish production in terms of quantity (p≥0.05) in all the treatments. The dietary overlapping indices between the co-habiting fishes were insignificant across the treatments except for pabda and mrigal in T3 (0.74). Thus, it is concluded that co-culture of pabda and IMCs is possible by replacing mrigal partially or fully to have a higher return in terms value from the carp-based culture system. Keywords : Butter catfish, Growth rate, Indian major carps, Pond culture, Survival