Feed Intake Pattern and Growth Performance of Indian Major Carps, Common Carp and Freshwater Prawn in a Rice-fish Integration System

摘要

This study was carried out to evaluate feed intake pattern, growth and yield performance of fish and prawn under rice-fish integration system in rainfed medium land ecosystem. Omnivorous feeding behaviour was observed in the case of each species except Catla catla, while the degree of omnivorous feeding behaviour was high in the case of Macrobrachium rosenbergii (giant freshwater prawn). Comparative degree of satiation, indicated a distinct declining trend from fry/juvenile stage to advanced fingerling stage in the case of each species. Positive indices of electivity were observed for phytoplankton (0.02 - 0.31) in monsoon- winter, while it was negative for zooplankton (-0.14 to - 0.46) during the same period. Matrix of dietary overlap(s) established a stronger possibility of competition for food among bottom dwellers. Irrespective of stocking density, faster growth rate was recorded for Catla catla followed by Cyprinus carpio, Cirrhinus mrigala, Labeo rohita and Macrobrachium rosenbergii. However,an average productivity of 906.6 - 1282.3 kg centre dot ha~(-1) of fish and prawn has been achieved, which was much higher than the earlier recorded productivity in a season under rice-fish integration system in India. Moreover, for short duration fry to advanced fingerling stage rearing under rice-fish culture system, a stocking density of 25000 ha~(-1) is recommended, beyond which biomass yield decreases and density-dependent growth takes place.