Experimental studies on the cannibalistic habit of Macrobrachium rosenbergii (de Man)

Abstract

Cannibalistic habit of Macrobrachium rosenbergii in intensive cultures was studied in a semi-recycled in a semi-recycled fresh water system under varying environmental conditions. Observations were made on the moulting rate, mortality rate, tube occupancy and substrate preference under different light intensities and their inter and intra relations studied through linear correlations and their variations by MANOVA. Growth pattern was determined using Schnutes versatile growth model. The morphometry of the animals were studied to understand the damage or loss of appendages due to cannibalism and its trend of variation in relation to number of tubes. In intensive culture, cannibalism appeared to be independent of the physical surroundings and the animals were found more susceptible to cannibalism soon after the moult. This can be guarded by providing suitable hideouts. Dried commercial feed, alternated with fresh animal tissues was found to reduce cannibalism upt 70%.