Juveniles of M. rosenbergii were obtained from the spawning of wild broodstock in a commercial hatchery located in Naihati,North 24 Parganas district of West Bengal, India and transported in oxygenated polythene bag (pH 7.5, alkalinity 100 ppm as CaCO3,hardness 120 ppm as CaCO3) to the laboratory. Before experimen-tation, healthy and active juveniles (transparent body and activelyswimming) were segregated into 500 L FRP (fibreglass reinforcedplastic) tanks filled with freshwater under constant aeration andacclimatized for three weeks at ambient temperature of 27–29.5◦C.About 30% of water was renewed daily. Prawn were fed ad libitumtwice daily (9:00 h and 16:00 h) with commercial pelleted feed (35%crude protein). The leftover food and faecal matters were removeddaily by siphoning.