The giant freshwater prawn Macrobrachium rosenbergii (de Man) is a commercially important species as a food item for local consumption as well as a valuable export product. Most of fresh water farms and fresh water reservoirs are located far from the coastal area. Fresh water prawn attains maturity in freshwater but requires brackish water for larval development. During present study, an attempt was made to evaluate the importance of each minor element in artificial seawater media for larval rearing of M. rosenbergii, due to which the cost of production of artificial sea water can be reduced....