Abstract: An investigation was made on the juveniles of a commercially important and cultivable species of second largest freshwater prawn Macrobrachium malcolmsonii for its responses to unilateral eyestalk ablation, different diets and some biochemical aspects. Protein content of the adult Artemia fed animals was higher than that of artificial feeds 1 and 2, oyster and earthworm fed eyestalk ablated prawns. In intact control animals, protein content was differ significantly when the animals were fed with different feeds except the artificial feed 1 and oyster. Eyestalk ablation had no significant effect on the body carbohydrate content of M. malcolmsonii fed with different feeds. The lipid content of the eyestalk ablated and intact control animals fed with adult Artemia showed significantly higher values when compared to other feeds. The content of free amino acids in eyestalk ablated animal fed with adult Artemia and earthworm was significantly higher from those fed with other feeds. Intact control animals offered with adult Artemia showed significantly higher contents of free amino acids as compared to those fed with other feeds. The eyestalk ablation had no effect on water content. The ash content of the eyestalk ablated animals fed with oyster and earthworm was significantly higher than those fed with other feeds. The intact control animals showed higher ash content when fed with earthworm, oyster and artificial feed 2 than those fed with other feeds. The energy content of the eyestalk ablated and intact control animals fed with adult Artemia was significantly higher than those fed with other feeds.