Abstract: Biochemical studies are very important from the nutritional point of view. The biochemical constituents in animals are known to vary with season, size of the animal, stage of maturity, temperature and availability of food also to elucidate the osmoregulatory ion concentration. The present study quantified the nutritive value of sea food and the ionic regulation which is good measure for leading a fruitful aquaculture. So for methods used for the detection of sodium and chlorideion concentrations are Elico digital flame photometer. Biochemical composition of hemolymph and different tissues was carried out and it has been observed that more protein content were found in eyestalk extract injected female crabs (64.0%) while as less percentage was found in normal female crab (10.66%) and lipids were found more in injected female and ablated male (16.8 mg mL-1) while it is very low in normal male crab (12.6 mg mL-1). Carbohydrate percentage was found more in ablated male (7.6%) and less in eyestalk extract injected male (3.3%). The variations of the sodium and chloride ionic level in the hemolymph were studied by comparing the levels in the experimental animals with that of control animals. In the ablated animals of male crabs, the hemolymph showed decreased sodiumionic level (428 milliequivalent L-1) when compared to control animals while as in female it showed increase in the Na+ ion concentration (454 milliequivalent L-1). However, eyestalk extract injected animals of both sexes at the final stage showed a much increase in the sodium ionic level when compared to control and ablated animals.