Histochemical changes of energy rich organic compounds like protein, glycogen and lipids in the gonads of Musculista senhausia (Biva1via:Mytilidae) from Cochin backwaters, west coast of India were studied for the first time. These fractions exhibited marked differences in male and female gonads during various developmental stages. Protein and lipid were found to have an important role as storage materials for utilization during gametogenesis. It is evident that gametogenesis and embryogenesis are two distinct energy demanding processes.

Protein, lipid and glycogen reserves, Gametogensis, mussel