BIOCHEMICAL UTILIZATION DURING EMBRYOGENESIS AND METAMORPHOSIS IN THE BAY SCALLOP, ARGOPECTEN IRRADIANS CONCENTRICUS (SAY).

Protein, total lipid, and carbohydrate were measured for spawned eggs, D-shaped larvae, premetamorphic, and metamorphic larvae of the bay scallop Argopecten irradians concentricus (Say). Spawned eggs were composed of 64.0% protein, 26.5% lipid, and 9.5% carbohydrate. After 48 hours of embryogenesis, 13.6% of the protein, 46.3% of the lipid, and 20.8% of the carbohydrate mass had been lost, providing 25.5%, 69.8%, and 4.8% of the total energy expenditure of 0.176 mJ per embryo. During 48 hours of metamorphosis, lipid was utilized first, followed by a heavy consumption of protein; protein, lipid and carbohydrate lost 55.6%, 59.4%, and 67.3% of their mass respectively. Protein and lipid supplied a comparable amount of energy for metamorphosis, 47.9% and 43.5%, respectively; whereas, carbohydrate contributed only 8.6%, to the 4.35 mJ per larva metamorphic energy expenditure. [ABSTRACT FROM AUTHOR]