Biochemical changes during larval development in the short neck clam, Paphia malabarica Chemnitz

Biochemical compositions were determined for eggs, D-shaped larvae, umbo larvae and pediveliger of the short neck clam Paphia malabarica Chemnitz. Spawned eggs were composed of 63.2% protein, 25.4% lipid and 11.4% carbohydrate. After 48 h of embryogenesis, 2.6% of the protein, 11.8% of the lipid and 3.2% of carbohydrate mass had been lost, providing 20.5%, 75.4% and 4.1% of the total energy expenditure of 0.2147 mJ embryo⁻¹. During 48 h of metamorphosis, lipid was utilized first, followed by a heavy consumption of protein; protein, lipid and carbohydrate lost 23.8%, 50.2% and 32.5% of their mass respectively. Protein and lipid supplied a comparable amount of energy for metamorphosis, 34.2% and 55.2%, respectively, whereas, carbohydrate contributed only 10.6% to the 2.733 mJ larva^−l metamorphic energy expenditure.