A biochemical study of the larval and postlarval stages of the Chilean scallop Argopecten purpuratus

Abstract

Eggs, larvae and postlarvae of northern scallop, Argopecten purpuratus, were collected from the experimental hatchery of the Estación Costera de Investigaciones Marinas (ECIM) of the Pontificia Universidad Católica de Chile at Las Cruces to compare their protein, lipid and carbohydrate composition. In the egg protein, lipid and carbohydrate accounted for 38.2, 34.1 and 1.5% ash-free dry weight (AFDW), respectively. Protein in the larvae increased from 43.9 to 55.9% AFDW throughout larval development, and after metamorphosis values varied between 39.8 and 62.1% AFDW, with highest values in 22 day-old postlarvae. Lipids were constant at 20% AFDW during larval development, decreasing to 7.4% AFDW in the premetamorphosis period and increasing again to a constant value of 15% AFDW during the 22 days after metamorphosis, then decreasing to 2.5% AFDW. Carbohydrate contents were lower than lipid and protein in all larval stages, varying between 5.1 and 16.5% AFDW; during the postmetamorphosis period, carbohydrate content varied between 6.6 and 14.4%, but they were higher than lipid by day 60 after metamorphosis. The premetamorphosis period was characterized by a considerable decrease in lipid accompanied by a small decrease in protein and carbohydrate. The planting-out stage (commercial seed) was characterized by a high content of protein and a reduced content of lipid in relation to carbohydrate. This work provides basic information on the role played by the balance of energy reserves in the metabolism of scallop larvae.