Biochemical indicator of sea scallop (Placopecten magellanicus) quality based on lipid class composition. Part I: Broodstock conditioning and young larval performance

摘要

The aim of this study was to test the validity of a lipid based indicator of larval quality of sea scallop Placopecten magellanicus. Objectives were 2-fold: (1) to determine the link between lipid class content and reproductive state of adults in the field and in the laboratory and (2) to follow lipid class content, growth, and survival during embryonic and early larval development. Adult scallops were periodically sampled during gametogenesis for lipid class and histological analysis of the gonads in the field at two locations and in the laboratory after feeding three different diets. Females were induced to spawn and lipid class content, larval growth, and survival of five batches of eggs were followed for 8 days after fertilization. Site, diet, and time had significant effects on lipid class composition of male and female gonads and gametogenesis of females. Triacyglycerol accumulation during vitellogenesis was characteristic of female gonads and explained respectively 56.4% and 71.3% of the variability in maturity and egg size. When spawning was induced, no major effect of location or diet on lipid composition of gonad and subsequent eggs was detected. Nevertheless, the mean number of eggs produced by females increased with atresia level in gonad, suggesting that egg quantity was incompatible with egg quality. Lipid class composition during embryogenesis and young larval development showed a high demand for triacyglycerol.