Abstract

Fulfilment of the nutritional requirements of pectinids in the reproductive conditioning, larval culture, and postlarval culture phases is determined by the levels and quality of the proteins and lipids in the diets utilised in their culture. The protein content of the microalgal diet affects the time to reach maturity, the fecundity of the females, and the energy balance in the broodstock, showing that diets high in protein favour all these parameters and also improve the quality of the larvae. An increase in the protein content of microalgal food by manipulation of their culture medium significantly increases larval growth and also favours improved growth of the postlarval juveniles to the 5mm size. Pectinid larvae show greater growth and survival when the diets contain high levels of DHA/PA together with low values for EPA/HUFA, with EPA being less important because the larvae are efficient in desaturation beginning with the linolenic acid (18:3n-3), and also seem to have the capacity for obtaining ARA from linoleic acid (18:3n-6). The microalgal diet for pectinids in the larval phase may be substituted up to 40% by lipid emulsions enriched with EPA and DHA, while in the postlarval phase to 2 mm this substitution may be up to 20% of the microalgal diet without damaging growth and survival in this phase. The carbohydrates begin to be important in late juvenile stages, which may be related to availability of enzymes in the digestive system where amylases only appear after the scallops reach the 5 mm size. Pectinids at all stages are assured of adequate levels of vitamins and pigments when fed with microalgae. Micronutrients in the marine environment of the scallops readily provide their mineral requirements by direct absorption from seawater. © 2006 Elsevier B.V. All rights reserved.