Changes in amino acids and essential fatty acids during early larval rearing of dentex

Samples of fertilized dentex, Dentex dentex, eggs and larvae fed enriched rotifers and Artemia according to standard hatchery procedures were analysed for free, total amino acid and fatty acid contents. Egg free amino acids (53 nmol ind–1) and total lipids (13.5 (mg ind–1) levels were considerably reduced in the newly hatched larvae (6.0 nmol and 5.7 (mg ind–1 respectively) while the amount of w-3 PUFA (Polyunsaturated fatty acid) and 20:4w-6 remained unchanged suggesting their possible role as essential fatty acids (EFA) in this species. In general, the changes in pattern of the major biochemical components during early development of dentex was similar to that outlined for other Sparidae species investigated to date. The essential amino acid profile of enriched live food did not show major imbalances when compared to that of dentex larvae. In contrast, the level of docosahexaenoic acid (22:6w3, DHA) and the DHA:EPA (eicosapentaenoic acid, 20:5w-3) ratio in larvae given rotifers and Artemia were significantly lower relative to the corresponding values in the unfed larvae.