INFLUENCE OF THE EPA DHA RATIO IN ROTIFERS ON GILTHEAD SEABREAM (SPARUS-AURATA) LARVAL DEVELOPMENT/

A feeding experiment was carried out to investigate the influence of t he eicosapentaenoic acid (EPA, 20:5n-3) to docosahexaenoic acid (DHA, 22:6n-3) ratio (EPA/DHA) on 17-day-old Sparus aurata larval developmen t. Larvae were fed rotifers (Brachionus plicatilis) enriched with four different lipid emulsions containing the same amount of total n-3 hig hly unsaturated fatty acids (n-3 HUFA) but different EPA/DHA ratios. T he different EPA/DHA ratios of the emulsions gave rise to different ra tios in the enriched rotifers, Furthermore, increments of the EPA/DHA ratio in rotifers produced a decrease in larval growth performance, so that larvae fed rotifers containing the highest EPA/DHA ratio showed the poorest growth rate, The analysis of fatty acids from larvae showe d that there was a significant linear relationship between EPA/DHA rat io in their total polar lipids (TPL) and larval growth, At the same ti me, when the EPA/DHA ratio increased in rotifers, there was an increas e in total n-3 HUFA in larvae total neutral lipid (TNL), which was mai nly due to the accumulation of EPA. Results obtained in the present st udy suggest that for the same level of total n-3 HUFA, larval growth p erformance can be improved by a decrease in EPA/DHA ratio in rotifers, indicating the importance of DHA during the first days of S. aurata l arval development. (C) 1997 Elsevier Science B.V.