Influence of eicosapentaenoic to docosahexaenoic acid ratio (EPA/DHA) of dietary lipids on growth and fatty acid composition of gilthead seabream (Sparus aurata) juveniles

A feeding experiment was conducted to investigate the influence of eicosapentaenoic acid (20:5n-3; EPA) to docosahexaenoic acid (22:6n-3; DHA) ratio (EPA/DHA) of dietary lipids on growth and fatty acid composition of gilthead seabream juveniles. Fish were fed three diets containing the same amount of total n-3 highly unsaturated fatty acids (n-3 HUFA) but different EPA/DHA ratios. No mortality was observed during the feeding trial, but significant differences were found in growth rate. The best growth rate and lowest hepatosomatic index was obtained in fish fed a diet containing an EPA/DHA ratio of 2/1. The dietary lipid treatment had no effect on the EPA/DHA ratio in neutral lipid of all the tissues studied. However, marked differences in EPA/DHA ratio were found in polar lipids of the liver, muscle and gills. It is concluded that, under the conditions employed, an EPA/DHA ratio of 2/1 in the diet improves the condition of juvenile gilthead seabream. (C) 1997 Elsevier Science B.V.