Effects of dietary eicosapentaenoic acid on growth, survival, pigmentation and fatty acid composition in Senegal sole (Solea senegalensis) larvae during the Artemia feeding period

We examined the effect of dietary eicosapentaenoic acid (EPA, 20:5n-3) on growth, survival, pigmentation and fatty acid composition of Senegal sole larvae. From 3 to 40 days post-hatch (dph), larvae were fed live food that had been enriched using one of four experimental emulsions containing graduated concentrations of EPA and constant docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6). Final proportions of EPA in the enriched Artemia nauplii were described as 'nil' (EPA-N, 0.5% total fatty acids, TFA), 'low' (EPA-L, 10.7% TFA), 'medium' (EPA-M, 20.3% TFA) or 'high' (EPA-H, 29.5% TFA). Significant differences among dietary treatments in larval length were observed at 25, 30 and 40 dph, and in dry weight at 30 and 40 dph, although no significant correlation could be found between dietary EPA content and growth. Eye migration at 17 and 25 dph was affected by dietary levels of EPA. Significantly lower survival was observed in fish fed EPA-H diet. Lower percentage of fish fed EPA-N (82.7%) and EPA-L (82.9%) diets were normally pigmented compared with the fish fed EPA-M (98.1%) and EPA-H (99.4%) enriched nauplii. Tissue fatty acid concentrations reflected the corresponding dietary composition. ARA and DHA levels in all the tissues examined were inversely related to dietary EPA. This work concluded that Senegal sole larvae have a very low EPA requirement during the live feeding period.