Requirements of Larval Yellowtail for Eicosapentaenoic Acid, Docosahexaenoic Acid, and n-3 Highly Unsaturated Fatty Acid

Abstract

This study was conducted to investigate the requirements of larval yellowtail Seriola quinqueradiata for eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and n-3 highly unsaturated fatty acid mixture (n-3 HUFA) by feeding them with Artemia nauplii containing different levels of these fatty acids or the mixture. Fish fed Artemia enriched with a low amount of n-3 HUFA showed low growth and survival, and poor vitality. These fish displayed swimming disorders such as spinning and disorientation. The best results were obtained in larvae fed on the nauplii containing 3.9% n-3 HUFA (on dry matter basis). Elevation of DHA level in the nauplii improved survival, growth and vitality. Fish fed EPA showed poor vitality as low as those fed EFA deficient nauplii, although growth and survival were improved by supplement of EPA. The requirement of larval yellowtail for n-3 HUFA is estimated to be about 3.9% (2.5% EPA, 1.3% DHA and others) in Artemia on dry matter basis. The requirement for DHA is estimated to be 1.39-2.63% in Artemia on the basis of larval vitality. On the other hand, it is satisfied with 1.39% DHA (2.25% n-3 HUFA) or 3.65% EPA on the basis of survival rate.