Effect of Artemia enrichment on the growth and survival of Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel) larvae.

This study was carried out to investigate the suitability of Artemia enriched with docosahexaenoic acid (DHA) and choline as live food on the growth and survival rate of the Pacific bluefin tuna (PBT; Thunnus orientalis) larvae. The PBT larvae were fed either Artemia enriched with oleic acid (Diet 1), DHA (Diet 2), DHA+choline 1.0 mg L−1 (Diet 3) and DHA+choline 2.0 mg L−1 (Diet 4) or striped knifejaw larvae (Diet 5, reference diet), in duplicate for 12 days. Enrichment of Artemia with DHA significantly increased the DHA levels to 13.9, 13.8 and 12.5 mg g−1 on a dry matter basis in Diets 2, 3 and 4 respectively; however, the levels were significantly lower than the reference diet (26.9 mg g−1 dry matter basis; Diet 5). Although growth and survival rate were significantly improved by the enrichment of Artemia with DHA and choline, the improvement was negligible compared with the enhanced growth and survival rate of the fish larvae-fed group ( P<0.05). The results demonstrated that enriched Artemia does not seem to be the right choice to feed the PBT larvae perhaps because of the difficulties in achieving the correct balance of fatty acid with higher DHA/EPA from Artemia nauplii. [ABSTRACT FROM AUTHOR]