Effects of Live Food enrichment on Yellowtail Amberjack Seriola lalandi dorsalis (Gill 1863) Larvae

Abstract

Our study examined the effect of live food enrichment on the rearing performance of yellowtail amberjack Seriola lalandi dorsalis from day 3 posthatch (DPH) to 12 DPH. Three rotifer enriched treatments, 1) Nannochloropsis sp, 2) S.presso® (INVE Aquaculture) half dose (Sp1/2), and 3) S.presso® full dose (Sp1) were administered. Growth of yellowtail amberjack larvae was not significantly affected by these enrichments (P>0.05) but final survival rates were significantly affected (P<0.05). Jaw malformation of fish fed with only Nannochloropsis sp. enriched rotifers was significantly higher than those fed S.presso enriched rotifers. Fatty acid composition of rotifers was significantly affected by the enrichment treatments (P<0.05). Arachidonic acid (ARA, 20:4n-6) and Eicosapentaenoic acid (EPA, 20:5n-3) were highest in rotifers enriched with Nannochloropsis. Docosahexaenoic acid (DHA, 22:6n-3) level was highest in Sp1 treatment. Total saturated fatty acids in rotifers was not significantly affected (P>0.05), but total polyunsaturated fatty acid content was significantly affected (P<0.05) by enrichment. DHA/EPA ratio in rotifers was significantly affected by the enrichment (P<0.05). Highest total polyunsaturated fatty acids were observed in rotifers enriched with Sp1. On 12 DPH, fatty acid composition in the larvae was significantly affected by the nutrient enhancement (P<0.05). ARA and EPA levels were highest in the larvae fed with Nannochloropsis sp. enriched rotifers; highest DHA/EPA ratio in fish larvae was found in Sp1 treatment. Total polyunsaturated fatty acid in the larvae enriched with Sp1/2 and Sp1 was similar to the amount observed in fertilized eggs of yellowtail amberjack (P>0.05). Results indicate that enriched live feed can significantly affect rearing performance of yellowtail amberjack larvae; S.presso full dose enrichment is suitable for their initial rearing stages.