Effects of n-3 fatty acids on dentex larvae survival and growth

Abstract

The rotifer Brachionus plicatilis (S-type) and Artemia were fed with three enrichment types (Nanno: Nannochloropsis occulata, CEP: Commercial Enrichment Products: Selco ® from INVE Aquaculture NV and CLO: Cod Liver Oil emulsion). The polyunsaturated fatty acid composition in the regimes was tested to estimate survival and growth of common dentex larvae. During rotifers feeding phase, EPA (20:5n-3) contents were of 4.6 ± 1.46 mg g-1 DW for Nanno regime, 5.1 ± 0.22 for the CEP regime and 6.1 ± 0.87 mgg-1 DW for the CLO regime; for DHA (22:6n-3), CLO regime contains the highest level (7.2 ± 1.26 mg g-1 DW) than the two other regimes. During Artemia feeding phase, EPA contents were 2.4 ± 0.05, 3.2 ± 0.03 and 8.3 ± 0.41 mg g-1 DW and in DHA 0.4 ± 0.00, 4.4 ± 0.13 and 8.6 ± 0.69 mg g-1 DW respectively for Nanno, CEP and CLO enrichments. The weight growth of larvae showed a significant difference (p < 0.05) for the rotifers and Artemia feeding phases. The respective SGR for the three enrichments are 8.8, 8.9 and 9.2 and survival rates were of 3.15, 4.03 and 8.35% respectively for Nanno, CEP and CLO regimes.