Fatty acid composition of polar and neutral lipid fractions of Octopus vulgaris Cuvier, 1797 paralarvae reared with enriched on-grown Artemia

Abstract

Up today, rearing of common octopus, Octopus vulgaris paralarvae is severely limited by the lack of success during the paralarval stage, with generalised mortalities occurring before the settlement of the juveniles. Among others, a lack of balance in the lipid and fatty acid composition of the food can be at the basis of this problem. The use of on grown Artemia cultured with the microalga Isochrysis galbana and further enriched with Nannochloropsis sp. has proven a certain degree of success. The present work aims at studying the effects of this rearing protocol on the fatty acid composition of paralarvae, by comparison with a diet based on on-grown Artemia further enriched with a high polyunsaturated fatty acid (PUFA) oil emulsion. Although apparently no clear association between the fatty acid composition of the enriched preys and that of total lipids of paralarvae could be established, further fractionation and fatty acid analysis of the total lipids of the paralarvae into polar and neutral classes, followed by PCA, revealed that irrespective of the diet, both lipid fractions showed distinct fatty acid patterns. Besides, the fatty acid composition of the polar lipids was more conservative, whereas that of the neutral lipids was more influenced by diet and showed more variation among dietary treatments.