Lipidomics analysis of juveniles’ blue mussels (Mytilus edulisL. 1758), a key economic and ecological species

AbstractBlue mussels (Mytilus edulisL.) are important components of coastal ecosystems functioning through benthopelagic coupling and ecosystem engineering. At the same time, mussel production is central in the economy of coastal areas. Therefore, understanding their nutritional, physiological and metabolic processes at key life stages is important for their management, both within food production systems and in wild populations.Lipids are crucial molecules for bivalve growth, but their diversity and roles have been considered from fatty acid (FA) perspective. In this paper, we applied lipidomics to bivalve nutrition. Lipidomics provides a holistic perspective on lipid patterns; by examining the lipidome, important physiological information can be acquired. Here, we use controlled laboratory experiments to elucidate the responses to changes in the diet of newly settled mussels juveniles, one of the most critical life stages. The diets considered in this study are single strains diet ofCylindrotheca fusiformisCCAP 1017/2 – CYL,Isochrysis galbanaCCAP 927/1– ISO,Monodopsis subterraneanCCAP 848/1 – MONO,Nannochloropsis oceanicaCCAP 849/10– NANNO and a commercial algae paste –SP.The diets had a significant effect on spat GR and WI, and according to their efficacy resulted ranked as follows: ISO>NANNO/CYL>SP>MONO. Spat FA composition and neutral lipid content (principally triacylglycerols - TG), were influenced by the diets. Furthermore, untargeted lipidomics also showed shifts in several phospholipid species, with changes related to the essential PUFA available from the diet. TG content, neutral lipids and several TG and FA species were correlated (Spearman R2>0.8 FDR p<0.05) with spat WI, suggesting their possible application as markers of mussel juvenile condition. The availability of dietary essential PUFA deeply modified the spat lipidome both for neutral and for polar lipids. This change in the lipidome could have major impacts on their ecology and their production for food.