title: Biological and environmental influence on tissue fatty acid compositions in wild tropical tunas.
abstract: This study examined the fatty acid composition of three sympatric tropical tuna species (bigeye Thunnus obesus, yellowfin T. albacares and skipjack tuna Kastuwonus pelamis) sampled in the Western Indian Ocean in 2013. The fatty acid compositions of neutral and polar lipids, respectively involved in energy storage and cell membrane structure, were explored and compared in four tissues (red and white muscles, liver and gonads), according to biological (size, sex and maturity) and environmental (season and area) factors. The liver and the red muscle were the fattest tissues (i.e., higher levels of storage lipids) in all species and polar lipids were the lowest in the white muscle. Species and tissue types explained most differences in fatty acid compositions, while environmental factors had limited effects, except in the hepatic cell membrane where fatty acid composition varied with monsoons. Docosahexaenoic acid (22:6n-3) was the major fatty acid in both polar and neutral lipid fractions, especially in muscles. Eicosapentaenoic acid (20:5n-3) and oleic acid (18:1n-9) were in higher proportion in neutral than in polar lipids. Arachidonic acid (20:4n-6) and 22:6n-3, together with docosapentaenoic acid (22:5n-6) and stearic acid (18:0), showed preferential accumulation in polar lipids. 20:4n-6 was particularly involved in cell membranes of ovary and white muscle. Overall, an important inter-individual variability in fatty acid compositions of structural lipids was found within tissue types despite considering biological factors that are most likely to influence this type of lipids. It suggests that fatty acid profiles are influenced by individual-specific behaviors.
authors.affiliation: IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles. Electronic address: Fany.Sardenne@hotmail.fr.
authors.forename: Fany
authors.initials: F
authors.lastname: Sardenne
authors.affiliation: UMR CNRS 6539-LEMAR (Laboratoire des Sciences de l'Environnement Marin), IUEM (Institut Universitaire Européen de la Mer), Université Européenne de Bretagne, Technopôle Brest Iroise, 29280, Plouzané, France.
authors.forename: Edouard
authors.initials: E
authors.lastname: Kraffe
authors.affiliation: IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles; TOXALIM, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Amiel
authors.affiliation: IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles; TOXALIM, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France.
authors.forename: Edwin
authors.initials: E
authors.lastname: Fouché
authors.affiliation: TOXALIM, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Debrauwer
authors.affiliation: Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ménard
authors.affiliation: IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bodin
mesh_terms: D000818:Animals; D002849:Chromatography, Gas; D005227:Fatty Acids / Q000378:metabolism*; D014413:Tuna / Q000378:metabolism*
chemical_list: D005227:Fatty Acids
keywords: Biological membrane; Essential fatty acids; Large pelagic fish; PUFA; Polar and neutral lipids; Western Indian Ocean