Geographic variation in stable isotopic and fatty acid composition of anguilliform leptocephali and particulate organic matter in the South Pacific

Liénart Camilla, Feunteun Eric, Miller Michael J., Aoyama Jun, Mortillaro Jean-Michel, Hubas Cédric, Kuroki Mari, Watanabe Shun, Dupuy Christine, Carpentier Alexandre, Otake Tsuguo, Tsukamoto Katsumi, Meziane Tarik. 2016. Geographic variation in stable isotopic and fatty acid composition of anguilliform leptocephali and particulate organic matter in the South Pacific. Marine Ecology. Progress Series, 544 : 225-241.

Quartile : Q1, Sujet : MARINE & FRESHWATER BIOLOGY / Quartile : Q2, Sujet : OCEANOGRAPHY / Quartile : Q2, Sujet : ECOLOGY

Résumé : The feeding ecology of leptocephali has remained poorly understood because they apparently feed on particulate organic matter (POM), which varies in composition, and it is unclear which components of the POM they assimilate. The δ13C and δ15N stable isotope (SI) and fatty acid (FA) compositions of 3 families of leptocephali and POM were compared in 3 latitudinal current zones of the western South Pacific. The δ15N signatures of leptocephali and POM overlapped, with both having their lowest values in the southern current zone. POM in general (across all zones) contained 38 FAs and was rich in saturated FAs (SFA) (16:0, 18:0, 14:0), while leptocephali contained 50 FAs, with high proportions of 16:0, and higher contributions of 22:6ω3, 20:5ω3, 18:1ω9, 16:1ω7 and other FAs than found in the POM. Serrivomeridae leptocephali in the north had higher δ15N signatures and were also distinguished from Nemichthyidae and Muraenidae larvae by their FA compositions (higher SFAs, lower 22:6ω3 and 20:5ω3). Although SI signatures of the Serrivomeridae larvae did not clearly vary with size, 16:0 and 18:0 FA proportions decreased with increasing larval size, and 22:6ω3 and 16:1ω7 increased in larger larvae. Correspondences between the latitudinal variations in nitrogen SI signatures and FA compositions of POM with those of leptocephali and the presence of FA markers of both autotrophic and heterotrophic organisms were consistent with leptocephali feeding on POM. POM can contain various materials from primary producers and heterotrophic microorganisms, but differences in the SI signatures and FA compositions in leptocephali remain to be explained through further research.

Mots-clés Agrovoc : larve de poisson, acide gras, isotope, alimentation des poissons, organisme indicateur, écologie animale, matière organique, azote, comportement alimentaire

Mots-clés géographiques Agrovoc : Pacifique Sud, Nouvelle-Calédonie, Fidji, Samoa, France

Mots-clés libres : Leptocephali, Fatty acids, Stable isotopes, Biomarkers, Trophic ecology, Oceanic currents

Classification Agris : M40 - Écologie aquatique
L51 - Physiologie animale - Nutrition

Champ stratégique Cirad : Hors axes (2014-2018)

Auteurs et affiliations

• Liénart Camilla, CNRS (FRA)
• Feunteun Eric, MNHN (FRA)
• Miller Michael J., University of Tokyo (JPN)
• Aoyama Jun, University of Tokyo (JPN)
• Mortillaro Jean-Michel, CIRAD-PERSYST-UMR ISEM (FRA) ORCID: 0000-0003-1911-9338
• Hubas Cédric, MNHN (FRA)
• Kuroki Mari, University of Tokyo (JPN)
• Watanabe Shun, Nihon University (JPN)
• Dupuy Christine, CNRS (FRA)
• Carpentier Alexandre, Université de Rennes (FRA)
• Otake Tsuguo, University of Tokyo (JPN)
• Tsukamoto Katsumi, University of Tokyo (JPN)
• Meziane Tarik, CNRS (FRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/580011/)

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