Lipid characterization of Pleuragramma antarcticum (Nothoteniidae) larvae off East Antarctica (139°E-145.10°E) during summer

• Main Authors: Tavernier, Eric, Mayzaud, P., Boutoute, M., Vallet, Carole, Koubbi, P.
• Other Authors: Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Nord )
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: Antarctic; East Antarctica; Mertz Glacier; Mertz Glacier Tongue; Terre Adélie; Terre-Adélie; The Antarctic; Antarc*; Antarctic silverfish; Antarctica; Polar Biology; Copepods
• Online Access: https://hal.archives-ouvertes.fr/hal-00761349

International audience Pleuragramma antarcticum (Antarctic silverfish) larvae are a key component of the neritic assemblages in the Antarctic coastal waters and can be considered as an indicator of the future changes that may occur in this area. Lipid class and fatty acid composition was studied to assess the nutritional status and evaluate the type of dominant trophic interactions of P. antarcticum larvae collected between Terre Adélie and the Mertz Glacier Tongue (139°E-145.10°E) during summer 2007. P. antarcticum larvae exhibit moderate lipid levels (11.9-15.0% dry weight). Lipid class analyses showed a similar pattern over the study area consisting mainly of polar lipids (61-75% of total lipids). During their first summer, larvae started to accumulate small amount of lipid reserves in the form of triacylglycerols (10-16% of total lipids). Polar lipids were dominated by phosphatidylcholine (55-59%) followed by phosphatidylethanolamine (19-21%). Fatty acid signature of triacylglycerols indicates (1) a dominance of copepod of the Oithona type in the trophic pattern of P. antarcticum larvae and (2) a significant contribution of phytoplankton. In the same way, the analysis of gut content shows that 70% of larvae fed on various assemblages of phytoplankton and zooplankton (mainly copepods) and 30% of larvae fed exclusively on phytoplankton. Although a carnivorous diet is commonly described, our results suggest that P. antarcticum larvae showed an opportunistic feeding strategy (i.e. high degree of omnivory) and that dietary energy seems to be mainly directed towards fast growth rather than energy storage for periods of starvation.