Lorrain Anne auteur aut IRD Paulet Y.M. auteur aut IRD Chauvaud L. auteur aut IRD Savoye N. auteur aut IRD Donval A. auteur aut IRD Saout C. auteur aut IRD text journalArticle eng There have been several studies where the isotopic composition of organisms has been determined seasonally, but fewer have examined separate organs. In this context, separate organs (e.g. gonad, digestive gland and muscle), of a suspension-feeder, the scallop Pecten maximus, were used to assess seasonal changes of both stable isotopes and biochemical components. Our study used multiple indicators (stable carbon and nitrogen isotopes ratios, biochemical components and seston Chl a) to track nutritive activity and energy allocation in P. maximus from the Bay of Brest (France). In addition to seasonal variation in the isotopic composition of P. maximus tissues, we found strong differences in the mean isotopic signatures of different organs. This has serious implications for interpretation of animal diets and potential use in animal physiology. Furthermore, we present evidence that seasonal variations of metabolism will cause changes in the isotopic composition not related to changes in the diet. Interpretation of isotopic data may require consideration of values from several separate organs. Finally, ?15N appears powerful to track metabolite fates in the scallop P. maximus. specialized 034 275 47-61 2002 https://www.documentation.ird.fr/hor/PAR00007491 https://www.documentation.ird.fr/hor/PAR00007491 IRD - Base Horizon / Pleins textes 2010-02-02 2011-07-18 PAR00007491 fre