Different food particle sources in the pearl oyster Pinctada margaritifera and its epibionts

• Published in: Aquaculture Reports
• Main Authors: Lacoste, Élise, Raimbault, Patrick, Gaertner-Mazouni, Nabila
• Other Authors: MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé Papeete (ILM), Institut de Recherche pour le Développement (IRD), Université de la Polynésie Française (UPF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: size; organic-matter; crassostrea-gigas; pacific oyster; crepidula-fornicata; Isotopic niche; Trophic interactions; french-polynesia; isotope fractionation; lagoon tuamotu archipelago; Pearl oysters; phytoplankton biomass; seasonal-variation; Stable isotope ratio analysis; Suspension feeders; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://hal.umontpellier.fr/hal-03475050; https://hal.umontpellier.fr/hal-03475050/document; https://hal.umontpellier.fr/hal-03475050/file/1-s2.0-S2352513421003033-main.pdf; https://doi.org/10.1016/j.aqrep.2021.100887

WOS:000706788500001 International audience Suspended bivalve culture (e.g. longlines) transfers benthic biomass including bivalves and various epibionts toward the water column, creating strong trophic interactions with the planktonic compartment. Trophic interactions are of central interest for ecologists, yet not well understood in coastal lagoon food webs, especially in tropical areas. Using stable isotope (SI) analyses, this study explored the trophic relationships between marine particulate organic matter (POM), pearl oysters and epibionts, in two contrasted production areas in French Polynesia. Different size classes of POM (0.7-2 mu m, 2-20 mu m, 20-80 mu m, 80-250 mu m and \textgreater250 mu m) were well discriminated both by their delta C-13 and delta N-15 signature and results showed a low dietary overlap between pearl oysters and epibionts, likely due to assimilation of large particles in greater proportion by pearl oysters. Pearl oyster diet may vary in time in relation with variations of the basal trophic resource and selective feeding, such that their isotopic signature is more variable compared with that of epibionts. Pearl oysters and epibionts might alter nutrient cycling in a different way as reflected by their different tissue C:N.