Effect of phytoplankton and temperature on the reproduction of the Pacific oyster Crassostrea gigas: investigation through DEB theory

• Published in: Journal of Sea Research
• Main Authors: Bernard, Ismael, de Kermoysan, Goulwen, Pouvreau, Stephane
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDV]Life Sciences [q-bio]; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://hal.science/hal-04499092; https://hal.science/hal-04499092/document; https://hal.science/hal-04499092/file/14606.pdf; https://doi.org/10.1016/j.seares.2011.07.009

International audience DEB theory can be used to obtain a detailed description of energy allocation in organisms and the control of this allocation by temperature and food concentration. In this study, we modified the model of Bourlès et al. (2009) developed for the Pacific oyster, Crassostrea gigas, to improve the description of reproductive effort. The model was amended in two ways: a new set of parameters was incorporated and a full description of gonad construction in spring was added, with a new state variable. The application of this model to a dataset for oyster growth measured in four bays over two years showed that this model better described reproductive effort, without modifying overall growth dynamics. We then explored the reproductive responses of oysters to their environment in greater detail, by applying this new version of the model with the theoretical forcing variables of phytoplankton concentration and temperature. Spawning time was found to be driving principally by yearly mean temperature, and reproductive effort was found to depend mostly on the halfsaturation coefficient of the functional response. These results highlight the importance of the half-saturation coefficient and provide additional support for field research on the food preferences of oysters.