Sources of paralytic shellfish toxin accumulation variability in the Pacific oyster Crassostrea gigas

• Published in: Toxicon
• Main Authors: Pousse, Emilien, Flye-Sainte-Marie, Jonathan, Alunno-Bruscia, Marianne, Hegaret, Helene, Jean, Frédéric
• 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 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), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), ANR-13-CESA-0019,ACCUTOX,De la caractérisation des déterminants de l'accumulation des toxines paralysantes (PST) chez l'huître (Crassostrea gigas) au risque sanitaire pour l'homme dans son contexte sociétal(2013), ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Alexandrium minutum; Paralytic shellfish poisoning; Accumulation; Clearance rate; Feeding behavior; Pacific oyster; ACL; [SDE]Environmental Sciences; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV]Life Sciences [q-bio]; [SDV.BA]Life Sciences [q-bio]/Animal biology; Pacific; Crassostrea gigas
• Online Access: https://hal.archives-ouvertes.fr/hal-02324600; https://hal.archives-ouvertes.fr/hal-02324600/document; https://hal.archives-ouvertes.fr/hal-02324600/file/Pousse_etal_Toxicon_2018.pdf; https://doi.org/10.1016/j.toxicon.2017.12.050

International audience This study was designed to assess the contribution of feeding behavior to inter-individual variability of paralytic shellfish toxin (PST) accumulation in the Pacific oyster Crassostrea gigas. For this purpose 42 oysters were exposed for 2 days to non-toxic algae and then for 2 other days to the PST producer Alexandrium minutum. Individual clearance rate (CR) of oysters was continuously monitored over the 4 days using an ecophysiological measurement system. Comparison of CR values when exposed to toxic and non toxic algae allowed to estimate a clearance rate inhibition index (CRII). Toxin concentration of oysters was quantified at the end of the experiment. These data allowed to estimate the toxin accumulation efficiency (TAE) as the ratio of toxin accumulated on toxin consumed. Changes of clearance rate during the experiment indicated that all individuals stopped feeding immediately after being exposed to A. minutum for at least 7 h. This fast response likely corresponded to a behavioral mechanism of avoidance rather to a toxin-induced response. Individuals also showed high inter-variability in their recovery of filtration after this period. Most of the inter-individual variability (78%) in PST accumulation in C. gigas could be explained by the consumption of A. minutum cells, thus emphasizing the importance of the feeding behavior in accumulation. Based on the toxin concentration in their tissues, oysters were clustered in 3 groups showing contrasted patterns of PST accumulation: the high accumulation group was characterized by high feeding rates both on non-toxic and toxic diet and subsequently a low CRII and high TAE. Inversely, the low accumulation group was characterized by low filtration rates, high CRII and low TAE. Both filtration capacity and sensitivity of oysters to toxins may account for the differences in their accumulation. The contribution of TAE in PST accumulation is discussed and might result from differences in assimilation and detoxification abilities among ...