Bioactive extracellular compounds produced by the dinoflagellate Alexandrium minutum are highly detrimental for oysters
MINER, Philippe
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
HUVET, Arnaud
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
QUILLIEN, Virgile
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
< Réduire
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Institut Français de Recherche pour l'Exploitation de la Mer [IFREMER]
Langue
EN
Article de revue
Ce document a été publié dans
Aquatic Toxicology. 2018, vol. 199, p. 188-198
Résumé en anglais
Blooms of the dinoflagellate Alexandrium spp., known as producers of paralytic shellfish toxins (PSTs), are regularly detected on the French coastline. PSTs accumulate into harvested shellfish species, such as the Pacific ...Lire la suite >
Blooms of the dinoflagellate Alexandrium spp., known as producers of paralytic shellfish toxins (PSTs), are regularly detected on the French coastline. PSTs accumulate into harvested shellfish species, such as the Pacific oyster Crassostrea gigas, and can cause strong disorders to consumers at high doses. The impacts of Alexandrium minutum on C. gigas have often been attributed to its production of PSTs without testing separately the effects of the bioactive extracellular compounds (BECs) with allelopathic, hemolytic, cytotoxic or ichthyotoxic properties, which can also be produced by these algae. The BECs, still uncharacterized, are excreted within the environment thereby impacting not only phytoplankton, zooplankton but also marine invertebrates and fishes, without implicating any PST. The aim of this work was to compare the effects of three strains of A. minutum producing either only PSTs, only BECs, or both PSTs and BECs, on the oyster C. gigas. Behavioral and physiological responses of oysters exposed during 4 days were monitored and showed contrasted behavioral and physiological responses in oysters supposedly depending on produced bioactive substances. The non-PST extracellular-compound-producing strain primarily strongly modified valve-activity behavior of C. gigas and induced hemocyte mobilization within the gills, whereas the PST-producing strain caused inflammatory responses within the digestive gland and disrupted the daily biological rhythm of valve activity behavior. BECs may therefore have a significant harmful effect on the gills, which is one of the first organ in contact with the extracellular substances released in the water by A. minutum. Conversely, the PSTs impact the digestive gland, where they are released and mainly accumulated, after degradation of algal cells during digestion process of bivalves. This study provides a better understanding of the toxicity of A. minutum on oyster and highlights the significant role of BECs in this toxicity calling for further chemical characterization of these substances.< Réduire
Mots clés en anglais
Harmful algal bloom (HAB)
Crassostrea gigas
Paralytic shellfish toxins (PST)
Bioactive extracellular compounds (BEC)
Histology
Behavior
ACL
Project ANR
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 - ANR-13-CESA-0019