Effects of Alexandrium minutum exposure on nutrition-related processes and reproductive output in oysters Crassostrea gigas.

• Published in: Harmful Algae
• Main Authors: Haberkorn, Hansy, Lambert, Christophe, Le Goïc, Nelly, Moal, Jeanne, Suquet, Marc, Guéguen, Marielle, Sunila, Inke, Soudant, Philippe
• 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), Université européenne de Bretagne - European University of Brittany (UEB), Physiologie et Ecophysiologie des Mollusques Marins, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire Phycotoxines, Bureau of Aquaculture, bureau of aquaculture
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: [SDV.EE.IEO]Life Sciences [q-bio]/Ecology; environment/Symbiosis; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://hal.archives-ouvertes.fr/hal-00589386; https://hal.archives-ouvertes.fr/hal-00589386/document; https://hal.archives-ouvertes.fr/hal-00589386/file/Haberkorn-et-al_2010_HarmAlg_9_427-439_MS.pdf; https://doi.org/10.1016/j.hal.2010.01.003

International audience This study assessed the effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon nutrition related processes and reproductive output of the Pacific oyster, Crassostrea gigas. Oysters were exposed to A. minutum, Paralytic Shellfish Toxins (PST) producer and compared to a control batch of oysters fed Isochrysis galbana clone Tahitian (T.Iso). The experiment was performed in June 2008, when oysters were found ripe. Several physiological variables of oysters, such as PSTs accumulation, digestive gland and histological observations as well as spermatozoa quality, were measured at the end of the exposure. Results indicate that the digestive gland was greatly impacted upon A. minutum exposure. Monoacylglycerol and diacylglycerol contents as well as phospholipids (mainly phosphatidylcholine) drastically decreased in the digestive gland of oysters exposed to A. minutum compared to control oysters. At the same time, many oysters exposed to the harmful microalgae presented a strong inflammatory response in different tissues of the digestive gland: in intestine as well as in digestive ducts and tubules. Spermatozoa in oysters exposed to A. minutum were morphologically and functionally modified compared to spermatozoa of control oysters. Indeed, spermatozoa were less motile and had lower ATP content in oysters exposed to A. minutum. Meanwhile, spermatozoa produced by control oysters showed higher percentage of mortality and relative DNA content than those produced by A. minutum exposed oysters. Finally, the characteristics of the mitochondria of spermatozoa also appeared to be modified upon A. minutum exposure. The results of this study suggests that an exposure of oysters to A. minutum, reducing energy status and motility of spermatozoa associated to morphological changes at the cellular and sub-cellular levels, can have consequences on spermatozoa fertility and reproduction success.