Abnormal mortality of triploid adult Pacific oysters: Is there a correlation with high gametogenesis in Normandy, France?

International audience Summer mortalities of the adult Pacific oysters Crassostrea gigas are an important economic concern. In 2015 and 2016, the mortality of hatchery origin spat comprising 4 diploid batches and 9 triploid batches as well as 12 batches of wild caught diploids was followed at 3 site...

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Bibliographic Details
Published in:Aquaculture
Main Authors: Houssin, Maryline, Trancart, Suzanne, Denéchère, Lucie, Oden, Elise, Adeline, Beatrice, Lepoitevin, Mélanie, Pitel, Pierre-Hugues
Other Authors: LABÉO, Pôle d’analyses et de recherche de Normandie (LABÉO), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2019
Subjects:
Online Access:https://hal-normandie-univ.archives-ouvertes.fr/hal-03400414
https://hal-normandie-univ.archives-ouvertes.fr/hal-03400414/document
https://hal-normandie-univ.archives-ouvertes.fr/hal-03400414/file/S0044848618320015.pdf
https://doi.org/10.1016/j.aquaculture.2019.02.043
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Summary:International audience Summer mortalities of the adult Pacific oysters Crassostrea gigas are an important economic concern. In 2015 and 2016, the mortality of hatchery origin spat comprising 4 diploid batches and 9 triploid batches as well as 12 batches of wild caught diploids was followed at 3 sites in Normandy. Abnormal mortalities (> 20%) were observed at one site only and were significantly higher in triploid animals (P < .05). Triploid oysters are believed to be partially sterile but a high level of gametogenesis was observed in all monitored triploid batches. In 2015, preliminary results revealed that triploid oysters underwent strong gametogenesis with mature gametes (stage 3) and 50% of them were non-perturbed (i.e. named alpha). In 2016, 42% of triploid oysters were alpha. This study revealed that triploid oyster maturation occurred in September, which corresponded to the time of high mortalities in Normandy.