Influence of the parasite worm Polydora sp. on the behaviour of the oyster Crassostrea gigas: a study of the respiratory impact and associated oxidative stress

• Published in: Marine Biology
• Main Authors: Chambon, Caroline, Legeay, Alexia, Durrieu, Gilles, Gonzalez, Patrice, Ciret, Pierre, Massabuau, Jean-Charles
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology; [SDV.EE.IEO]Life Sciences [q-bio]/Ecology; environment/Symbiosis; [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology; Crassostrea gigas
• Online Access: https://hal.science/hal-04547524; https://hal.science/hal-04547524/document; https://hal.science/hal-04547524/file/2007%20Chambon%20polydora%20%26%20oyster.pdf; https://doi.org/10.1007/s00227-007-0693-1

International audience The aim of this study was to investigate how the worm Polydora sp., which induces oysters into creating mud blisters in response to an irritation within their shells, could interfere with the oyster Crassostrea gigas physiology and ethology. The impact was characterized by studying two groups of oysters (non-parasitized and parasitized) during a 30 days period: (1) the animal behaviour by analysing their valve activity (valvometry), and (2) the animal respiratory physiology by measuring in vivo the oxygen partial pressure and the specific oxygen consumption in selected tissues (heart, fast and slow adductor muscle). We also researched a putative impact on the expression of several oxidative stress genes at the heart level. Our results show that Polydora sp. is clearly an oyster’s parasite as it induces a decrease in oyster growth according to the infestation intensity. Moreover, it modifies the behaviour and the respiratory physiology of the molluscs. Infested animals opened more frequently but for less time and their level of blood oxygenation was systematically higher than healthy molluscs. These high levels of oxygenation had no effect on the oxidative metabolism of the tissues studied but they induced oxidative stress. Indeed, the superoxide dismutase gene showed a threefold increase in expression in the heart of infested oysters. A putative scenario of the weakening mechanism is proposed.