Swim Bladder Nematodes ( Anguillicoloides crassus ) Disturb Silvering In European Eels ( Anguilla anguilla ).

• Published in: Journal of Parasitology
• Main Authors: Fazio, Géraldine, Sasal, Pierre, Mouahid, Gabriel, Lecomte-Finiger, Raymonde, Moné, Hélène
• Other Authors: Independent Researcher, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-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), Ecologie et évolution des interactions 2011-2014 (2EI), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Anguilla anguilla
• Online Access: https://hal.science/halsde-00728919; https://hal.science/halsde-00728919/document; https://hal.science/halsde-00728919/file/Fazio-2012-JParasitol-Swimblader.pdf; https://doi.org/10.1645/GE-2700.1

International audience Abstract : The introduced parasite Anguillicoloides crassus is thought to play an important role in the decline of freshwater eel ( Anguilla spp.) populations. These nematodes are known to negatively affect many fitness-related traits in eels. We used experimental infections to study the effect of A. crassus on the relative size or mass of organs, and the expression of functionally relevant genes (total of 12 parameters) that are involved in the silvering process of Anguilla anguilla . Our results showed that the liver mass, the hemoglobin α-chain, and androgen receptors α expression levels were significantly higher in infected eels, whereas the freshwater rod opsin expression level and the gut mass were significantly lower in infected eels. Our results suggested that infected eels were at a more advanced stage in the silvering process than uninfected counterparts of similar size. These results may be explained by 2 hypotheses. First, A. crassus could trigger physiological mechanisms involved in the silvering process as a side-effect of infection. Second, eels may adjust their life history traits in response to infection. The implications for eel migration and reproductive success may be either negative or positive, depending on whether the response to A. crassus infection results in an additional cost of the parasite or is due to the phenotypic plasticity of the host.