title: Methylmercury effects on migratory behaviour in glass eels (Anguilla anguilla): an experimental study using isotopic tracers.
abstract: The effect of methylmercury (MeHg) on glass eels' propensity to migrate, mitochondrial activity and antioxidative defence systems was investigated. Marine glass eels were first sorted in an experimental flume according to their response to dusk. Fish responding to the decrease in light intensity by ascending in the water column and moving with or against the flow were considered as having a high propensity to migrate (migrant). Glass eels still sheltering at the end of the 24 h catching period were considered as having a low propensity to migrate and were called non-migrant. Migrant and non-migrant glass eels were then individually tagged and exposed to isotopically enriched (201)MeHg (50 ng L(-1)) for 11 days. The effect of contamination was studied on muscle fibre structure, and the expression level of genes involved in mitochondrial activity and antioxidative defence systems. To investigate the effect of MeHg on glass eel behaviour, migrant and non-migrant glass eels were sorted again and the bioaccumulation of (201)MeHg and its demethylation product ((201)Hg(II)) were determined for each individual. MeHg exposure increased activity in non-migrant glass eels but not migratory behaviour. Contamination affected mitochondrial structure and metabolism and suggests a higher oxidative stress and activation of antioxidative defence systems in non-migrant glass eels. Overall, our results suggest that exposure to MeHg might induce an increase in energy expenditure and a higher vulnerability to predation in non-migrant glass eels in the wild.
authors: INRA, UMR 1224 Ecobiop, Aquapôle, 64310 Saint Pée sur Nivelle, France; Université de Pau et des Pays de L'Adour, UMR 1224 Ecobiop, UFR Sciences et Techniques Côte Basque, Anglet, France. Electronic address: jclaveau@st-pee.inra.fr.
authors: Julie
authors: J
authors: Claveau
authors: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS, Université de Pau et des Pays de l'Adour, Hélioparc Pau Pyrénées, 2 av. P. Angot, 64053 9 Pau cedex 9, France. Electronic address: mathilde.monperrus@univ-pau.fr.
authors: Mathilde
authors: M
authors: Monperrus
authors: INRA, UMR 1224 Ecobiop, Aquapôle, 64310 Saint Pée sur Nivelle, France; Université de Pau et des Pays de L'Adour, UMR 1224 Ecobiop, UFR Sciences et Techniques Côte Basque, Anglet, France. Electronic address: marc.jarry@univ-pau.fr.
authors: Marc
authors: M
authors: Jarry
authors: Université de Bordeaux, UMR 5805 EPOC, Team Aquatic Ecotoxicology, Place du Dr Peyneau, 33120 Arcachon, France. Electronic address: m.baudrimont@epoc.u-bordeaux1.fr.
authors: Magalie
authors: M
authors: Baudrimont
authors: Université de Bordeaux, UMR 5805 EPOC, Team Aquatic Ecotoxicology, Place du Dr Peyneau, 33120 Arcachon, France. Electronic address: p.gonzalez@epoc.u-bordeaux1.fr.
authors: Patrice
authors: P
authors: Gonzalez
authors: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS, Université de Pau et des Pays de l'Adour, Hélioparc Pau Pyrénées, 2 av. P. Angot, 64053 9 Pau cedex 9, France. Electronic address: joana.cavalheiro@univ-pau.fr.
authors: Joana
authors: J
authors: Cavalheiro
authors: Université de Bordeaux, UMR 5805 EPOC, Team Aquatic Ecotoxicology, Place du Dr Peyneau, 33120 Arcachon, France. Electronic address: n.mesmer-dudons@epoc.u-bordeaux1.fr.
authors: Nathalie
authors: N
authors: Mesmer-Dudons
authors: INRA, UMR 1224 Ecobiop, Aquapôle, 64310 Saint Pée sur Nivelle, France; Université de Pau et des Pays de L'Adour, UMR 1224 Ecobiop, UFR Sciences et Techniques Côte Basque, Anglet, France. Electronic address: bolliet@st-pee.inra.fr.
authors: Valérie
authors: V
authors: Bolliet
mesh_terms: D000811:Anguilla / Q000502:physiology*; D025041:Animal Migration / Q000187:drug effects*; D000818:Animals; D001267:Atlantic Ocean; D001711:Biotransformation; D004734:Energy Metabolism / Q000187:drug effects; D005602:France; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008629:Mercury Isotopes; D008767:Methylmercury Compounds / Q000378:metabolism / Q000633:toxicity*; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008954:Models, Biological; D018485:Muscle Fibers, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D016877:Oxidants / Q000493:pharmacokinetics / Q000633:toxicity; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D052817:Phototrophic Processes / Q000187:drug effects; D014018:Tissue Distribution; D066007:Toxicokinetics; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D016877:Oxidants; D014874:Water Pollutants, Chemical; C030957:methylmercury II; D010088:Oxidoreductases
keywords: Anguilla anguilla; Antioxidative defence; Demethylation; Glass eel; Isotopic tracers; Methylmercury; Migratory behaviour