title: Climbing experience in glass eels: A cognitive task or a matter of physical capacities?
abstract: The European eel is a panmictic species, whose decline has been recorded since the last 30 years. Among human-induced environmental factors of decline, the impact of water dams during species migration is questioned. Indeed, water impoundments can be a severe obstacle for young eels trying to reach the upstream freshwater zones, even if they are equipped with fish-friendly passes. The passage by such devices could be an important event shaping the outcome of the future life and life history traits of eels. We studied what phenotypic traits were associated with the event of experience of passage by water obstacles. We analyzed specific enzyme activities and/or gene transcription levels in the muscle and brain to test whether the obstacle passage is rather a physical or cognitive task. We found that after a long period of maintenance under homogenous conditions, transcription levels of several genes linked to synaptic plasticity, neurogenesis and thyroid activity differed among the field-experience groups. In contrast, muscle gene transcription levels or enzymatic activities did not show any differences among fish groups. We suggest that cognitive processes such as learning and memory acquisition rather than swimming-related metabolic capacities are involved in passage of water obstacles by young eels.
authors.affiliation: Irstea Bordeaux, UR EABX, HYNES (Irstea - EDF R&D), 50 avenue de Verdun, Cestas 33612 Cedex, France. Electronic address: tomasz.podgorniak@irstea.fr.
authors.forename: T
authors.initials: T
authors.lastname: Podgorniak
authors.affiliation: Irstea Bordeaux, UR EABX, HYNES (Irstea - EDF R&D), 50 avenue de Verdun, Cestas 33612 Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Angelini
authors.affiliation: Station d'écologie Expérimentale du CNRS à Moulis, USR 2936, 09 200 Moulis, France; CNRS, UPS, ENFA, Évolution & Diversité Biologique (EDB) UMR 5174, 118 Route de Narbonne, Toulouse 31062 Cedex 9, France.
authors.forename: S
authors.initials: S
authors.lastname: Blanchet
authors.affiliation: EDF R&D LNHE, HYNES (Irstea-EDF R&D), 6, quai Watier, Bat Q, Chatou 78400, France.
authors.forename: E
authors.initials: E
authors.lastname: de Oliveira
authors.affiliation: Univ. Bordeaux, EPOC, UMR 5805, F-33400 Talence, France; CNRS, EPOC, UMR 5805, F-33400 Talence, France.
authors.forename: F
authors.initials: F
authors.lastname: Pierron
authors.affiliation: Irstea Bordeaux, UR EABX, HYNES (Irstea - EDF R&D), 50 avenue de Verdun, Cestas 33612 Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Daverat
mesh_terms: D000704:Analysis of Variance; D000811:Anguilla; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D053263:Gene Regulatory Networks; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009043:Motor Activity / Q000502:physiology*; D011770:Pyruvate Kinase; D013053:Spectrophotometry; D013550:Swimming; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D014157:Transcription Factors; D007770:L-Lactate Dehydrogenase; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D011770:Pyruvate Kinase
keywords: Brain; Cognition; Eel dams; Migration; Muscle