title: Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity.
abstract: Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot.
authors.affiliation: INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle, France; Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet, France.
authors.forename: Zoé
authors.initials: Z
authors.lastname: Gauthey
authors.affiliation: INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Panserat
authors.affiliation: Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48080 Bilbao, Spain.
authors.forename: Arturo
authors.initials: A
authors.lastname: Elosegi
authors.affiliation: INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Herman
authors.affiliation: INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle, France; Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Tentelier
authors.affiliation: INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle, France; Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet, France. Electronic address: labonne@st-pee.inra.fr.
authors.forename: Jacques
authors.initials: J
authors.lastname: Labonne
mesh_terms: D000818:Animals; D002980:Climate; D055864:Droughts; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D008018:Life Cycle Stages; D011157:Population Dynamics / Q000706:statistics & numerical data*; D012098:Reproduction; D012621:Seasons; D014337:Trout / Q000502:physiology*
keywords: Climate change; Ecological contrast; Environmental stochasticity; Reproductive investment; Salmonids