title: From autochthonous to allochthonous resources: seasonal shifts in food use by stream-dwelling YOY Arctic charr Salvelinus alpinus through the ice-free season.
abstract: Substantial seasonal changes in resource use associated with enhanced water-column use were revealed in stream-living YOY Arctic charr Salvelinus alpinus during the ice-free season. In July, YOY individuals showed a diet dominated by aquatic invertebrates (mainly Chironomidae larvae), but despite the small size of the fish, the abundance of terrestrial insects in their diet increased markedly from July to September (from 1·9 to 62·8%). Similarly, the frequency of surface drifting foragers, i.e. individuals feeding on allochthonous resources, increased from July to September (from 20·6 to 80%); allochthonous resources thus constituting an important energy subsidy for YOY S. alpinus during the late sub-Arctic summer.
authors.affiliation: Department of Zoology and Physical Anthropology, Faculty of Biology, University of Santiago de Compostela, Campus Sur s/n, 15782 Santiago de Compostela, Spain.|Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Sánchez-Hernández
authors.affiliation: Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: H-M
authors.initials: HM
authors.lastname: Gabler
authors.affiliation: Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: P-A
authors.initials: PA
authors.lastname: Amundsen
mesh_terms: D000818:Animals; D001110:Arctic Regions; D004032:Diet / Q000662:veterinary*; D005247:Feeding Behavior; D020387:Food Chain; D007313:Insecta; D007448:Invertebrates; D007814:Larva; D009664:Norway; D045483:Rivers; D012621:Seasons; D014337:Trout / Q000502:physiology*
keywords: age 0; diet; foraging mode; sub-Arctic river; surface insects