title: Shifts in δ15 N signature following the onset of exogenous feeding in rainbow trout Oncorhynchus mykiss: importance of combining length and age data.
abstract: The δ(15) N isotopic change of recently emerged rainbow trout Oncorhynchus mykiss due to diet shift from yolk sac to exogenous feeding was evaluated in a field study. The fit of a general model including both fish length and age in days as co-variables indicates that the specific δ(15) N of individual fish at any given time along the ontogeny is determined by its growth trajectory. The results suggest that estimations based on fish size alone could bias data interpretation and maternal origin determinations in partially migratory salmonids.
authors.affiliation: Centro Nacional Patagónico-CONICET, Boulevard Brown 2915, 9120, Puerto Madryn, Chubut, Argentina. liberoff@cenpat.edu.ar
authors.forename: A L
authors.initials: AL
authors.lastname: Liberoff
authors.forename: C M
authors.initials: CM
authors.lastname: Riva Rossi
authors.forename: M L
authors.initials: ML
authors.lastname: Fogel
authors.forename: J E
authors.initials: JE
authors.lastname: Ciancio
authors.forename: M A
authors.initials: MA
authors.lastname: Pascual
mesh_terms: D000818:Animals; D049628:Body Size; D004032:Diet; D015233:Models, Statistical; D009587:Nitrogen Isotopes / Q000032:analysis; D017686:Oncorhynchus mykiss / Q000254:growth & development*; D010037:Otolithic Membrane / Q000254:growth & development
chemical_list: D009587:Nitrogen Isotopes