title: Environmental endocrinology of salmon smoltification.
abstract: Smolting is a hormone-driven developmental process that is adaptive for downstream migration and ocean survival and growth in anadromous salmonids. Smolting includes increased salinity tolerance, increased metabolism, downstream migratory and schooling behavior, silvering and darkened fin margins, and olfactory imprinting. These changes are promoted by growth hormone, insulin-like growth factor I, cortisol, thyroid hormones, whereas prolactin is inhibitory. Photoperiod and temperature are critical environmental cues for smolt development, and their relative importance will be critical in determining responses to future climate change. Most of our knowledge of the environmental control and endocrine mediation of smolting is based on laboratory and hatchery studies, yet there is emerging information on fish in the wild that indicates substantial differences. Such differences may arise from differences in environmental stimuli in artificial rearing environments, and may be critical to ocean survival and population sustainability. Endocrine disruptors, acidification and other contaminants can perturb smolt development, resulting in poor survival after seawater entry.
authors.affiliation: Fish Endocrinology Laboratory, Department of Zoology/Zoophysiology, University of Gothenburg, Box 463, SE-40530 Göteborg, Sweden.
authors.forename: Björn Thrandur
authors.initials: BT
authors.lastname: Björnsson
authors.forename: Sigurd O
authors.initials: SO
authors.lastname: Stefansson
authors.forename: Stephen D
authors.initials: SD
authors.lastname: McCormick
mesh_terms: D025041:Animal Migration; D000818:Animals; D052244:Endocrine Disruptors / Q000494:pharmacology; D004703:Endocrine System / Q000187:drug effects / Q000502:physiology*; D004777:Environment; D005618:Fresh Water; D048788:Growth and Development / Q000187:drug effects; D006728:Hormones / Q000502:physiology; D012474:Salmon / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012623:Seawater
chemical_list: D052244:Endocrine Disruptors; D006728:Hormones