title: Seasonal and sex-related variations in serum steroid hormone levels in wild and farmed brown trout Salmo trutta L. in the north-west of Spain.
abstract: Serum steroid profiles were investigated in order to evaluate the potential use of circulating sex steroid levels as a tool for sex identification in brown trout. Changes in the serum concentrations of testosterone (T), progesterone (P), 17-β-estradiol (E2), and cortisol (F) in wild and farmed mature female and male brown trout, Salmo trutta L., were measured in each season (January, May, July, and October) in six rivers and four hatcheries located in the north-west of Spain. Serum cortisol levels in farmed brown trout were significantly higher and showed a seasonal pattern opposite to that found in wild trout. Because levels of the hormones under study can be affected by disruptive factors such as exposure to phytoestrogens (which alters the hypothalamic-pituitary-gonadal axis) and infection with Saprolegnia parasitica (which alters the hypothalamic-pituitary-adrenal axis), both factors are taken into account.
authors: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071 León, Spain.
authors: Juan M
authors: JM
authors: Fregeneda-Grandes
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Salvador
authors: S
authors: Hernández-Navarro
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Ignacio A
authors: IA
authors: Fernandez-Coppel
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Adriana
authors: A
authors: Correa-Guimaraes
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Norlan
authors: N
authors: Ruíz-Potosme
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Luis M
authors: LM
authors: Navas-Gracia
authors: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071 León, Spain.
authors: J Miguel
authors: JM
authors: Aller-Gancedo
authors: Servicio de Análisis Clínicos. Hospital Universitario Rio Hortega, 47014 Valladolid, Spain.
authors: Francisco J
authors: FJ
authors: Martín-Gil
authors: Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid (Campus de Palencia), 34004 Palencia, Spain E-mail: jesusmartingil@gmail.com.
authors: Jesús
authors: J
authors: Martín-Gil
mesh_terms: D000818:Animals; D000835:Animals, Wild; D017756:Aquaculture; D004958:Estradiol / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood* / Q000502:physiology*; D008297:Male; D011374:Progesterone / Q000097:blood; D012621:Seasons; D013030:Spain; D013739:Testosterone / Q000097:blood; D014337:Trout / Q000097:blood* / Q000502:physiology
chemical_list: D012739:Gonadal Steroid Hormones; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol