title: Strong Effects of Temperature on the Early Life Stages of a Cold Stenothermal Fish Species, Brown Trout (Salmo trutta L.).
abstract: Temperature is the main abiotic factor that influences the life cycle of poikilotherms. The present study investigated the thermal tolerance and phenotypic plasticity of several parameters (development time, morphometric measures, bioenergetics) for both embryos and fry of a cold stenothermal fish species, brown trout (Salmo trutta L.) in order to allow for a holistic evaluation of the potential effects of temperature. Five temperatures (4°C, 6°C, 8°C, 10°C, and 12°C) were tested, and the effects of temperature were analyzed at three stages: hatching, emergence, and first food intake. A mean of 5,440 (S.E. ± 573) eggs, coming from seven females and seven males (seven families) captured close to Linkebeek (Belgium), were used for each temperature. Maximum survival of well-formed fry at first food intake and better use of energy budget were found at 6°C and 8°C, temperatures at which the possible contribution to the next generation should therefore be greatest. At 12°C, the experimental population fell dramatically (0.9% survival rate for well-formed fry at first food intake), and fry had almost no yolk sac at first food intake. The present results on survival at 12°C are in accordance with predictions of a sharp decrease in brown trout numbers in France over the coming decades according to climate change projections (1°C to 5°C temperature rise by 2100 for France). At 10°C, there was also a lower survival rate (55.4% at first food intake). At 4°C, the survival rate was high (76.4% at first food intake), but the deformity rate was much higher (22% at first food intake) than at 6°C, 8°C, and 10°C. The energetic budget showed that at the two extreme temperatures (4°C and 12°C) there was less energy left in the yolk sac at first food intake, suggesting a limited ability to survive starvation.
authors.affiliation: University of Lorraine, UR AFPA, USC INRA 340, Vandoeuvre-lès-Nancy, F-54506, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Réalis-Doyelle
authors.affiliation: University of Lorraine, UR AFPA, USC INRA 340, Vandoeuvre-lès-Nancy, F-54506, France.|CNRS (National Center for Scientific Research) Délégation Régionale Centre Est. 17 rue Notre Dame des Pauvres, F -54500 Vandoeuvre-lès-Nancy, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Pasquet
authors.affiliation: Instituut voor Natuur- (INBO), Dwersbos 28, 1630 Linkebeek, Belgium.
authors.forename: Daniel
authors.initials: D
authors.lastname: De Charleroy
authors.affiliation: University of Lorraine, UR AFPA, USC INRA 340, Vandoeuvre-lès-Nancy, F-54506, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Fontaine
authors.affiliation: University of Lorraine, UR AFPA, USC INRA 340, Vandoeuvre-lès-Nancy, F-54506, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Teletchea
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004435:Eating; D004734:Energy Metabolism; D005260:Female; D005306:Fertilization; D008018:Life Cycle Stages / Q000502:physiology*; D008297:Male; D025341:Principal Component Analysis; D013045:Species Specificity; D015996:Survival Rate; D013997:Time Factors; D014337:Trout / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology*