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Research article - Peer-reviewed, 2009

Thermal growth performance of juvenile brown trout Salmo trutta: no support for thermal adaptation hypotheses

Forseth, T; Larsson, Stefan; Jensen, A J; Jonsson, B; Näslund, I.; Berglund, I


Using thermal growth data from eight populations of anadromous and lake-feeding brown trout Salmo trutta, hypotheses of adaptation to local optima and countergradient variation in growth were tested. The adaptation to local optima hypothesis suggests that natural selection can shift optimal performance temperatures to match the prevailing temperature in a new or changed thermal niche. In contradiction, the countergradient variation hypothesis suggests that populations from hostile environments perform better than conspecifics from benign environments at all temperatures. In this study, growth capacity varied between populations but there was no significant correlation between any of the estimated thermal performance parameters (e.g. lower and upper thermal growth limits, optimal temperature for growth and maximum growth capacity) and natural climatic conditions among populations. Hence, S. trutta growth response to temperature lends no support for either of the two suggested thermal adaptation hypotheses. Instead, growth capacity among populations tended to correlate positively with female size at maturity.


adaptive variation; climate change; countergradient variation; growth models; optimum temperature

Published in

Journal of Fish Biology
2009, Volume: 74, number: 1, pages: 133-149

    SLU Authors

    • Larsson, Stefan

      • Department of Aquaculture, Swedish University of Agricultural Sciences
      • Berglund, I

        • Department of Aquaculture, Swedish University of Agricultural Sciences

      Sustainable Development Goals

      SDG13 Climate action

      UKÄ Subject classification

      Fish and Aquacultural Science

      Publication Identifiers


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