Rainbow trout in seasonal environments: phenotypic trade‐offs across a gradient in winter duration

Ecology and Evolution

Ellen V. Lea¹  Jonathan A. Mee¹  John R. Post¹  Sean M. Rogers¹ 

[1] Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada

关键词: Bioenergetics;    elevation gradient;    energy deficit;    life‐history;    metabolic demands;    overwinter survival;    trade‐offs;   

DOI  :  10.1002/ece3.1636

来源: Wiley

【 摘 要 】

Abstract

Survival through periods of resource scarcity depends on the balance between metabolic demands and energy storage. The opposing effects of predation and starvation mortality are predicted to result in trade-offs between traits that optimize fitness during periods of resource plenty (e.g., during the growing season) and those that optimize fitness during periods of resource scarcity (e.g., during the winter). We conducted a common environment experiment with two genetically distinct strains of rainbow trout to investigate trade-offs due to (1) the balance of growth and predation risk related to foraging rate during the growing season and (2) the allocation of energy to body size prior to the winter. Fry (age 0) from both strains were stocked into replicate natural lakes at low and high elevation that differed in winter duration (i.e., ice cover) by 59 days. Overwinter survival was lowest in the high-elevation lakes for both strains. Activity rate and growth rate were highest at high elevation, but growing season survival did not differ between strains or between environments. Hence, we did not observe a trade-off between growth and predation risk related to foraging rate. Growth rate also differed significantly between the strains across both environments, which suggests that growth rate is involved in local adaptation. There was not, however, a difference between strains or between environments in energy storage. Hence, we did not observe a trade-off between growth and storage. Our findings suggest that intrinsic metabolic rate, which affects a trade-off between growth rate and overwinter survival, may influence local adaptation in organisms that experience particularly harsh winter conditions (e.g., extended periods trapped beneath the ice in high-elevation lakes) in some parts of their range.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.