title: Generalist-specialist trade-off during thermal acclimation.
abstract: The shape of performance curves and their plasticity define how individuals and populations respond to environmental variability. In theory, maximum performance decreases with an increase in performance breadth. However, reversible acclimation may counteract this generalist-specialist trade-off, because performance optima track environmental conditions so that there is no benefit of generalist phenotypes. We tested this hypothesis by acclimating individual mosquitofish (Gambusia holbrooki) to cool and warm temperatures consecutively and measuring performance curves of swimming performance after each acclimation treatment. Individuals from the same population differed significantly in performance maxima, performance breadth and the capacity for acclimation. As predicted, acclimation resulted in a shift of the temperature at which maximal performance occurred. Within acclimation treatments, there was a significant generalist-specialist trade-off in responses to acute temperature change. Surprisingly, however, there was also a trade-off across acclimation treatments, and animals with greater capacity for cold acclimation had lower performance maxima under warm conditions. Hence, cold acclimation may be viewed as a generalist strategy that extends performance breadth at the colder seasons, but comes at the cost of reduced performance at the warmer time of year. Acclimation therefore does not counteract a generalist-specialist trade-off and, at least in mosquitofish, the trade-off seems to be a system property that persists despite phenotypic plasticity.
authors.affiliation: School of Biological Sciences, University of Sydney , New South Wales 2006, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Seebacher
authors.affiliation: Department of Ecology and Evolution, UNIL Sorge, Le Biophore , Université de Lausanne , 1015 Lausanne, Switzerland.
authors.forename: Varlérie
authors.initials: V
authors.lastname: Ducret
authors.affiliation: School of Biological Sciences, University of Sydney , New South Wales 2006, Australia.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Little
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow , Glasgow G12 8QQ, UK.
authors.forename: Bart
authors.initials: B
authors.lastname: Adriaenssens
keywords: environmental variability; individual variation; locomotor performance; performance breadth; performance curves