Hybridization effects on phenotypic plasticity: experimental compensatory growth in farmed-wild Atlantic salmon
Date
2011-05
Authors
Morris, Matthew R. J.
Fraser, Dylan J.
Eddington, James
Hutchings, Jeffrey Alexander
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Abstract
Compensatory growth (CG) is a means by which organisms can increase their growth rate above
their routine growth rate after a period of environmentally induced growth depression. Despite a
focus on the implications of CG for aquaculture, little research has evaluated the effect of
domesticated-wild hybridization on CG. Any deviation in the mean compensatory ability of hybrids
relative to their wild progenitors, or any notable costs to compensation in terms of body
morphology, could affect the ability of hybrids to persist in changing environments. We compared CG
of farmed, wild and hybrid (F1, F2, wild backcross) juvenile Atlantic salmon (Salmo salar). Wild
salmon experienced both lower routine and CG rates relative to farmed salmon, while hybrids were
intermediate. However, the compensatory responses (slopes of the reaction norms) for each cross were
parallel, indicating that hybridization did not affect the CG response itself. Morphological costs
to compensation were not detected. In addition to contributing to risk assessments of the
consequences of interbreeding between wild and escaped domesticated organisms, we conclude that
plasticity studies on domesticated-wild hybrids and their progenitors are useful for testing basic
predictions about the evolution of phenotypic plasticity, as well as understanding the evolutionary
significance of hybrids.
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Citation
Morris, Matthew R. J., Dylan J. Fraser, James Eddington, and Jeffrey A. Hutchings. 2011. "Hybridization effects on phenotypic plasticity: experimental compensatory growth in farmed-wild
Atlantic salmon." Evolutionary Applications 4(3): 444-458.