Masked expression of life-history traits in a highly variable environment

Great Plains Research
By: , and 

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Abstract

Differing life-history strategies may act as a constraint on reproductive expression that ultimately limits the ability of individual species to respond to changes in the magnitude or frequency of environmental variation, and potentially underlies the variation often inherent in phenotypic and evolved responses to anthropogenic change. Alternatively, if there are environmental cues that predict reproductive potential, differential expression of life-history strategies may represent differences in the adaptive capacity to optimize current reproductive value given variation in environmental conditions. We compared several aspects of walleye Sander vitreus spawning ecology at two reservoirs that differ in environmental variability (i.e., annual water-level fluctuation) to identify the capacity of phenotypic expression and the corresponding association with age. Despite significant differences in female body and liver masses between reservoirs that differ in environmental variability, we found no difference in reproductive investment measured by egg size and fecundity. Walleye in a highly variable environment appear to exhibit reproductive traits more typical of a short-lived life-history strategy, which may be resultant from the interaction of environmental and anthropogenic pressures. This finding emphasizes the need to identify the degree to which life-history expression represents physiological constraints versus ecological optimization, particularly as anthropogenic change continues to alter environmental conditions.

 

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Masked expression of life-history traits in a highly variable environment
Series title Great Plains Research
DOI 10.1353/gpr.2015.0015
Volume 25
Issue 1
Year Published 2015
Language English
Publisher University of Nebraska Press
Contributing office(s) Coop Res Unit Seattle
Description 14 p.
First page 25
Last page 38