Title
Ecological consequences of hybridization between native westslope cutthroat (Oncorhynchus clarkii lewisi) and introduced rainbow (Oncorhynchus mykiss) trout: effects on life history and habitat use
Document Type
Article
Publication Date
2010
Publication Title
Canadian Journal of Fisheries and Aquatic Sciences
Volume
67
Issue
2
First Page
357
Keywords
behavior; british-columbia; endangered species act; growth-rate; Hybrids; markers; populations; salmonids; steelhead; stream
Last Page
370
Abstract
In the Upper Oldman River, Alberta, Canada, hybridization between introduced rainbow trout (RT; Oncorhynchus mykiss) and native westslope cutthroat trout (WCT; Oncorhynchus clarkii lewisi) has produced a genotypic gradient with rainbow trout alleles undetectable (<1%) at high elevations and increasing in abundance downstream. Few F, hybrids were found, and genotype frequencies suggest strong backcrossing of hybrids to pure parental populations at both ends of the gradient. The increasing prevalence of RT alleles downstream is accompanied by a life history gradient such that RT alleles were positively associated with growth rate and negatively associated with survivorship. Although physical barriers extended the distribution of pure WCT downstream, several streams held genetically pure WCT in their uppermost reaches, even when no barriers were present. For example, RT alleles were undetectable in headwaters of Dutch Creek, which had no barriers but was very cold (average summer temperature <7.3 degrees C). We propose that RT alleles affect the choice of habitat, as well the metabolic characteristics that determine their life history and competitive abilities. Factors such as climate change, clear-cut logging, and anthropogenic enrichment that can lead to increased temperature and (or) productivity might be expected to result in an upstream shift of RT alleles.
DOI
10.1139/F09-191
Recommended Citation
Rasmussen, Joseph B.; Robinson, Michael D.; and Heath, Daniel D.. (2010). Ecological consequences of hybridization between native westslope cutthroat (Oncorhynchus clarkii lewisi) and introduced rainbow (Oncorhynchus mykiss) trout: effects on life history and habitat use. Canadian Journal of Fisheries and Aquatic Sciences, 67 (2), 357-370.
https://scholar.uwindsor.ca/glierpub/29
Comments
This is an accepted manuscript version of an aritcle whose version of record was published in:Canadian Journal of Fisheries and Aquatic Sciences: http://dx.doi.org/10.1139/F09-191