Effects of hybridization between nonnative Rainbow Trout and native Westslope Cutthroat Trout on fitness-related traits

Transactions of the American Fisheries Society
By: , and 

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Abstract

Hybridization between introduced and native fauna is a risk to native species and may threaten the long-term persistence of numerous taxa. Rainbow Trout Oncorhynchus mykiss has been one of the most widely introduced species around the globe and often hybridizes with native Cutthroat Trout O. clarkii in the Rocky Mountains. Previous work has shown that hybridization negatively affects reproductive success, but identification of the traits contributing to that reduction has been elusive. In this study, we used a combination of field and laboratory techniques to assess how hybridization with Rainbow Trout affects seven traits during several stages of Westslope Cutthroat Trout development: embryonic survival, ova size, ova energy concentration, sperm motility, juvenile weight, juvenile survival, and burst swimming endurance. Rainbow Trout admixture was correlated with an increase in embryonic survival and ova energy concentration but with a decrease in juvenile weight and burst swimming endurance. These correlations differed from previously observed patterns of reproductive success and likely do not explain the declines in reproductive success associated with admixture. Future investigation of additional, unstudied traits and the use of different environments may shed light on the traits responsible for reproductive success in admixed Cutthroat Trout.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Effects of hybridization between nonnative Rainbow Trout and native Westslope Cutthroat Trout on fitness-related traits
Series title Transactions of the American Fisheries Society
DOI 10.1080/00028487.2015.1064475
Volume 144
Issue 6
Year Published 2015
Language English
Publisher American Fisheries Society
Publisher location Bethesda, MD
Contributing office(s) Northern Rocky Mountain Science Center
Description 17 p.
First page 1275
Last page 1291
Online Only (Y/N) N
Additional Online Files (Y/N) N