Impacts of non-native species on the morphology of threespine stickleback (Gasterosteus aculeatus)

Date
2018-04-16
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Abstract
Invasive species have demonstrated their capability to greatly modify ecosystems and communities. Introducing multiple species can potentially alter how a native population adapts relative to when species are introduced individually. I assessed whether native threespine stickleback (Gasterosteus aculeatus) exhibit distinct morphological characteristics corresponding to a varying combination of the presence of introduced smallmouth bass (Micropterus dolomieu) and signal crayfish (Pacifastacus leniusculus) on Vancouver Island. I also examined morphological changes over 18 - 43 years to determine whether contemporary characteristics become magnified in the presence of non-native species. There are clear distinctions in stickleback traits and body shape among non-native species combinations. Bass and crayfish lake stickleback are highly armoured, whereas bass-only lakes contain stickleback with reduced armour. Klein and Dougan Lake stickleback, which coexist with signal crayfish, showed significant increases in size over time. These patterns suggest that smallmouth bass and signal crayfish may have differential impacts on stickleback morphology.
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Keywords
Threespine Stickleback, evolutionary ecology, Invasive species, morphological adaptation, smallmouth bass, signal crayfish
Citation
Kienzle, H. A. (2018). Impacts of non-native species on the morphology of threespine stickleback (Gasterosteus aculeatus) (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/31792