title: Myxobolus cerebralis (Hofer) infection risk in native cutthroat trout Oncorhynchus clarkii (Richardson) and its relationships to tributary environments in the Yellowstone Lake Basin.
abstract: Conservation of native species is challenged by the introduction of non-native pathogens and diseases into aquatic and terrestrial environments worldwide. In the Yellowstone Lake basin, Yellowstone National Park, the invasive parasite causing salmonid whirling disease Myxobolus cerebralis (Hofer) has been identified as one factor contributing to population declines of native Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri (Jordan & Gilbert). In 2002 and 2003, we examined relationships between the stream environment and severity of M. cerebralis infection in native trout. Coefficients of variation of environmental features were calculated to examine variability. Ten years later, we reassessed infection levels at 22 tributaries broadly across the system. Results of principal component analysis (PCA) of physical features (2003) were negatively correlated with infection severity, mostly in lower jaw cartilage of cutthroat trout, and PCA of chemical features (and temperature) correlated with infection severity in cranial cartilage. Pelican Creek, where M. cerebralis prevalence and severity was high 2002-2003, remained high in 2012. We did not find evidence that the parasite had dispersed further within the system. Variable environmental features (physiological stress) across short spatiotemporal scales within a stream or season may possibly predispose salmonids to infection in the wild and facilitate parasite establishment.
authors: Department of Ecology, Montana State University, Bozeman, MT, USA.
authors: S
authors: S
authors: Murcia
authors: Department of Ecology, Montana State University, Bozeman, MT, USA.
authors: B L
authors: BL
authors: Kerans
authors: Center for Resources Fisheries and Aquatic Sciences Program, Yellowstone National Park, Mammoth, WY, USA.
authors: T M
authors: TM
authors: Koel
authors: US Fish and Wildlife Service, Bozeman Fish Health Center, Bozeman, MT, USA.
authors: E
authors: E
authors: MacConnell
mesh_terms: D000818:Animals; D004777:Environment; D005393:Fish Diseases / Q000453:epidemiology* / Q000473:pathology; D055766:Myxobolus / Q000502:physiology*; D017683:Oncorhynchus / Q000469:parasitology*; D010273:Parasitic Diseases, Animal / Q000453:epidemiology* / Q000473:pathology; D025341:Principal Component Analysis; D012307:Risk Factors; D045483:Rivers / Q000737:chemistry; D014959:Wyoming
keywords: Yellowstone cutthroat trout; biotic and abiotic factors; histopathology; whirling disease