The freshwater polychaete Manayunkia speciosa was identified as an obligate host of the salmonid parasite Ceratomyxa shasta in 1997, prompting increased research on the small benthic invertebrate. Ceratomyxa shasta infection in fish can cause mortality, and presents a disease risk for both hatchery and wild salmon and trout. Ceratomyxa shasta...
The within-host interactions that can occur as a result of mixed infections in wildlife likely influence the outcome of an infection. We investigated the infection frequency and outcome as well as the potential mechanisms regulating mixed infections with two Ceratonova shasta genotypes within the Chinook salmon host. Previous research in...
Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial prerequisite to this research was proper identification of parasites, which can be difficult for species lacking...
Pre-spawning mortality (PSM) presents a major problem for population recovery of spring Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River basin. In certain reaches and years, PSM has exceeded 90%. Histology has been used as the primary diagnostic method to investigate PSM in the Chinook Salmon, and a collection of...