Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish tha...

Rainbow and brown trout have been intentionally introduced into tailwaters downriver of dams globally and provide billions of dollars in economic benefits. At the same time, recruitment and maximum length of trout populations in tailwaters often fluctuate erratically, which negatively affects the value of fisheries. Large recruitment events may increase dispersal downriver where other fish spec...

Sex steroids appear to be responsible for hyperactivation of the hypothalamus-pituitary-interrenal (HPI) axis that occurs in mature semelparous Pacific salmon as a prelude to post-spawning (programmed) death. This study was undertaken to examine the direct effects of sex steroids on interrenal activity of semelparous (chinook salmon) and iteroparous (rainbow trout) salmonids using an in vitro i...

Newly formed hybrid populations provide an opportunity to examine the initial consequences of secondary contact between species and identify genetic patterns that may be important early in the evolution of hybrid inviability. Widespread introductions of rainbow trout (Oncorhynchus mykiss) into watersheds with native cutthroat trout (Oncorhynchus clarkii) have resulted in hybridization. These in...

We describe 12 diagnostic single nucleotide polymorphism (SNP) assays for use in species identification among rainbow and cutthroat trout: five of these loci have alleles unique to rainbow trout (Oncorhynchus mykiss), three unique to westslope cutthroat trout (O. clarkii lewisi) and four unique to Yellowstone cutthroat trout (O. clarkii bouvieri). These diagnostic assays were identified using a...

--Allelic frequencies at 27 polymorphic allozyme loci were compared among 15 collections of naturalized migratory rainbow trout Salmo gairdneri sampled from 10 stream drainages leading to Lake Superior. Multiple collections were made within the Brule River drainage in Wisconsin: one of spring-run spawning adults, one of fall-run adults, and four from Brule River tributaries. Significant allele ...

The innate immune system of fish is critical for rapid detection and immediate response to infection, as well as to orchestrate the adaptive branch of the immune system. Rainbow trout Oncorhynchus mykiss ladderlectin and intelectin are plasma pattern recognition receptors (PRR) for bacterial and fungal pathogens of rainbow trout, but their role as PRRs for virus is unknown. Viral hemorrhagic se...

BACKGROUND Furunculosis, caused by Aeromonas salmonicida, continues to be a major health problem for the growing salmonid aquaculture. Despite effective vaccination programs regular outbreaks occur at the fish farms calling for repeated antibiotic treatment. We hypothesized that a difference in natural susceptibility to this disease might exist between Baltic salmon and the widely used rainbow ...

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, and its occurrence is associated with a number of environmental factors including ingestion of the dietary contaminant aflatoxin B(1) (AFB(1)). Research over the last 40 years has revealed rainbow trout (Oncorhynchus mykiss) to be an excellent research model for study of AFB(1)-induced hepatocarcinogenesis; how...