We investigated the spatial and temporal relationship of catch rates and angler party location for two days following a publicly announced put-and-take stocking of rainbow trout (Oncorhynchus mykiss). Catch rates declined with time since stocking and distance from stocking. We hypothesized that opportunity for high catch rates would cause anglers to fish near the stocking location and disperse ...

The simultaneous effect of weight, initial density (kg/m3, temperature and O2 concentration on rainbow trout body composition (fat, protein, moisture and ash) has been studied. In 3 successive experimental phases fish were kept in different lots of varying initial weight (178-372 g), initial density (7.2-38.8 kg/m3) and temperature (15-20 degrees C). Simple correlations were statistically signi...

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...

Juvenile rainbow trout (Oncorhynchus mykiss) were given ethambutol (900 mg kg-1 body mass per day) for 4 weeks to examine its effects on vision. Using multi-unit recording from the optic nerve, spectral sensitivity of the on-responses were significantly affected in two regions, 340-440 nm and 600-660 nm. Off-responses were statistically unaffected. Changes in sensitivity to polarised light were...

Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened sa...

The incidence of hybridization between coastal cutthroat (Oncorhynchus clarki clarki) and rainbow trout (Oncorhynchus mykiss) varies widely among populations. The breakdown of reproductive isolation is of concern to managers, and raises the question: how have the two species retained their genetic and morphological divergence? Using a combination of mitochondrial DNA and nuclear DNA markers cou...

This study investigated the stimulation of specific host defenses to IHNV that are created by prior exposure to an avirulent reovirus (chum salmon reovirus; CSV). Preexposure of rainbow trout to CSV for 1 h resulted in a relative percent survival that ranged from 68 to 100% when fish were challenged with IHNV over an 8 week period. The levels of serum neutralizing antibodies detected 28 d after...

Environmental DNA (eDNA) sampling is a powerful tool for detecting invasive and native aquatic species. Often, species of conservation interest co-occur with other, closely related taxa. Here, we developed qPCR (quantitative PCR) markers which distinguish westslope cutthroat trout (Oncorhynchus clarkii lewsi), Yellowstone cutthroat trout (O. clarkii bouvieri), and rainbow trout (O. mykiss), whi...