Ammonia has been documented as a respiratory gas that stimulates ventilation, and is sensed by peripheral neuroepithelial cells (NECs) in the gills in ammoniotelic rainbow trout. However, the hyperventilatory response is abolished in trout chronically exposed (1+ months) to high environmental ammonia [HEA; 250 μmol l(-1) (NH4)2SO4]. This study investigates whether the brain is involved in the a...

We compared seawater tolerance, gill Na(+)/K(+)-ATPase and Na(+)/K(+)/2Cl(-) cotransporter (NKCC) abundance, and mitochondria-rich cell (MRC) morphology of three salmonids, lake trout Salvelinus namaycush, brook trout Salvelinus fontinalis and Atlantic salmon Salmo salar. They were transferred directly from 0 p.p.t. (parts per thousand; freshwater) to 30 p.p.t. seawater, or transferred graduall...

We hypothesized that body shape differences between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), rainbow trout (Oncorhynchus mykiss), and their hybrids may influence swimming ability and thus play an important role in the invasion of nonnative rainbow trout and hybrid trout into native cutthroat trout populations. We reared Yellowstone cutthroat trout, rainbow trout, and recipro...

Trout stocking in the mid-1960s eliminated the calanoid copepod Hesperodiaptomus arcticus and other largebodied crustaceans such as Gammarus lacustris, Daphnia middendorffiana, and Daphnia pulex from many alpine lakes in the Rocky Mountain Parks of Canada. H. arcticus frequently dominates the plankton communities of fishless lakes, preying on rotifers and nauplius larvae. Following the extirpat...

We evaluated methylmercury (MeHg) concentrations in native apex predators, lake trout Salvelinus namaycush before and after the large-scale removal of introduced predators, smallmouth bass Micropterus dolomieu in a 270 ha Adirondack lake. Previous studies show that removing competitors can result in increased growth and decreased mercury concentrations in remaining fish. Instead, we observed a ...

The experimental pathogenesis of Aeromonas salmonicida for the sea trout (Salmo trutta) and the brown trout (Salmo fario) in sea and brackish waters was examined by contact between infected and healthy fishes. Sea trout and brown trout both acquired infection by contact with infected S. fario at salinity values from 2-54 yo to 3.3 I yo (wlw) when water temperatures ranged from 5.6" to 14.5". Th...

Despite the importance of predator recognition in mediating predator-prey interactions, we know little about the specific characteristics that prey use to distinguish predators from non-predators. Recent experiments indicate that some prey who do not innately recognize specific predators as threats have the ability to display antipredator responses upon their first encounter with those predator...

Rainbow trout are classified as Oncorhynchus mykiss, and as such belong to the same genus as Pacific salmon, and to the family Salmonidae, which includes Atlantic salmon (Salmo salar), various trout (Salvelinus sp.), Arctic char (Salvelinus alpinus), Arctic grayling (Thymallus arcticus) and whitefish (Coregonus sp.). Rainbow trout are native to areas around the North Pacific Ocean, from souther...

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...