Effect of Ammonium Chloride on Predatory Consumption Rates of Brook Trout (Salvelinus fontinalis) on Juvenile Chinook Salmon (Oncorhynchus tshawytscha) in Laboratory Streams James L. Hedtke' and Logan A. Norris2 'Department of Fisheries and Wildlife, Oak Creek Laboratory of Biology, Oregon State University, Corvallis, Or. 97331 2U.S. Department of Agriculture, Forest Service, Pacific Northwest ...

Amphibian population declines and extinctions are occurring even in the world's least impacted areas. The introduction and spread of nonnative predators is one of many proposed causes of amphibian declines. Correlational studies have shown a negative relationship between introduced fishes and declining amphibians, but little direct experimental evidence is available. This study experimentally m...

MCFARLAND, W. N. , and D. M. ALLEN. 1977. The effect of extrinsic factors on two distinctive rhodopsin-porphyropsin systems. Can. J . Zool. 55: 1000-1009. The effects of light, temperature, and thyroxine on the proportions of two visual pigments (rhodopsin and porphyropsin) are compared for three species of fishes in which the pigment proportions change oppositely in response to light (rainbow ...

Trout and salmon commonly coexist in stream networks. Exploring similarities differences among species can help explain coexistence invasive ability. Here, we describe spatial distribution, cohort strengths size-at-age of three co-occurring a small network. Spatial distributions varied dramatically species; native brook trout occupied all reaches, naturalized brown were found the mainstem lower...

We examined habitat factors related to reach-scale brook trout Salvelinus fontinalis counts of four size classes in two headwater stream networks within two contrasting summers in Connecticut, USA. Two study stream networks (7.7 and 4.4 km) were surveyed in a spatially continuous manner in their entirety, and a set of Bayesian generalised linear mixed models was compared. Trout abundance was be...

Wild brook charr populations (Salvelinus fontinalis) completely introgressed with the mitochondrial genome (mtDNA) of arctic charr (Salvelinus alpinus) are found in several lakes of northeastern Québec, Canada. Mitochondrial respiratory enzymes of these populations are thus encoded by their own nuclear DNA and by arctic charr mtDNA. In the present study we performed a comparative sequence analy...

Broad-scale studies of climate change effects on freshwater species have focused mainly on temperature, ignoring critical drivers such as flow regime and biotic interactions. We use downscaled outputs from general circulation models coupled with a hydrologic model to forecast the effects of altered flows and increased temperatures on four interacting species of trout across the interior western...