Understanding how abundance regulates the effects of organisms on their ecosystems remains a critical goal of ecology, especially for understanding inter-ecosystem transfers of energy and nutrients. Here we examined how territoriality and nest-digging by anadromous salmon mediate trophic subsidies to stream fishes. Salmon eggs become available for consumption primarily by the digging of salmon ...

We have documented an early life survival advantage by naturalized populations of anadromous rainbow trout Oncorhynchus mykiss over a more recently introduced hatchery population and outbreeding depression resulting from interbreeding between the two strains. We tested the hypothesis that offspring of naturalized and hatchery trout, and reciprocal hybrid crosses, survive equally from fry to age...

Estimation of quantitative genetic parameters conventionally requires known pedigree structure. However, several methods have recently been developed to circumvent this requirement by inferring relationship structure from molecular marker data. Here, two such marker-assisted methodologies were used and compared in an aquaculture population of rainbow trout (Oncorhynchus mykiss). Firstly a regre...

Degree of silvering (colouration) is often used as an index of the degree of srnoltification in salmonids. To judge the reliability of silvering a s an indicator of migratory readiness, we examined the silvering of wild coho salmon, Oncorhynchus kisutch, smolts upon entry into the Carnation Creek, British Columbia, estuary. Silvering of migrants was greater in larger fish and increased over the...

The modulation transfer function due to measured longitudinal chromatic aberration was calculated for the otherwise unaberrated eye of the adult rainbow trout (Oncorhynchus mykiss) under daylight conditions assuming light absorption by single retinal cone pigments, and by photopic mechanisms involving interaction between cones. The adult trout eye, with its large immobile pupil, is limited by c...

RESEARCH ARTICLE Skin Spotting Variation Associated with Biometric and Reproductive Parameters in Naturalized Populations of Rainbow Trout, Oncorhynchus mykiss, from Southern Chile Nelson Colihueque, Francisco Javier Estay and Miguel Yáñez Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Osorno, Chile Piscícola Huililco Ltda., Pucón, Chile Departamento de Estadísti...

background & aim: continuous use of antibiotics leads to drug resistance and thereby to a reduced efficacy of the drugs. antibiotics accumulate in the environment and fish pose a potential risk to consumers and to the environment.increased public awareness of the negative effects caused by overexposure to synthetic chemicals has led to the search for ‘‘green drugs’’, such as organic and syn...

Offspring traits are greatly influenced by maternal effects, and these maternal effects may provide an important pathway through which populations can adapt to changing thermal environments. We investigated the effect of egg size on the among- and within-population variation in early life history traits among introduced Great Lakes Chinook salmon (Oncorhynchus tshawytscha) populations under var...

Allochronic divergence, like spatial isolation, may contribute to population diversity and adaptation, however the challenges for tracking habitat utilization in shared environments are far greater. Adult Klukshu River (Yukon, Canada) sockeye salmon, Oncorhynchus nerka, return as genetically distinct "early" and "late" runs. Early and late adult spawning populations (1999 and 2000) and their su...

Data from pelagic trawl surveys by TINRO-center from 1987 to 1996 in the Okhotsk Sea indicate that coho abundance is underestimated by coastal observations. The approximate Asian coho spawning biomass is 7,300-16,000 tons for the 1990s. Ways of improving Asian coho salmon resource management are discussed. Collection of precise fishery and escapement statistics must be expanded in areas previou...