the objective of this study was to compare growth performance and feed conversion ratios of rainbow trout (oncorhynchus mykiss) and brook trout (salvelinus fontinalis) juveniles in monoculture and duo-culture in freshwater and seawater under aquarium conditions. the fish were about 2-months old hatchery-reared brook and rainbow trout with initial weights of 0.934±0.033 (n=360) and 1.014±0.019 (...

We explored potential negative effects of exotic brown trout (Salmo trutta) on native sculpin (Cottus sp.) on the Logan River, Utah, USA by (i) examining factors most strongly correlated with sculpin abundance (e.g., abiotic conditions or piscivory?), (ii) contrasting the extent of brown trout predation on sculpin with that by native cutthroat trout (Oncorhynchus clarkii utah) and (iii) estimat...

Rainbow trout native to the McCloud River, California, USA (Oncorhynchus mykiss stonei) are thought to represent a relic, nonanadromous trout adapted to harsh, fragmented environments. These fish, commonly named McCloud River 'redband' trout, survive in their most primitive form in a small, spring-fed stream, Sheepheaven Creek, in the upper McCloud River drainage. Turn-of-the-century fisheries ...

Hybridization between rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) and westslope cutthroat trout (Oncorhynchus clarkii lewisi (Girard, 1856)) occurs commonly when rainbow trout are introduced into the range of westslope cutthroat trout. Typically, hybridization ismost common inwarmer, lower elevation habitats, butmuch less common in colder, higher elevation habitats. We assessed the tole...

Multiple Hemoglobin Components in Cutthroat and Rainbow Trout Multiple hemoglobin components in fish is a well-documented phenomenon, with cutthroat trout having twelve (Figure 1a) and rainbow trout having nine (Figure 1b) hemoglobin components (Braman et al.1977). A high-resolution starch gel electrophoresis method was developed to resolve eight negatively charged hemoglobin components from bo...

abstract the growth is a one of biological aspects of fishes and is a good index in order to determine of health of these population. the aim of this study was to investigate the effect of different color lights on condition factor and weight- length relationships (lwr) of rainbow trout. fertilized eggs of fish were kept under light conditions, 14h light and 10h dark for 5 months at seven light...

BACKGROUND Estimates of fishing and natural mortality are important for understanding, and ultimately managing, commercial and recreational fisheries. High reward tags with fixed station acoustic telemetry provides a promising approach to monitoring mortality rates in large lake recreational fisheries. Kootenay Lake is a large lake which supports an important recreational fishery for large Bull...

—Cutthroat trout Oncorhynchus clarkii frequently are displaced by nonnative brook trout Salvelinus fontinalis, but the ecological mechanisms of displacement are not understood. Competition for food and predation between greenback cutthroat trout O. c. stomias and brook trout were investigated in montane streams of Colorado. A replicated field study was used to describe the population density, d...

The article highlights the analyzes of ecosystem Lake Khedo (Republic Karelia) under conditions growing anthropogenic load caused by using lake for breeding trout in fish cages based on proper and literature data. Comparative analysis hydrochemical data before operation farm (until 2005) after showed a twofold increase water color (70-150°), which indicates an increased content organic pollutan...