نتایج جستجو برای: brook trout
تعداد نتایج: 12957 فیلتر نتایج به سال:
The aims of this study were to determine hatching performance, body and yolk weight at hatching, the growth rate during the yolk absorption and yolk conversion efficiency of Black Sea trout, brook trout and their hybrid larvae, and to compare the relationships between length, total wet weight, dry yolk body weights of alevins and degree-days. The Black Sea trout egg has shorter incubation durat...
The objectives of the present study were to compare growth performance and feed conversion ratios of brook trout (Salvelinus fontinalis) and Black Sea trout (Salmo trutta labrax) in monoculture and duo-culture tank reared conditions. The fish were about 9-month-old hatchery reared brook trout and Black Sea trout with initial weights of 24.18±0.64 (n=60) and 23.87±1.11 (n=60) g, respectively. Fi...
—Outlet barriers in stocked lakes of the Adirondack Mountains were used to test the hypothesis that preventing fall emigration by adult brook trout Salvelinus fontinalis would increase trap-net and angling catch rates as well as the number of large trophy fish. Outlet barriers were maintained during the fall spawning season for 6 years on one lake and 10 years on another lake. We compared preba...
Title of Document: MANAGEMENT AND CONSERVATION OF BROOK TROUT IN WESTERN MARYLAND David Charles Kazyak, Ph.D., 2015 Directed By: Dr. Robert H. Hilderbrand Associate Professor University of Maryland Center for Environmental Science, Appalachian Laboratory Widespread declines have been observed in the abundance, distribution, and size structure of Brook Trout for nearly 200 years. Although broadl...
Competition and Predation as Mechanisms for Displacement of Greenback Cutthroat Trout by Brook Trout
—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...
Current distributions of native brook trout (Salvelinus fonfinalis) in the southern Appalachians are restricted to upper elevations by multiple factors, including habitat requirements, introduced rainbow (Oncorhynchus mykiss) and brown (Salmo fnrtia) trout, and other human activities. Present-day distribution of brook trout habitat is already fragmented. Increased temperatures predicted by vari...
Non-indigenous species may be the most severe environmental threat the world now faces. Fishes, in particular, have been intentionally introduced worldwide and have commonly caused the local extinction of native fish. Despite their importance, the impact of introduced fishes on threatened populations of Pacific salmon has never been systemically examined. Here, we take advantage of several uniq...
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...
I used multiple approaches to study brook trout invasions in mountainous streams of Idaho and Montana, USA. After studying marked fish in experimental reaches and fish distributions throughout a drainage, I concluded that larger brook trout (95mm) moved more than smaller ones and were probably responsible for most dispersal leading to invasion. Contrary to earlier hypotheses, poor swimming abil...
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