Download or read book Life History of Colorado River Cutthroat Trout Oncorhynchus Clarki Pleuriticus and the Effects of Introgression with Rainbow Trout O Mykiss and Yellowstone Cutthroat Trout O C Lewisi written by Michael N. McGee and published by . This book was released on 1998 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conservation Status of Colorado River Cutthroat Trout written by and published by . This book was released on 1996 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Management and Life History Consequences of Hybridization Between Westslope Cutthroat Trout oncorhynchus Clarkii Lewisi and Rainbow Trout oncorhynchus Mykiss written by Matthew Corsi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of introductions of nonnative fishes in the decline of native fishes cannot be overstated. Westslope cutthroat trout (Oncorhynchus clarkii lewisi, WCT) are a salmonid native to the northern Rocky Mountains. These trout hybridize with rainbow trout (O. mykiss, RBT) where they are sympatric; however, in portions of the WCT range where RBT have been introduced, hybridization appears to spread rapidly and threatens continued existence of WCT. The conservation value of these hybridized populations is equivocal, and a better knowledge of the ecological, demographic, behavioral, and genetic consequences of hybridization is needed to better inform conservation strategies. I investigated three related questions: specifically, what landscape factors are associated with estimates of introgression; what are life history differences between WCT and hybrids; and what are tradeoffs in restoring migratory life history in populations threatened by hybridization? The riverscape context plays a substantial role in the distribution of hybrids, as estimates of introgression declined with increases in stream slope, elevation, and distance from a primary source of RBT, three correlated landscape variables. Spatial variation in patterns of hybridization suggests clarifying objectives for sampling and careful designs are necessary to adequately understand the status of populations. Variation in location may relate to some of the ecological differences, such as growth, among fish with different levels of introgression. In the Jocko River, hybrids with ancestry> 20% RBT demonstrated higher growth, earlier migration, increased egg size, and lower fecundity versus WCT. These lines of evidence demonstrate the importance of limiting further hybridization even in populations that already have low levels of hybridization. Given that many unaltered populations currently reside in isolated habitat fragments, I evaluated several demographic tradeoffs of restoring a migratory life history weighed against the risks of increased potential for hybridization from removing barriers or selectively passing migratory fish above the barriers using both matrix and genetic population models. Restoration of migratory life history substantially increases population viability; however, hybridization in above-barrier population increases predictably relative to hybridization status of below-barrier population, which may reduce viability if vital rates are reduced in hybrids. Hybridization creates a challenging set of management problems, but this research adds several important pieces to the puzzles to help develop and evaluate conservation strategies.
Download or read book Colorado River Cutthroat Trout Oncorhynchus Clarkii Pleuriticus written by Michael K. Young and published by . This book was released on 2008 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus) was once distributed throughout the colder waters of the Colorado River basin above the Grand Canyon. About 8 percent of its historical range is occupied by unhybridized or ecologically significant populations. It has been petitioned for listing under the Endangered Species Act and is accorded special status by several state and federal agencies. Habitat alteration and nonnative trout invasions led to the extirpation of many populations and impede restoration. Habitat fragmentation exacerbated by climate change is an emerging threat. A strategic, systematic approach to future conservation is likely to be the most successful.
Download or read book Cutthroat written by Pat Trotter and published by Univ of California Press. This book was released on 2008 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cutthroat tells the full story of the genuine native trout of the American West. This new edition, thoroughly revised and updated after 20 years, synthesizes what is currently known about one of our most interesting and colorful fishes, includes much new information on its biology and ecology, asks how it has fared in the last century, and looks toward its future. In a passionate and accessibly written narrative, Patrick Trotter, fly fisher, environmental advocate, and science consultant, details the evolution, natural history, and conservation of each of the cutthroat's races and incorporates more personal reflections on the ecology and environmental history of the West's river ecosystems. The bibliography now includes what may be the most comprehensive and complete set of references available anywhere on the cutthroat trout. Written for anglers, nature lovers, environmentalists, and students, and featuring vibrant original illustrations by Joseph Tomelleri, this is an essential reference for anyone who wants to learn more about this remarkable, beautiful, and fragile western native.
Download or read book Introgression Between Colorado River Cutthroat Trout and Rainbow Trout in an Isolated Drainage System written by Catherine M. Bischoff and published by . This book was released on 1995 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conservation Status of Colorado River Cutthroat Trout written by and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behavioral Ecological and Fitness Consequences of Hybridization Between Native Westslope Cutthroat Trout Oncorhynchus Clarkii Lewisi and Nonnative Rainbow Trout O Mykiss written by Clint Cain Muhlfeld and published by . This book was released on 2008 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic hybridization is one of the greatest threats to global biodiversity. Hybridization and introgression may lead to a loss of locally adapted gene complexes and ecological adaptations in native populations, yet these potential consequences have not been fully evaluated in nature. I investigated factors influencing the spread of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and nonnative rainbow trout (O. mykiss) in the upper Flathead River system, Montana (USA) and British Columbia (Canada). The fundamental questions of my dissertation were: what are the behavioral, ecological, and fitness consequences of hybridization and what factors influence successful invasion of hybrids? First, I assessed the patterns of spawning between parental species and their hybrids and found that hybridization alters the spawning behavior of migratory westslope cutthroat trout, and is spreading via long distance dispersal of hybrids from downstream sources and some temporal overlap during spawning. Second, I describe for the first time how a wide range of levels of nonnative admixture affect fitness of cutthroat trout in the wild by estimating reproductive success in a recently invaded stream using parentage analysis with multilocus microsatellite markers. Small amounts of hybridization markedly reduced reproductive success, with fitness exponentially declining by ~50% with 20% nonnative genetic admixture. Finally, I evaluated the association of local-habitat features, landscape characteristics, and biotic factors with the spread of hybridization in the system, and found that hybridization increases in streams with warmer water temperatures, high land use disturbance and close proximity to the source of hybridization; however, none of these factors appeared sufficient to prevent further spread. These combined results suggest that hybrids are not only genetically different than westslope cutthroat trout but also have reduced fitness and are ecologically different, and that hybridization is likely to continue to spread if hybrid populations with high amounts of rainbow trout admixture are not reduced or eliminated. I conclude that extant aboriginal cutthroat trout are at greater conservation risk due to hybridization than previously thought and policies that protect hybridized populations need reconsideration.
Download or read book Colorado River Cutthroat Trout Oncorhynchus Clarki Pleuriticus Management Activities and Accomplishment Report 1999 2003 Colorado Wyoming and Utah written by and published by . This book was released on 2005* with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecological Consequences of Hybridization Between Native Westslope Cutthroat Trout Oncorhynchus Clarkii Lewisi and Introduced Rainbow Trout O Mykiss in South Western Alberta written by Michael D. Robinson and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Water Temperature on Interactions Between Colorado River Cutthroat Trout Oncorhynchus Clarki Pleuriticus and Brook Trout Salvelinus Fontinalis written by James De Staso and published by . This book was released on 1993 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Colorado River Cutthroat Trout written by Michael K. Young and published by . This book was released on 2008 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus) was once distributed throughout the colder waters of the Colorado River basin above the Grand Canyon. About 8 percent of its historical range is occupied by unhybridized or ecologically significant populations. It has been petitioned for listing under the Endangered Species Act and is accorded special status by several state and federal agencies. Habitat alteration and nonnative trout invasions led to the extirpation of many populations and impede restoration. Habitat fragmentation exacerbated by climate change is an emerging threat. A strategic, systematic approach to future conservation is likely to be the most successful.
Download or read book Range wide Status of Colorado River Cutthroat Trout Oncorhynchus Clarkii Pleuriticus written by Christine L. Hirsch and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Naturally Occurring Hybridization and Introgression Between Westslope Cutthroat Oncorhynchus Clarki Lewisi and Native Rainbow Trout Oncorhynchus Mykiss Within Three Tributaries of the Middle Fork Salmon River Idaho written by Michael Patrick Peterson and published by . This book was released on 2004 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conservation Genetics of the Greenback Cutthroat Trout Oncorhynchus Clarkii Stomias written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conservation genetics of the greenback cutthroat trout (Oncorhynchus clarkii stomias).
Download or read book Ecological and Environmental Investigations of Competition Between Native Yellowstone Cutthroat Trout Oncorhynchus Clarkii Bouvieri Rainbow Trout Oncorhynchus Mykiss and Their Hybrids written by Steven Michael Seiler and published by . This book was released on 2007 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduced species can have dramatic impacts within the native communities where they become established. In western North America, native cutthroat trout (Oncorhynchus clarkii) are experiencing drastic declines due to habitat alteration and fish introductions. Rainbow trout ( O. mykiss) are thought to be especially detrimental to cutthroat trout because they share similar life histories and can form fertile hybrid offspring, compounding interspecific competition through added pressure from hybrids. My dissertation consists of five studies developed to test ecological and environmental factors that may influence the spread of rainbow trout and cutthroat-rainbow hybrid trout within native Yellowstone cutthroat trout ( O. c. bouvieri) populations. I raised Yellowstone cutthroat trout, rainbow trout, and reciprocal first generation hybrids under common conditions and tested for differences in morphology and swimming stamina (Chapter 1), aggression and foraging ability (Chapter 2), and the strength of interspecific competition on the growth rate of Yellowstone cutthroat trout (Chapter 3). I also surveyed trout and environmental characteristics from the South Fork of the Snake River watershed to test for morphological differences between wild Yellowstone cutthroat trout, rainbow trout, and hybrids (Chapter 4) and to examine the influence of environmental characteristics on the extent of hybridization (Chapter 5). I found differences in morphology, swimming stamina, foraging behavior, and growth between Yellowstone cutthroat trout, rainbow trout, and their hybrids that place cutthroat trout at a disadvantage. The field survey found body shape differences between Yellowstone cutthroat trout, rainbow trout, and hybrids consistent with those of trout raised in the laboratory with high predictability of genetic class based on morphology alone. The degree of hybridization present at field sampling locations was related to the size of the stream and summer water temperature of the sampling location; however, level of hybridization could also be the result of distance from a location where most rainbow trout were stocked. My work provides some of the first tests of competition between cutthroat trout and rainbow trout and the influence of hybridization. This dissertation will aid in cutthroat trout conservation efforts and be of general interest to invasive species ecologists in better understanding the dynamics of invasive species success.
Download or read book Native Trout of Western North America written by Robert J. Behnke and published by . This book was released on 1992 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
