scholarly journals Seasonal behaviours of coastal cutthroat trout (Oncorhynchus clarkii clarkii) in the Kitimat River watershed: observations and influences

2017 ◽  
Author(s):  
Eric Adam Vogt
Keyword(s):  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
River Watershed ◽  
Coastal Cutthroat Trout

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Evolutionary Biology ◽  
Cutthroat Trout ◽  
Westslope Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout ◽  
Lahontan Cutthroat Trout ◽  
Museum Samples ◽  
Yellowstone Cutthroat Trout ◽  
The 1960S

<em>Abstract</em>.—There has been considerable interest in the systematics and classification of Cutthroat Trout since the 1800s. Cutthroat Trout native to western North America (currently classified as <em>Oncorhynchus clarkii</em>) have historically been grouped or separated using many different classification schemes. Since the 1960s, Robert Behnke has been a leader in these efforts. Introductions of nonnative trout (other forms of Cutthroat Trout, and Rainbow Trout <em>O. mykiss</em>) have obscured some historical patterns of distribution and differentiation. Morphological and meristic analyses have often grouped the various forms of Cutthroat Trout together based on the shared presence of the “cutthroat mark,” high scale counts along the lateral line, and the presence of basibranchial teeth. Spotting patterns and counts of gill rakers and pyloric caeca have in some cases been helpful in differentiation of groups (e.g., Coastal Cutthroat Trout <em>O. c. clarkii</em>, Lahontan Cutthroat Trout <em>O. c. henshawi</em>, and Westslope Cutthroat Trout <em>O. c. lewisi</em>) currently classified as subspecies. The historical genetic methods of allozyme genotyping through protein electrophoresis and chromosome analyses were often helpful in differentiating the various subspecies of Cutthroat Trout. Allozyme genotyping allowed four major groups to be readily recognized (Coastal Cutthroat Trout, Westslope Cutthroat Trout, the Lahontan Cutthroat Trout subspecies complex, and Yellowstone Cutthroat Trout <em>O. c. bouvieri </em>subspecies complex) while chromosome analyses showed similarity between the Lahontan and Yellowstone Cutthroat trout subspecies complex trout (possibly reflecting shared ancestral type) and differentiated the Coastal and Westslope Cutthroat trouts from each other and those two groups. DNA results may yield higher resolution of evolutionary relationships of Cutthroat Trout and allow incorporation of ancient museum samples. Accurate resolution of taxonomic differences among various Cutthroat Trout lineages, and hybridization assessments, requires several approaches and will aid in conservation of these charismatic and increasingly rare native fishes.

Anadromous Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) as a Host for Argulus pugettensis (Crustacea, Branchiura): Parasite Prevalence, Intensity and Distribution

2020 ◽  
Vol 94 (2) ◽  
Author(s):  
James P. Losee ◽  
Simon R. M. Jones ◽  
Caitlin A. E. McKinstry ◽  
William N. Batts ◽  
Paul K. Hershberger
Keyword(s):  
Cutthroat Trout ◽  
Parasite Prevalence ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout

Discovery and characterization of novel genetic markers for coastal cutthroat trout (Oncorhynchus clarkii clarkii)

2013 ◽  
Vol 5 (3) ◽  
pp. 611-618
Author(s):  
Victoria L. Pritchard ◽  
John Carlos Garza
Keyword(s):  
Genetic Markers ◽  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout

Factors influencing coastal cutthroat trout (Oncorhynchus clarkii clarkii) seasonal survival rates: a spatially continuous approach within stream networks

2009 ◽  
Vol 66 (4) ◽  
pp. 613-632 ◽  
Author(s):  
Aaron M. Berger ◽  
Robert E. Gresswell
Keyword(s):  
Survival Rates ◽  
Fork Length ◽  
Cutthroat Trout ◽  
Population Level ◽  
Fish Length ◽  
Watershed Scale ◽  
Stream Networks ◽  
Oncorhynchus Clarkii ◽  
Discharge Temperature ◽  
Coastal Cutthroat Trout

Mark–recapture methods were used to examine watershed-scale survival of coastal cutthroat trout ( Oncorhynchus clarkii clarkii ) from two headwater stream networks. A total of 1725 individuals (≥100 mm, fork length) were individually marked and monitored seasonally over a 3-year period. Differences in survival were compared among spatial (stream segment, subwatershed, and watershed) and temporal (season and year) analytical scales, and the effects of abiotic (discharge, temperature, and cover) and biotic (length, growth, condition, density, movement, and relative fish abundance) factors were evaluated. Seasonal survival was consistently lowest and least variable (years combined) during autumn (16 September – 15 December), and evidence suggested that survival was negatively associated with periods of low stream discharge. In addition, relatively low (–) and high (+) water temperatures, fish length (–), and boulder cover (+) were weakly associated with survival. Seasonal abiotic conditions affected the adult cutthroat trout population in these watersheds, and low-discharge periods (e.g., autumn) were annual survival bottlenecks. Results emphasize the importance of watershed-scale processes to the understanding of population-level survival.

Diversity of movements by individual anadromous coastal cutthroat trout Oncorhynchus clarkii clarkii

2013 ◽  
Vol 83 (5) ◽  
pp. 1161-1182 ◽  
Author(s):  
F. A. Goetz ◽  
B. Baker ◽  
T. Buehrens ◽  
T. P. Quinn
Keyword(s):  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout

scholarly journals A Comparison of Nonlethal Methods for Evaluating the Reproductive Status of Female Coastal Cutthroat Trout

2014 ◽  
Vol 5 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Peter D. Bangs ◽  
James J. Nagler
Keyword(s):  
Ultrasound Imaging ◽  
Lipid Content ◽  
Cutthroat Trout ◽  
Reproductive Status ◽  
Annual Reproductive Cycle ◽  
Body Lipid ◽  
Oncorhynchus Clarkii ◽  
The Pacific ◽  
Coastal Cutthroat Trout ◽  
Estradiol Levels

Abstract Knowledge of the state of sexual development is important for management of coastal cutthroat trout Oncorhynchus clarkii clarkii, a fish species targeted for sport fishing throughout its range along the Pacific coast of North America. The purpose of this study was to compare the nonlethal methods of ultrasound imaging, body lipid content, and the measurement of plasma vitellogenin and estradiol levels for assessing the reproductive status of female coastal cutthroat trout. This was examined in a population living in Florence Lake, Alaska, during the spring–early autumn period of the annual reproductive cycle. All methods, except body lipid content, were effective at determining maturity status in either the spring (ultrasound imaging), or spring and autumn (plasma vitellogenin and estradiol). These approaches could be useful for conducting nonlethal assessments of length- or age-at-maturity on populations of coastal cutthroat trout that are small, have conservation concerns, or are heavily utilized by anglers.

Effects of stream-adjacent logging in fishless headwaters on downstream coastal cutthroat trout

2016 ◽  
Vol 73 (12) ◽  
pp. 1898-1913 ◽  
Author(s):  
Douglas S. Bateman ◽  
Matthew R. Sloat ◽  
Robert E. Gresswell ◽  
Aaron M. Berger ◽  
David P. Hockman-Wert ◽  
...  
Keyword(s):  
Riparian Forest ◽  
Cutthroat Trout ◽  
Late Summer ◽  
Timber Harvest ◽  
Negative Effects ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout ◽  
Commercial Logging ◽  
Watershed Approach ◽  
Paired Watershed

To investigate effects of headwater logging on downstream coastal cutthroat trout (Oncorhynchus clarkii clarkii) populations, we monitored stream habitat and biotic indicators including biomass, abundance, growth, movement, and survival over 8 years using a paired-watershed approach. Reference and logged catchments were located on private industrial forestland on ∼60-year harvest rotation. Five clearcuts (14% of the logged catchment area) were adjacent to fishless portions of the headwater streams, and contemporary regulations did not require riparian forest buffers in the treatment catchment. Logging did not have significant negative effects on downstream coastal cutthroat trout populations for the duration of the sample period. Indeed, the only statistically significant response of fish populations following logging in fishless headwaters was an increase in late-summer biomass (g·m−2) of age-1+ coastal cutthroat trout in tributaries. Ultimately, the ability to make broad generalizations concerning effects of timber harvest is difficult because response to disturbance (anthropogenically influenced or not) in aquatic systems is complex and context-dependent, but our findings provide one example of environmentally compatible commercial logging in a regenerated forest setting.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Author(s):  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Rainbow Trout ◽  
Evolutionary Biology ◽  
Isolation By Distance ◽  
Cutthroat Trout ◽  
Population Connectivity ◽  
Oncorhynchus Clarkii ◽  
Habitat Alterations ◽  
Coastal Cutthroat Trout

<em>Abstract</em>.—We examined patterns of dispersal and colonization after Cordilleran glaciations, population connectivity, levels of genetic diversity, and potential impacts of anthropogenic changes to Coastal Cutthroat Trout <em>Oncorhynchus clarkii clarkii</em>. Populations were mostly small with restricted dispersals but exchanged one to two migrants per generation on average. Genetic differences among local populations of Coastal Cutthroat Trout accounted for approximately three-fourths of the total genetic variation among groups, with differences among different geographical groups accounting for the rest. Because of this, hierarchical geographical population structure was difficult to detect except at small geographical scales that reflected local dispersal and gene flow or at broad geographical scales that reflected divergence associated with long-term isolation during Cordilleran glacial advances. Evolutionary processes such as gene flow and genetic drift reflected in isolation by distance occurred at distances up to 600–700 km but mostly lesser distances, whereas divergence associated with Pleistocene glaciation occurred at 1,900 km or greater. Glacial refugia existed south of the Salish Sea along the Washington, Oregon, and California coasts; in the Haida Gwaii or Alexander Archipelago; and possibly near the central coast of British Columbia near Bella Coola. Throughout the range, hybridization with Rainbow Trout <em>O. mykiss </em>or steelhead (anadromous Rainbow Trout) appears to occur naturally at low levels, but releases of hatchery-produced <em>O. mykiss </em>can lead to higher levels of hybridization and rarely hybrid swarms. Degraded habitat may contribute to hybridization, but most anthropogenic habitat alterations reduce habitat quantity and quality and disrupt opportunities for dispersal, contributing to declines in abundance, population connectivity, and genetic diversity.

Landscape-scale evaluation of genetic structure among barrier-isolated populations of coastal cutthroat trout, Oncorhynchus clarkii clarkii

2008 ◽  
Vol 65 (8) ◽  
pp. 1749-1762 ◽  
Author(s):  
Troy J. Guy ◽  
Robert E. Gresswell ◽  
Michael A. Banks
Keyword(s):  
Genetic Diversity ◽  
Isolation By Distance ◽  
Cutthroat Trout ◽  
Dominant Factor ◽  
Coast Range ◽  
Isolated Populations ◽  
Regional Patterns ◽  
Oncorhynchus Clarkii ◽  
Genetic Patterns ◽  
Coastal Cutthroat Trout

Relationships among landscape structure, stochastic disturbance, and genetic diversity were assessed by examining interactions between watershed-scale environmental factors and genetic diversity of coastal cutthroat trout ( Oncorhynchus clarkii clarkii ) in 27 barrier-isolated watersheds from western Oregon, USA. Headwater populations of coastal cutthroat trout were genetically differentiated (mean FST = 0.33) using data from seven microsatellite loci (2232 individuals), but intrapopulation microsatellite genetic diversity (mean number of alleles per locus = 5, mean He = 0.60) was only moderate. Genetic diversity of coastal cutthroat trout was greater (P = 0.02) in the Coast Range ecoregion (mean alleles = 47) than in the Cascades ecoregion (mean alleles = 30), and differences coincided with indices of regional within-watershed complexity and connectivity. Furthermore, regional patterns of diversity evident from isolation-by-distance plots suggested that retention of within-population genetic diversity in the Coast Range ecoregion is higher than that in the Cascades, where genetic drift is the dominant factor influencing genetic patterns. Thus, it appears that physical landscape features have influenced genetic patterns in these populations isolated from short-term immigration.

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