scholarly journals Swimming Performance of Rainbow Trout and Westslope Cutthroat Trout in an Open-Channel Flume

2019 ◽  
Vol 11 (1) ◽  
pp. 217-225
Author(s):  
Matt D. Blank ◽  
Kevin M. Kappenman ◽  
Kathryn Plymesser ◽  
Katharine Banner ◽  
Joel Cahoon
Keyword(s):  
Rainbow Trout ◽  
Confidence Interval ◽  
Open Channel ◽  
Swimming Performance ◽  
Weighted Least Squares ◽  
Fork Length ◽  
Cutthroat Trout ◽  
Fish Passage ◽  
Least Squares Regression ◽  
Westslope Cutthroat Trout

Abstract We used an open-channel flume to characterize the swimming performance of Rainbow Trout Oncorhynchus mykiss and Westslope Cutthroat Trout Oncorhynchus clarki lewisi ranging nominally in fork length from 15 to 30 cm. With an open-channel flume, we observed volitional swim performance of wild-caught Rainbow Trout and Westslope Cutthroat Trout; the fish were not coerced, prodded, or spooked into action. We also observed the maximum short-duration swim speed of the fish, providing important effective leap or velocity challenge information for the design of intentional barriers. We conducted the experiment with a consistently low water velocity challenge and characterized swim speeds by using weighted least-squares regression, revealing no evidence of a difference in swim speeds between the two species. We estimated the overall average swim speed for Rainbow Trout to be 0.84 m/s (SE = 0.02), with a 95% confidence interval of 0.79–0.89 m/s, and that for Westslope Cutthroat Trout to be 0.84 m/s (SE = 0.03), with a 95% confidence interval of 0.78–0.90 m/s. The maximum swim speeds observed were 2.72 m/s for Rainbow Trout and 3.55 m/s for Westslope Cutthroat Trout. The project results provide new information on the swimming ability of wild Rainbow Trout and Westslope Cutthroat Trout that can be used to improve fish passage or barrier design.

Spatial and temporal spawning dynamics of native westslope cutthroat trout, Oncorhynchus clarkii lewisi, introduced rainbow trout, Oncorhynchus mykiss, and their hybrids

2009 ◽  
Vol 66 (7) ◽  
pp. 1153-1168 ◽  
Author(s):  
Clint C. Muhlfeld ◽  
Thomas E. McMahon ◽  
Durae Belcer ◽  
Jeffrey L. Kershner
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cutthroat Trout ◽  
River System ◽  
Westslope Cutthroat Trout ◽  
Time And Space ◽  
Long Distance ◽  
Oncorhynchus Clarkii ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Spring Runoff

We used radiotelemetry to assess spatial and temporal spawning distributions of native westslope cutthroat trout ( Oncorhynchus clarkii lewisi ; WCT), introduced rainbow trout ( Oncorhynchus mykiss ; RBT), and their hybrids in the upper Flathead River system, Montana (USA) and British Columbia (Canada), from 2000 to 2007. Radio-tagged trout (N = 125) moved upriver towards spawning sites as flows increased during spring runoff and spawned in 29 tributaries. WCT migrated greater distances and spawned in headwater streams during peak flows and as flows declined, whereas RBT and RBT hybrids (backcrosses to RBT) spawned earlier during increasing flows and lower in the system. WCT hybrids (backcrosses to WCT) spawned intermediately in time and space to WCT and RBT and RBT hybrids. Both hybrid groups and RBT, however, spawned over time periods that produced temporal overlap with spawning WCT in most years. Our data indicate that hybridization is spreading via long-distance movements of individuals with high amounts of RBT admixture into WCT streams and stepping-stone invasion at small scales by later generation backcrosses. This study provides evidence that hybridization increases the likelihood of reproductive overlap in time and space, promoting extinction by introgression, and that the spread of hybridization is likely to continue if hybrid source populations are not reduced or eliminated.

Cold tolerance performance of westslope cutthroat trout (Oncorhynchus clarkii lewisi) and rainbow trout (Oncorhynchus mykiss) and its potential role in influencing interspecific hybridization

2014 ◽  
Vol 92 (9) ◽  
pp. 777-784 ◽  
Author(s):  
M.M. Yau ◽  
E.B. Taylor
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Water Temperature ◽  
Cold Water ◽  
Cutthroat Trout ◽  
Acclimation Temperature ◽  
Westslope Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Differential Adaptation

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 is most common in warmer, lower elevation habitats, but much less common in colder, higher elevation habitats. We assessed the tolerance to cold water temperature (i.e., critical thermal minimum, CTMin) in juvenile rainbow trout and westslope cutthroat trout to test the hypothesis that westslope cutthroat trout better tolerate low water temperature, which may explain the lower prevalence of rainbow trout and interspecific hybrids in higher elevation, cold-water habitats (i.e., the “elevation refuge hypothesis”). All fish had significantly lower CTMin values (i.e., were better able to tolerate low temperatures) when they were acclimated to 15 °C (mean CTMin = 1.37 °C) versus 18 °C (mean CTMin = 1.91 °C; p < 0.001). Westslope cutthroat trout tended to have lower CTMin than rainbow trout from two populations, second–generation (F2) hybrids between two rainbow trout populations, and backcrossed rainbow trout at 15 °C (cross type × acclimation temperature interaction; p = 0.018). Differential adaptation to cold water temperatures may play a role in influencing the spatial distribution of hybridization between sympatric species of trout.

scholarly journals Vive la résistance: genome-wide selection against introduced alleles in invasive hybrid zones

2016 ◽  
Vol 283 (1843) ◽  
pp. 20161380 ◽  
Author(s):  
Ryan P. Kovach ◽  
Brian K. Hand ◽  
Paul A. Hohenlohe ◽  
Ted F. Cosart ◽  
Matthew C. Boyer ◽  
...  
Keyword(s):  
Invasive Species ◽  
Rainbow Trout ◽  
Natural Populations ◽  
Cutthroat Trout ◽  
Field Studies ◽  
Selective Advantage ◽  
Hybrid Zones ◽  
Introduced Fish ◽  
Westslope Cutthroat Trout ◽  
Genome Wide

Evolutionary and ecological consequences of hybridization between native and invasive species are notoriously complicated because patterns of selection acting on non-native alleles can vary throughout the genome and across environments. Rapid advances in genomics now make it feasible to assess locus-specific and genome-wide patterns of natural selection acting on invasive introgression within and among natural populations occupying diverse environments. We quantified genome-wide patterns of admixture across multiple independent hybrid zones of native westslope cutthroat trout and invasive rainbow trout, the world's most widely introduced fish, by genotyping 339 individuals from 21 populations using 9380 species-diagnostic loci. A significantly greater proportion of the genome appeared to be under selection favouring native cutthroat trout (rather than rainbow trout), and this pattern was pervasive across the genome (detected on most chromosomes). Furthermore, selection against invasive alleles was consistent across populations and environments, even in those where rainbow trout were predicted to have a selective advantage (warm environments). These data corroborate field studies showing that hybrids between these species have lower fitness than the native taxa, and show that these fitness differences are due to selection favouring many native genes distributed widely throughout the genome.

Swimming performance of upstream migrant fishes in open-channel flow: a new approach to predicting passage through velocity barriers

2004 ◽  
Vol 61 (9) ◽  
pp. 1590-1601 ◽  
Author(s):  
Alex Haro ◽  
Theodore Castro-Santos ◽  
John Noreika ◽  
Mufeed Odeh
Keyword(s):  
Fish Species ◽  
Open Channel ◽  
Swimming Performance ◽  
Fish Passage ◽  
Maximum Distance ◽  
Migratory Fish ◽  
Alosa Pseudoharengus ◽  
Interspecific Differences ◽  
Alosa Aestivalis ◽  
Few Data

The ability to traverse barriers of high-velocity flow limits the distributions of many diadromous and other migratory fish species, yet very few data exist that quantify this ability. We provide a detailed analysis of sprint swimming ability of six migratory fish species (American shad (Alosa sapidissima), alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), striped bass (Morone saxatilis), walleye (Stizostedion vitreum), and white sucker (Catostomus commersoni)) against controlled water velocities of 1.5–4.5 m·s–1 in a large, open-channel flume. Performance was strictly voluntary: no coercive incentives were used to motivate fish to sprint. We used these data to generate models of maximum distance traversed, taking into account effects of flow velocity, body length, and temperature. Although the maximum distance traversed decreased with increasing velocity, the magnitude of this effect varied among species. Other covariate effects were likewise variable, with divergent effects of temperature and nonuniform length effects. These effects do not account for all of the variability in performance, however, and behavioral traits may account for observed interspecific differences. We propose the models be used to develop criteria for fish passage structures, culverts, and breached dams.

Propagated Fish in Resource Management

2004 ◽  
Keyword(s):  
Rainbow Trout ◽  
Low Frequency ◽  
Cutthroat Trout ◽  
Natural Hybridization ◽  
Westslope Cutthroat Trout ◽  
Sympatric Populations ◽  
Oncorhynchus Clarkii ◽  
Mitochondrial Haplotypes ◽  
Directional Preference ◽  
Time Of Year

<em>Abstract.</em>—Westslope cutthroat trout <em>Oncorhynchus clarkii lewisi </em>are currently under a second review for listing as a threatened species under the Endangered Species Act. Both natural and anthropogenically induced hybridization has been previously documented between this subspecies and rainbow trout <em>O. mykiss </em>and between steelhead (anadromous rainbow trout) and coastal cutthroat trout <em>O. clarkii clarkii</em>. However, levels of reported introgression have varied greatly. To assess natural hybridization and the extent to which it may affect the frequency and persistence of <em>O. mykiss </em>alleles among sympatric populations of westslope trout, we used three nuclear loci to detect hybrids, and mitochondrial DNA to assess the direction of hybridization and introgression in Big Creek, Idaho and its tributaries. Natural hybridization between westslope cutthroat and sympatric rainbow trout/steelhead appears to occur at a relatively low frequency with numerous parental types still present in varying numbers within the drainage. Subsequent genetic analyses revealed no hybridization in samples from 2001 and percentages of hybrid genotypes within sample locations ranging from 1.6% to 13.3% in 2002. Differences between years may be attributable to sampling, time of year, and seasonal movements of westslope cutthroat trout and their hybrids. Furthermore, hybrids were more frequently observed (<em>p </em>< 0.01) with mitochondrial haplotypes of westslope cutthroat trout indicating a directional preference of westslope cutthroat females spawning with <em>O. mykiss </em>males.

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