Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Life History ◽  
Evolutionary Biology ◽  
Conservation Management ◽  
Cutthroat Trout ◽  
Life History Strategies ◽  
Oncorhynchus Clarkii ◽  
The Past ◽  
Management Plans ◽  
Anthropogenic Processes ◽  
Bonneville Basin

<em>Abstract</em>.— Cutthroat Trout <em>Oncorhynchus clarkii </em>of the Yellowstone River, Snake River, and Bonneville Basin exhibit tremendous diversity in the habitats and landscapes in which they are found, diversity in the life-history strategies they employ, and diversity in the coloration and spotting patterns they display. This chapter reviews substantial research conducted over the past 35 years that has described this diversity and the historical and more recent anthropogenic processes that have shaped it and highlights key findings that should be considered during taxonomic reassessments and the writing of conservation management plans.

Using nitrogen stable isotopes to detect long-distance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)

2009 ◽  
Vol 66 (4) ◽  
pp. 672-682 ◽  
Author(s):  
Adam J. Sepulveda ◽  
Warren T. Colyer ◽  
Winsor H. Lowe ◽  
Mark R. Vinson
Keyword(s):  
Water Quality ◽  
Stable Isotopes ◽  
Life History ◽  
Headwater Streams ◽  
Cutthroat Trout ◽  
Trophic Levels ◽  
Life History Strategies ◽  
Nitrogen Stable Isotopes ◽  
Long Distance ◽  
Oncorhynchus Clarkii

Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a population is critical to these efforts. We tested the application of nitrogen stable isotopes to discern fluvial from resident Bonneville cutthroat trout (BCT; Oncorhynchus clarkii utah ) in a headwater stream. Fluvial BCT migrate from headwater streams with good water quality to mainstem habitats with impaired water quality. Resident BCT remain in headwater streams. We tested two predictions: (i) fluvial BCT have a higher δ15N than residents, and (ii) fluvial BCT δ15N reflects diet and δ15N enrichment characteristics of mainstem habitats. We found that fluvial δ15N was greater than resident δ15N and that δ15N was a better predictor of life history than fish size. Our data also showed that fluvial and resident BCT had high diet overlap in headwater sites and that δ15N of lower trophic levels was greater in mainstem sites than in headwater sites. We conclude that the high δ15N values of fluvial BCT were acquired in mainstem sites.

scholarly journals Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes

2012 ◽  
Vol 69 (5) ◽  
pp. 906-915 ◽  
Author(s):  
Clint C. Muhlfeld ◽  
Simon R. Thorrold ◽  
Thomas E. McMahon ◽  
Brian Marotz
Keyword(s):  
Life History ◽  
Isotope Composition ◽  
Cutthroat Trout ◽  
Large River ◽  
River Network ◽  
Life History Strategies ◽  
Westslope Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Spatial Differences ◽  
Highly Correlated

We used natural variation in the strontium concentration (Sr:Ca) and isotope composition (87Sr:86Sr) of stream waters and corresponding values recorded in otoliths of westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) to examine movements during their life history in a large river network. We found significant spatial differences in Sr:Ca and 87Sr:86Sr values (strontium isoscapes) within and among numerous spawning and rearing streams that remained relatively constant seasonally. Both Sr:Ca and 87Sr:86Sr values in the otoliths of juveniles collected from nine natal streams were highly correlated with those values in the ambient water. Strontium isoscapes measured along the axis of otolith growth revealed that almost half of the juveniles had moved at least some distance from their natal streams. Finally, otolith Sr profiles from three spawning adults confirmed homing to natal streams and use of nonoverlapping habitats over their migratory lifetimes. Our study demonstrates that otolith geochemistry records movements of cutthroat trout through Sr isoscapes and therefore provides a method that complements and extends the utility of conventional tagging techniques in understanding life history strategies and conservation needs of freshwater fishes in river networks.

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.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Rainbow Trout ◽  
Rocky Mountains ◽  
Evolutionary Biology ◽  
Cutthroat Trout ◽  
Taxonomic Revision ◽  
River Basins ◽  
Evidence Based ◽  
Oncorhynchus Clarkii ◽  
Southern Rocky Mountains ◽  
Green Lineage

<em>Abstract</em>.—One objective of systematics is to recognize species in a manner that minimizes the disparity between species as real entities in nature and species as a Linnaean category. Reconciliation requires a conceptualization of species consistent with evolutionary processes that yields predictive delimitation criteria. Here we review the unified species concept (USC) and its associated delimitation criteria as a prelude to revising the taxonomy of Cutthroat Trout <em>Oncorhynchus clarkii</em>. Additionally, in the context of the conceptualizing species as a separately evolving metapopulation, we briefly review how climate change may have influenced the connectivity and isolation of Cutthroat Trout within and among river basins, with a focus mainly on the Cutthroat Trout of the Southern Rocky Mountains. We summarize evidence based on delimitation criteria that distinguishes Rainbow Trout <em>O. mykiss</em> and Cutthroat Trout, Gila Trout<em> O. gilae </em>and Rainbow Trout, and blue lineage and green lineage Cutthroat Trout from the Southern Rocky Mountains. We advocate adopting the USC as a guide for taxonomic revision of Cutthroat Trout, recommend eliminating subspecies as a valid taxonomic designation, and expect—based on our evaluation of three pairs of species—that the taxonomy of Cutthroat Trout will be revised in ways that elevate some recognized subspecies to species status.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Evolutionary Biology ◽  
Species Concept ◽  
Management Strategies ◽  
Cutthroat Trout ◽  
Ecological Processes ◽  
Oncorhynchus Clarkii ◽  
Voucher Specimens ◽  
Captive Propagation ◽  
Analytical Tools

<em>Abstract</em>.—The broad distribution and regional variation of Cutthroat Trout <em>Oncorhynchus clarkii </em>across western North America has led to considerable interest in the different forms from both scientific and recreational perspectives. This volume represents an attempt to describe this observed diversity with the most current information available and suggests a revised taxonomy for Cutthroat Trout. However, what is proposed in this volume will be subject to change or refinement as new techniques and analytical tools become available. In particular, remaining uncertainty would benefit from a comparison of all described lineages with a common set of morphological and genetic markers. A range-wide collection of voucher specimens will help to document variation in these characteristics, and we encourage field biologists to prioritize these collections. Future revisions will benefit from agreement on a species concept and explicitly state the assumptions of the chosen species concept. We encourage collaboration between managers and taxonomists to accurately delineate units of conservation that can be used by decision makers tasked with ensuring the long-term persistence of Cutthroat Trout lineages. The proposed taxonomic revisions herein validate many of the ongoing management strategies to conserve Cutthroat Trout, but we advise additional consideration of life-history diversity as an attainable management target. For long-term persistence of all Cutthroat Trout, maintaining and expanding the availability of high quality, well-connected stream and lake habitats will be a necessary first step to achieving desired conservation outcomes. Moreover, restoring and protecting ecological processes are key to conserving the diversity found within and among lineages of Cutthroat Trout. In systems where native Cutthroat Trout have been extirpated or suppressed, captive propagation and translocation are two potentially available tools to re-establish or reinvigorate populations. Last, we encourage fisheries managers and taxonomists to embrace the challenges that come with conserving locally unique forms of wide-ranging species like Cutthroat Trout.

Ecological consequences of hybridization between native westslope cutthroat (Oncorhynchus clarkii lewisi) and introduced rainbow (Oncorhynchus mykiss) trout: effects on life history and habitat use

2010 ◽  
Vol 67 (2) ◽  
pp. 357-370 ◽  
Author(s):  
Joseph B. Rasmussen ◽  
Michael D. Robinson ◽  
Daniel D. Heath
Keyword(s):  
Life History ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Metabolic Characteristics ◽  
Clear Cut ◽  
Genotype Frequencies ◽  
Physical Barriers ◽  
High Elevations

In the Upper Oldman River, Alberta, Canada, hybridization between introduced rainbow trout (RT; Oncorhynchus mykiss ) and native westslope cutthroat trout (WCT; Oncorhynchus clarkii lewisi ) has produced a genotypic gradient with rainbow trout alleles undetectable (<1%) at high elevations and increasing in abundance downstream. Few F1 hybrids were found, and genotype frequencies suggest strong backcrossing of hybrids to pure parental populations at both ends of the gradient. The increasing prevalence of RT alleles downstream is accompanied by a life history gradient such that RT alleles were positively associated with growth rate and negatively associated with survivorship. Although physical barriers extended the distribution of pure WCT downstream, several streams held genetically pure WCT in their uppermost reaches, even when no barriers were present. For example, RT alleles were undetectable in headwaters of Dutch Creek, which had no barriers but was very cold (average summer temperature <7.3 °C). We propose that RT alleles affect the choice of habitat, as well the metabolic characteristics that determine their life history and competitive abilities. Factors such as climate change, clear-cut logging, and anthropogenic enrichment that can lead to increased temperature and (or) productivity might be expected to result in an upstream shift of RT alleles.

scholarly journals Are mitochondria the main contributor of reactive oxygen species in cells?

2021 ◽  
Vol 224 (5) ◽  
pp. jeb221606
Author(s):  
Yufeng Zhang ◽  
Hoi Shan Wong
Keyword(s):  
Reactive Oxygen Species ◽  
Life History ◽  
Evolutionary Biology ◽  
Reactive Oxygen ◽  
Life History Strategies ◽  
Ros Production ◽  
Oxygen Species ◽  
Intact Cells ◽  
Main Contributor ◽  
In Cells

ABSTRACTPhysiologists often assume that mitochondria are the main producers of reactive oxygen species (ROS) in cells. Consequently, in biomedicine, mitochondria are considered as important targets for therapeutic treatments, and in evolutionary biology, they are considered as mediators of life-history tradeoffs. Surprisingly, data supporting such an assumption are lacking, at least partially due to the technical difficulties in accurately measuring the level of ROS produced by different subcellular compartments in intact cells. In this Commentary, we first review three potential reasons underlying the misassumption of mitochondrial dominance in the production of cellular ROS. We then introduce some other major sites/enzymes responsible for cellular ROS production. With the use of a recently developed cell-based assay, we further discuss the contribution of mitochondria to the total rate of ROS release in cell lines and primary cells of different species. In these cells, the contribution of mitochondria varies between cell types but mitochondria are never the main source of cellular ROS. This indicates that although mitochondria are one of the significant sources of cellular ROS, they are not necessarily the main contributor under normal conditions. Intriguingly, similar findings were also observed in cells under a variety of stressors, life-history strategies and pathological stages, in which the rates of cellular ROS production were significantly enhanced. Finally, we make recommendations for designing future studies. We hope this paper will encourage investigators to carefully consider non-mitochondrial sources of cellular ROS in their study systems or models.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Evolutionary Biology ◽  
Cutthroat Trout ◽  
River Basins ◽  
Lake Basin ◽  
Evolutionarily Significant Unit ◽  
Oncorhynchus Clarkii ◽  
Northern Nevada ◽  
Lahontan Cutthroat Trout ◽  
Carson River ◽  
Evolutionary Units

<em>Abstract</em>.—Lahontan Cutthroat Trout (LCT) <em>Oncorhynchus clarkii henshawi </em>and Paiute Cutthroat Trout (PCT) <em>O. c. selernis </em>are found in the Lahontan hydrographic basin of northern Nevada, northeastern California, and southeastern Oregon and together form the Lahontan Basin evolutionary lineage of Cutthroat Trout <em>O. clarkii</em>. The Alvord Cutthroat Trout <em>O. c. </em>ssp. native to the Alvord Lake subbasin in the northwestern Lahontan Basin was also part of this lineage but went extinct due to Rainbow Trout <em>O. mykiss </em>introgression in the mid-20th century. Both LCT and PCT are federally listed as threatened under the U.S. Endangered Species Act. Given its historic distribution in a single small stream and both phenotypic and genetic distinctiveness, PCT is currently recognized as a separate evolutionarily significant unit (ESU). For LCT, three ESUs are identified based upon meristic, morphological, ecological, and genetic data. These putative LCT ESUs separate lacustrine forms in the western Lahontan Basin (Truckee, Carson, and Walker River basins) from largely fluvial forms in the eastern Lahontan Basin (Humboldt and Reese River basins) and northwestern Lahontan Basin (Quinn River, Coyote Lake, and Summit Lake basins). The more recent recognition of a much longer evolutionary history of Cutthroat Trout and several influential genetic papers identifying previously unrecognized diversity within Cutthroat Trout have prompted a need to re-evaluate the overall taxonomy of this species. Here, we review earlier literature and draw on new information from recent studies to delineate uniquely identifiable evolutionary units within the Lahontan Basin lineage of Cutthroat Trout. Though in several cases various anthropogenic and natural influences have made definitive conclusions difficult, based on this collective information and the goal of conserving potentially important genetic, evolutionary, and life history diversity, we propose recognition of six uniquely identifiable evolutionary units within the Lahontan Cutthroat Trout lineage: (1) Paiute Cutthroat Trout—upper East Carson River; (2) western Lahontan Basin—Truckee, Walker, and Carson rivers together with Summit Lake; (3) northwestern Lahontan Basin—Quinn River; (4) eastern Lahontan Basin—Humboldt and Reese rivers; (5) Lake Alvord basin—Virgin-Thousand and Trout Creek drainages; and (6) Coyote Lake basin—Willow and Whitehorse rivers.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Classification System ◽  
Evolutionary Biology ◽  
Scientific Evidence ◽  
Molecular Genetic ◽  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Widespread Species ◽  
Geological Evidence ◽  
New Information ◽  
Western Division

<em>Abstract</em>.—Cutthroat Trout <em>Oncorhynchus clarkii </em>are currently considered a single, widespread species composed of many subspecies following the classification system proposed by Robert J. Behnke in 1979. More recently, molecular genetic and geological evidence has yielded results that are inconsistent with Behnke’s classification, which suggests that a re-evaluation of the existing phylogenetic tree is timely. Additionally, several varieties of Cutthroat Trout are either listed under the U.S. Endangered Species Act or are considered to be at risk by the states in which they reside, making it important that the classification and evolutionary relationships among Cutthroat Trout be based on the best available scientific evidence. In 2015, the Western Division of the American Fisheries Society convened a special workshop in which a panel of experts was asked to weigh carefully evidence on Cutthroat Trout phylogeny and classification, from the oldest published studies to the most recent and answer two questions: (1) does Behnke’s 14-subspecies classification remain scientifically tenable and defensible given all available evidence, and (2) if not, what taxonomic classification does satisfy this array of evidence? From new information, the panel concluded that the existing classification system is no longer supported by existing evidence; however, the panel was unable to reach consensus on what a new phylogeny and classification system should be. In the interim, we suggest that the four major evolutionary lineages of Cutthroat Trout be elevated to full species designation and that several uniquely identifiable evolutionary units receive additional investigation to elucidate additional evolutionary structure. This chapter provides the background and context for topics that are covered in the following chapters and suggests fruitful lines of investigation that should help resolve outstanding questions.

Reproductive biology of female franciscana dolphins (Pontoporia blainvillei) from Argentina

2015 ◽  
Vol 96 (4) ◽  
pp. 831-840 ◽  
Author(s):  
María V. Panebianco ◽  
Daniela L. Del Castillo ◽  
Pablo E. Denuncio ◽  
María F. Negri ◽  
Ricardo Bastida ◽  
...  
Keyword(s):  
Life History ◽  
Pregnancy Rate ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Sexual Maturity ◽  
Conservation Management ◽  
Positive Trend ◽  
History Information ◽  
Management Plans ◽  
Pontoporia Blainvillei

The ovaries of 31 franciscana dolphins (19 immature and 12 mature) by-caught in coastal waters of Argentina were examined to describe the reproductive biology. No ovarian polarity was found, both ovaries were functional and showed similar amounts of corpora. A positive trend was observed between the number of corpora and age (3–8 years old), indicating that ovulation scars are detectable for at least 4 years, and a ovulation rate of 0.39 was found for the sampled population. Age, length and weight at sexual maturity were estimated at 3.92 ± 0.09 years, 133.47 ± 11.11 cm and 32.68 ± 2.72 kg, respectively. The annual pregnancy rate was 0.36 ± 0.02 (95% CI = 0.10–0.65). The proportion of lactating and resting females found were 0.25 and 0.33 respectively. These outcomes constitute the first reproductive and life history information on franciscana dolphins from the southernmost population and are important in relation with adequate conservation management plans for this small cetacean.

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