Return of a Giant: Coordinated Conservation Leads to the First Wild Reproduction of Lahontan Cutthroat Trout in the Truckee River in Nearly a Century

Fisheries ◽  
2019 ◽  
Vol 45 (2) ◽  
pp. 63-73 ◽  
Author(s):  
Robert Al‐Chokhachy ◽  
Lisa Heki ◽  
Tim Loux ◽  
Roger Peka
2017 ◽  
Vol 4 (11) ◽  
pp. 171253 ◽  
Author(s):  
Mary M. Peacock ◽  
Evon R. Hekkala ◽  
Veronica S. Kirchoff ◽  
Lisa G. Heki

Currently one small, native population of the culturally and ecologically important Lahontan cutthroat trout ( Oncorhynchus clarkii henshawi , LCT, Federally listed) remains in the Truckee River watershed of northwestern Nevada and northeastern California. The majority of populations in this watershed were extirpated in the 1940s due to invasive species, overharvest, anthropogenic water consumption and changing precipitation regimes. In 1977, a population of cutthroat trout discovered in the Pilot Peak Mountains in the Bonneville basin of Utah, was putatively identified as the extirpated LCT lacustrine lineage native to Pyramid Lake in the Truckee River basin based on morphological and meristic characters. Our phylogenetic and Bayesian genotype clustering analyses of museum specimens collected from the large lakes (1872–1913) and contemporary samples collected from populations throughout the extant range provide evidence in support of a genetically distinct Truckee River basin origin for this population. Analysis of museum samples alone identified three distinct genotype clusters and historical connectivity among water bodies within the Truckee River basin. Baseline data from museum collections indicate that the extant Pilot Peak strain represents a remnant of the extirpated lacustrine lineage. Given the limitations on high-quality data when working with a sparse number of preserved museum samples, we acknowledge that, in the end, this may be a more complicated story. However, the paucity of remnant populations in the Truckee River watershed, in combination with data on the distribution of morphological, meristic and genetic data for Lahontan cutthroat trout, suggests that recovery strategies, particularly in the large lacustrine habitats should consider this lineage as an important part of the genetic legacy of this species.


Author(s):  
Joseph P. Brunelli

<em>Abstract</em>.—A Y chromosome marker shared with Rainbow Trout <em>Oncorhynchus mykiss </em>has been sequenced in many Cutthroat Trout <em>O. clarkii </em>subspecies. The marker is found in and inherited through males. It evolves more slowly than the maternally inherited mitochondrial DNA. The marker delineates the four major groups of Cutthroat Trout: the Lahontan Cutthroat Trout <em>O. c. henshawi </em>subspecies complex, the Yellowstone Cutthroat Trout <em>O. c. bouvieri</em> subspecies complex, Westslope Cutthroat Trout <em>O. c. lewisi</em>, and Coastal Cutthroat Trout <em>O. c. clarkii</em>. The paternal inheritance pattern of the Y marker makes it useful for dissecting the origins of fish with mixed ancestries. We describe a case study using both Y and mitochondrial markers in Lahontan Cutthroat Trout subspecies complex trout populations. Our results confirmed Lahontan Cutthroat Trout affinities for the Paiute Cutthroat Trout <em>O. c. seleniris</em> and Willow–Whitehorse Creek Cutthroat Trout. However, we found evidence of a complex ancestry for Guano Creek, Oregon trout, a group that has been proposed by some to be related to the Alvord Cutthroat Trout, a subspecies thought to be extinct.


<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.


2010 ◽  
Vol 1 (2) ◽  
pp. 86-92 ◽  
Author(s):  
John P. Bigelow ◽  
Wendy M. Rauw ◽  
Luis Gomez-Raya

Abstract We investigated the effectiveness of two acclimation protocols for 8-month-old Lahontan cutthroat trout Oncorhynchus clarkii henshawi, reared at Lahontan National Fish Hatchery in terms of survival during a week-long challenge in water from saline, alkaline Walker Lake, Nevada. Fish were acclimated for 0 (control), 3, and 8 d by increasing the ratio of lake water to hatchery water. For the 3-d acclimation treatment, 50% of the tank water was replaced with lake water each day. For the 8-d treatment, 33% of the water was replaced with lake water on the first through fourth day of acclimation. Survival during acclimation (i.e., prior to the challenge) was lowest for fish acclimated 3 d. Median survival time during the lake water challenge was 8 h for unacclimated fish, and 8 and 12 h for fish surviving the 3- and 8-d acclimation treatments, respectively. No fish survived the entire week-long challenge. Compared with no acclimation, 3- and 8-d acclimation decreased the hazard of mortality during the challenge. Increased fork length also reduced the hazard of death. Our results indicate acceptable survival rates cannot be achieved for subyearling, hatchery-reared Lahontan cutthroat trout stocked in Walker Lake without acclimation or with the acclimation methods employed in this study. Our results indicate that the acclimation method might be improved by the use of longer fish, longer acclimation, and better control of water temperature, ammonia concentration, and alkalinity.


2021 ◽  
Author(s):  
Jonathan E. Stead ◽  
Virginia L. Boucher ◽  
Peter B. Moyle ◽  
Andrew L. Rypel

Lahontan Cutthroat Trout Oncorhynchus clarkii henshawi have experienced massive declines in their native range and are now a threatened species under the US Endangered Species Act. A key management goal for this species is re-establishing extirpated populations using translocations and conservation hatcheries. In California USA, two broodstocks (Pilot Peak and Independence Lake) are available for translocation, in addition to potential wild sources. Yet suitability of these sources for re-introduction in different ecosystem types and regions remains an open and important topic. We conducted growth experiments using Lahontan Cutthroat Trout stocked into Sagehen Creek, CA USA. Experiments evaluated both available broodstocks and a smaller sample of wild fish translocated from a nearby creek. Fish from the Independence Lake source had significantly higher growth in weight and length compared to the other sources. Further, Independence Lake fish were the only stock that gained weight on average over the duration of the experiment. Our experiments suggest fish from the Independence Lake brood stock may be useful for re-introduction efforts into small montane headwater streams in California.


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