(DRAFT) - Taxonomy
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

TAXONOMY

NAME - TROUT, CUTTROAT, LAHONTAN

OTHER COMMON NAMES - TROUT, CUTTHROAT, LAHONTAN; TROUT, CUTTHROAT; BLACK TROUT OF LAKE TAHOE; SILVER TROUT OF LAKE TAHOE; TROUT, TAHOE; TROUT, BLACK; TROUT, SILVER; TROUT, BROWN; REDFISH;TOMOO-AGAIH;WINTER TROUT; TOMMY; TAMA-AGAIH; SPRING TROUT; SALMON-TROUT; CUTTHROAT OF PYRAMID LAKE; TROUT, PYRRAMID LAKE; CUTTHROAT, PYRAMID LAKE;TROUT, BLACKSPOTTED;TROUT, SALMON; TROUT and MOUNTAIN

ELEMENT CODE -

CATEGORY - Fish

PHYLUM AND SUBPHYLUM - CHORDATA,

CLASS AND SUBCLASS - OSTEICHTHYES,

ORDER AND SUBORDER - SALMONIFORMES,

FAMILY AND SUBFAMILY - SALMONIDAE,

GENUS AND SUBGENUS - SALMO,

SPECIES AND SSP - CLARKI, HENSHAWI

SCIENTIFIC NAME - SALMO CLARKI HENSHAWI

AUTHORITY -

TAXONOMY REFERENCES -

COMMENTS ON TAXONOMY -
Lahontan Cutthroat Trout

Salmo clarki henshawi Gill and Jordan, 1878

KINGDOM: Animal GROUP: Fish

PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Salmoniformes FAMILY: Salmonidae

The Lahontan cutthroat, Salmo clarki henshawi, can be
differentiated from all other subspecies of S. clarki, by a higher
number of gillrakers (21-28) and pyloric caeca (45-70), and by its
spotted pattern, with relatively large spots, more-or-less evenly
distributed over the sides of the body (01,02,03). This subspecies
also exhibits allelic distinctions at several gene loci, detected
with electrophoresis (04). Following my previous classification of
cutthroat trout (01,02) and the classification in the recent Lahontan
cutthroat recovery plan (05), the cutthroat trout native to the
Humboldt River drainage of the Lahontan basin is considered as an
undescribed subspecies, distinct from S. c. henshawi. Although
electrophoretic distinctions between the Humboldt subspecies and
henshawi are slight (04), the Humboldt subspecies averages about three
fewer gillrakers, 20 fewer scales in the lateral series, and its
spotting pattern is sparser and less evenly distributed in comparison
Taxonomy - 1 (DRAFT) - Taxonomy
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

with henshawi (01,02,03). Thus, the taxon Salmo clarki henshawi Gill
and Jordan 1878, is modified to exclude the cutthroat trout native
to the Humboldt River drainage of the Lahontan basin.
An historical over-view for the Lahontan cutthroat trout follows
(over-view taken from La Rivers (08)):

"The early day practice of describing fishes from one or a few
specimens from widely separated localities without knowledge of the
characteristics of intervening populations led to the creation of
numerous species resonably distinct from each other.... One of the
most confusing synonymicons involved S. c. henshawi.
The entity henshawi, named in honor of Henry W. Henshaw,
naturalist with the Wheeler survey of the 100th meridian, who is
credited with its discovery, began its existence in a state of
confusion. The same year it was described as "Salmo henshawi" by Gill
and Jordan in the second edition of Jordan's Manual of the
Vertebrates, etc. (1878), it was referred to as "Salar henshawi" by
Jordan in a seperate paper and the name "Salmo tsuppitch" of
Richardson (1836), a synonym of Oncorhynchus kisutch, was applied by
Jordan and Henshaw to a color variant of the Lake Tahoe cutthroat
population; "tsuppitch" they called the "Black Trout of Lake Tahoe,"
and "henshawi" the "Silver Trout of Lake Tahoe." ...
By 1882, Jordan was listing henshawi as a subspecies of Salmo
purpuratus (Jordan and Gilbert, 1882), in 1891 as S. mykiss henshawi
and in 1896 Jordan and Evermann had abandoned the name "Tsuppitch"
for any Tahoe trout, recognizing the misidentification, and were using
henshawi for both Black and Silver Tahoe trout, regarding the two as
color variants unworthy of formal seperation. They felt the black
type to be the typical henshawi, the silver type to be the variant.
However, in 1898, Jordan and Evermann reconsidered their earlier
stand and described the silver type as the new subspecies
Salmo clarkii tahoensis, reapplying to it their old name of "Silver
Trout of Lake Tahoe." Henshawi was again thus restricted to the
smaller, darker fish which spawned in the streams while tahoensis
designated the deeper water silvery lake population spawning in the
lake itself; distinctions of no value, as we now know. Snyder's
1917 elucidation of the different color, size and age groups of
Lahontan Cutthroat trout running up the Truckee River from Pyramid
Lake clearly showed the integrity of the name henshawi for the
populations as a single taxonomic unit....
The color variants of Salmo clarki henshawi were briefly summed
up by Snyder (1917), who considered henshawi as a specific unit:

LAKE TAHOE PYRAMID AND WINNEMUCCA LAKES
AND LOWER TRUCKEE RIVER
(1) "Tahoe Trout," large-spotted, "Redfish," brilliantly colored
dark; larger. with prominent red cheeks;
large, with some silvery
examples.
(2) "Silver Trout," small elongate "Tommy," relatively large-
spots, chunky body, silvery spotted; smaller, with some
color; smaller. silvery examples.

Taxonomy - 2 (DRAFT) - Taxonomy
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

The name tahoensis lingered in the literature untill the late 1930s,
and it was somewhat later, within the last ten years, that henshawi
became stabilized in its present subspecific status."

In conjunction with the above over-view, the following
chronological taxononmic break-down is from La Rivers (08):

Salmon-trout, Fremont, 1845
Salmo henshawi Gill and Jordan 1878
Salmo tsuppitch, Jordan, 1878
Salar henshawi, Jordan and Copeland, 1878
Salmo tsuppitch, Jordan and Henshaw, 1878
Salmo henshawi, ibid
Salmo purpuratus henshawi, Jordan and Gilbert, 1882
Salmo purpuratus henshawi, Cope, 1883
Salmo purpuratus Henshaui, Russell, 1885
Salmo mykiss henshawi, Eigenmann and Eigenmann, 1891
Salmo mykiss henshawi, Jordan, 1891
Salmo mykiss henshawi, Jordan and Evermann, 1896
Salmo clarkii henshawi, ibid, 1898
Salmo clarkii tahoensis, ibid
Salmo henshawi, ibid, 1902
Salmo tahoensis, ibid
Salmo henshawi, Rutter, 1903
Salmo henshawi, Juday, 1907
Salmo tahoensis, ibid
Salmo clarkii tahoensis, Snyder, 1917
Salmo henshawii, ibid
Salmo henshawii, Pratt, 1923
Salmo tahoensis, ibid
Salmo tahoensis, Jordan, Evermann and Clark, 1930
Salmo clarkii henshawi, Schrenkeisen, 1938
Salmo clarkii tahoensis, ibid
Cut-throat of Pyramid Lake, Snyder, 1940
Salmo henshawi, Murphy, 1941
Salmo henshawi, Shapovalov, 1941
Salmo henshawi, Smith, 1941
Salmo clarkii henshawi, Calhoun, 1944
Salmo clarkii henshawi, La Monte, 1945
Salmo clarkii henshawi, Miller and Alcorn, 1946
Salmo clarkii henshawi, Eddy and Surber, 1947
Salmo clarkii henshawi, Smith, 1947
Salmo clarkii henshawi, Miller, 1950
Salmo clarkii henshawi, Shapovalov and Dill, 1950
Salmo clarki henshawi, La Rivers, 1952
Salmo clarki henshawi, La Rivers and Trelease, 1952
Salmo clarkii henshawi, Bohlke, 1953
Salmo clarkii henshawi, Shapovalov, Dill and Cardone, 1959
Salmo clarkii henshawi, Needham and Gard, 1959

The type locality for the taxon henshawi is Lake Tahoe.
Ono et al. (06) and Behnke (07) published historical color
illustrations of male and female henshawi of Lake Tahoe (or Truckee
Taxonomy - 3 (DRAFT) - Taxonomy
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

River drainage) which are excellent representations of this taxon.
Other common name synonyms used in the literature to refer to
the Lahontan cutthroat trout are; brown trout, Pyramid Lake trout,
Pyramid Lake cutthroat, salmon trout, mountain trout, Tama-Agaih
(Piute for - spring trout, these are the same fish refered to as
"tommy"), and Tomoo-Agaih (Piute for - winter trout, these are the
same fish refered to as "redfish") (taken from: 01,06,08,17).

Taxonomy - 4 (DRAFT) - Status
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

STATUS

Coded Status

T: Federal Threatened

Commercial
Commercial/consumption
Game (Consumptive Recreational)

COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Lahontan cutthroat trout (Salmo clarki henshawi) has been
designated an Threatened species pursuant to the Endangered Species
Act of 1973 (50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
1531-1540), as amended. The species/subspecies has this status
wherever found including the States of California and Nevada.
Special rules concerning "take" for this subspecies can be found
in 50 CFR 17.44(a).
This subspecies is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation, or foreign law; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.

RESPONSIBLE FEDERAL AGENCIES:

USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
BIA -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Bureau of Indian Affairs
lands.
BLM -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control (43 CFR 4140). Also
Status - 1 (DRAFT) - Status
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

responsible for management/recovery on Bureau of Land
Management lands.
USFS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Forest Service lands. The
Forest Service is responsible for integrating
management, protection, and conservation of Federally
listed species into the Forest Planning process
(36 CFR 219.19 and 219.20). Management practices that
would cause detrimental changes in water temperature
or composition, water course blockage, or sediment
deposits within 100 feet of the edges of perennial
streams, lakes or other bodies of water are prohibited
(36 CFR 219.27(e)).

All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.

STATE STATUSES AND LAWS:

STATE: California
DESIGNATED STATUS: Recognized Threatened
ADMINISTRATIVE AGENCY: (CA) Dept. of Fish and Game
STATE STATUTE: Calif. Endangered Species Act; Fish and Game Code
Chapter 1.5, Art. 1, Sect. 2050.

STATE: Nevada
DESIGNATED STATUS: Game Fish
ADMINISTRATIVE AGENCY: (NV) Dept. of Wildlife
STATE STATUTE: Nev. Revised Statutes 501.181, 501.351, 503.584,
503.585, 503.587, and 503.589

INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The IUCN Red List of Threatened Animals (1986) has this fish
listed under the broad grouping of "Salmo clarki (subspecies) -
Cutthroat Trout", as Threatened.

ECONOMIC STATUSES:
This species has value as a component of California's and
Nevada's natural diversity, non-commercially as a game fish, and
as a commercial food source (past problem that aided in the decline
of the species).

70/10/13:35 FR 16047/ - Listed as Endangered
75/07/16:40 FR 29864/ - Reclassified to threatened, w/spec. rules
85/07/22:50 FR 29901/29909 - 5-year review

Status - 2 HABITAT ASSOCIATIONS

HABITAT - AQUATIC
INLAND AQUATIC

SOCIETY OF AMERICAN FORESTRY TYPES
SAF TYPE STAGE CLOSURE
Aspen-paper birch mature tree
Aspen-paper birch Old Growth
Douglas-fir-western hemlock mature tree
Douglas-fir-western hemlock Old Growth
Interior Ponderosa Pine mature tree
Interior Ponderosa Pine Old Growth
Western white pine mature tree
Western white pine Old Growth
mature tree
Old Growth

LAND USE -
Herbaceous Rangeland
Shrub and Brush Rangeland
Mixed Rangeland
Evergreen Forest Land
Mixed Forest Land
Streams and Canals
Lakes
Reservoirs
Forested Wetland

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Riverine, tidal FL1
Riverine, tidal BB1
Lacustrine, littoral AB1
Lacustrine, littoral
Lacustrine, limnetic AB1
Lacustrine, limnetic

COMMENTS ON HABITAT ASSOCIATIONS -
The habitat types in which the lahontan cutthroat trout is
distributed is a wide ranging variation of types. Within the higher
altitudes coniferous forests (of fir, spruce, and ponderosa pine)
inandate the land. Lower altitudes and reduced gradients produce
a semi-desert area of sand, sagebrush and grasses (19). Other areas
consist of alkali bottomlands, semi-playa-greasewood bottomlands,
wet saline bottomlands, greasewood-saltgrass bottomlands, semiwet
meadows, meadow grasses-forbs-sedges, winterfat-bud sagebrush, low
sagebrush-grasses, pinyon-juniper-grasses, and browse-aspen-conifer-
grasses. Some of the typical plant species associated with the
streambanks include: willow (Salix sp.), big sagebrush (Artemesia
tridentata), rabbitbrush (Chrysothamus nauseosus), wild rose
(Rosa sp.), chokecherry (Prunus melanocarpa), and aspen (Populus
tremuloides) (20).
The only unique environmental tolerance distinguishing Salmo
clarki henshawi from other trouts and most fishes in general, is its
ability to survive (and thrive) in waters of high alkalinity.
Habitat Associations - 1 Salinity (or total dissolved solids) levels of more than 12,000
(Walker Lake) and carbonate-bicarbonate levels of more than 2000
(Walker Lake) that are lethal to most fishes are tolerated by henshawi
(11). Other than this unique adaptation to high alkalinity, S. c.
henshawi, in general, has similar habitat requirements and preferences
to other trouts of the genus Salmo (12). It must be recognized,
however, that henshawi had a long evolutionary history for lacustrine
specialization in ancient Lake Lahontan (02,03), which likely makes it
"less adapted" to typical small stream habitat than brook, brown, or
rainbow trout (why it is readily replaced by non-native trouts). As
with most other forms of Salmo, Lahontan cutthroat trout prefers water
temperatures from about 10 degress Celsius (C) to about 18 degrees C.
It is known to utilize depths to 200 feet in Pyramid Lake (09,10).
For successful restoration efforts, it can be assummed that any
stream or lake with suitable habitat for brook, brown, or rainbow
trout, can support a population of S. c. henshawi, as long as no other
species of trout is present.

Habitat Associations - 2 (DRAFT) - Food Habits
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

FOOD HABITS

TROPHIC LEVEL -
CARNIVORE

LIFESTAGE FOOD FOOD PART
General Zooplankton
General Arthropods
General Crustaceans
General Molluscs
General Worms
General Fish

Food Habits - 1 (DRAFT) - Environment Associations
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

ENVIRONMENTAL ASSOCIATIONS

Environment Associations - 1 (DRAFT) - Life History
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

LIFE HISTORY

FOOD HABITS:
The evolutionary history of Salmo clarki henshawi, led to
specialization as the top level predator in large lake environment
(02,03). Thus, there is likely a hereditary propensity for henshawi
to be more predacious than other subspecies of cutthroat trout (02,
03). In Pyramid Lake, henshawi (introduced Summit Lake stock),
becomes increasingly predacious when its length reaches about 300 mm
(09,10). Its major prey species in Pyramid lake is the tui chub
(Gila bicolor).
Smaller henshawi in lakes, and stream populations of henshawi
opportunistically feed mainly on invertebrates similar to other
species of trout, essentially consuming aquatic and terrestrial
organisms in relation to their availability. Besides the probable
specialization for fish predation, I can find no evidence that S. c.
henshawi feeding is any way different from other trout species of
similar sizes in similar environments.
Lea (14) found that after kokanee salmon (Oncorhynchus nerka)
were established in Independence Lake, kokanee made up the greatest
food volume of the larger henshawi. However, competitive interactions
between kokanee and small henshawi for invertebrate food, had an
overall negative effect on the Lahontan cutthroat population of
Independence Lake (14,15).
It should be mentioned that henshawi can exhibit rapid growth and
attain a large size without fish in its diet. Foe example, Lahontan
cutthroat trout stocked in Lake Lenore, washington, exhibit extremely
rapid growth on crustacean diet (13).

HOME RANGE/TERRITORY:
Similar to all the trouts of the genus Salmo, S. c. henshawi, in
streams, becomes territorial and typically the largest individual
inhabits and defends the most preferred habitat within any particular
stream section (12). In large lakes, individuals roam all areas of
the lake with suitable temperatures and oxygen during feeding.
Although, they should not be characterized as a schooling fish,
henshawi, in lakes, do aggregate by age-size groups (09,10).

PERIODICITY:
Feeding activity is mainly diurnal, with typical peaks at dawn
and dusk, but henshawi (as all trout species) will readily change
daily activity paterns to opportunistically take advantage of
available food (09,10).

MIGRATION PATTERNS:
In streams, Lahontan cutthroat trout, after establishing a
territory, do not typically migrate. They will move for spawning to
the nearest sith with suitable gravel (08,12). The original
population in Pyramid Lake may have made spawning migrations in
Truckee River of 100 miles or more, before the river was blocked by
Derby Dam in 1905 (07,16).

COVER/SHELTER REQUIREMENTS:
Life History - 1 (DRAFT) - Life History
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

There are no known unique cover or shelter attributes,
distinguishing henshawi from other species of trout. In streams,
they prefer to remain near overhead cover to avoid bird and mammal
predators.

REPRODUCTIVE SITE REQUIREMENTS:
No known differences from other trout species. Water
temperatures between 6 to 12 degrees C are optimal for egg incubation
and water should be saturated with oxygen. Gravel from 6 to 50 mm
is optimum for redd construction and egg incubation (12).

REPRODUCTIVE CHARACTERISTICS:
In stream populations sexual maturity is generally attained in
third year of life (age II+). Lake populations typically mature at an
older age (III+, IV+). The original Pyramid Lake population may have
had an old age structure (to X-XI) with much repeat-spawning (07).
S. c. henshawi is a spring spawner. Spawning is initiated when water
temperature reaches about 7 degrees C (12). The female constructs a
redd and buries the fertilized eggs. About 30 days is required for
hatching and fecundity averages about 700 to 1000 eggs per pound of
body weight (12).

PARENTAL CARE:
After the nest (redd) is constructed and fertilized eggs
deposited and covered, the spawning site is abandoned and no further
parental care occurs.

POPULATION BIOLOGY:
Most lake populations are sustained by annual stocking of
artificially propagated fish. Their population is governed by
stocking density, survival and growth influenced by competition with
other fish species and food availability. In streams, populations
can be expected to be at carrying capacity of the particular habitat
and food supply. Habitat degradation from logging and livestock
grazing (loss of cover, increased sediments) will depress a population
(15).

SPECIES INTERRELATIONSHIPS:
As discussed, Salmo clarki henshawi, essentially, does not
coexist with any other species of trout. The introduction of kokanee
salmon in Independence Lake, although providing a new food supply to
adult Lahontan cutthroat trout, had an overall negative impact on
the population, because of competition between young trout and kokanee
for zooplankton (14,15).

OTHER LIFE HISTORY DESCRIPTORS:
It should be recognized that the taxon Salmo clarki henshawi, is
not a homogeneous unit in relation to life history and ecology.
Different populations evolved with different selective pressures and
most probably evolved different life history characteristics such as
age at maturity and maximum life span. Only the original population
of Pyramid Lake continued to evolve in a large lake environment with
the full range of Lahontan fish species. The original Pyramid Lake
Life History - 2 (DRAFT) - Life History
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

population would be expected to most closely resemble the original
ancestor henshawi of Lake Lahontan (07).

Life History - 3 (DRAFT) - Management Practices
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Adverse Commercial Exploitation
Existing Commercial Exploitation
Adverse Hybridization
Existing Hybridization
Adverse Predation
Existing Predation
Adverse Surface Mines
Existing Surface Mines
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Siltation
Existing Siltation
Adverse Salinity alteration
Existing Salinity alteration
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Irrigating
Existing Irrigating
Adverse Reservoirs
Existing Reservoirs
Adverse Migration barriers
Existing Migration barriers
Adverse Dredging
Existing Dredging
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Erosion
Existing Erosion
Adverse Grazing
Existing Grazing
Adverse
Existing
Adverse Forest Alteration
Existing Forest Alteration
Adverse Harvesting
Existing Harvesting

COMMENTS ON MANAGEMENT PRACTICES -
Many reasons have been identified for the decline and virtual
extinction of Salmo clarki henshawi as pure populations, such as
habitat degradation (i.e., forest clearing and alteration,
agricultural development; grazing; urban development; water
pollution from agriculture, industrial, surface mines and urban
runoff; and erosion resulting from the before mentioned actions, and
inturn siltation which destroys breeding areas and will result in
direct mortality of the eggs); blocking of spawning runs (i.e.,
Management Practices - 1 (DRAFT) - Management Practices
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

dam/reservoirs, channel modification, and irrigation projects which
result in direct blockage of spawning runs and by altering water and
salinity levels; exploitation (i.e., sport and commercial fish
industry), etc. (01,02,03,04,05,06,07,08).
A good example of how over-use and poor management of a fishery
led to extinction of a population can be taken from the Pyrimid Lake
cutthroat fishery:
The Lahontan cutthroat was a staple in the diet of the
Paiute Indians living in this area, and with the intervention
of white-man, a ready market was developed for the fish
caught by the indians. Durring the late 1800s, 100,000 to 200,000
pounds of trout from Pyramid Lake and the Truckee River were
transported each year to Nevada towns and mining camps and the surplus
was shipped to San Francisco and Chicago. With such an extensive and
large fishery, came the sport fishing boom (in the 1920s, it was
considered typical to catch 100 ponds of trout in a couple of hours).
Pyramid Lake produced the world record for the Lahontan cutthroat -
41 pounds. Fish up to 60 pounds had been reported taken by the
commercial industry, but were not officially recorded. The Pyrimid
Lake fishery began its decline in 1906. The last good spawning run
took place in 1928, and by 1938 no spawning runs took place at all.
By 1940, all cutthroat trout were gone from Pyrimid Lake (18).
Nevada and California fish commision reports from the early years
noted that rampant poaching, uncontrolled exploitation, river
obstructions and pollution were adversely affecting the fishery.
With the construction of the Newlands Irrigation Project (in 1906)
this ultimately aided in the the extirpation of the Pyramid Lake
population (18). The most all encompassing influence causing
decline and limiting large-scale restoration is the introduction and
establishment of non-native species of trout (resulting in
competition, predation, and hybridization with the Lahontan cutthroat
trout) such as: brook trout (Salvelinus fontinalis), lake trout
(S. namaycush), brown trout (Salmo trutta) (which have replaced
S. c. henshawi from most of its original distribution) and rainbow
trout (S. gairdneri) (which hybridizes with S. c. henshawi) (02). To
establish a new population of henshawi for restoration efforts, the
waters must contain no other species of trout.
Ecological distinctions between henshawi and the Humboldt
subspecies are apparent from the fact that the Humboldt subspecies, in
contrast to henshawi, persist in numerous streams in its native range,
despite widespread stocking of non-native trouts (02).
The most obvious future threat to established henshawi
populations is the introduction of other species of trout. Logging
and livestock grazing also pose threats to habitat (05).

APPROVED PLAN:
U.S. Fish and Wildlife Service. 1987. Recovery Plan for the Lahontan
Cutthroat Trout. U.S. Fish and Wildl. Serv., Portland, OR.

Management Practices - 2 (DRAFT) - References
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****

01 Behnke, R.J. 1979. Monograph of the native trouts of the genus
Salmo of western North America. U.S. Fish and Wildl. Serv.,
Denver, CO. (presently under revision).
02 Behnke, R.J. 1981. Systematic and zoogeographic interpretation of
Great Basin trouts. Pages 95-124 in R.J. Naiman and D. L. Soltz
(eds.). Fishes in North American deserts. John Wiley & Sons, NY.
03 Hickman, T.J., and R.J. Behnke. 1979. Probable discovery of the
original Pyramid Lake cutthroat trout. Progressive Fish Culturist
41:135-137.
04 Loudenslager, E.J., and G.A.E. Gall. 1980. Geographic patterns
of protein variation and subspeciation in cutthroat trout, Salmo
clarki. Syst. Zool. 29:27-42.
05 U.S. Fish and Wildlife Service. 1987. Recovery plan for the
Lahontan cutthroat trout. U.S. Fish and Wildl. Serv., Portland,
OR.
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of North America. Stone Wall Press, Wash., D.C. 257 pp.
07 Behnke, R.J. 1986. Pyramid Lake and its cutthroat trout. The
Am. Fly Fisher (Jour. of Am. Mus. Fly Fishing) 13:18-22.
08 La Rivers, I. 1962. Fishes and fisheries of Nevada. Nev. Fish
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09 Sigler, W.F., and J.L. Kennedy (eds.). 1978. Pyramid Lake
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Nevada. Great Basin Naturalist 43:1-29.
11 Galat, D.L., G. Post, T.J. Keefe, and G.R. Bouck. 19 .
Histological changes in the gill, kidney and liver of Lahontan
cutthroat trout, Salmo clarki henshawi, living in lakes of
different salinity-alkalinity. J. Fish Biol. 27:533-552.
12 Behnke, R.J., and M. Zarn. 1976. Biology and management of
threatened and endangered western trouts. USDA, Forest Serv.,
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13 Raymond, S. 1985. The year of the trout. Wincester Press.
14 Lea, R.N. 1968. Ecology of the Lahontan cutthroat trout, Salmo
clarki henshawi, in Independence Lake, California. M.A. thesis,
Univ. of Calif., Berkeley.
15 Gerstung, E.R. 1986. The status and management of the Lahontan
cutthroat trout (Salmo clarki hemshawi). Pages 81-101 in J.S.
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of cutthroat trout. West. Div. Am. Fish. Soc. Spec. Publ.
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17 International Union for Conservation of Nature and Natural
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California. July-Aug.:1-5.
References - 1 (DRAFT) - References
Species TROUT, CUTTROAT, LAHONTAN
Species Id ESIS251025
Date 14 MAR 96

19 Hoffman, R.J., and G. Scoppettone. 1984. Effect of water quality
on survival of Lahontan cutthroat trout eggs in the Truckee River,
West-Central Nevada and Eastern California. U.S. Geological
Survey. Report 84-437:4.
20 Coffin, P.D. 1981. Distribution and life history of the
Lahontan/Humboldt cutthroat trout Humboldt River drainage basin.
Nevada Dept. of Wildl. Fed. Aid Proj. F-20-17.

***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****

References - 2