7634

• UCREFRP Catalog Number: 7634
• Author: U.S. Fish and Wildlife Service.
• Title: Threatened Wildlife of the United States.
• USFW Year: 1973.
• USFW - Doc Type: Washington, D.C.
• Copyright Material: NO

LAHONTAN CUTTHROAT TROUT Salmo clarki henshawi (Gill and Jordan, 1878)
Order: SALMONIFORMES Family: SALMONIDAE
Significance: This subspecies is an important and beautiful sport fish, which reaches a
large size (10 to 15 pounds) and is adapted to the highly alkaline waters of a few ancient
lakes in the Lahontan Basin .
Distin uishin characteristics: Sports large, evenly distributed; gillbrakers 21-28; pyloric
caeca typically 40-50; has a dash of red between the lower jaw and the isthmus; reaches a
larger size than other cutthroats.
Present distribution: Pure populations are known to be in Independence Lake, California,
Macklin Creek, California, and Summit Lake, Nevada, and a few tributaries in the
Lahontan Basin. Possible hybrids are present in Pyramid and Walker Lakes, Catnip
Reservoir, Truckee, Carson and Walker Rivers in Nevada, and Heenan Lake in California.
Former distribution
Lahontan Basin, California and Nevada.
Status: Scarce . The original populations are extinct in Pyramid Lake and Lake Tahoe .
Estimated numbers: Dr . Robert J . Behnke estimates that there are about 1, 000 to 2, 000 of
the pure strain in Summit and Independence Lakes and about 1, 000 in tributary streams .
The possible hybrid strains are common in the waters mentioned above, except for Walker
Lake where they are nearly extinct.
Fecundity: Adult females from Catnip Reservoir on the Sheldon National Antelope Refuge
average about 2, 500 eggs per fish; 230 to 315 eggs per ounce; about 1, 200 eggs per pound
of female .
Reasons for decline: Damage to spawning beds resulting from forest removal, fires and
overgrazing; dams which block spawning runs; pollution; diversion of water for irrigation;
and hybridization and competition with rainbow trout and other cutthroats .
Protective measures already taken: Rainbow trout and Heenan Lake cutthroat are no
longer stocked in Independence Lake; Summit Lake was placed in a special protected
category by the U . S . Bureau of Land Management. The Bureau of Sport Fisheries and
Wildlife is constructing the Lahontan National Fish Hatchery (1970) for the primary purpose
of rearing this subspecies. The hatchery began production in 1966. When completed,
the hatchery will produce about 125 , 000 pounds of cutthroat trout annually .
Measures proposed: Improvements of the lower Truckee River to permit natural spawning
are under consideration. Withdrawal of Macklin Creek into public ownership is also being
considered.
Number in captivity: About 2 million eggs are taken annually from wild fish. This results
in a million or so fry and several hundred thousand fingerlings .
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