Species: Oncorhynchus clarkii henshawi
Lahontan Cutthroat Trout
Species
Encyclopedia of Puget Sound
Formerly attained mass of up to at least 18.6 kg; now rarely exceeds 6-7 kg. The genetic potential for exceptionally large size was lost with the extinction of the original Pyramid Lake population.
Classification
Kingdom
Animalia
Phylum
Craniata
Class
Actinopterygii
Order
Salmoniformes
Family
Salmonidae
Genus
Oncorhynchus
NatureServe
Classification
Informal Taxonomy
Animals, Vertebrates - Fishes - Bony Fishes - Salmon and Trouts
Formal Taxonomy
Animalia - Craniata - Actinopterygii - Salmoniformes - Salmonidae - Oncorhynchus - ), and Humboldt cutthroat trout revealed that genetic variation was partitioned as follows: 9.8% among subspecies, 27.7% among populations, and 62.5% within populations of Lahontan cutthroat trout (Nielsen and Sage 2002). Genetic distance analyses supported unique population structure in trout from the Humboldt and Pilot Peak drainages. This information, plus further data on the genetic affinities of hatchery stocks, indicates the need to consider patterns of variation when conducting transplants and releasing hatchery stock (Nielsen and Sage 2002).
Ecology and Life History
Formerly attained mass of up to at least 18.6 kg; now rarely exceeds 6-7 kg. The genetic potential for exceptionally large size was lost with the extinction of the original Pyramid Lake population.
Short General Description
A trout.
Habitat Type Description
Freshwater
Migration
false - true - true - Migration distance varies with population; reportedly, migrations of over 100 miles formerly occurred in the Truckee River (see USFWS 1994).
Non-migrant
false
Locally Migrant
true
Food Comments
Opportunistic feeder (Behnke 1992). Small individuals eat small invertebrates such as crustceans and aquatic insects; larger fishes eat large invertebrates and samll fishes; fishes dominate the diet of large, lake-dwelling adults.
Reproduction Comments
Life history characteristics are greatly influenced by the environment. Spawns in spring or early summer, the timing depending on stream flow and temperature. Spawning migrations have been observed at water temperatures of 5-16 C. Eggs hatch in 4-6 weeks (Spahr et al. 1991), and fry emerge 13 to 23 days later. Sexually mature in 2-3 years in streams, 3-5 years in lakes; males generally mature a year sooner than do females. Consecutive-year spawning by individuals is uncommon. Up to a few percent spawn a second time after an interval of one or more years (usually after at least two years). Longevity generally is less than 5 years in stream populations, up to 5-9 years in lakes (USFWS 1994).
Length
38
Conservation Status
NatureServe Global Status Rank
G4T3
Global Status Last Reviewed
2003-03-12
Global Status Last Changed
1998-08-06
Distribution
Conservation Status Map
<img src="http://www.natureserve.org/explorer/servlet/GetMapGif?US.CA=S2&US.ID=SE&US.NV=S3&US.OR=S1&US.UT=SE&US.WA=SE&US.WY=SE" alt="Conservation Status Map" style="width: 475px; height: auto;" />
Global Range
F - 20,000-200,000 square km (about 8000-80,000 square miles) - F - Historically this subspecies was abundant in lakes and streams throughout the physiographic Lahontan basin of northern Nevada, eastern California, and southern Oregon, including the Truckee, Carson, Walker, Susan, Humboldt, Quinn, Summit Lake/Black Rock Desert, and Coyote Lake watersheds (USFWS 2009). Large inhabited lakes included Lake Tahoe, Fallen Leaf Lake, and Cascade Lake in the Tahoe watershed; Donner Lake, Independence Lake, Winnemucca Lake (now dry), and Pyramid Lake in the Truckee River watershed; Walker Lake in the Walker River watershed; and Summit Lake in the Black Rock Desert watershed; other headwater lakes in the Walker River watershed were also historically occupied (Gerstung 1988).<br><br>Currently this subspecies exists in about 0.4% of its former lake habitat and approximately 9 percent of the former stream habitat within the native range; Independence and Summit lakes support the only remaining reproducing lacustrine form within the native range (USFWS 1994, 2009). The subspecies has been introduced outside the native range, primarily for recreational fishing purposes (USFWS 1994, 2009).
Global Range Code
F
Global Range Description
20,000-200,000 square km (about 8000-80,000 square miles)