Official Status: Threatened
Lahontan
cutthroat trout are steel gray to olive green above, with yellow-brown sides and red or pink along the belly. Round black spots scattered over fish, but more closely grouped towards the tail. Fins are uniform in color, lacking the white tips that identify similar fish. The crimson red or orange slash marks on throat under the jaw give this fish its namesake appearance.
Female sexual maturity is reached between the ages of three and four, while males mature at two to three years of age. Like other cutthroat trout species, Lahontan cutthroat trout is a stream spawner, spawning between February and July. Spawning depends upon stream flow, elevation, and water temperature. Over 60 percent of male and female Lahontan cutthroat die after their first time spawning, and those that remain usually spawn again two or more years later. Consecutive repeat spawning is very rare.
Lahontan cutthroat trout, like other trout species, are found in a wide variety of cold-water habitats including large terminal alkaline lakes (e.g., Pyramid and Walker lakes); alpine lakes (e.g., Lake Tahoe and Independence Lake); slow meandering rivers (e.g., Humboldt River); mountain rivers (e.g., Carson, Truckee, Walker, and Marys Rivers); and small headwater tributary streams (e.g., Donner and Prosser Creeks).
Generally, Lahontan cutthroat trout occur in cool flowing water with available cover of well-vegetated and stable stream banks, in areas where there are stream velocity breaks, and in relatively silt free, rocky riffle-run areas.
The Lahontan cutthroat trout is endemic or native to the Lahontan basin of northern Nevada, eastern California , and southern Oregon. In 1844, there were 11 lake dwelling populations of Lahontan cutthroat trout and 400 to 600 steam dwelling populations in over 3,600 miles of streams within the major basins of Lake Lahontan.
Lahontan cutthroat trout currently occupy between 123 to 129 streams within the Lahontan basin and 32 to 34 streams are outside the basin, totaling approximately 482 miles of occupied habitat. The species is also found in five lakes, including two small populations in Summit and Independence Lakes . Self-sustaining populations of the species occur in 10.7 percent of the historic stream habitats and 0.4 percent of the historic lake habitats. As subpopulations of the species become isolated due to physical and biological fragmentation, migration rates decrease, local extirpation may become permanent, and the entire population may move incrementally toward extinction. Maintaining a networked population may provide the ability to recover LCT without having to establish fish in every tributary as well as establishing self-sustaining lake populations for long term persistence. Although the presence of non-native species have dramatically altered aquatic ecosystems, hybridization and competitive interaction between lake dwelling LCT and non-native species is not well understood.
Threats As subpopulations of the species become isolated due to physical and biological fragmentation, migration rates decrease, local extirpation may become permanent, and the entire population may move incrementally toward extinction. Maintaining a networked population may provide the ability to recover LCT without having to establish fish in every tributary as well as establishing self-sustaining lake populations for long term persistence. Although the presence of non-native species have dramatically altered aquatic ecosystems, hybridization and competitive interaction between lake dwelling LCT and non-native species is not well understood.
Listed as endangered in 1970; reclassified as threatened in 1975.
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