Lahontan cutthroat trout | |
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O. clarkii henshawi, stream form | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Salmoniformes |
Family: | Salmonidae |
Genus: | Oncorhynchus |
Species: | O. clarkii |
Subspecies: | O. c. henshawi |
Trinomial name | |
Oncorhynchus clarkii henshawi (Gill and Jordan, 1878) |
Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is the largest subspecies of cutthroat trout, and the state fish of Nevada. It is one of three subspecies of cutthroat trout that are listed as federally threatened.
The Lahontan cutthroat is native to the drainages of the Truckee River, Humboldt River, Carson River, Walker River, Quinn River and several smaller rivers in the Great Basin of North America. These were tributaries of ancient Lake Lahontan during the ice ages until the lake shrank to remnants such as Pyramid Lake and Walker Lake about 7,000 years ago, although Lake Tahoe—from which the Truckee flows to Pyramid Lake—is still a large mountain lake.
Lahontan cutthroats evolved into a large (up to 1 m or 39 in) and moderately long-lived predator of chub, suckers, and other fish as long as 30 or 40 cm (16 in). The trout was able to remain a predator in the larger remnant lakes where prey fish continued to flourish, but upstream populations were forced to adapt to eating smaller fish and insects. Some experts consider O. c. henshawi in the upper Humboldt River and tributaries to be a separate subspecies, O. clarkii humboldtensis or the Humboldt cutthroat trout, adapted to living in small streams rather than large lakes.