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 . 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.