Cutthroats usually display distinctive red, pink, or orange linear marks along the undersides of their mandibles in the lower folds of the gill plates. These markings are responsible for the common name "cutthroat" given to the trout by outdoor writer Charles Hallock in an 1884 article in The American Angler., although the red slashes are not unique to the cutthroat trout and some coastal rainbow trout and redband trout also display throat slashes. The sea-run forms of coastal cutthroat average , while stream-resident forms attain much smaller sizes .
Cutthroats frequently display red, pink, or orange linear markings along their mandibles beneath gill folds. These markings are the source of the "cutthroat" name for trout, as described by Charles Hallock in an 1884 article. Although these slashes are characteristic of cutthroat trout, they can also be observed on coastal rainbow and redband trout. Sea-run forms of coastal cutthroat usually measure , whereas stream-resident forms tend to be smaller.