Cutthroat Trout Science and Facts

Cutthroat trout are a species of salmon. They are a member of the Genus Oncorhynchus . Other members of this genus include apache trout, Biwa trout, gila trout, golden trout, rainbow trout, and Mexican golden trout. The Cutthroat trout is considered to be the most diverse trout species in all of North America due to its 15 recognized subspecies. These subspecies include the Lahontan cutthroat trout, Oncorhynchus clarki henshawi , Bonneville cutthroat trout, Oncorhynchus clarki utah, Colorado River cutthroat trout, Greenback cutthroat trout, Rio Grande cutthroat trout and the Yellowstone cutthroat trout. Other common names for the cutthroat trout are sea trout, sea-run cutthroat, red-throat trout, and harvest trout.

Cutthroat Trout Facts

Due to the vast variety of subspecies of cutthroat trout, these fish demonstrate a wide variety of appearances including overall general size, color, and even their habitat selection. The cutthroat’s color range includes gray, green, and gold. The coloration is determined based on the fish’s subspecies strain and habitat choices. All cutthroat trout have the characteristic red, orange, or pink marks below the lower jaw and gill plates on the underside of the fish.

Mature cutthroat vary in length from 6 to 40 inches. This large variation is due to the availability of food and chosen habitat. The cutthroat trout’s size is not indicative of its subspecies.


Cutthroat trout commonly interbreed with rainbow trout, O. gilae subspecies, the Gila trout and Apache trout. Spawn from breeding with the rainbow trout are fertile and known as cutbows. Cutthroats begin spawning at 4 years of age. They spawn on alternate years. The cutthroat trout spawn from February through May, depending upon location. Coastal cutthroats spawn during February and March while their inland counter parts spawn in April and May.

Cutthroats’ diets consist of fish. Young cutthroats also eat freshwater shrimp and insect larvae.

Life Cycle

Cutthroats are anadromous, or migratory, fish. Costal cutthroats swim to the ocean between the ages of 2 to 3 years. These fish typically habitat the ocean for approximately 2 years. At the conclusion of that time these trout will return to the rivers to spawn. The female cutthroat digs a nest and lays eggs during spawning season. The male will then come and fertilize the eggs. A female cutthroat can lay anywhere from 200 to 4400 eggs. The young hatch about 1 month after fertilization. They will remain in the gravel for approximately two weeks before they emerge.

Adult cutthroats tend to make their homes in large pools and the young tend to live in riffles. These homes tend to be upstream in the tributaries and rivers that these fish reside. Young are usually laid and reside in slow flowing backwater areas, low velocity pools, and side channels. It is important for these areas to have close proximity to the forest canopy and woody debris to ensure a steady supply of insects for the young to feed upon and survive. Adult cutthroat that are in their migratory phase typically live in tidal sloughs, marshes, and swamps. These also serve as holding areas and feeding grounds.

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