The Bonneville Cutthroat Trout (Oncorhyncus clarki utah) is a subspecies of fish that once inhabited the Late Pleistocene-aged Lake Bonneville of Utah (USA). Since the drainage of that lake, the fish has been evolutionarily isolated in small populations in the headwaters of cool mountain streams and lakes of the Bonneville Drainage basin. The isolation has resulted in much phenotypic variation among populations. This species is one of 14 recognized subspecies of Cutthroat trout native to the western United States.

This fish has sparsely scattered, very distinct round spots over its upper body. They are clothed in subdued colors of silver-gray to charcoal, the upper body having subtle hues of pink on the flanks during spawning. These fish, particularly the Bear Lake strain, often lack the bright crimson jaw slash that, at times, may be yellow.

The differences between the Bonneville Cutthroat Trout and the Rainbow Trout are the basibranchial (hyoid) teeth in their throat between the gill arches. They also typically have longer heads and jaws than the Rainbow and often times can be distinguished from the Rainbow by their larger spots.

Bonneville Cutthroat Trout primarily eat insects, but large individuals also eat other fish. They spawn near the mouths of streams over gravel substrate in the springtime, having an incubation period of 24 to 25 days.

The Bonneville Cutthroat is known to be more vulnerable to anglers because of a general lack of wariness and can be caught on a wide variety of bait. As the only native salmonid of the inland west, cutthroat trout suffered intense fishing pressure for commerce and sustenance from the 1850's through the 1920's. At one time they were so numerous they were considered a nuisance, but today they are on the Utah Sensitive Species List. They are threatened by predation and competition by non-native fish, hybridization with non-native fish (in particular the rainbow trout) and loss of habitat.

The Bonneville Cutthroat has recently been designated the official fish of the State of Utah. It was important to the Indians and the Mormon pioneers as a source of food. Most of the fish's current and historic range is in Utah, but they are also found in Idaho, Wyoming, and Nevada.

References

• The Bonneville Cutthroat Trout
• State of Utah Division of Wildlife Resources
• From the Utah Division of Wildlife Resources "Utah fish species".