Greenback Cutthroat Trout Is The Official State Fish Of Colorado. The Greenback Cutthroat Trout Or Oncorhynchus clarki somas, Was adopted as the official State Fish Of Colorado on March 15, 1994. It Was Accepted by an act of the General Assembly Of Colorado. The Rainbow Trout was considered the state fish from 1954 to 1994, however, it was never officially adopted.
The Colorado State Fish Greenback Cutthroat Trout was at one time indigenous to many small creeks, streams, and rivers throughout most of Colorado. As mining and human occupation expanded across the state, the State Fish Of Colorado greenback easily succumbed to pollution from mine tailings in the state’s streams and to competition from other species of trout introduced to Colorado waters.
The demise was so complete that up until the late 1980s biologists feared the extinction of this native fish. However, researchers in the early 1990s discovered several small populations of the greenback in a few remote streams in Rocky Mountain National Park. Colorado Division of Wildlife and National Park personnel took immediate steps to protect and propagate the Colorado State Fish greenback.
Plans have been made to reintroduce this colorful fish to other waters within the state which is suitable for its repopulation. The Colorado State Fish greenback cutthroat trout (Oncorhynchus clarkii stomias) is the easternmost subspecies of cutthroat trout. The greenback cutthroat’s maximum size is 18 inches (46 cm). It has the largest spots of all cutthroats and is reported to have the most brilliant spawning coloration.
“Greenback Cutthroat Trout”
Oncorhynchus clarki stomias
Listed: March 11, 1967, Endangered
Declassified: April 18, 1978, Threatened
Family: Salmonidae (Trout)
Description: Heavily spotted trout; males often have a blood-red belly
Habitat: Flowing mountain streams.
Food: Aquatic insects.
Reproduction: Spawns in the spring.
Threats: Competition with non-native trout, habitat degradation from mining and logging, water diversion.
Because O. clarkii is such a widespread species it occupies many different habitats. Cutthroat trout habitats range from coastal marine to freshwater rivers and streams with gravel substrates (Behnke, 1992). The diversity in habitat also leads to a diversity in the elevations in which the species can be found.
A cutthroat trout’s diet changes as they progress through the life stages. As a fry, they feed on small crustaceans and algae. As they progress into fingerlings they feed on small insects, and crustaceans.
As adults, different populations and subspecies of cutthroat can range from 6–40 inches (15–100 cm) in length making size an ineffective indicator as to species.