Formerly Extinct State Fish Finds Its Way Back to Native Waters of Colorado

The Colorado state fish is now known to be naturally reproducing in its natural habitat or native waters, despite once being thought to be extinct.

After a time when it was thought that the greenback cutthroat trout, the state fish of Colorado, had disappeared into extinction, it is now reproducing in the wild once more, experts say.

Small populations of what was presumably listed as extinct in the 1930s were discovered in various locations of the state's river systems, although they were believed to be hybrids.

Purebred Greenback Cutthroat

Conservationists with Colorado Parks & Wildlife discovered a small school of purebred greenback cutthroat trout along a 3.5-mile stretch of Bear Creek in 2012, which sparked a flurry of activity.

It's typical for a critically endangered species to recover after a nerve-wracking effort to try and get a few captive individuals to breed in an aquarium, and this situation is no different.

To catch greenbacks and successfully collect roe and milt-eggs and sperm-CPW aquatic biologists have to toilsomely hike up Bear Creek while wearing bulky electro-fishing backpacks.

Using the treats, CPW was able to breed the fish in a trout hatchery. By 2016, they began a repopulation effort in Herman Gulch, where the fish were now adults and capable of reproducing on their own.

Kevin Rogers, an aquatics researcher from Colorado Parks and Wildlife, said that this is just more evidence that conservation strategies are effective and that endangered species can be saved.

Trout Unlimited's chapter in Colorado is also having success with its breeding program; in 2017, it released 13,000 small fry into four locations near Cameron Pass and Loveland Pass.

The state fish can reach lengths of up to 18 inches and weights 10 pounds. It has a sickly green color with rusty spots. It is believed to have the cutthroat trout species' most brilliant spawning coloration.

Cutbows

The native greenback cutthroat has been driven out of much of its former habitat as a result of the introduction of non-native brown, rainbow, and brook trout into Colorado streams, though sometimes the relationship isn't so bad. Cutbows are fertile hybrids made when greenback cutthroat and rainbow trout spawn, Good News Network reports.

They frequently have larger spots that are located toward the back of the fish, giving them the appearance of a rainbow trout. The Cutbow is a hybrid cross that exhibits traits from both lines. Depending on the amount of water, light, and general habitat conditions present, different Cutbow specimens and "races" will exhibit different field marks. However, the typical red-orange or red color slash near the jaws, as well as the typically wide pink or reddish band just below the lateral line, are constant throughout, as per Nevada Department of Wildlife data.

The species is raised in Nevada hatcheries and stocked in numerous northern Nevada lakes and reservoirs.

According to The Hook & Hackle Company, young Cutbows consume all life stages of marine and terrestrial insects as well as other aquatic invertebrates as they become available, as is typical of stream-dwelling and lake-dwelling western trout species. Forage fish make up an increasing portion of the diet of adult Cutbows.