Grand Canyon's Extirpated Fish Species

Three of the eight species of native species of fish are no longer found in Grand Canyon National Park.

 

Colorado pikeminnow (Ptychocheilus lucius) Status: Endangered

Illustration by Joe Tomelleri

 

Colorado pikeminnow caught in 1911

Kolb Brothers

Colorado pikeminnow (Ptychocheilus lucius)

Status: Endangered

The Colorado pikeminnow is endemic to the Colorado River and is the largest member of the minnow family on the continent, with a maximum length of six feet (72 inches or 1800 mm). The Colorado pikeminnow is extirpated from Grand Canyon, with the last verified record in 1972. Pikeminnow are still found in the upper end of Lake Powell, in the San Juan River, and in the Yampa and Green Rivers in Dinosaur National Park. The Colorado pikeminnow was the top predator in the Colorado River, feeding on all species of fish. These torpedo-shaped fish have large mouths and are slow-stalking predators.

Pikeminnow were once common in the Colorado River, including in Grand Canyon. Early settlers called them "Colorado white salmon" because of their migratory behavior and quality of their meat. Dynamite was used to harvest pikeminnow near Lees Ferry in the early part of the twentieth century. Early Grand Canyon pioneers, including Emery and Ellsworth Kolb, who operated a photography studio and completed a historic 1911-1912 trip on the Green and Colorado Rivers, caught pikeminnow in Grand Canyon. Pikeminnow have been absent from Grand Canyon since the early 1970s.

Pikeminnow suffered decline due to overharvest by early settlers. The species' decline continued with the construction of dams on the lower Colorado River, including Hoover Dam that blocked their migratory spawning runs. In addition, interactions with non-native fish can lead to pikeminnow mortality.

 

Bonytail (Gila elegans) Status: Endangered

llustration by Joe Tomelleri

 

Bonytail (Gila elegans)
Status: Endangered

Bonytail is the most critically endangered of the Colorado River's native fish, with no reproducing populations in the wild. A number of hatcheries have refuge populations of the species.

These streamlined chub have large fins and are powerful swimmers. They reach a maximum length of 22 inches (550 mm). They likely inhabited areas of moderate current in the mid part of the river channel. Bonytails are closely related to humpback and roundtail chubs.

Relatively little is known about the species habitat in the wild, or its previous distribution in Grand Canyon. Records are known from Bright Angel and Phantom Creeks in the early 1940s, and bonytail skeletal remains were recovered from Stanton's Cave.

 

Roundtail chub (Gila robusta)

Illustration by Joe Tomelleri

 

Roundtail chub (Gila robusta)

Roundtail chub are one of three species of chub historically found in Grand Canyon. The species was likely extirpated from the canyon by the late 1960s. Although their populations have decreased because of human-caused changes to the Colorado River system, including introduction of non-native warm-water fish species, and the construction and operation of dams and water diversions, roundtail chub are the most abundant of the river's three species of chub outside of Grand Canyon. They are similar in size to humpback chub (20 inches or 500 mm), and are closely related. In fact, it is difficult for fisheries biologists to distinguish juvenile members of the two species. |

Roundtail chub probably inhabited low-velocity reaches of the Colorado River in Grand Canyon. The species was first described from specimens collected near Grand Falls on the Little Colorado River in the 1850s. Roundtail chub have been absent from Grand Canyon since the 1960s.