Fish and Aquatic Conservation



illustration of a Colorado pikeminnow

Colorado pikeminnow

Ptychocheilus Lucius, (Girard, 1856)

Cool Facts

The Colorado pikeminnow was a valuable food source that was prized by early settlers. Early settlers used to call this species the “white salmon” because of its migratory behavior. The Colorado pikeminnow is the largest minnow in North America. The maximum reported age for the Colorado pikeminnow is 12 years.

SIZE: The common length of the Colorado pikeminnow is 52.5 cm (20.7 in) with the longest reported length being 180 cm (70.9 in).

RANGE: Within the U.S., the Colorado pikeminnow used to inhabit the Colorado River drainages in Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada and California. But now, due to construction of large dams in rivers within the Colorado River basin, the Colorado pikeminnow is now mostly restricted to Utah and Colorado. Today two wild populations of the Colorado pikeminnow are found in the Upper Colorado River Basin. The San Juan River Basin Recovery Implementation Program continues to stock Colorado pikeminnow with the purpose of developing a new, separate, self-sustaining population.

HABITAT: The Colorad o pikeminnow inhabits medium to large rivers. Young pike minnows prefer small, quiet backwaters. Adult pikeminnows use various habitats which include deep, turgid, strongly flowing waters, eddies, runs, flooded bottoms or backwaters (especially during high flows). They can also utilize inundated lowlands.

DIET: Young pikeminnows feed on insects and plankton. Adults feed primarily on fish.

Natural History

The Colorado pikeminnow is a native fish of the Colorado River thought to have evolved more than three million years ago. The Colorado pikeminnow is adapted to warm rivers and requires uninterrupted passage and a hydrologic cycle characterized by large spring peaks of snowmelt runoff and lower, relatively stable base flows.

Reproducing pikeminnow adults seek white water canyons to spawn. It appears that Colorado pikeminnows seek out river canyons that receive freshwater input from groundwater seeping from sandstone or limestone. Adult pikeminnows return to previous spawning sites.

After hatching, young pikeminnow larvae, drift downstream and then move to shoreline areas and backwaters. The young-of-the year colorado pikeminnows tend to congregate into receding backwaters that are formed in late summer. Young pikeminnows tend to occur downstream from areas occupied by adult Colorado pikeminnows.

Conservation

The Colorado pikeminnow was listed as an Endangered Species by the U.S. Fish and Wildlife Service under the Endangered Species Act in 1967. The pikeminnow was given full protection under the Endangered Species act in 1973. The Colorado pikeminnow was listed as Endangered under Colorado law in in 1976. In 1998, the Endangered Status for the pikeminnow was changed to Threatened under Colorado law. The Colorado pikeminnow has been protected under Utah law since 1973.

The Colorado pikeminnow is represented by three wild populations residing in the Green River, Upper Colorado River and San Juan River sub-basins. The trend over the past ten years or three generations has been relatively stable. The Green River adult population declined and then increased in the beginning years of this century. Recruitment actually increased as of 2011. The Colorado River Adult population and recruitment were relatively stable in the 1990’s and 2000’s.