A small native sucker adapted to cold mountain streams. Excellent indicator of stream health.

Native status: Native to western US/Canada

§ Quick facts

SizeLength 15–30 cm
Weight100–400 g
LifespanWild 5–10 years
OrderCypriniformes
FamilyCatostomidae

§ Encyclopedia

The mountain sucker is a sucker found throughout western North America, on both sides of the Rocky Mountains, including the upper Missouri River, Columbia River, Sacramento River, and Colorado River. It was formerly placed in the genus Catostomus, but was later moved to the genus Pantosteus, while still remaining in the Catostomidae family. Recent phylogenetic studies suggest that it comprises three species: P. platyrhynchus sensu stricto found in the northern Great Basin, P. lahontan found in Nevada and northeastern California, and P. jordani found east of the Rocky Mountains. The name “Catostomidae” is derived from the New Latin words “cato,” meaning “down,” and “stoma,” meaning “mouth,” and refers to their inferior mouths positioned on the underside of the fish, which is characteristic of sucker fish. The lips of the mouth are protruding, fleshy, and covered with numerous papillae; this, along with the positioning of the mouth, facilitate the fish’s feeding habits of scraping food off of river bottoms. Both the upper and bottom lips are cleft at the junction of the lips. 

Source: Wikipedia — Mountain sucker Licensed under CC BY-SA 4.0

§ Identification

Field marks. Small olive-bronze sucker with underslung mouth; deeply forked tail; small scales.

Similar species. White Sucker (larger; broader range). Bluehead Sucker (blue heads in breeding). Other Catostomus species.

Voice. Silent.

§ Diet & behavior

Diet. Algae scraped from rocks; some aquatic insects.

Behavior. Small native sucker of clear cold mountain streams in western North America. Indicator species for cold-water stream health; sensitive to siltation, warming, and chemical pollution. Important food source for native trout and other predators.

§ Range

Western North America

§ Habitat

Cold mountain streams

§ Threats

Stream warming, dam construction.

§ Conservation status

According to the IUCN Red List, the mountain sucker is currently classified as Least Concern.

§ What helps

Support cold mountain stream conservation.

Support our work More ways to help

§ Further reading

§ Sources cited

  • American Fisheries Society
  • Trout Unlimited
  • Western Native Trout Initiative
  • IUCN Red List 2013