Mountain sucker

The mountain sucker (Pantosteus platyrhynchus) 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 (downward pointing) 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.