Pantosteus

Pantosteus, the mountain suckers, is a genus of North American freshwater ray-finned fish in the family Catostomidae. Long treated as a subgenus of Catostomus, phylogenetic evidence has found them to a form a monophyletic group that diverged from other members of Catostomus during the Miocene, and they are thus treated better as a distinct genus.

They are native to mountainous regions of western North America, from southern Canada to north-central Mexico. They are primarily found in the Interior West, where they are known from the Black Hills, Rocky Mountains,parts of the Sierra Madre Occidental, much of the Great Basin, and parts of the Cascade Range. However, a single isolated species (the Santa Ana sucker) is found west of the Cascades, in the San Gabriel Mountains.

Pantosteus species tend to be smaller than those in Catostomus. They inhabit cool, fast-flowing streams located in high-elevation environments.