Catostomus latipinnis (flannelmouth sucker) is a North American fish identified by its enlarged lower lips.

Flannelmouth suckers are classified as benthic fish, spending most of their time near the river floor where they forage for food.

[2] Young fish are usually silvery-colored all over, but adults have a typical light gray or tan coloration (often with a lighter underside).

[4] It is extinct in California although strays from the reintroduced Nevada population are occasionally caught in the Californian Colorado River.

This species is known to eat inorganic material, planktonic organisms such as copepods, filamentous algae and other macroinvertebrates; this was discovered by examining the stomach contents of flannelmouth sucker larvae.

These threats include alterations of river habitats (thermal and hydrologic) caused by hydroelectric dams; blockage of migration; and predation by introduced organisms.