**Description:** A primitive fish with a large, rectangular head and a specialized mouth designed for suction on river stones.
**Size & Weight:** Typically 10–15 inches long. Weighs 1–2 lbs.
**Identification:** Look for the three or four dark, oblique bars on the sides. Their large "shoulders" and flat head are distinctive.
**Behavior:** Scrapes algae and small invertebrates from rocks. Their presence is a sign of high water quality and high dissolved oxygen.
**Habitat:** Rocky riffles of clear rivers and larger streams.