**Description:** A master of camouflage with a large head and fan-like pectoral fins used to wedge between rocks.
**Size:** 3 to 5 inches long.
**Behavior:** Lacks a swim bladder and "hops" along the bottom rather than swimming. Highly dependent on high dissolved oxygen.
**Identification:** Look for broad dark bands across the back. Nearly invisible against river cobble.
**Habitat:** Clear, cold, rocky riffles of mountain streams.