Mottled Sculpin Identification Guide

Key identification features

• Small, elongated body rarely exceeding 10-12 cm
• Broad, flattened head with eyes set high and close together
• Mottled brown, olive, and tan blotching that breaks up the outline against gravel
• Large, rounded pectoral fins used to prop against the substrate
• Two dorsal fins that are close together or slightly connected, the front one low and spiny
• Smooth, scaleless skin with fine prickling near the pectoral base in some populations

Common look-alikes

• Slimy Sculpin: has a single continuous lateral line and a slimier, more uniformly dark body without strong mottling
• Banded Sculpin: shows bolder, more regular dark bars across the back rather than irregular blotching
• Torrent Sculpin: has a more complete lateral line running the full body length and a more robust build

Where you'll see one

Mottled Sculpins live in cool, clear, well-oxygenated streams, rivers, and rocky lake margins across much of North America, hiding under stones and gravel where their coloring nearly disappears against the bottom.