Slimy Sculpin

Cottus cognatus

The slimy sculpin (Cottus cognatus) is a small, bottom-dwelling freshwater fish reaching up to 12 cm. It has a broad, flattened head, large fan-like pectoral fins, and a dark mottled brown body that provides excellent camouflage against rocky substrates. Found across northern North America from Alaska and Canada to the northern United States, it inhabits cold, clear streams, rivers, and lake bottoms at depths of 0 to 20 meters. This species lacks a swim bladder and rests on the substrate, using its large pectoral fins to brace against currents. It feeds on aquatic insects, small crustaceans, and fish eggs. Males guard eggs in nests under rocks. Its cryptic appearance and sedentary nature make it a challenge to spot but a rewarding find for divers exploring cold, clear freshwater environments.