Tidepool Sculpins – Fish that Breathe out of Water

Sculpins are small little fish that you often see in the shallow tidepools from Southern California up to Alaska. They sit very still until you get too close or startle them.

Measuring just under 4 inches when full grown, these fish always live around the same tidepool where they were born, even if they are displaced up to 100 meters by waves or otherwise.

Sculpins vary in color from green to gray with mottled or striped textures to camouflage among the rocks or algae they inhabit. They have a large head with eyes close to the top of their head to watch for predators outside the water.

As the tide drops, sculpins still hang out in the shallowest of water (less than 1” deep) where they can burrow in sheltered areas or under kelp and wet seaweed even if exposed to air. Remarkably, these are one of the fish species that can even breathe surface air for up to 24 hours through their skin.

Other amphibious fish include mudskippers and clingfish that can survive out of water for several days and jump or skip across land to hunt or find new pools of water. It is likely that prehistoric fish that made the transition into land-based animals had similar capabilities back in the late Devonian to early Carboniferous (~350 million years ago).

Sculpins have no scales but rather “fluffy flesh” behind their dorsal fin that is needed for breathing through their skin. This type of breathing is called cutaneous respiration or cutaneous gas exchange.

Sculpins eat small bony fish, amphipods, insects, and marine worms.

Because they sit very still at the bottom of the tide pool, the US Navy named one of its attack nuclear submarines the Sculpin (SSN 590) since it, too, slowly maneuvers at the bottom of the ocean.