Inhabit rocky or hard bottom and is a voracious eater. Food includes crustaceans, mollusks, sea urchins, fishes such as herring, sand lance and silver hake, and any bottom invertebrates that are available. When taken out of the water the belly becomes inflated so that when returned to the water they are unable to submerge. Adults attach their eggs near the base of a sponge to use as a spawning bed (Ref. 34819, 41075).