The grunt sculpin or grunt-fish, Rhamphocottus richardsonii, is the only member of the fish family Rhamphocottidae. It is native to temperate coastal waters of the North Pacific, from Japan to Alaska and south to California where it inhabits tide pools, rocky areas, and sandy bottoms at depths of up to 165 metres. It uses its spiny pectoral fins to crawl over the sea floor. It grows up to 9 cm in length. It frequently takes shelter in discarded bottles and cans, as well as the empty shells, such as those of the giant barnacle (Balanus nubilis). During reproduction, the female chases a male into a rock crevice and keeps him there until she lays her eggs.