Found clustered against the surfaces of craggy rocks and roughened shells, Balanus balanus is a cold-water species of barnacle that can measure up to 5cm in diameter. Greyish-white in color, B. balanus is primarily identified by its steeply conical shell, deep longitudinal ridges, strongly beaked tergum, and yellow opercular membrane. This hearty crustacean prefers to dwell in waters above 150m deep and often shares its habitat with other barnacles of the same Family.