Facts: The Rough Keyhole Limpet

The rough keyhole limpet is a species of sea snail. Rough keyhole limpets typically range from Alaska to Baja, California, but they are recorded to occur as far south as Nicaragua. Underneath, they have one big foot for locomotion and suction. Their soft body is protected by a hard shell. The shell has a rough texture and often has barnacles growing on it. Their shell color varies from light brown to gray, often with banding. Their shell is heavy with a high profile and an off-center opening, or keyhole, at the shell apex. The opening is about one-tenth the length of the shell. The keyhole is used for exhaling and disposing of waste. Ribs radiate from the top of the shell. Every fourth rib is larger. There are numerous concentric growth lines that cross the ribs at right angles. The shell can be up to three inches long. Rough keyhole limpets can be found on rocky beaches, from the intertidal zone to 130 feet deep. They use their radula, a tooth-bearing tongue, to graze on algae, bryozoans, and sponges attached to rocks. To protect themselves from predators such as the purple sea star, they can erect a thin, soft mantle to cover their shell and prevent the sea star's tube feet from attaching to their shell. The red-banded commensal scale worm is sometimes found on the underside of these limpets. For more marine facts, click the SUBSCRIBE button!!