Mediterranean Limpet

Mollusc

Identification & Biology

• IdentificationA common limpet with a low, conical shell that is broadly oval in outline. The exterior is ribbed and often encrusted with algae. The shell colour is variable, typically grey to olive-green. The interior is white to pale blue with a distinctive dark horseshoe-shaped muscle scar.
• SizeShell length up to 7 cm. Commonly 3 to 5 cm.
• Social HabitSolitary. Returns to the same home spot on the rock after each grazing trip, grinding a perfect-fit scar into the rock surface over time. Active mainly when submerged or splashed by waves.
• HabitatRocky intertidal zone, particularly on wave-exposed surfaces. One of the most characteristic animals of Mediterranean rocky shores.
• DepthIntertidal to 1 m. Strictly a shore-zone species.
• Feeds OnMicroalgae scraped from rock surfaces using a rasping radula. Each limpet maintains a grazing territory around its home scar.
• DistributionThroughout the Mediterranean Sea and the Black Sea. Abundant on all Maltese rocky shores.
• DescriptionPatella caerulea is the most common limpet on Mediterranean shores, visible on virtually every wave-washed rock in Malta. Each individual grinds a home scar into the rock that matches its shell shape exactly, forming a watertight seal that prevents desiccation at low water. The radula (tongue) of a limpet contains the strongest known biological material, made of goethite nanofibres stronger than spider silk.