Florida Rocksnail

Mollusc

Identification & Biology

• IdentificationA robust sea snail with a thick, oval shell bearing prominent spiral ridges and sometimes short knobs. The shell colour varies from grey to brown, often with faint spiral banding. The aperture (opening) is orange to reddish inside.
• SizeShell length up to 8 cm. A solid, heavy-shelled species.
• Social HabitFound in groups, especially during breeding. Predatory, drilling through the shells of other molluscs. Lays clusters of capsule-shaped eggs on rock surfaces.
• HabitatRocky shores, intertidal to shallow subtidal. Prefers wave-exposed rock surfaces with abundant prey.
• Depth0 to 15 m. Mainly intertidal and very shallow subtidal.
• Feeds OnBivalves, barnacles, and other gastropods. Drills through prey shells using its radula and chemical secretions.
• DistributionAtlantic coasts of Europe and Africa, and throughout the Mediterranean Sea. Common on Maltese rocky shores.
• DescriptionStramonita haemastoma is a common predatory snail on rocky shores around Malta. It plays an important ecological role in controlling mussel and barnacle populations. The orange-red aperture is distinctive and makes identification straightforward. Groups of egg capsules cemented to rock surfaces in the intertidal zone are a common sight in spring and summer.