Lithophyllum byssoides forms pink-white calcified crusts on wave-exposed rocks of the intertidal zone. Colonies fuse into true horizontal rims protruding from the host rock. Characteristic reef-building species of wave-exposed Mediterranean rocky coasts, iconic in Corsica and Sardinia. Sensitive to sea-level rise: used as a geological marker. IUCN Near Threatened.
Photo of Mediterranean rim
Frequently asked questions
How big is the Mediterranean rim?
Mediterranean rim (Lithophyllum byssoides) reaches 10–200 cm in length.
At what depth can you find the Mediterranean rim?
Mediterranean rim is found between 0–2 m deep.
Is the Mediterranean rim dangerous to divers?
Danger level: Harmless.
What is the conservation status of the Mediterranean rim?