Mediterranean Stony Corals, also known as Hidden Cup Corals or Dark Colonial Coral, feature flower-like polyps ranging from yellow-brown to red-brown. The circular skeletal wall of each polyp has six inward-protruding septa and may be overgrown by algae and sponges.
These corals inhabit the eastern coast of the Atlantic Ocean and parts of the Mediterranean Sea, including the Maltese Islands. They are found in various depths, from shallow waters to over 80 meters deep.
Mediterranean Stony Corals are azooxanthellate, meaning they lack photosynthetic symbionts. They thrive in nutrient-poor environments by digesting microorganisms and dissolved organic matter. They reproduce asexually through budding and can build modest reefs despite harsh conditions.
You can spot Mediterranean Stony Corals in Gozo’s dive sites, particularly at Ras il-Ħobż on the south coast. These corals grow on the undersides of rocks, ledge overhangs, cave ceilings, cavern walls, and inside wrecks serving as artificial reefs.