Disc coral

Turbinaria peltata may be foliaceous or encrusting, and tends to form thick, flat plates, often in overlapping tiers. The colonies may be several metres in diameter. The corallites are found on a single side of each plate and are about 3 to 5 mm (0.12 to 0.20 in) in diameter, being either immersed in the skeleton or raised on tubular mounds. On the upper surfaces of larger colonies, two-sided ridges or cylindrical columns may form. The calyces are 3 to 5 mm (0.12 to 0.20 in) in diameter, circular and leaning towards the plate margin. The septa are arranged in three cycles, the third one often being reduced or absent. The septa are granulated and the columella is domed and spongy, or alternatively, has a central plate. The polyps of this species are often extended to feed during the daytime. They have thick tentacles up to 1 cm (0.4 in) long. This coral is usually some shade of grey or brown. It is a zooxanthellate coral that houses symbiont dinoflagellates in its tissues.