Honeycomb Coral

zooxanthellate

Colonies are distinctive, massive, and often exceed 1 metre across. Corallites are round and closely packed, plocoid, and formed by extratentacular budding. They are 8 to 10 mm diameter. The most characteristic feature of Diploastrea heliopora is its corallite wall structure. Walls are not solid but are delineated or formed by the thickened outer ends of the septa, which are not attached to each other laterally. This feature can even be detected beneath the tissue of the live corals. Shallow and mid-depths are preferred, almost always in sheltered water. The largest colonies are usually seen in silty environments, so it is commonly found on protected fringing reefs and back reef slopes, often beside sandy patches. Although it may grow to great size and colonies are by no means rare, vast expanses dominated by this species, as may occur in Indian Ocean atoll lagoons, have not been seen in areas such as the Red Sea. The coral is always a uniform brown. (Sheppard, 1998 ) Colonies are dome-shaped with a very even surface and may be up to 2 m high and 7 m in diameter. The skeleton is very dense. Corallites are plocoid. Columellae are large. Septa are equal and are thick at the wall and thin where they join the columellae. Polyps are extended only at night. Colour: usually uniform cream or grey, sometimes greenish. Abundance: occurs in both exposed and protected reef habitats but is usually uncommon except on some back reef margins. (Veron, 1986 ) May form large, massive domed colonies up to 5 m across or more. Corallites closely packed and domed, 10-20 mm across, with clearly visible columellae and distinct septal walls. Colour: uniform pale green to grey or cream. Habitat: diverse. (Richmond, 1997)