Porcelain Coral

zooxanthellate

Coralla are thin leaves, often symmetrical discs, but also irregular, contorted and even branched. Calices are 3 to 4 mm diameter. In shallow or well lit areas, calices tend to run in rows parallel to the leaf edge, and slightly inclined towards it, and are separated by 3 to 10 mm. As depth increases, calices become more scattered, and in very dim sites the thin leaves have extensive areas without calices. In these, calices may be found near the central attachment area. Septa are strongly alternating. However, in many cases, only the first order septa reach the calice, so that septa around the low calical mound are equal; in such cases, second order calices emerge only outside the calice. This is fairly common on deep reef slopes, generally in clear water. It can survive in extremely low light levels, such as in caves. (Sheppard, 1998 ) Colonies are composed of unifacial laminae which may be horizontal with entire or lobed margins, or contorted and partly upright. Corallites are widely spaced and outwardly inclined. Septo-costae alternate strongly, forming fine but conspicuous radiating ridges. Colour: pale brown or yellow-brown, often with white margins. Abundance: seldom common except on vertical or overhang faces, especially of lower reef slopes. (Veron, 1986 ) Forms distinctive leaf or plate-like colonies which may be lobed or grow in a complete whorl. The septo-costae connecting the corallites are linear and the corallites themselves protrude outwards, giving a characteristic appearance. Colour: usually pale orange or brown with paler margins. Habitat: vertical sides of deeper reefs. (Richmond, 1997)