Cyphastrea serailia (Forskål 1775)

zooxanthellate

Colonies are commonly up to 40 cm diameter, often greater. Calices are round, and separated by half or a full calice diameter, but in many cases are more crowded. They may be neat conical shapes, or largely sunken with very thin, raised rims. There are 12 primary septa. The species is common and widespread. It is found on reef flats in conditions of raised salinity and temperature, and on clear water reef slopes down to at least 40 metres. Cyphastrea serailia and C. chalcidicum are similar. Their separation is based only on whether costae are equal or sub-equal, or unequal. In Red Sea specimens, many examples of Cyphastrea have calices with thin, raised rims with no costae at all, thus completely removing the main distinguishing criteria. However, specimens from Australia indicate a clearer division there. In Arabian specimens, where corallites are sufficiently plocoid, costae are usually "sub-equal", so the name C. serailia is used. (Sheppard, 1998 ) Corallites have costae which do not alternate strongly. There are 12 primary septa. Colour: usually grey, brown or cream. Abundance: very common and occurs in all reef habitats. (Veron, 1986 ) Protruding, cone-shaped corallites, 1-3 mm across, with obvious septa (in multiples of twelve) and costae giving the polyps a star-like quality. Surface colony between polyps is papillate. Forms thick encrustations. Colour: varying in colour from grey to brown or reddish-brown. Habitat: diverse. (Richmond, 1997)