Colonies are phaceloid to plocoid, and consist of a few to large numbers of corallites. Corallites are less than 7 millimetres diameter. Septa are mostly in two cycles of which only the first reaches the columella. Septa have slightly serrated margins. Primary septa may be exsert. Columellae are poorly developed. Mantles, but not tentacles, are extended during the day and may form a continuous surface obscuring the underlying growth-form.
Commonly dark red with conspicuous green oral discs. May also be pink, orange, brown or uniform dark grey with white margins to primary septa.
Reef environments, especially where the water is turbid.
Taxonomic note: Red Sea colonies are mostly plocoid and have been described as a separate species (Blastomussa loyae Head, 1978). There are, however, no consistent differences between these colonies and plocoid colonies in other regions. Source reference: Veron (2000). Taxonomic references: Wells (1961), Chevalier (1975), Veron and Pichon (1980). Additional identification guides: Veron (1986), Sheppard and Sheppard (1991), Nishihira and Veron (1995), Coles (1996).
displaying probable distribution of species. Points indicate recorded sightings from OBIS.