Eight-ray finger coral
Colonies form densely packed clumps of thick, relatively short branches with blunt and occasionally expanded and double-lobed tips. Colony up to 1.5 m in diameter
Tan to yellow-brown, yellow-green, green and brown; polyp's mouth yellow.
Corallites separated, up to 1.0-1.3 mm in diameter, usually with eight septa. Columella massive, styliform.
Inhabit deep outer reefs, often on outcroppings and ledges along wall, between 20 and 70 meters.
Some other species of the genus occur on Curacao: Madracis decactis , Madracis mirabilis , Madracis pharensis , Madracis senaria and a recent described species, Madracis carmabi . Recent investigations suggest that M. senaria and M. mirablis form monophyletic groups, while M. formosa , M. pharensis and M. decactis form a species-complex. It seems that hybridization occurs between the M. pharensis / M. decactis -complex and M. formosa and polyphenism within the M. pharensis / M. decactis -complex.