Yellow pencil coral
Madracis mirabilis
(Duchassaing & Michelotti, 1861)
Description:
Colonies slightly convex pillow-shaped, sometimes several meters in diameter (M. mirabilis colony). Short branches 6-10 mm in diameter, brittle, with blunt forks at the tips. Polyps often expanded during day.
Color:
Color of the living colony bright yellow.
Corallites:
Corallites between 1.1 and 1.6 mm in diameters, with ten or more septa. Coenosteum 1.0 mm in width. Columella massive, styliform (M. mirabilis close-up).
Habitat:
In water usually deeper than 6 m.
Remarks:
Some other species of the genus occur on Curacao: Madracis formosa , Madracis decactis , 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.