Characters: Colonies are encrusting to massive and are rarely over one metre across. Corallites are cerioid or subplocoid, circular and have thick walls. Septa have long pointed teeth. Colonies have thick fleshy tissue over the skeleton which usually forms concentric folds.
Colour: Uniform or mottled dull brown, grey or green, but sometimes brightly coloured.
Similar Species: Acanthastrea subechinata and A. brevis. See also A. hemprichii. Skeletons may be confused with those of Favites abdita or F. flexuosa, but underwater their fleshy polyps are distinctive.
Habitat: Most reef environments.
Abundance: Usually uncommon, but by far the most common Acanthastrea on tropical reefs.
Identification Guides: Veron (1986a); Sheppard and Sheppard (1991); Nishihira and Veron (1995); Coles (1996); Carpenter, Harrison, Hodgson et al. (1997); Pillay, Terashima, Venkatasami et al. (2002); Chan, Choi, McCorry et al. (2005); Pichon, Benzoni, Chaineau et al. (2010); Turak and DeVantier (2011b);