It is the only genus in the monotypic family Montastraeidae and contains a single species, Montastraea cavernosa, known as great star coral.

[2] Great star coral colonies form massive boulders and domes over 5 feet (1.5 m) in diameter in waters of shallow and moderate depths.

This coral occasionally has a fluorescent red or orange color during daytime; it has recently been suggested that this hue is due to phycoerythrin, a cyanobacterial protein.

[3] The species is gonochoric (colonies can be either male or female) and spawns one week after the full moon in late August.

[4] The distinction of bleaching in reefs of M. cavernosa from merely white-coloured corals was shown to be difficult using standard reflectance techniques.