Montastrea cavernosa 

Montastrea cavernosa is a colonial coral with bulbous corallites. Montastrea is easy to spot on most Caribbean reefs making it a good place to start when learning to identify corals. This coral can be a solid color or have contrasting colored corallites, which makes it exciting to find on a dive.
Montastrea grows into massive colonies which can be flat or domed shape. This is a hardy coral which can grow in most reef habitats. You can find colonies ofMontastrea in the shallowest part of the reef and it is possible to see this coral while snorkeling.

During the day the coral polyps are retracted inside the corallite and, at night the polyps emerge to consume any food drifting in the current.
If you go scuba diving at night, worms, plankton, and other marine invertebrates often flock to your dive light. If you shine your light near the open polyps chances are the coral will quickly snatch up the meal.

Great Star Coral

The common name for Montastrea cavernosa is the Great Star Coral. If you remember our articles about Orbicella coral you might notice some similarities between the two species.  Until recently Orbicella was classified under Montastrea and older reference books and some online resources still classify Orbicella as Montastrea.
One of the biggest differences between these two corals is the corallite size. Montastrea corallites can be a few centimeters or an inch across where as Orbicella corallites are less than 1cm across.

Colonies of Montastrea can grow into towering colonies several meters across. Or they can encrusting along the ocean floor like the three colonies above.