Great Star Coral in Cozumel
Great Star Coral (*Montastraea cavernosa*) in Cozumel: how to identify it, why it flattens at depth, and what it is confused with.
Boulders and plates covered in evenly spaced raised polyp cups, each about the size of a pencil eraser, giving a distinctly beaded surface.
Quick ID
| Scientific name | Montastraea cavernosa |
|---|---|
| Group | Hard Corals |
| Typical size | Colonies to 3 m across |
| Depth range | 3–40 m |
| When to see it | Year-round |
| Active | Polyps feed at night |
| Conservation status | Least Concern |
| Notes | — |
Where You Will See It In Cozumel
One of the main structural corals on the Cozumel walls — Santa Rosa, Palancar and Colombia Deep.
Reliable sites: Santa Rosa Wall, Palancar Horseshoe, Colombia Deep.
Behaviour
A major framework builder that grows in boulders in the shallows and flattens into plates at depth to catch more light. At night the polyps extend into a field of translucent tentacles.
Commonly Confused With
- Brain coral — Continuous valleys rather than separate raised cups.
- Boulder star coral — Boulder star coral has smaller, less prominent cups.
Diving Etiquette And Safety
Do not touch. Neutral buoyancy on a wall is what protects these colonies.
Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip
Photo: NOAA, Public domain, via Wikimedia Commons.
