Brain Coral in Cozumel

A rounded boulder covered in a maze of interconnected valleys and ridges, tan to yellow-green. The valleys are continuous, not separate pits.

Quick ID

Where You Will See It In Cozumel

Brain Coral works the 6 to 98 foot band. On this island that means the sheltered west-coast reefs, and the shallow east-side entries when the sea is flat — these are the sites where the depth and the habitat line up for it.

Without a boat. It is worth looking for at Tikkila Shallow, Chankanaab Shallow and Chen Rio — all shore entries, so you dive them on your own schedule.

On an ordinary beginner boat dive. It should be within reach at Yellow House, Yucab, Casa Blanca, Chankanaab Bolones and Columbia Shallows. No advanced certification needed.

Deeper, and on the walls. It is also plausible on Santa Rosa Wall, Tormentos, Villa Blanca Wall and Barracuda Reef.

Conditions change the odds more than the site does — the current, the time of day and how much the group has already stirred up the sand. Ask your guide what they have been seeing that week.

Behaviour

A slow reef-building coral, growing roughly half a centimetre to a centimetre a year. A brain coral the size of a car is centuries old. Polyps extend to feed after dark.

Commonly Confused With

• Grooved brain coral — Grooved brain coral has a distinct groove running along the top of each ridge.
• Star coral — Star coral has separate raised polyp cups rather than continuous valleys.

Diving Etiquette And Safety

Slow growth means damage is effectively permanent. Do not touch, kneel on or steady yourself against coral.

Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip

Photo: Emma Hickerson, NOAA Flower Garden Banks National Marine Sanctuary, Public domain, via Wikimedia Commons.