Bluehead Wrasse in Cozumel

One fish, three completely different looks. Most of what you see are small yellow fish with a dark stripe; the blue-headed version that gives the species its name is the large terminal male, and there is usually only one per patch of reef.

Quick ID

How To Identify It

Terminal males have a deep blue head, two black bars and a green-blue body. Initial-phase fish and juveniles are yellow with a dark lateral stripe or a row of dark blotches.

Where You Will See It In Cozumel

Bluehead Wrasse works the 3 to 79 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 Punta Morena, Tikkila Shallow and Chankanaab Shallow — all shore entries, so you dive them on your own schedule.

On an ordinary beginner boat dive. It should be within reach at Palancar Gardens, Paradise, Punta Dalila, San Clemente and Yellow House. No advanced certification needed.

Deeper, and on the walls. It is also plausible on Paso del Cedral, Punta Tunich, San Francisco Wall and San Juan.

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

Bluehead wrasse change sex. Fish begin as females or as initial-phase males; the largest becomes a terminal male, turns blue-headed and defends a spawning site. Remove that male and the next fish in line changes.

They also act as cleaners when young, picking parasites off larger fish — worth watching at a cleaning station.

Commonly Confused With

• Yellowhead wrasse — Yellow head, not blue, and a dark bar behind the pectoral fin.
• Juvenile parrotfish — Blunter head and a beak; the wrasse has a pointed snout and separate teeth.

Diving Etiquette And Safety

Keep fins off the reef and hands to yourself. Nothing here needs to be touched, moved or provoked to be seen well.

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

Photo courtesy of the Cozumel Coral Reef Restoration Program, used with permission.