Blue Tang in Cozumel
Blue Tang (*Acanthurus coeruleus*) in Cozumel: how to identify it, where it is reliably seen, and what it is commonly confused with.
A flat blue disc with a small mouth and a yellow scalpel-like spine at the base of the tail. Juveniles are bright yellow and look nothing like the adults.
Quick ID
| Scientific name | Acanthurus coeruleus |
|---|---|
| Group | Colourful Reef Fish |
| Typical size | 20–35 cm |
| Depth range | 2–25 m |
| When to see it | Year-round |
| Active | Daytime |
| Conservation status | Least Concern |
| Notes | — |
Where You Will See It In Cozumel
Shallow reef tops across Chankanaab, Paradise Reef and Las Palmas, often in roving groups that sweep across the coral.
Reliable sites: Chankanaab Reef, Paradise Reef, Las Palmas.
Behaviour
Algae grazers that form loose foraging shoals, sometimes mixed with parrotfish and surgeonfish. Grazing shoals overwhelm the territorial damselfish that would otherwise chase individuals off.
Commonly Confused With
- Ocean surgeonfish — Ocean surgeonfish is brown-grey with fine body lines rather than a solid blue disc.
- Doctorfish — Doctorfish shows faint dark body bars and a rounder profile.
Diving Etiquette And Safety
The tail spine is a defensive blade. There is no reason to handle one.
Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip
Photo: Sylfred1977, CC BY-SA 3.0, via Wikimedia Commons.
