Caribbean Reef Octopus in Cozumel
Caribbean Reef Octopus (*Octopus briareus*) in Cozumel: how to identify it, where it is reliably seen on night dives, and how to behave around one.
Blue-green iridescence over a body that changes colour and texture continuously, with long arms joined by a deep web. Usually first spotted as movement rather than shape.
Quick ID
| Scientific name | Octopus briareus |
|---|---|
| Group | Molluscs — Octopus, Squid & Snails |
| Typical size | 30–60 cm including arms |
| Depth range | 2–20 m |
| When to see it | Year-round |
| Active | Night |
| Conservation status | Least Concern |
| Notes | Best seen on night dives |
Where You Will See It In Cozumel
Night dives on the shallow reefs — Money Bar, Paradise Reef and Chankanaab shallows.
Reliable sites: Money Bar, Paradise Reef, Chankanaab Reef.
Behaviour
Hunts by parachuting the webbed arms over a coral head and trapping whatever is underneath. Changes colour and skin texture in under a second, and will pour its entire body through a gap the size of its beak.
Commonly Confused With
- Caribbean reef squid — Squid hover in mid-water in small groups; octopus stay on the reef.
- Common octopus — Hard to separate underwater; the reef octopus is the usual night-dive species on Cozumel's shallow reefs.
Diving Etiquette And Safety
Do not corner or handle. Keep the torch beam off it once you have found it — hold the light to the side and let it carry on hunting.
Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip
Photo: Laszlo Ilyes, CC BY 2.0, via Wikimedia Commons.
