Channel Clinging Crab in Cozumel

The largest crab on the reef: a heavy knobbled carapace, thick legs and blunt pale claws. Also called the king crab or spider crab locally.

Quick ID

Where You Will See It In Cozumel

Channel Clinging Crab is tagged on reef profiles right along the west coast, across a depth band of roughly 9 to 98 feet.

Without a boat. It turns up at Tikkila Shallow — a shore entry, so you can dive it on your own schedule.

On an ordinary beginner boat dive. It is recorded at La Francesa. No advanced certification needed.

Deeper, and on the walls. It also shows up on Barracuda Reef.

Where else the habitat suits it. The depth and reef type also line up at El Cielo, El Islote, El Mirador, El Presidente, Las Palmas and Los Atolones, though those are not sites where we have it logged.

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

An algae grazer despite the size and the claws — it is not a predator. Wedges itself into a hole by day and comes out to feed after dark.

Commonly Confused With

• Arrow crab — Tiny body, spindly legs, striped rostrum.
• Spiny lobster — Lobsters have long antennae and a segmented tail rather than a broad carapace.

Diving Etiquette And Safety

Do not reach in. The claws are strong and the crab has nowhere to retreat inside a crevice.

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

Photo: Nick Hobgood, CC BY-SA 3.0, via Wikimedia Commons.