Yellowline Arrow Crab in Cozumel

A tiny triangular body on absurdly long thin legs, with a long spiked rostrum striped in gold and brown, and violet claw tips.

Quick ID

Where You Will See It In Cozumel

Yellowline Arrow Crab works the 9 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 Money Bar, Playa Corona and Punta Morena — all shore entries, so you dive them on your own schedule.

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

Deeper, and on the walls. It is also plausible on C-53 Wreck, Cantarel (Eagle Ray Wall), Chun-Chacaab and Colombia Deep.

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

Scavenges small invertebrates and detritus. Often shares a crevice with an anemone or a cleaner shrimp.

Commonly Confused With

• Channel clinging crab — Far larger and heavy-bodied with thick legs.
• Other spider crabs — The gold-and-brown striped rostrum and violet claw tips are diagnostic.

Diving Etiquette And Safety

Nothing required.

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

Photo: Diego Delso, CC BY-SA 4.0, via Wikimedia Commons.