Crabs

From tiny porcelain crabs hiding in anemones to large spider crabs on night dives, crabs are everywhere if you know where to look. Check crevices, sponges, and coral heads — they're masters of tucking themselves away.

Last updated April 2026

Hermit crab9 photos

Up to 10 cm1–30mRocky reefCoral reefSand

A small crustacean living inside a borrowed snail shell, with only its legs and claws visible. Carries its mobile home everywhere and upgrades to larger shells as it grows.

Scuttles across the reef dragging its shell — watch for the comedy of two hermit crabs fighting over a desirable shell.

Crab5 photos

Up to 20 cm1–40mRocky reefCoral reefSand

A general term for the many crab species divers encounter — from tiny decorator crabs covered in sponges to larger spider crabs. Hard exoskeleton with pincers.

Hides in crevices during the day, more active at night — look closely at sponges and coral for tiny, perfectly camouflaged decorator crabs.

Observed at

Baja Bocarones(El Hierro)El desierto(El Hierro)

Harlequin crabLissocarcinus laevis2 photos

Rocky reef

Observed at

El Río(El Hierro)

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