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

Species

Crab

(12 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)La Calita(La Herradura)

Hermit crab

(10 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.

Observed at

Mar Menuda(Tossa de Mar)El Santuari(Costa del Maresme)Punta de la Mona(La Herradura)

Leach's spider crab

Inachus phalangium(5 photos)

Rocky reef

Observed at

Mar Menuda(Tossa de Mar)Pedra de Déu(Illes Medes)Roca Muladera(Tossa de Mar)

Long-legged spider crab

Macropodia rostrata(3 photos)

Rocky reef

Observed at

Bajo de Dentro(Cabo de Palos)

Harlequin crab

Lissocarcinus laevis(2 photos)

Rocky reef

Observed at

El Río(El Hierro)

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