Spiny Spider Crab - Maja squinado

Spiny spider crabs are one of the most distinctive crustaceans found around the waters of Fuerteventura. Their spiny, angular shells and habit of camouflaging with seaweed make them surprisingly easy to miss despite their size.

They are part of the local marine ecosystem and are often found in deeper coastal waters and rocky seabeds.

What they look like

Spiny spider crabs have a rough, spiny carapace and long, thin legs that give them a very distinctive appearance.

They are typically brownish-red in colour and often cover their bodies with algae and seaweed for camouflage, making them look like moving patches of vegetation on the seabed.

Top view of spiny spider crab showing distinctive spiny carapace

Where they are found in Fuerteventura

These crabs are usually found on rocky or sandy seabeds in coastal waters, often at moderate depths.

They are more commonly encountered by divers than snorkellers due to their preference for deeper or more sheltered environments.

Behaviour and habits

Spiny spider crabs are omnivores, feeding on a varied diet that includes algae, molluscs, sea urchins and other small marine organisms depending on seasonal availability.

They are known to migrate seasonally, particularly during breeding periods, and use chemical and behavioural signals to locate mates.

Despite their appearance, they are not aggressive towards humans.

Life cycle

Spiny spider crabs go through multiple life stages, shedding their exoskeleton several times as they grow.

During moulting, they are particularly vulnerable until their new shell hardens.

Larvae are released into the open ocean where they drift with currents before settling into benthic (seabed) habitats as they mature.

Camouflage and survival

One of their most fascinating behaviours is their use of camouflage. They actively attach seaweed and other materials to their shells to blend into their surroundings.

This makes them extremely difficult to spot and helps protect them from predators.

In Fuerteventura waters

Spiny spider crabs are a fascinating find for divers exploring rocky seabeds and offshore environments around Fuerteventura. Their camouflage and unusual shape make them one of the more interesting crustaceans in the region.

Spiny spider crabs are part of the reef and seabed invertebrate community found around Fuerteventura’s coastal waters.

For more marine species found in the region, see the Marine Life in Fuerteventura guide.