European Spider Crab

Crustacean

Identification & Biology

• IdentificationA large crab with a roughly triangular, pear-shaped carapace covered in short hairs and often encrusted with algae, sponges, and other organisms for camouflage. Long, spindly legs give it a spider-like appearance. Two small spines project forward from the front of the shell.
• SizeCarapace length up to 20 cm. Leg span up to 70 cm. Weight up to 3 kg.
• Social HabitForms spectacular mass aggregations of hundreds or thousands of individuals during moulting events. Otherwise mostly solitary. Decorates its shell with algae and sponge fragments for camouflage.
• HabitatRocky reefs, sandy bottoms, and seagrass meadows. Found on a wide range of substrates.
• Depth0 to 120 m. Most common between 5 and 50 m.
• Feeds OnAlgae, seagrass, small invertebrates, and carrion. Primarily a grazer and scavenger.
• DistributionEastern Atlantic from the British Isles to West Africa, and throughout the Mediterranean Sea. Common in Maltese waters.
• DescriptionMaja squinado is a master of disguise, attaching pieces of algae, sponge, and other organisms to its shell to blend into the reef. The mass moulting aggregations that occur in some parts of its range are one of the most impressive spectacles in European marine life. In Malta, individuals are regularly seen on rocky reefs, though the large gatherings are less commonly reported.