Camouflaged Common Spider Crab

The Common Spider Crab is a master at camouflage, using algae to cover itself.

The Common Spider Crab (Libinia emarginata) is a marine (saltwater) crustacean in the Epialtidae family of stenohaline crabs. It is also known as the Portly Spider Crab or the Nine-Spined Spider Crab. It is native to the Atlantic coastal waters of North America.

Common Spider Crab

The Common Spider Crab is almost triangular in shape with an olive-khaki-green exo-skeleton (shell) called a carapace. The carapace is covered in spines called tubercles. 

Its body grows to about 10 centimetres (4 inches) wide. Its ten orange legs are much longer than its body, growing up to 30 centimetres (12 inches) long. Most crabs walk sideways, but the Common Spider Crab walks forward.

It covers its carapace with marine algae and plants as camouflage to ward off predators.

Common Spider Crab
Common Spider Crab


Location of photographs: Aquarium de Paris-Cinéaqua

Photographer: Martina Nicolls


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