Decorator Crab

Decorator crab is the common name given to a wide range of crab species, most belonging to the superfamily Majoidea, that camouflage themselves by attaching pieces of sponge, algae, hydroids, and other debris from their surroundings onto hooked bristles covering their shell and legs. As the crab moves into a new habitat, it typically strips off its old covering and replaces it with material better suited to its new surroundings, keeping its camouflage matched to the environment it currently occupies. The covering can grow so thick and well established that a decorated crab becomes almost impossible to distinguish from the surrounding rock, rubble, or seaweed to the eye of a predator. Some decorator crab species even favor particular defensive materials, such as stinging anemones or toxic sponges, gaining an added layer of protection beyond simple visual camouflage. The behavior is widespread across many unrelated crab lineages, found on tide pools, shallow reefs, and deep sea habitats around the world. Because the covering is actively gathered and maintained rather than a fixed part of the body, individual decorator crabs can look strikingly different from one another depending on what materials are locally available to them.