With shells covered in algae and barnacles, decorator crabs are experts at blending in with their environments. But for one species of crab, it’s not just camouflage that keeps the hungry fish away.
Found in shallow water and seagrass habitats, decorator crabs are part of the spider crab family. A decorator crab’s shell is covered with specialized hook-shaped bristles, called setae. Crabs use the setae to attach materials from the environment, such as algae or tiny non-moving animals, to their backs and legs. This “decoration” camouflages the crab from predators.