The Seaweed Decorator Crab has a carapace covered with spines, knobs and fine hooked hairs, through which the crab threads snipped off algae and sponge pieces, effectively camouflaging itself. The carapace is pear-shaped, with a pair of short horns between the eyes. The Seaweed Decorator Crab is found at low tide levels and below, often in rock pools, under rocks or among algae. These relatively common crabs are rarely detected unless seen moving.