Decorator crabs, also called Sponge crabs or Dresser crabs, are enthralling creatures. These crabs have successfully found a way to hide from their predators. How do they do this? As their name suggests they decorate and dress themselves with bits of corals, sponges, sea anemone and whatever else they can get their claws on. They have a set of specially adapted legs that they use to cut large sponges and coral into small bits. They place these decorative objects on their shells which bear Velcro-like spines. The objects placed on the crab’s back are fastened by these spines and completely change the appearance of the crab. Their disguises help them hide from their predators because they are now camouflaged with their surroundings. The crabs observe their environment and design their shell accordingly. When they sense the presence of a predator, they freeze. These ‘decorations’ can also provide a form of chemical defence. Some types of decorator crabs place poisonous sea weeds on their shells. Some have sea anemones on their backs. These sea anemones have stinging cells, giving the crabs’ predators another reason to stay away. Some of the crab’s living decorations continue to grow. When they become too big, the crabs simply cut them again. When crabs grow, their shells, which cannot expand enough to accommodate them, are discarded and new ones are formed. Decorator crabs recycle their ornaments, removing them from the old shell and placing them on the new one, once it is fully formed. These crabs may even use man-made materials, like clothes, slippers and sandals that have found their way into the sea. For these crabs, what they wear is very important because it could potentially save their lives.
