Porcelain crabs are small decapod crustaceans which resemble true crabs, but are in fact closer to squat lobsters in their structure. Reaching a maximum 15 - 20 mm across, their compact and flattened bodies allow them to live and hide in rock crevices for protection.
Although delicate in appearance, porcelain crabs are protected by a tough calcium carbonate exoskeleton which is shed as they grow. If attacked by a predator, the crab can cast off a limb and escape. The lost limb can be regrown over time with each shed of their exoskeleton.
Porcelain crabs have finely laced fans on their mouth parts which are used to filter food out of the water. Their large front claws are used for territorial struggles and are not used to catch prey.