What protective structure do crabs lobster and scorpoin have in common?

Crabs, lobsters, and scorpions all possess a protective exoskeleton, which is a hard outer structure that provides support and protection for their bodies. This exoskeleton is made of chitin, a tough, flexible material that helps prevent water loss and shields them from predators. The exoskeleton also plays a crucial role in their growth, as these animals must molt to accommodate their increasing size.