The radical change in body form and physiology from immature larval stage to adult is called metamorphosis. It is third most important characteristic of the arthropods. Metamorphosis reduces competition between adult and immature stages. The evolution of arthropods has created increasing divergence of body forms, behaviors,and habitats between immature and adult stages. For example. adult crabs prow!on the sandy bottoms of their marine habitats. They prowl for prey or decaying organic matter. One the other hand, the larval crabs lives and feed on the plankton. Similarly, the caterpillar (insect larva) feeds on leafy vegetation. It develops into a nectar-feeding adult butterfly or moth. Thus adult and immature stages do not compete with each other for food or living space. In some arthropod larvae also acts as dispersal stage.