The Crustacea is one of the dominant invertebrate groups, displaying staggering diversity in form and function, and spanning the full spectrum of Earth's environments. Crustaceans are increasingly used as model organisms in all fields of biology, as few other taxa exhibit such a variety of body shapes and adaptations to particular habitats and environmental conditions. Physiology is the fourth volume in The Natural History of the Crustacea series, and the first book in over twenty-five years to provide an overview of the comparative physiology of crustaceans. An understanding of physiology is crucial to a comprehension of the biology of this fascinating invertebrate group. Written by a group of internationally recognized experts studying a wide range of crustacean taxa and topics, this volume synthesizes current research in a format that is accessible to a wide scientific audience.