Written by acknowledge leaders in this field, this book not only fills a 40 year gap in the literature, but presents a markedly changed field with new approaches, outlooks, and findings. After discussing the chemistry of ions in solution, membrane transporters, and cellular ion and volume regulation, the book is organized around various animal taxa. The chapter authors provide a thorough discussion of the physiology and molecular biology of the membrane transporters. Each chapter reviews everything from the basic anatomy and ecophysiology to the molecular mechanisms and control. The extensive chapter references provide an access point to the primary literature.