This comprehensive book provides new insights into the physiological and behavioral adaptations of marine mammals for an aquatic life. It presents a detailed discussion of the anatomical, metabolic, thermoregulatory, locomotory, diving and behavioral adaptations of cetaceans (whales and dolphins), pinnipeds (seals, sea lions and walrus), sirenians (manatees and dugongs) and sea otters. The results are based on research using new technology, especially advances made during the past 25 years. Readers will gain an understanding of the remarkable adaptations that enable marine mammals to spend months at sea and make deep, long dives in pursuit of prey.