Some of the world's most beautiful, intelligent, and highly adapted mammals inhabit our seas and oceans and have stirred the human imagination for many centuries. As our knowledge of marine mammals grows, the need exists for a reliable and complete reference to the ecology and biology of these fascinating creatures. To address this need, the Handbook of Marine Mammals series has been founded. Scientists, conservationists, and informed laypersons alike will be able to find definitive reviews of all the world's living whales, dolphins, porpoises, seals, sea lions, sea cows, and marine otters and bears. Seven volumes cover all the living species of marine mammals. This third volume in the series, River Dolphins and Larger Toothed Whales, consists of species review chapters written by leading global experts on brackish and freshwater dolphin species, as well as larger toothed whales. Each chapter includes a description of the species, followed by sections on distribution and abundance, anatomy, physiology, behavior, ecology, reproduction, parasites and diseases, and the impacts of human activities on the species.