People love dolphins. We go to the ocean in hopes of glimpsing some riding the waves. We go to zoos, aquariums, and ocean theme parks to see them perform. But in seeking out these creatures in their salt water habitats, we often forget that dolphins are not fish but mammalsanimals who breathe air using lungs, are warm blooded, have backbones, and nurse their young. This book, part of the "What Kind of Animal is it?" series, presents dolphins, porpoises, and whales in the context of marine mammalsmammals that live in , around, or in and out of the sea.. Easy to understand text focuses on four groups of mammals. Whales, porpoises, and dolphins make up one group; dugongs and manatees a second; walruses, sea lions and seals a third; and polar bears a fourth. The book includes how marine mammals breathe air, how their strong bodies help them swim, how they maintain body temperature, find food, and bear their young, under or out of water. Chapters provide details about whale watching, specific marine mammals, when and why specific marine mammals that spend most of the time in the sea, like walruses and seals, also spend periods of time on land. The book is filled with spectacular illustrations. Most intriguing is the chapter about blubber and its importance in keeping these creatures warm, along with an experiment that shows students how they can experience the insulating power of blubber first hand. The book includes a simple picture glossary and brief index. A fine, affordable introduction to marine mammals. 2006, Crabtree Publishing Company, and Ages 6 to 12.