7Young readers looking for information about their favorite marine mammals will find everything they are looking for in Dolphins , the latest Animal Planet Chapter Book. Information about dolphins' anatomy, behavior, social relationships, and more offer a complete survey of this high-interest topic. Illustrated chapters and species profiles highlight how dolphins live, eat, and interact with each other. Did you know that the longest dolphin--at up to 30 feet--is the orca, also known as the killer whale, and that dolphins sleep with half of their brains on? More than 100 gorgeous photos showcase dolphins around the world in this memorable book for fans of these charismatic cetaceans