Many kinds of animals live in Earth’s oceans, and many of them have fins and flippers. These special adaptations have developed over the course of many thousands of years. They help animals maneuver through the waters in which they live and hunt. Penguins have flippers to make them move quickly through the water to catch fish to eat. Some fish use their fins to move at rapid speeds to catch their prey. This book explains flipper and fin anatomy and describes how these adaptations help the animals that have them. Conservation issues and threats to these animals’ survival are also highlighted.