Most of Earth is covered by oceans and seas that are home to an amazing variety of animals. Some have adapted to life in the cold, dark aphotic zone. Others live in the disphotic zone where predators attack from above or below. Still others live in the top layer, the euphotic zone, where food is plentiful but competition for it is fierce. In this book, readers in grades 3-5 will discover how animals survive in saltwater biomes and the skies above them. This NGSS-aligned series is packed with interesting facts and vivid photos that introduce readers to a variety of land and water animals. Each book includes a glossary, comprehension questions, and an activity for home or the classroom.