Annotation: "Vast numbers of Earth's plants and animals live in the planet's oceans-but scientists estimate we know about far less than half of them! It may be impossible to know just how many creatures live there, but it's clear that marine habitats are home to thousands of species. In this intriguing book, readers will get a peek into one of the most unusual, least known habitats on the planet. From brightly colored (and endangered) coral reefs to the darkest of ocean depths, this volume will fascinate kids with information about Earth's most mysterious habitat"-- cProvided by publisher.