The crustacean subphylum can be broken down into decapods, amphipods, copepods, and other types. This title offers readers from grades 1 through 4 comparisons between the needs and roles of different crustaceans, which will allow readers to understand the subphylum's importance. Readers will recognize and expand their knowledge about familiar species like the lobster and the shrimp, while being introduced to the likes of the wood louse and zooplankton. Dynamic photography and methodically organized information will help readers examine the many sizes, types of limbs, and other features of this diverse group.