This book introduces readers to the biology of fish. Students will learn about oxygen and how fish absorb it from water into their bodies. Vivid photographs, infographics, and easy-to-read text aid comprehension for early readers. QR Codes in the book give readers access to book-specific resources to further their learning. Aligned to Common Core Standards and correlated to state standards. Cody Koala is an imprint of Pop!, a division of ABDO.