Introduction -- Diverse and numerous -- Inside a simple animal -- Origins of simple animals -- No brain successes -- Sponge shapes and sizes -- Made mainly of jelly -- Ocean wanderers --- Tiny trees to big bubbles -- Deadly stingers -- Living with others -- Fans and pens -- Tiny builders -- Glories of the reef -- Reef in danger -- Ghostly catchers -- Moss animals -- Bears and wheels -- Bags and bottles --Animal classification -- Animal phyla -- Glossary -- further resources -- Index.