Fabulous Flatworms enables users to distinguish and learn about hundreds of marine polyclads, commonly known as flatworms. Using an innovative key based on body patterns, it allows both amateurs and specialists to identify these beautiful underwater creatures.Over 1200 colour photographs showcase the diversity of patterning and colour found across some 400 species of flatworms from around the world. For each species there are notes on appearance, size, habitat and distribution as well as multiple photographs to highlight their variability. A section on look-a-likes explains how to distinguish them from the more well known, but unrelated nudibranchs and other animals. A wealth of information is also provided on their unusual biology, including videos of their more remarkable behaviours, and tips on collecting, handling and identifying these fragile animals.