Polyclad Flatworms of the World provides a fascinating introduction to the colourful and intriguing world of polyclad flatworms, a group of large, free-living marine Platyhelminthes, found throughout the world, but at their most colourful in tropical waters. Although not related to molluscs, they are often mistaken for sea slugs because of their brilliant colour patterns. Written in an accessible style by two leading experts in the field, Polyclad Flatworms of the World explores their unusual structure, feeding habits, their curious reproductive behaviour (including "penis fencing"), their mimicry and toxicology. With a forward by Professor Reinhardt Kristensen of the Copenhagen Zoological Museum, Polyclad Flatworms of the World is the first comprehensive guide to polyclad families and genera, with more than 250 colour photographs from every part of the world.