This dictionary presents a comprehensive documentation of all natural products produced by marine organisms (sponges, worms, algae). A vast array of novel molecules are produced, many containing structural features that are unique to marine organisms and are a consequence of the aquatic environment. These novel characteristics make them suitable for investigation as drug candidates, as well as pesticides and marine anti-fouling agents, This revision represents a through updating of this rapidly progressing field, with over 13,000 compounds added since the last edition.