In the marine aquarium hobby we can look back on to a long and successful history. Initially, during the 1960‘s, with aquariums containing only fishes, such as the magnificent butterfly– and angelfishes, and from there on to the highly specialized coral reef aquariums of today, where a large diversity of reef-building stony corals are successfully being kept and bred. This book addresses both of these aspects of the marine aquarium hobby: In the first part of the book, several chapters are dedicated to various fish families (butterflyfishes, angelfishes and doctorfishes, as well as damselfishes, hawkfishes, dottybacks, basslets, longfins and mini-groupers), while the second part deals with hydroid animals (fire corals and lace corals), as well as with all the other types of corals (soft corals, leather corals, gorgonian corals and stony corals). The concluding chapter addresses one of the major problem areas of the coral reef aquarium: diseases and parasites of corals.