The text concentrates on the infectious viral and bacterial diseases that are most prevalent in aquaculture. Although much information has been derived from North American studies, important diseaase problems from other parts of the world are included. Also, where applicable, the influence of the various diseases on wild populations has been included. This book is intended for students and scientists who are interested in health maintenance of aquatic animals, aquatic pathobiology, and infectious diseases of fin fish. Hopefully, it will be used as a text for beginning fish pathologists and as a reference source for those of broader experience.