The book is a comprehensive approach, designed to enable the reader to quickly access the most current information as well as to obtain alternative perspective on interdisciplinary subjects. It is a holistic approach in understanding the subject of microbial diversity in aquatic organisms. Key features of this book include the following: such as that each chapter begins with a list of expected presented and coverage of microbiology applications in agriculture, aquaculture, medicine, health, biotechnology, industry and environment. The book in its coverage is suitable as a text for an introductory course in Fishery Microbiology and Biotechnology in academic discipline at Post graduate level and also in research.