With fish considered an important component of a well-balanced human diet in many industrialized nations and the primary source of animal protein in many less-developed countries, it is increasingly necessary to ensure the health of those aquatic species on which our food security relies. Focusing on protozoan and metazoan parasites that cause disease and mortality in economically important captive and wild fish populations, this second edition of Fish Parasites: Pathobiology and Protection provides an update on the latest research in the field of fish parasitology. It concentrates on parasites that have a financial impact on the aquaculture industry, those that have been introduced to new regions through infected fish, those that are pathogenic to groups of fish and detrimental to production, those that are highly adaptable and not host-specific with worldwide distributions and those that may serve as disease models for studies on other pathogens. For each parasite, this book provides: An introduction to the species, including description, life cycle, hosts, geographical distribution and impact on fish production. A pathobiology, such as diagnosis, clinical signs, lesions, disease mechanism, pathophysiology, and factors that enhance or reduce parasite multiplication. Protection and control strategies, including vaccination and protective mechanisms, chemotherapy and immunochemotherapy, environmental modification and vector control. Synthesizing more than a decade of further research and discovery since the publication of the first book, this new edition provides a vital resource for research scientists, fish health consultants and managers of laboratories working in the aquaculture sector. It is also valuable for fish health specialists and graduate students working on the diseases of aquatic organisms and anyone interested in aquaculture, fisheries or parasitology.