This book covers detailed accounts of viral, bacterial and fungal diseases affecting shrimp, finfish and molluscan aquaculture. It also discusses different aquatic animal health management measures such as disease diagnostics, biosecurity, bioremediation, and application of probiotics, antibiotics and vaccines. Further, the book provides information on the roles of genetics and genomics, disease surveillance, aquatic animal health policies and the effects of climate change in aquaculture. The book is structured into five sections: (i) Pathogens and Diseases of Finfish, (ii) Pathogens and Diseases of Shellfish, (iii) Aquatic Animal Health and Environment, (iv) Health Management in Aquaculture, and (v) Aquatic Animal Health Policy and Regulations. Aquaculture plays a pivotal role in food and nutritional security, export earnings and the livelihood of millions of people globally. However, aquatic animal diseases have been a major limiting factor in sustainable aquaculture production in terms of economic losses caused by mass mortality and morbidity. In order to combat these endemic and emerging diseases, researchers are formulating strategies to mitigate the negative impact of diseases by understanding the pathogens, hosts and their environment. This book is a useful reference book for students, researchers, aquaculture technicians, farm and hatchery managers, and policy makers of aquaculture regulatory agencies.