For aquaculture species with mature technologies, the major constraints in production are usually related to health maintenance, disease occurrence, and product quality. These issues are inter-related, especially if disease prevention or control implements have long-term effects on the environment or produce residues that make products unacceptable for consumption. Although Fish Health is a relatively young discipline, numerous publications are already available for reference. One of the best references that discuss about disease, health, monitoring and surveillance is the Survey Toolbox for Aquatic Animal Diseases. Most of the information in this section is derived from various sections of that book.