The study of fish and shellfish diseases requires a wide knowledge, not only of the potential pathogens, but also of the environmental constraints and specialist adaptations, which govern the ectothermic, aqueous, existence of teleosts. The inflammatory and immune responses are greatly modified by the nature of their environment. These in turn influence the epizootiology and the clinical characteristics of the various conditions and the methods by which they can be controlled. Fish and shellfish pathology is clearly a multidisciplinary field. Despite of the extensive technical advances in biological and ecotoxicological research, histopathology continues to be a valuable tool for investigating the morphologic features and extent of both naturally occurring and experimentally induced disease and it remains one of the most reliable, sensitive, and comprehensive assays for identifying and characterizing a vast array of physical disorders.

The objective of this Research Topic is to collect manuscripts dealing with spontaneous or experimentally-induced pathology of fish and shellfish, including diagnostic procedures, methods of treatment and disease control. Studies focusing on bacterial diseases, viral diseases, mycoses, parasitic diseases, nutritional disorders, oncology, and all pathological events related to the environment, genetics, toxicology, nutrition and reproduction will be accepted. Manuscripts describing how histopathology and related novel diagnostic methods can give an important contribution to diagnosis are encouraged.

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.