Fish immunology

Unlike terrestrial mammals, teleost fish is a poikilothermic vertebrate that lives in the aquatic environment. Although the fish immune system has many similarities with mammalian ones, fish also possess unique systems adapted to their environment. In this chapter, we provide a general overview of the fish immune system including innate and adaptive immunity, cellular and humoral immunity, and ontogenetic development of immunity in comparison with other vertebrate systems. Furthermore, we also focus on the interaction of fish immunity with viral, bacterial, and parasitic pathogens. Understanding of the fish immunity will provide useful insight into the control of the infectious diseases.