Stress and Immunity in Fish

Fish inhabit microbial- and parasite-enriched environments that constrict the adaptive choices and evolutionary pathways of regulatory physiological systems. Teleost immune architecture reflects those selective pressures, and the modulation of immune performance by glucocorticoids and other mediators of perceived stress have sculpted the type, intensity and scope of stress-related immunity in fish. In this chapter, the immune response to stress in teleosts and the role of the principal mediators such as hormones, cytokines and neurotransmitters are reviewed. The interactions between the immune, endocrine and neural regulatory systems and the influence of the local environment in the response are also considered.