Stress and Fish Health: Towards an Understanding of Allostatic Load

In aquaculture, stress related disease problems which are leading to serious limitations in sustainability of the sector are of major importance however, stressors in aquaculture are unavoidable. In terms of characteristics of interaction of stress and health in aquaculture, stress physiology has been the center of attention. In fish, the physiological stress response to stressors causes primary response involving neurohormonal stimulation, resulting in an increase in corticosteroid and catecholamine secretions. In turn, these primary effects cause a number of physiological changes known as a secondary response. Tertiary stress response involves the effects on immunocompetence and potential susceptibility to diseases. The effects of stress on the fish physiology have been extensively studied for many years. It is known that acute stress can have beneficial effects in short-term, however, chronic stress hinders the immune system from functioning in teleost fish. Thus, the recent approach to explain the negative effects of stress, allostasis theory and allostatic load is presumed, concerning with how stability of the body’s is achieved through change. The correlation between the stressors and disease was reported for various fish species cultured and the diseases. To characterize the stress response, the immunocompetence state may provide better approach to understand the disease emergence. Stress response measurements are mainly based on the levels of cortisol nevertheless, it might be better to characterize the stress response with an index of immunological parameters and/or allostatic load.

Keywords: Allostatic load, Aquaculture, Fish, Fish health, Physiological stress response.