Role of Antioxidant Systems and Heat Shock Response in Aquatic Animals Under Multistress Conditions

The multistress concept is a recent approach developed to better understand the effects of environmental stress in animals under real-world conditions. In nature, animals are exposed to simultaneous environmental fluctuations on daily and seasonal time scales, and interactions among stressors can produce antagonistic, additive, or synergistic physiological responses. Consequently, studies examining only one stressor under controlled laboratory conditions may fail to reflect responses in natural habitats. This review discusses the effects of multiple stressors on redox metabolism and heat shock protein (HSP) responses, focusing on aquatic environments. We discuss the multistress approach in laboratory and field studies, highlighting major abiotic stressors such as salinity changes, solar radiation, temperature, and low oxygen availability, including hypoxia and aerial exposure. The effects of multiple stressors on HSPs and antioxidants are summarized using examples from the literature. Finally, the role of social stress and life history stage in shaping responses to multiple abiotic stressors is considered. Overall, the review highlights the application of the multistress approach in laboratory and field experiments, emphasizing key stress responses involving endogenous antioxidants and HSPs, both initiated by reactive oxygen species (ROS).