Elucidating the effects of cortisol and stress on economically important traits in channel catfish

The channel catfish Ictalurus punctatus is an important aquaculture species in the United States and has received considerable research attention in efforts to improve production. Three traits of importance to the U.S. farm-raised channel catfish industry are disease resistance, growth, and reproduction. While many factors affect these three traits, a fish's response to stress can have a substantial impact on production attributes. Understanding the relationships between the stress response and components of that response, such as plasma cortisol concentration, is important to the development of better management and breeding practices to maximize production. Although much of the data regarding the fish physiological consequences of stress and elevated plasma cortisol has been collected from studies of salmonids, recent advances have been made toward understanding these relationships in channel catfish. The present review synthesizes the research conducted over the past several years regarding the effects of stress and cortisol on disease susceptibility, growth, metabolism, and reproduction of channel catfish in the context of how stress and cortisol affect economically important production traits for aquaculture.