Impact of increasing temperatures on neuroendocrine and molecular responses of skeletal muscle and liver in fish: A comprehensive review

Recent projections suggest that food security may face threats due to climate change and population growth. Global warming is altering ocean temperatures, impacting productivity and aquatic ecosystems. This review delves into the impact of heat stress on fish aquaculture, focusing on the neuroendocrine system, controlled by the hypothalamic-pituitary-interrenal (HPI) axis. This axis regulates stress responses via cortisol and catecholamines, influencing energy metabolism and stress adaptation. The review discusses molecular adaptations in skeletal muscle and liver, affecting gene expression related to growth and energy metabolism. On the other hand, heat stress provokes notable molecular responses, altering the expression of genes involved in glycolysis and oxidative phosphorylation, and hormonal pathways like growth hormone and insulin growth factors, which are vital for metabolic regulation and muscle growth. In summary, this review provides insights into the neuroendocrine and molecular mechanisms underlying fish responses to thermal stress, emphasizing the importance of skeletal muscle and liver tissues in mediating physiological adaptations. Furthermore, it analyzes the implications for protein synthesis, cellular signaling pathways, oxidative stress, and enzymatic responses in aquatic organisms, highlighting the importance of understanding these molecular adaptations to develop effective mitigation strategies that ensure the sustainability of aquaculture systems amidst changing conditions.