Amino acids as functional nutrients in stress mitigation of aquatic species: mechanisms and applications in aquaculture

Abstract Stress is a pervasive challenge in aquaculture, significantly affecting fish health, growth, and overall productivity. Environmental fluctuations, handling, transportation, and disease outbreaks are common stressors that disrupt homeostasis, impair immune responses, and increase disease susceptibility in fish. This review focuses on the critical role of amino acids in mitigating stress and enhancing resilience in aquaculture species. Specific amino acids, such as glutamine, arginine, taurine, tryptophan, and methionine, are highlighted for their multifaceted roles in stress physiology, including immune modulation, antioxidant defence, osmoregulation, and neurotransmitter synthesis. These amino acids influence key biochemical pathways, such as the nitric oxide and glutathione pathways, and play essential roles in hormonal regulation and energy metabolism under stress conditions. By optimizing dietary amino acid profiles, aquaculture practices can enhance fish welfare, improve growth performance, and reduce mortality rates. This review provides insights into the mechanisms through which amino acids contribute to stress mitigation and discusses practical implications for sustainable aquaculture, aiding researchers, feed manufacturers, and fish farmers in formulating functional diets to improve fish resilience and productivity.