β-glucan and nucleotides have beneficial impacts on aquaculture species' health and growth. Studies on fish dietary nucleotides have revealed that may alter the structure of the intestines, increase resistance to stress, enhance the quality of the larvae by fortifying the brood supply, and promote growth. In the early phases of development and modify both innate and adaptive immunity. Nucleotides and β-glucan supplementation have demonstrated very constant positive effects on a variety of fish species, despite sporadic variability in physiological responses. Despite the fact that research on fish nutrition based on nucleotides is just getting started, and there are a lot of fundamental questions have not yet been addressed, observations to date have supported the idea that fish require nucleotides as contingent or semi-essential nutrients, and that further study is required to improve fish culture by supplementing the diet with nucleotides. Scientists have demonstrated that β-glucan can alter some significant immunological (lysozyme, phagocytic, oxidative burst and phenoloxidase activities) and biochemical (serum hemoglobin, serum protein, and total hemocyte count) characteristics, giving fish and aquatic organisms a more effective immune profile. These beneficial effects are thought to be caused by the supply of physiologically necessary amounts of nucleotides by diet because some tissues have a restricted capacity for synthesis (e.g. lymphoid). Fish feed on diet supplemented with β-glucan exhibited decreased susceptibility to genes linked to acute inflammatory reactions. Research has demonstrated that fish's immune defense is enhanced by β-glucan of fish and other aquatic creatures, strengthening their resilience to disease by boosting beneficial responses and lowering harmful ones.