Journal of Advances in Biology & Biotechnology

Taurine (2-aminoethanesulfonic acid) is a sulfur-containing compound occurring predominantly in free form in animal tissues. Although taurine can be synthesised from methionine and cysteine, endogenous biosynthetic capacity varies among fish species and developmental stages, making dietary supplementation necessary under certain nutritional conditions. This review examines taurine chemistry, biosynthesis, metabolism, tissue distribution, dietary sources and physiological functions, with particular emphasis on its significance in fish nutrition. Taurine contributes to osmoregulation, bile acid conjugation, lipid metabolism, antioxidant defence, immune responses, cardiovascular function and neural development. Its nutritional importance has received increasing attention because plant-derived protein ingredients used to replace fish meal generally contain little or no taurine. Studies involving different fish species indicate that dietary taurine supplementation may improve growth performance, feed utilisation, digestive enzyme activity, antioxidant status and selected immune parameters. Beneficial responses have also been reported in broodstock and larvae, including improvements in reproductive performance, survival and development. However, supplementation outcomes are inconsistent across species and experimental conditions, with some studies reporting limited or no significant improvements. Such variability reflects differences in endogenous taurine synthesis, developmental stage, dietary composition and supplementation level. Evidence concerning optimal dietary requirements and mechanisms underlying these variable responses remains incomplete. Overall, taurine represents an important consideration in the formulation of nutritionally balanced aquafeeds, particularly when animal-derived ingredients are extensively replaced with plant proteins.