Fish meal, the conventional protein source in aqua feed, supports good growth because of its protein quality and palatability. It is expensive and scarce, for which the cost of fish production and nutrition is often very high. Considering the economic importance of aquafeed, growing demand to substitute fish meal has compelled to search less expensive and protein rich non-conventional feed resources of vegetative origin. Most of the plant ingredients are known to contain a wide variety of anti-nutritional factors (ANFs), limiting their use in fish feed. This book, therefore, provides a detailed account of impact of tannins, one of the potent anti-nutritional factors, on the physiology, metabolic processes, haematology and growth of tropical freshwater fish, Labeo rohita. The information generated will have wider significance in its application in future for preparation of low cost, high efficient formulated diet without compromising the fish growth and will be of interest to aquaculturist, professionals in aquafeed industry and researchers.