ABSTRACT
Carbohydrates are one of the most prevalent organic compounds in the biosphere and are known for the cheapest source of energy. Even though there is an unlimited carbohydrate source present in nature, only a few have nutritional value in animal nutrition. However, in fish nutrition carbohydrates are not indispensable in fish diets, although it constitutes an inexpensive source of energy. In fishes, it is found that there is no dietary requirement for carbohydrates; however, if carbohydrates are not provided in the diet, other nutrients such as protein and lipids are catabolized for energy and metabolic intermediates for the synthesis of other biologically important compounds. The use of carbohydrate-rich ingredients in fish feed is gaining day in day importance because of their ability to spare the more expensive protein. So various methodologies and techniques have been used to utilize and uses of carbohydrates in fish feed range from highly digestible and indigestible hemicellulose and cellulose recovered from various sources, including seaweed, algae, and plankton, to refined grain and other numerous products. The present chapter gives the idea about the importance, methods, 280mechanism, and ways to utilize more carbohydrate sources in fish nutrition and reduce the cost of fish feed.
