Carbohydrates

Abstract

This chapter discusses the carbohydrates available for metabolism (digestible carbohydrates). Glucose plays a part in energy homeostasis, feeding control, and functions that are regulated by levels of circulating nutrients. Different pathways are involved in the regulation of glucose homeostasis in fish, including glycolysis, lipogenesis, glycogenogenesis, glycogenolysis and gluconeogenesis. Carbohydrate utilization in fish is affected by different factors which can be categorized as: biological factors; dietary factors; and environmental factors. In order to obtain a comprehensive evaluation of carbohydrate utilization and its effect on fish, it is recommended that a long_term feeding study with integrated biomarkers based on response from cellular, tissue, and whole organism responses is conducted. In fish, both non_specific (innate) and specific immune system helps to protect against damage caused by infectious agents. Other hormones, such as growth hormone, IGF_1, T3, and T4, are also involved in the regulation of carbohydrate metabolism.