Carbohydrates: chapter 7

Although carbohydrates and sugars are not considered indispensable dietary nutrients for fish or shrimp, they contribute in a significant manner as a source of digestible energy. This chapter addresses different aspects of the issues related with inclusion and utilization of dietary carbohydrates by aquatic animals. Raw complex carbohydrates are poorly digested by many species of fish, but utilization can be significantly improved by appropriate technological treatments of the feedstuffs or the feeds themselves. Utilization of absorbed glucose is known to differ from that in terrestrial vertebrates and to vary between species of fish. Much progress has been made over the past decades to obtain insights on various aspects of glucose metabolism and homeostasis. Identifying the fine balance between endogenous glucose production and glucose utilization in different species of farmed fish and shrimp is a challenging and promising area of research and can provide the basis for taking full benefit of the potential of all sources of digestible carbohydrates.