Fish nutrition—history and perspectives

Abstract Fish farming based on natural food production in ponds has been practiced for millennia. Such systems are categorized as extensive aquaculture, the aquatic equivalent of grazing in livestock production. Food production could be enhanced by fertilizing ponds, but the practice of supplying feed to be consumed directly by fish was not developed until the adoption of semiintensive and intensive production. The capacity to formulate fish feeds to meet the essential nutrient requirements arose from discoveries in human and animal nutrition. In 1910, scientists discovered that foods contain factors that are essential for life. It is now known that 12 vitamins and 10 amino acids are essential in feeds for fish and other vertebrates. Fish nutrition research lagged behind animal nutrition research until the development of suitable semipurified research diets to which individual nutrients could be supplemented or deleted. This development accelerated fish nutrition research, leading to estimates of the quantitative dietary requirements of most essential nutrients for farmed fish, summarized in the 1973 National Research Council's bulletin, “Nutrient requirement of trout, salmon and catfish.” Aquaculture production and fish feed production have grown rapidly in the past three decades and required changes in feed formulations to reduce dependency on ingredients derived from marine resources. The focus of fish nutrition research is now on developing the knowledge needed for precision feed formulation through more precise estimates of nutritional requirements and use of alternate feed ingredients, especially for marine species. New technologies, specifically high-throughput “omics,” are being applied to fish nutrition research with the potential to advance understanding at the genetic, cellular, and organism levels. The role of fish nutrition in promoting fish health and reducing the environmental effects of aquaculture production will continue to be important research areas.