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Biotechnology applied in many fields of aquaculture, including nutrition field. Fish feed cost represents about 50% of the cost of marine farms because it depends mainly on fish meal and fish oil in diet formulation. Also, marine fish do not depend on carbohydrates supplied in their diets as an energy source and could not digest them efficiently thereby, depend on fish oil as the main source of energy and may depend also on protein. Biotechnology searches unconventional alternatives to fish meal and oil, also searches tools to enhance carbohydrates utilization in fish either by using exoenzymes, probiotics, fish programming or even gene transfer. Biotechnology help in controlling outbreaks of diseases in intensive mariculture by using antibiotics alternatives. Recently, the concept of smart meal depends on addition of food additives started to be applied in aquaculture. Epigentics is a recent concept in nutritional biotechnology which is used in programming the fish through nutrition. Biotechnology is applied in hatcheries, biofloc and periphyton systems. Biotechnological tools are under development to improve and develop mariculture sector and lower feed and production cost.

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Norhan E. Saleh, Associate professor of fish nutrition, Aquaculture Division at National Institute of Oceanography and Fisheries, Alexandria, Egypt. Studied fish biology at Alexandria University.Shared in many projects which searched impact of using fish meal and fish oil alternatives and also using of feed additives on fish performance.

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