Effects of Dietary Microalgae Inclusion on Feed Utilization, Morphological and Chemical Characteristics and Body Health in Fish: Advantages and Disadvantages

Abstract

Background: Dietary microalgae inclusion in small or large amounts to fish species is considered one of the sources for improving nutritional values and productive performances throughout the world. Methods: The microalgae are classified through light and electron microscopes into four groups: blue-green, green, golden and diatoms algae. The microalgae can be cultured in the laboratory under controlled conditions. Hence, the grown microalgae biochemical analysis of pigments, proteins and carbohydrates were differed over controlled conditions. Moreover, molecular biology concerning genes and genomes enabled to study ecology, evolution and physiology of microalgae. The fascinating field of microalgae genetic engineering was applied to produce invaluable microalgae compounds as omega-3 fatty acids. The microalgae and their purified compounds were used as direct nutritional sources or as indirect contributors through improvement of water quality and reduction of stress. Result: The chemical composition of microalgae differed depending on nutrient availability for production and microalgae species. The microalgae invaluable compounds include “proteins, lipids, polysaccharides, polyunsaturated fatty acids, pigments, vitamins and other bioactive constituents”. The dietary microalgae and their purified compounds have been shown to provide beneficial effects in growth performance and body health. The roles of microalgae and their constituents as antioxidant, antibacterial, antiviral and anti-tumour materials have been well-established versus challenging problems. In this context, this review is designed to compile and discuss the advantages and disadvantages effects of microalgae on feed utilization, reproductive and therapeutic performances in fish.