International Journal of Medical Science in Clinical Research and Review Available Online at http://www.ijmscrr.in eISSN: 1234-5678 Volume 01|Issue 01|2018| International Journal of Medical Science in Clinical Research and Review, Volume 01, Issue 01, Page no: 01-07 Page | 1 Received: July 08, 2018 Accepted: November 20, 2018 Corresponding Author: ONIANWAH, Ifeanyichukwu Fidelis Rexall Research Servives, Port Harcourt, Rivers State, Nigeria E-mail: w.eoh@samsung.com Microorganisms in Sustainable Aquaculture Development ONIANWAH, Ifeanyichukwu Fidelis Rexall Research Servives, Port Harcourt, Rivers State, Nigeria Abstract: Microbes found in aquaculture are usually from source water, feeds including augmented live foods. These microbes are found in the gills, intestine, muscles and on the surface of fish, shrimps, crustaceans and other aquatic organisms. Microorganisms in aquaculture play several roles including their use as live food, food supplements, probiotics, in pond aeration and in the purification of aquarium. As food, microbes provide the essential nutrients such as vitamins, enzymes, polyunsaturated fatty acids, amino acids, pigments and steroids. They also serve as carbon and nitrogen sources. Microbial diversity in aquaculture depends largely on the quality (physicochemical properties) of the farm water and this has greatly influenced the growth of every aquaculture. Fungi, Bacteria, Protozoa, Helminthes and Microalgae are present in aquaculture, each performing its unique role in the ecosystem. While some are beneficial, others are not. To minimize the use of antibiotics in aquaculture treatment, probiotics are used. These probiotics antagonizes some existing pathogenic species by competing with them for attachment, substrate utilization, lowering the environmental pH (characteristics of lactic acid bacteria) and by production of antimicrobial substances like bacteriocins. Microbial live foods include Bacteria, Fungi, Microalgae and Protozoa. Microbes used as live food include lactic acid bacteria, Bacillus, Chlorella vulgaris, Saccharomyces, Aspergellus, Artemia, Copepods, Infusoria and Rotifers. These live foods have the advantage of small size, ease of digestion and ability to stimulate enzyme synthesis. Besides, microbes function in pond purification (biofilters) as well as its bioenergetic cycle. Microalgae, specifically aerate ponds through the release of oxygen during photosynthesis. The beneficial roles of microbes contribute to the growth, development and quality of fish, shrimps and crustaceans in an aquaculture by way of better growth rate, survival and disease resistance. Keywords: Aquaculture, Ecosystem, Larviculture, Live Feeds, Microorganisms Biofilters, Pathogens, Probiotcs, Producers Introduction: Aquarium microbiology refers to the population of microorganisms found in aquaculture such as in prawns, shrimps, mollusks, crustaceans, fish, and its associated environment. Microorganisms are found on the gills, intestinal tract, muscles and on the surface of these aquatic organisms. These microbes include bacteria, fungi, algae and protozoa. However, viruses and helminthes have also been isolated from aquaculture. They may be beneficial or non-beneficial to the host, but both play significant role in the quality of the aquaculture. The quality of water in the aquarium determines the diversity of its microbial population. These microbes have functioned as live food, probiotics and have helped in improving the quality of the aquarium water. The beneficial functions of microorganisms have contributed immensely to the growth and the development of fish in fish farms. However, some microorganisms are known pathogens and have caused diseases and possible death of their hosts. This paper will be limited to discourse on the important role of microorganisms in a fish farm. Original Article