Culturing live foods for fish larviculture using non-microalgal diet: The role of waste-generated bacteria and selected commercial probiotics-A review

Condensed suspension of live microalga cells, for example, Chlorella vulgaris, Nannochloropsis oculata and Tetraselmis tetrathele is often utilized as diets for mass production of live food resources, that is, rotifers, copepods, cladocerans and Artemia. These live food resources are essential for fish larviculture in hatcheries. However, the production of sufficient microalgae is costly, laborious and fragile, and thus require cost-effective and stable production technologies, especially for the emerging countries. Studies have shown that locally available biowastes such as fish wastes and chicken manure provide substrates for generating billions of heterotrophic bacterial cells and microparticles as well as growth hormones, which can be used in propagating live food resources. The fish wastes contain essential nutrients that are important for the growth of both live foods and fish larvae. With single feeding of fish wastes, the culture condition of live foods may become unstable, and thus bacterial isolates and selected probiotics, for example, genus Pseudomonas, Moraxella and Micrococcus are needed to stabilize the culture conditions to increase reproduction capacity of the cultured live foods. This article consolidates the results and conclusions of our recent studies on the culture of live food resources, that is, Proales similis de Beauchamp, Brachionus rotundiformis Tschugunoff, Tigriopus japonicus Mori and Diaphanosoma celebensis Stingelin, using waste-generated bacteria from fish waste diet (FWD) and selected probiotics. The non-algal materials reviewed in this article are important to ensure constant supply of cheap live foods to improve aquaculture, especially in the developing countries, which lack sophisticated technology for production of high-density microalgae.