The objective of this study was to evaluate the effect of three carbon sources: molasses (Control), tapioca flour and banana peel, for the development of a biofloc system in the culture of the ornamental fish Puntius tetrazona. To ensure floc formation, a C/N ratio=20:1 was maintained for each of the carbon sources, considering three replicates per treatment. According to the results, the environmental parameters showed fluctuations, especially in the first three weeks of culture, within the optimal ranges for the species. Fish growth expressed as biomass gain did not show significant differences (P > 0.05) among treatments, but the standard length did (P < 0.05). The highest absolute and specific growth rates were obtained in plantain peel and tapioca, regarding the feed conversion factor, molasses had the highest value (0.91 g), followed by tapioca with 0.27 g, and banana peel with 0.25 g. Survival was 100% in the banana peel group, followed by tapioca, and molasses. The Phyla of microfauna recorded in the experimental groups were, Ciliphora, Rotifera, Annelida, Nematoda, Plathelmintes, Gastrotricha, and Amoebozoa with variations among treatments throughout the experiment. The results of the present study demonstrate the potential of using Dominican plantain hull meal as a carbon source for the development of ornamental fish cultures in biofloc, being an option that, due to its low cost, will increase the profitability of the cultures. Key words: Biofloc, tiger barbel, molasses, banana peel, tapioca.
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