Application of Biofloc Technology to the Production of Andinoacara rivulatus Fry using Different Carbon Sources and Protein Regimes

Andinoacara rivulatus is a freshwater aquatic species native to South America with a high consumption rate in Ecuador. Despite its high consumption demand, scientific production related to the production systems and proximal composition of this species is limited. The present study evaluated the effect of Biofloc technology on water quality, the growth of old bluefish and the final quality of the flocs. For this purpose, seven treatments were applied with three levels of crude protein (24, 30, 35%) and two carbon sources (molasses and corn starch). The treatments were carried out in glass aquaria (50x34x34cm) with 57L capacity, under a factorial design in triplicate, including a control without carbon source. The results indicated that the treatment with molasses and 35% protein (TM-3) presented the best values in water quality parameters, such as lower biochemical oxygen demand (9.40 ± 0.11mg/ L) and lower levels of total ammonia nitrogen (0.97 ± 0.07mg/ L), suggesting higher microbial efficiency. In addition, TM-3 showed the highest specific growth rate (SGR), the highest protein efficiency index (PEI), and the highest crude protein content in the flocs (39.57 ± 1.18%). These results indicate that molasses is an effective carbon source for improving both water quality and zootechnical performance of A. rivulatus. In comparison, starch treatments also improved TCE, but to a lesser extent. The control presented the worst results in all parameters evaluated. Regarding floc analysis, molasses treatments, particularly TM-3, presented a higher crude protein (39.57 ± 1.18%) and crude fat (2.55 ± 0.27%) content, which makes them more suitable as a supplementary food source for fish. This superior composition of the flocs suggests a higher nutritional quality, favoring the zootechnical performance of Andinoacara rivulatus.