Evaluating Growth, Welfare, Sustainability, and Economic Viability in High-Tech Tilapia-Catfish Aquaculture System. A Case Study of Species Ratio.

This study investigates the effects of varying species ratios of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) on growth performance, welfare, sustainability, and economic viability within a high-tech recirculating aquaculture system (RAS). Over a 90-day period, five treatments were assessed: tilapia monoculture (T100), catfish monoculture (C100), and three polyculture combinations: Tilapia75%-Catfish25% (T75), Tilapia50%-Catfish50% (T50), and Tilapia25%-Catfish75% (T25), each replicated three times. Growth metrics, including biomass gain, specific growth rate, condition factor, and feed conversion ratio, showed significant variation across treatments. The C100 group achieved the highest total production (kg/m³) due to its superior feed efficiency. This was followed by the polyculture treatments, particularly T50 and T25, which provided a favorable balance between yield and resource utilization. Welfare assessments, based on plasma electrolyte levels, total protein (TP), glucose (GLU), and albumin concentrations, indicated no signs of chronic stress or severe physiological impairment, with most fish showing baseline reference levels. The economic analysis revealed that while C100 was the most profitable option, polyculture systems, offered substantial economic returns coupled with enhanced sustainability and reduced risks associated with monoculture practices. In conclusion, the study suggests that polyculture systems in high-tech RAS, particularly those with balanced species ratios like T50 and T25, can promote optimal fish growth, ensure good welfare, enhance environmental efficiency, and support profitability. These findings underscore the potential of integrated species systems to advance sustainable aquaculture in controlled environments.