Enhancing the growth of Gulsha Tengra (Mystus cavasius) in biofloc technology systems: Roles of probiotic supplementation, feeding rate and aeration

Abstract

The purpose of this study was to investigate the growth performance of Gulsha Tengra (Mystus cavasius), a nutritionally and economically important freshwater fish native to South Asia, for sustainable culture under biofloc technology (BFT). A five-month controlled experimental study was conducted using biofloc-treated culture tanks in which fish were reared under different management conditions designed to simulate practical aquaculture environments. Key water quality parameters, including temperature, pH, dissolved oxygen (DO), nitrite, nitrate, and total ammonia nitrogen (TAN), were carefully monitored and maintained within predetermined ranges, while growth performance was assessed biweekly through measurements of body weight, length increment, specific growth rate, and survival. Periodic water quality analyses were also performed to ensure environmental stability throughout the culture period. The findings demonstrated that Mystus cavasius achieved significantly improved growth performance in probiotic-treated BFT systems with appropriate feeding rates and aeration, showing higher body weight gain, greater length increment, enhanced specific growth rate, and improved survival under optimal conditions of temperature (27–31 °C), pH (7.0–8.4), and dissolved oxygen (6.5–8.5 mg/L). In contrast, deviations from these optimal environmental conditions, particularly increases in nitrite, nitrate, and TAN concentrations, resulted in reduced growth performance and higher mortality, highlighting the species’ sensitivity to changes in water quality. These findings provide practical guidance for aquaculture practitioners by demonstrating that maintaining suitable water quality through effective probiotic application, balanced feeding strategies, and adequate aeration can substantially improve fish health, growth, and production efficiency, thereby supporting the sustainable and profitable culture of Mystus cavasius under a BFT system.