The impact of indoor biofloc-based system on water quality, growth, and disease resistance of black tiger shrimp

The present study investigates the efficiency of an indoor biofloc-based system for the intensive culture of black tiger shrimp (<em>Penaeus monodon)</em>. Water quality, growth performance, and disease resistance of black tiger shrimp (0.35 ± 0.07 g) were evaluated after 90 days of rearing in a zero-water exchange system. Shrimp were stocked at 180 individuals/m³ in nine 5-ton concrete tanks under three treatments: biofloc with molasses (M), biofloc with wheat flour (WF), and a control group reared in a conventional clear water (CW) flow-through system. The WF treatment resulted in significantly higher final weight and improved FCR compared to CW (<em>p</em> &lt; 0.05). Survival was also significantly higher in both biofloc-based treatments despite elevated concentrations of total ammonia nitrogen, nitrite-nitrogen, and nitrate-nitrogen levels in the WF group (<em>p</em> &lt; 0.05). Additionally, Kaplan–Meier survival analysis indicated that shrimp reared and challenged in the biofloc system exhibited better resistance to <em>Vibrio parahaemolyticus</em> (VP_AHPND1212), as evidenced by higher survival rates. Although total hemocyte count, prophenoloxidase, and respiratory burst activities were not significantly different from the control group (<em>p</em> &gt; 0.05), they were consistently elevated in the biofloc-based treatments. Overall, biofloc-based treatments, specifically WF, proved effective in biofloc formation, contributing to improved water quality, enhanced immune response and disease resistance, and superior growth performance in <em>P. monodon</em>. This study highlights the potential of indoor biofloc systems as a sustainable strategy for intensive <em>P. monodon</em> culture in indoor biofloc tanks.