Comparative Study of Biofloc, Bio-Phyton and Aquamimicry System Using Millet as Carbon Source in Catla catla

A 65-day comparative study was conducted to evaluate the effects of three culture systems Biofloc (T1), Bio phyton (T2), and Aquamimicry (T3) alongside a control (T4) on growth performance, water quality parameters, proximate composition, and microbial dynamics of Catla catla fingerlings (initial weight: 0.69 ± 0.02 g). Millet was used as a carbon source in all treatments, whereas no carbon source was added in the control. Among all treatments, Biofloc technology (T1) exhibited superior performance across most evaluated parameters. Fish reared under T1 showed significantly higher body weight gain (39.49 ± 4.35%), specific growth rate (2.30 ± 0.01), feed efficiency ratio (0.88 ± 0.07), protein efficiency ratio (2.20 ± 0.17), lipid efficiency ratio (14.67 ± 1.18), and survival rate (90.21 ± 1.77), along with a lower feed conversion ratio (1.15 ± 0.09), compared to other treatments. Water quality parameters in T1 remained within optimal ranges throughout the experimental period, reflecting efficient nutrient recycling and enhanced microbial activity. Microbial analysis through total plate count (TPC) revealed significantly higher microbial abundance in both water and fish gut samples under Biofloc (T1), followed by Bio phyton (T2), Aquamimicry (T3), and the control (T4). In water samples, T1 (3.5107CFU/ml) and T2(3.2107 CFU/ml) recorded the highest TPC values, while similar trends were observed in fish gut samples, with T1 exhibiting the maximum microbial load. The elevated microbial populations in biofloc systems likely contributed to improved nutrient assimilation, health status, and growth performance of fish by promoting beneficial heterotrophic microbial communities. the findings demonstrate that millet-based biofloc technology effectively enhances microbial abundance, water quality, and growth performance of C. catla, suggesting its suitability as a sustainable and productive aquaculture strategy.