Comparative Study on the Hematological Parameters and Nutritional Composition of Heteropneustes fossilis Cultured in RAS and Pond in Relation to Water Quality

This study compared the effects of Recirculatory Aquaculture Systems (RAS) and traditional pond systems on the hematological parameters and nutritional composition of Heteropneustes fossilis, emphasizing the influence of water quality parameters. Hematological analyses showed that RAS-reared fish had higher red blood cell (RBC) counts (3.67 × 10⁶/µL for males, 2.65 × 10⁶/µL for females) and hemoglobin levels (9.0 g/dL for males, 8.61 g/dL for females), reflecting an enhanced oxygen transport efficiency. Conversely, pond-reared fish exhibited elevated white blood cell (WBC) counts (7.18 × 10⁴/µL for males, 6.67 × 10⁴/µL for females) and blood glucose levels (127.96 mg/dL for males, 128.23 mg/dL for females), indicating higher stress responses. Nutritional analysis revealed higher crude protein content in RAS-produced fish (16.37% for males, 16.04% for females) and crude lipid levels (3.47% for males, 5.00% for females). In contrast, pond-produced fish had significantly higher carbohydrate content (3.30% for males, 3.97% for females). Moisture, ash, and crude fiber content showed no notable differences between the systems. Water quality assessments highlighted the advantages of RAS, with stable dissolved oxygen (5.03–8.83 mg/L), pH (8.01–8.86), and temperature (27.72–29.23°C) compared to the seasonal variability in the pond. These controlled conditions minimized stress and supported better fish health and growth in RAS. The study demonstrates the potential of RAS to produce healthier, nutritionally superior fish while mitigating environmental stressors common in pond systems. These findings underscore the value of RAS in sustainable aquaculture, addressing challenges associated with traditional systems, particularly in environmentally sensitive regions.