Effects of stocking density on growth, serum parameters, antioxidant status, liver and intestine histology and gene expression of largemouth bass (Micropterus salmoides) farmed in the in‐pond raceway system

In China, the in‐pond raceway system (IPRS) recirculating culture is a new model of freshwater aquaculture. A 120‐day feeding study was carried out to evaluate the influence of stocking density on growth, digestive enzymes activity, serum parameters, antioxidant status, liver and intestine histology and gene expression of HSP70 and Cu/Zn‐SOD of largemouth bass farmed in IPRS. Largemouth bass, Micropterus salmoides (initial body weight, 4.50 ± 0.23 g), were randomly farmed in nine raceways stocked at three stocking densities of 0.2 (LSD), 0.4 (MSD) and 0.6 (HSD) kg/m3, and sampled at 30, 60, 90 and 120 days. The results showed that body weight, specific growth rate and weight gain of fish farmed at MSD group were higher than that farmed at LSD and HSD treatments on 30 days (p