Effect of dissolved oxygen levels on growth performance,energy budget and antioxidant responses of yellow catfish,Pelteobagrus fulvidraco (Richardson)

This study was conducted to determine the effect of dissolved oxygen (DO) levels on growth performance, energy budget and antioxidant responses of yellow catfish Pelteobagrus fulvidraco. Yellow catfish was exposed to four levels of DO, consisting of hypoxia (2.28 mg L^?1), moderate hypoxia (4.04 mg L^?1), saturation (6.51 mg L^?1) and super‐saturation groups (9.11 mg L^?1), respectively, for 8 weeks. Specific growth rate and feed efficiency in dry matter were lowest in hypoxia and highest in the saturation and super‐saturation groups. Apparent digestibility coefficients of dry matter and energy increased with increasing DO levels. Gross energy and growth energy were lowest for hypoxia, followed by moderate hypoxia and the highest for other two groups. Faecal energy was highest in hypoxia and lowest in saturation and super‐saturation group. DO levels also significantly influenced activities of antioxidant enzymes and malondialdehyde level in liver and serum. Based on the observation described previously, saturated DO level helps to improve growth performance, feed utilization and antioxidant responses in yellow catfish. Super‐saturation did not increase fish performance. To our knowledge, this is the first study involved in the effect of DO levels on energy budget of fish and provides new insight into aeration regime for yellow catfish culture.