气/水混合溶解机在封闭式循环养殖系统中的应用试验

Application of a Gas/Water Mixing Machine in Closed Recirculating System in Aquaculture

在封闭式循环养殖系统中，采用气／水混合溶解机调节虹鳟养殖水中的溶氧量。设置4种溶氧量，分别为7．05、8．82、11．84、15．80mg／L，其中8．82mg／L为对照组，充空气；试验30d，对虹鳟幼鱼（体长13．0—18．5em）的生长率、能量收支及机体的营养组成进行研究。试验结果表明，7．05mg／L的低溶氧组鱼在生长率和饲料转化效率方面均明显低于对照组（P〈0．05），而11．84mg／L和15．80mg／L的高氧组鱼食物转化效率高，生长率明显提高。由摄食能的分配结果可见，随着溶解氧的升高，虹鳟幼鱼的摄食能用于生长和代谢的比例提高。表明在封闭式循环养殖系统中高溶解氧对虹鳟幼鱼生长具有良好的促进作用。

Dissolved oxygen （DO） levels were regulated by a gas/water mixing machine in closed recirculating system for the culture of juvenile rainbow trout Oncorhynchus rnykiss. The trial groups were designed to maintain the dissolved oxygen at 4 levels：7.05, 8.82, 11.84 and 15.80 mg/L. The level of 8.82 mg/L was the control group and be aerated. The whole experiment lasted for 30 days. Growth rate, energy budgets and approximate composition of the fish were examined in the experiments. The results showed that there were significantly lower crease of dissolved oxygen, the distribution of feed energy in and metabolism were improved, indicating that the young raibow trout had better growth in high level of dissolved oxygen in the closed recirculating system.