Abstract: In order to further study the feasibility of recirculating aquaculture system in the production process of marine fish fry.Methods: Using the principle of material balance, combined with the construction technology of recirculating aquaculture water treatment facilities and equipment. The water treatment process was optimized and the key parameters such as volume and circulation of moving bed bioreactor were designed. A set of recirculating aquaculture hatchery system was constructed.Two water treatment loops were designed, and efficient water treatment technologies and equipment such as dual drain system in hatchery tank,  radial flow separator and moving bed bioreactor were integrated. The experiment of hybrid grouper (Epinephelus lanceolatus♂×E. fuscoguttatus♀)hatching was carried out by using this system, focusing on three water quality parameters of dissolved oxygen concentration(DO), pH and total ammonia nitrogen(TAN), as well as three growth parameters of total length, body weight and emergency rate. Results: The growth of larvae and juveniles was well, with an average length of (75.1 ± 0.55) mm, an average body weight of (9.2 ± 0.42) g, and a hatching emergence rate of 16.28%. The water quality test results showed that the temperature was 26.8-27.7℃, dissolved oxygen concentration was 6.6-7.2mg/L, the average pH was 8.31, and the average concentration of total ammonia nitrogen was （0.183±0.191）mg/L, indicating good water quality. The economic analysis results show that the single crop profit is 18600 yuan, and the annual profit is 55800 yuan (calculated based on three crops per year), which has good economic benefits. Conclusion: This research can provide technical support for the application and popularization of recirculating aquaculture system.

Key words: hybrid grouper(Epinephelus lanceolatus♂×E. fuscoguttatus♀), material balance, water treatment equipment, recirculating aquaculture system

摘要： 为了进一步研究封闭式循环水养殖系统在海水鱼育苗生产过程中应用的可行性，采用物质平衡相关原理，结合循环水养殖水处理设施设备构建技术，优化了水处理工艺流程并设计了生物滤器体积与循环量等关键参数，构建了一套封闭式可控型循环水育苗系统。设计了2路水处理环路，集成构建了育苗池双排水、竖流沉淀、移动床生物过滤等高效水处理技术和装备。使用该育苗系统开展虎龙杂交斑（Epinephelus lanceolatus♂×E. fuscoguttatus♀）育苗试验，重点考虑溶氧、pH和氨氮3个水质指标及全长、体质量和出苗率3个生长指标。结果显示：仔稚鱼生长情况良好，平均全长（75.1±0.55）mm，平均体质量（9.2±0.42）g，出苗率16.28%。水质检测结果显示：温度26.8~27.7℃，溶氧6.6~7.2mg/L，pH平均为8.31、总氨氮平均质量浓度为（0.183±0.191）mg/L，水质情况良好。经济性分析结果表明：单茬利润1.86万元，年利润5.58万元（按1年3茬计），具有良好的经济效益。该研究可为工厂化循环水育苗系统应用及推广提供技术支持。

关键词: 虎龙杂交斑（Epinephelus lanceolatus♂×E. fuscoguttatus♀）, 物质平衡, 水处理设备, 循环水养殖系统