Abstract: To investigate the feasibility of applying a Recirculating Aquaculture System (RAS) in the hatchery production of turbot (Scophthalmus maximus) and provide a theoretical foundation for promoting RAS-based hatchery systems. A comparative analysis was conducted between the recirculating aquaculture system (RAS) and the flow-through aquaculture system (FTS) regarding water quality parameters, growth performance of larvae and juveniles, and economic efficiency. Water quality monitoring indicated: temperature ranged from 15.7°C to 22.6°C, dissolved oxygen (DO) from 5.6 mg/L to 8.6 mg/L, and the average pH was 8.27, indicating stable water quality. The average total ammonia nitrogen (TAN) concentration in the FTS group [(0.179 ± 0.087) mg/L] was significantly lower than that in the RAS group [(0.272 ± 0.167) mg/L, P < 0.01], while the average nitrite nitrogen concentration in the FTS group [(0.017 ± 0.010) mg/L] was also lower than that in the RAS group [(0.112 ± 0.087) mg/L]. The RAS group achieved greater larval performance, with an average total length of 65.7 mm, an average body weight of (1.63 ± 0.17) g, and a survival rate of 37.2%, compared with 52.1 mm, (1.49 ± 0.18) g, and 30.4% in the FTS group. Economic analysis demonstrated: profit per production cycle reached 22,700 CNY for RAS and 20,500 CNY for FTS, translating to annual profits of 90,800 CNY (4 cycles/year) and 61,500 CNY (3 cycles/year), respectively. The RAS-based seedling rearing system demonstrated effective water treatment performance and yielded favorable turbot seedling production outcomes. This model exhibits significant potential for application and promotion.

Key words: turbot(Scophthalmus maximus), recirculating aquaculture system (RAS), flow-through aquaculture system(FTS), hatchery effect

摘要： 为推广循环水育苗系统提供理论依据，开展了循环水养殖系统（RAS）在大菱鲆苗种培育生产过程中应用的可行性研究。对比分析循环水养殖系统（RAS）与流水育苗系统（FTS）的水环境参数、仔稚鱼生长性能及经济效益，系统分析了两种育苗系统的差异。结果显示：育苗期水温维持在15.7~22.6℃，溶氧5.6~8.6 mg/L，平均pH为8.27，水质状况稳定；FTS组总氨氮（TAN）平均质量浓度为（0.179±0.087）mg/L，显著低于RAS组的（0.272±0.167）mg/L（P<0.01）；FTS组亚硝酸盐氮质量浓度（0.017±0.010）mg/L低于RAS组（0.112±0.087）mg/L。RAS组稚鱼平均全长65.7 mm，平均体质量（1.63±0.17）g，出苗率37.2%；均高于FTS组的52.1 mm、（1.49±0.18）g和30.4%。RAS系统单茬利润2.27万元，年利润9.08万元（按年4茬计）；FTS系统单茬利润2.05万元，年利润6.15万元（按年3茬计）。循环水育苗系统具备高效的水处理能力、显著的育苗成效及良好的经济效益，具有推广应用价值。

关键词: 大菱鲆, 循环水系统, 流水系统, 育苗效果