Abstract: A feeding trial was designed to study the fish farming system – high density recirculating aquaculture system (HD-RAS) and developed to achieve extreme high densities of fish culture in a designated area and controlled environment. The study used the hybrid grouper - Epinephelus fuscoguttatus (♀) × Epinephelus lanceolatus (♂) as an experimental fish model to test the performance of the high density recirculating aquaculture system, and analyzed the growth dynamics of the groupers in the HD-RAS. In the experiment, growth indexes and main water quality indicators were analyzed to determine farming system. The temperature of water in the HD-RAS was between 26 to 29°C, the salinity was 25 to 30 ‰, and the DO was equal to or greater than 8 mg/L. The concentrations of ammoniacal nitrogen and nitrite were 0.3 to 0.9 mg/ L and 0.1 to 0.25 mg/ L respectively. The whole test lasted for 250 days and was divided into three successive stages. Phase 1 (Day 1 to 87), the density of grouper culture increased from 13.82 kg/ m3 to 28.89 kg/ m3, the survival rate was 95.28%, the average weight increased from (150 ±18) g to (329±42) g, and the SGR was 0.90±0.06. Phase 2 (the following 106 days after Phase 1), the culture density increased from 28.89 kg/ m3 to 53.36 kg/ m3, the survival rate was 90.44%, the average weight increased from (329±42) g to (672±66 )g, and the SGR was 0.67±0.02. Phase 3 (the last 57 days), the culture density continued to increase from 46.98 kg/ m3 to 69.50 kg/ m3, the survival rate was 98.6%, the average weight increased from (676±52) g to (1 014±75) g, and the SGR was 0.71±0.02. In the whole 250-day cultivation period the average SGR was 0.76±0.02, the total survival rate was 84.9%, the average feed conversion ratio (FCR) was 1.04 and economical input/output ratio was 1:2.02. In summary, the study provided strong evidences for the possibility to culturing E. fuscoguttatus (♀) × E. lanceolatu (♂) at large scale and extremely high density using the novel HD-RAS.

Key words: Epinephelus fuscoguttatus (♀) ×, Epinephelus lanceolatu (♂), High density, Recirculating aquaculture system (HD-RAS), Growth indexes, Water quality indicators

摘要： 为研究循环水高密度养殖珍珠龙胆石斑鱼[Epinephelus lanceolatu (♂) ×Epinephelus fuscoguttatus (♀)]的养殖效果，在自行研制的循环水养殖系统中进行了试验。试验中对珍珠龙胆石斑鱼生长指标及养殖系统主要水质指标进行分析测定。结果显示，养殖期间的水质指标：水温26~29℃，盐度25~30，溶氧(DO)≥8 mg/L，氨氮浓度0.3~0.9 mg/L，亚硝酸盐氮0.1~0.25 mg/L。试验共持续250 d，分3个生长阶段：第1阶段87 d，密度由13.82 kg/m3增加到28.89 kg/m3，存活率 95.28%，平均体重由（150±18）g增加到（329±42）g，特定生长率（SGR）为（0.90±0.06）%；第2阶段106 d，密度由28.89 kg/m3增加到53.36 kg/m3，存活率90.44%，平均体重由（329±42）g增加到（672±66）g，SGR为（0.67±0.02）%；第3阶段57 d，密度由46.98 kg/m3增加到69.50 kg/m3，存活率 98.6%，平均体重由（676±52）g增加到（1 014±75）g，SGR为（0.71±0.02）%。养殖期间的平均SGR为（0.76±0.02）%，总存活率84.9%，饲料系数1.04，投入产出比为1:2.02。本研究成果可为高密度养殖珍珠龙胆石斑鱼提供参考。

关键词: 珍珠龙胆石斑鱼, 高密度, 循环水养殖系统, 水质指标, 特定生长率