关键词: 珍珠龙胆石斑鱼, 投喂频率, 生长, 血浆抗应激酶活力, 工厂化循环水养殖, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂, feeding frequency, growth, plasma anti-stress enzyme activities, industrialized recirculating aquaculture systems

Abstract: The experiment was conducted for 60 days in order to determine the effects of different feeding frequencies (1 time per day, 2 times per day, and once every 2 days) on the growth and plasma anti – stress enzyme activities of the hybrd grouper ( Epinephelus fuscoguttatus 5 x E. lanceolatus $ ) with initial weight of (297. 79 ±59. 94) g at water temperature of ( 29. 96 ± 0. 40 ) °C ! reared with arificial fomulated in industrial recirculating aquaculture systems. The results showed that the survival rate of the fish fed once every 2 days (99. 39 ±0. 01) % was significantly higher than those of the fish fed once per day (96. 75 ±0. 66 ) % and twice a day (97. 08 ±0. 66 ) % ( P <0. 05) . There were not significant effects on the specific growth rate (SGR = 1 .0 5 ~ 1 .1 9 ^ ^ d ) , condition factor ( CF = 1. 63 ~ 1. 77 ) , relative weight gain ( RWG = 187. 65% ~205. 04% ) , daily weight gain ( DWG = 4. 33 ~ 5. 00 g/d ) , coefficient of size variation ( SV = 14. 50 ~18. 30) , food intake ( FF = 1. 07 ~ 1. 24 % /d ) , food conversion efficiency ( FCE = 81. 77% ~ 87. 38% ) and food conversion ratio ( FCR = 1. 15 ~ 1. 25 ) among the three groups ( P >0. 05 ) . The plasma anti – stress enzyme activities ( i. e. AKP = 8. 07 ~ 8. 26 King100mL, CAT = 1. 92 ~ 2. 52 U/mL and SOD = 23. 39 ~24. 34 U/mL) of the fish was not significantly different in all treatments ( P >0. 05) . Under the experimental conditions, the feeding frequency of once every two days could be used to improve the survival rate of the hybrid grouper ( Epinephelus suscoguttatus 5 x E. lanceolatus $ ) in industrial recirculating aquaculture systems .