Note: Each value representsmean ± S.D. (n = 30). Values in the same rowwith different
superscript letters are significantly different (P b 0.05). 10 fish were taken out from each
tank on day 30 day and day 60. Therefore, at the end of the experiment, the fish number in
each tank was 80. RAS: recirculating aquaculture system. BFT: biofloc technology.