RT Journal Article SR Electronic T1 Effects of substrate on shrimp growth, water quality and bacterial community in the biofloc system nursing Penaeus vannamei postlarvae JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.02.08.479639 DO 10.1101/2022.02.08.479639 A1 Hai-Hong Huang A1 Chao-Yun Li A1 Yan-Ju Lei A1 Wei-Qi Kuang A1 Bo-Lan Zhou A1 Wan-Sheng Zou A1 Pin-Hong Yang YR 2022 UL http://biorxiv.org/content/early/2022/03/19/2022.02.08.479639.abstract AB This study aimed to investigate the effects of substrate on water quality, shrimp growth and bacterial community in the biofloc system with a salinity of 5‰. Two treatments, biofloc system with (sB) or without (nB) addition of elastic solid packing filler (nylon) as substrate, were set up. Penaeus vannamei postlarvae (PL, ∼ stage 15) were stocked at a density of 4000 PL m-3 in each treatment with triplicates for a 28-days culture experiment, taking glucose as carbon source (C:N 15:1). Results showed that the survival rate (96.3±3.6%), FCR (0.76±0.06) and productivity (1.54±0.12 kg m-3) in sB treatment were significantly better than those in nB treatment (81.0±7.1%, 0.98±0.08 and 1.14±0.09 kg m-3, P<0.05). All water parameters were in the recommended ranges. Substrate showed significant effect on TAN, TSS, turbidity, biofloc volume, pH and carbonate alkalinity (P < 0.05). Actinobacteria (4.0-22.7%), Bacteroidetes (10.4-33.5%), Firmicutes (0.2-11.2%), Planctomycetes (4.0-14.9%) and Proteobacteria (29.4-59.0%) were the most dominant phyla for both treatments. However, the bacterial community in sB treatment showed to be significantly different from that in nB treatment (Jaccard distance 0.94±0.01, P=0.001). Substrate showed significant effects on Shannon, Heip, Pielou and Simpson index, as well as relative abundances of Actinobacteria, Bacteroidetes and Planctomycetes (P < 0.05). The results suggested that addition of substrate affected the shrimp growth, water quality and bacterial community in the biofloc system nursing P. vannamei PL with a 5‰ salinity.Competing Interest StatementThe authors have declared no competing interest.