Aquaculture of Scylla Paramamosain in Northern China: The Impact of the Bacterial Community on Growth Indexes

We investigated the bacterial communities in the aquaculture ponds of Scylla paramamosain at the Yellow River Delta. The water and the sediment samples were obtained from one seawater pond and one saline-alkali pond in summer and in fall, and the bacterial communities were analyzed by 16S rRNA gene sequencing. The main bacterial phyla in the two ponds included Proteobacteria, Cyanobacteria, Bacteroidota, Desulfobacterota, and Firmicutes. According to principal coordinate analysis (PCoA) and non-metric multidimensional scaling (NMDS), both ponds had similar bacterial communities in the sediment, but they had rather different bacterial communities in the water. The differences in the Chao1, Pielou_e, Shannon, and Simpson indices of the bacterial communities in the water samples from the two ponds were small, whereas the differences were very large for the sediments. The redundancy analysis (RDA) revealed significant impacts of dissolved oxygen, salinity, temperature, and ammonia nitrogen on the bacterial communities in the water, while salinity, dissolved oxygen, nitrite nitrogen, and sulfide were found to significantly influence the bacterial communities in the sediment. Between the two ponds, significant differences existed in the growth index of S. paramamosain in June (p < 0.05) but not in September. From the Pearson correlation analysis, a significant correlation could be noted between the indicator bacterial species and the growth of S. paramamosain. This study offers valuable data references for understanding the dynamics of the bacterial communities in the aquaculture ponds of S. paramamosain in northern China.