CORRELATION BETWEEN THE INTESTINAL MICROBIOTA OF LARVAL AND JUVENILE ACROSSOCHEILUS FASCIATUS AND BACTERIAL COMMUNITY OF CULTURE WATER

Acrossocheilus fasciatus has been main economical fish in the mountain areas of Zhejiang Province because of its high economic value and increasing demand. Based on 16S rRNA high-throughput sequencing, we systematically studied the correlation between intestinal microbiota of larval and juvenile Acrossocheilus fasciatus and bacterial community of culture water within the same period. The results showed that Chao1 and Shannon indices had no significant changes in intestinal microbiota of larval and juvenile A. fasciatus (P>0.05); however, the Chao1 and Shannon indices of culture water showed a significant downward trend with the development ofA. fasciatus (P<0.05). ANOSIM analysis revealed that the compositions of intestinal microbiota in the larval and juvenileA. fasciatus were significantly different from the bacterial community of culture water (P<0.05). The dominant phyla were Proteobacteria, Bacteroidetes and Firmicutes in the intestinal microbiota of larvalA. fasciatus, while Proteobacteria was the dominant phylum in culture water within the same period. Fusobacteria and Proteobacteria were the dominant phyla in the intestinal microbiota of juvenile A. fasciatus, while the dominant phylum in culture water within the same period consisted of Proteobacteria, Bacteroidetes and Fusobacteria. Linear regression analysis revealed that the changes of relative abundance of Proteobacteria, Firmicutes and Fusobacteria were consistent in the A. fasciatus and culture water. At the genus level, Acetobacter was the dominant genus in the intestinal microbiota of larval A. fasciatus, while Cetobacterium was the dominant genus in juvenile A. fasciatus. Rare taxa and conditional rare taxa were the main taxa in the intestinal microbiota of A. fasciatus and bacterial community of culture water. Correlation analysis showed that no significant correlation was observed between intestinal microbiota of A. fasciatus and bacterial community of culture water (P>0.05). SourceTracker analysis verified that the proportional contributions of culture water to shaping the intestinal microbiota of the larval and juvenileA. fasciatus ranged from 0.39% to 28.67%. This study revealed the composition, structure and succession changes of the intestinal microbiota in larval and juvenile A. fasciatus and the bacterial community in culture water, which provided a reference for further study on the intestinal microbiota and healthy cultivation of A. fasciatus.