Dietary effect of low fishmeal aquafeed on gut microbiota of olive flounder (Paralichthys olivaceus) at different growth stages (MBO3_2019_06_0239_raw data)

Two experimental diets were prepared to contain 74% FM (control) or 52% FM with 22% PPS (30% FM replacement, FM30). Fish were fed one of the two experimental diets for eight months, and we collected the midgut contents to analyze the gut bacterial community by Illumina Miseq based on the metagenomic sequences in the V3-V4 regions of 16S rRNA.

We found that there were nine dominant phyla, which in turn presented Proteobacteria, Firmicutes, and Actinobacteria as the three major phyla in the gut microbiota of the flounder. At genus level, the dominant genera were Delftia , Prevotella , and Chthoniobacter at the juvenile stage (below 100 g/fish); Chthoniobacter , Bacillus , and Bradyrhizobium at the grower stage (400 g/fish); Chthoniobacter , Bacillus , and Delftia at the sub-adult stage (800 g/fish); and Lactobacillus , and Prevotella at the adult stage (over 1,000 g/fish).