Effects of biological flocculation technology on water quality</p><p>dynamics and immune response of grass carpHere, we hypothesized that there are significant differences in the gut microbiota of grass carp in different water circulation systems and biological flocs have certain effects on water quality regulation and immune function of grass carp. To test the hypothesis, we used high-throughput sequencing of the 16S rRNA gene to investigate the community composition and potential functions of the grass carp gut microbiota and its surrounding cultured water microbiota.