Fig. 2

Microbial diversity analysis. a Box-and-whisker plots of alpha diversity metrics (Observed ASVs and Shannon index). Each box represents interquartile range; the line inside the box is a median. b Bray–Curtis dissimilarity-based non-metric multidimensional scaling (NMDS) plot showing the distribution of antibiotic-treated and control fish samples in ordination space. c) Bar plot showing the relative abundance (> 1%) of gut microbiota at the phylum level. Five phyla indicated in cherry-red color in legend were significantly higher (Welch’s t-test, p < 0.05) in antibiotic-treated fish, whereas the one indicated in cyan (Fusobacteria) was significantly depleted (Welch’s t-test, p < 0.05). The phylum Fusobacteria was dominated by genus Cetobacterium