Supplementary materials

Supplementary material Fig. 1. Relative abundance of the main microbial phyla detected in skin, gill, proximal (intP) and distal intestine (intD) three fish species (G - gudgeon; P - perch; S - stone loach) site 1 (unpolluted).

Supplementary material Fig. 2. Alpha diversity of microbiomes among species (data for external body regions: gill and skin mucus pooled) in site 1 (unpolluted water) and site 2 (polluted water) measured with the Shannon index. Gsite 1 - gudgeon in site 1, Gsite 2 - gudgeon in site 2, Psite 1 - perch in site 1, Psite 2 - perch in site 2, Ssite 1 - stone loach in site 1, Ssite 2 - stone loach in site 2.

Supplementary material Fig. 3. Average relative abundance (±SE) of microbial families, identified by SIMPER analysis, with the highest contribution to the overall dissimilarity between sites for gudgeon (a), perch (b) and stone loach (c).

Supplementary material Table 1. Comparison of parameters describing the study site and water quality for the River Gać during sample collection (5th July 2019).

Supplementary material Table 2. Pairwise comparisons (Bonferroni test) of fish microbiota following one-way ANOSIM and SIMPER analysis.

© J. Grabowska et al., Published by EDP Sciences 2025