Seasonal and spatial dynamics of the intestinal microbiome in tropical freshwater fish: insights from Astyanax aeneus and Brycon costaricensis in the Peñas Blancas river basin, Costa Rica

The similarities in microbiome diversity and structure in both species could arise from parallels in taxonomy, habitat and diet. However, temporal and spatial shifts in the A. aeneus microbial community structure may be associated with sensitivity to changes in environmental stressors such as precipitation, temperature, and runoff. Microbial network analysis revealed that taxa in A. aeneus are more tightly interconnected and form fewer distinct clusters, making it a promising bioindicator for monitoring water quality and anthropogenic impacts.