Ecological filtering drives rapid spatiotemporal dynamics in fish skin microbiomes

Area of Science:

• Microbiology
• Ecology
• Aquatic Biology

Background:

• The functions of skin microbiomes are crucial, but the factors influencing their structure in non-model organisms are not well understood.
• Investigating fish skin microbiome assembly is key to understanding host-microbe interactions in aquatic environments.

Purpose of the Study:

• To determine the drivers of fish skin microbiome composition and dynamics.
• To assess the impact of environmental habitat, antibacterial treatment, and social environment on fish skin microbial communities.

Main Methods:

• High-throughput sequencing of 16S rRNA gene V3-V4 regions for metabarcoding.
• Experimental manipulations including habitat translocation (freshwater vs. brackish water), antibacterial disinfectant treatment, and social grouping (alone vs. pairs).

Main Results:

• Fish skin microbiomes were distinct from ambient bacterioplankton and highly dynamic.
• Microbiome composition was primarily influenced by environmental habitat (freshwater vs. brackish water).
• Microbiome composition showed convergence upon return to the original habitat, indicating environmental influence and resilience to antibacterial treatment.

Conclusions:

• External environmental conditions and individual-specific factors are key determinants of fish skin microbiome dynamics.
• Inter-host microbial dispersal had minimal impact on microbiome composition.
• The fish skin microbiome exhibits high resilience to disturbance, with environmental factors playing a more significant role than social interactions.