Habitat specificity modulates the bacterial biogeographic patterns in the Southern Ocean

Area of Science:

• Microbial Ecology
• Biogeography
• Marine Biology

Background:

• Conceptual frameworks suggest habitat characteristics influence microbial distribution.
• Few experimental studies demonstrate the effect of habitat specificity on microbial biogeography.

Purpose of the Study:

• To investigate how habitat specificity affects bacterial biogeographic patterns.
• To determine the impact of habitat specificity on bacterial community assembly processes.
• To explore these effects in Southern Ocean benthic coastal ecosystems.

Main Methods:

• Utilized a natural experimental design using the Abatus sea urchin model.
• Examined a habitat specificity gradient from sediment to intestinal tissue.
• Employed 16S rRNA gene metabarcoding for bacterial community analysis.

Main Results:

• Bacterial communities clearly differentiated by geographic site, with similar contributions from geographic and environmental distances.
• Biogeographic pattern strength decreased with increasing habitat specificity.
• Sediment bacterial communities exhibited stronger geographic and environmental divergence than gut communities.
• Bacterial assembly processes varied with scale and specificity, with increased dispersal limitation in gut habitats.

Conclusions:

• Habitat specificity is a crucial factor in shaping bacterial biogeography and assembly.
• Understanding diverse habitats is essential for comprehending microbial distribution patterns.
• Findings highlight the interplay between geography, environment, and habitat specificity in marine microbial ecology.