Invasive freshwater snails form novel microbial relationships.

Area of Science:

• Ecology
• Microbiology
• Evolutionary Biology

Background:

• Resident microbes (microbiota) influence host adaptation to environmental changes.
• Invasive species face novel selection pressures, impacting their associated microbiota and host-microbiome relationships.

Purpose of the Study:

• To investigate the impact of invasion on the microbiota of the freshwater snail *Potamopyrgus antipodarum*.
• To determine if novel host-microbiome relationships form after invasion and if microbes influence invasion success.

Main Methods:

• High-throughput 16S rRNA sequencing was used to analyze microbial communities.
• Native (New Zealand) and invasive (European) populations of *Potamopyrgus antipodarum* were compared.

Main Results:

• Invasive snails harbor distinct microbial communities, with some core taxa carried over from native populations.
• Native microbiomes have fewer core microbes, suggesting streamlining, while invasive microbiomes show higher diversity but less inter-individual variation.
• Invasive snails exhibit higher alpha diversity but are more similar to each other compared to native snails.

Conclusions:

• Invasions lead to the formation of novel host-microbiome associations.
• Microbiota comparisons reveal coevolutionary history and specialization in native ranges, alongside new associations post-invasion.
• Understanding these microbial relationships is crucial for managing invasive species and their ecological impact.