The Antarctic mite, Alaskozetes antarcticus, shares bacterial microbiome community membership but not abundance between adults and tritonymphs

The Antarctic mite (Alaskozetes antarcticus) is widely distributed on sub-Antarctic islands and throughout the Antarctic Peninsula, making it one of the most abundant terrestrial arthropods in the region. Despite the impressive ability of A. antarcticus to thrive in harsh Antarctic conditions, little is known about the biology of this species. In this study, we performed 16S rRNA gene sequencing to examine the microbiome of the final immature instar (tritonymph) and both male and female adults. The microbiome included a limited number of microbial classes and genera, with few differences in community membership noted among the different stages. However, the abundances of taxa that composed the microbial community differed between adults and tritonymphs. Five classes—Actinobacteria, Flavobacteriia, Sphingobacteriia, Gammaproteobacteria, and Betaproteobacteria—comprised ~ 82.0% of the microbial composition, and five (identified) genera—Dermacoccus, Pedobacter, Chryseobacterium, Pseudomonas, and Flavobacterium—accounted for ~ 68.0% of the total composition. The core microbiome present in all surveyed A. antarcticus was dominated by the families Flavobacteriaceae, Comamonadaceae, Sphingobacteriaceae, Chitinophagaceae and Cytophagaceae, but the majority of the core consisted of operational taxonomic units of low abundance. This comprehensive analysis reveals a diverse microbiome among individuals of different stages, with overlap likely due to their shared habitat and common feeding preferences as herbivores and detritivores. The microbiome of the Antarctic mite shows considerably more diversity than observed in mite species from lower latitudes.