A survey across many ways of life
The researchers sampled 1,090 spiders from 34 families at 11 sites in Sichuan and Guizhou. They grouped the animals as web-building, wandering, or ambushing hunters and used 16S rRNA sequencing to compare the bacterial communities associated with their guts.
Wandering and ambushing spiders showed higher microbial diversity in this dataset, while web-building spiders had the lowest diversity and the highest endosymbiont infection rates. Spiders collected closer together also tended to have more similar diversity levels.
What the study does not prove
The correlations do not show that a particular hunting style directly causes a particular microbiome. Diet, habitat exposure, geography, host lineage, and chance can overlap. The authors found that stochastic processes were the main drivers of community assembly and explicitly limited the environmental conclusions to the sampled region.
Why it is interesting
Most spider biology is discussed in terms of silk, venom, senses, and prey. This work adds a less visible ecological layer and provides a large comparative starting point for testing how microbes interact with spider life histories.