Tetrodotoxin, Fungal Pathogen Infection, and Bacterial Microbiome Associations are Variable in the Skin Microecosystems of Two Taricha Newt Species

In this field observational study, we aimed to describe the relationship between natural tetrodotoxin levels, skin microbiome composition, and Bd infection in 12 populations of two species of Taricha newts. We evaluated whether these patterns were consistent between host species. We hypothesized that individuals with higher tetrodotoxin concentration would have lower Bd infection prevalence. We also hypothesized that higher tetrodotoxin concentration would influence microbiome alpha and beta diversity and that sites with high and low tetrodotoxin concentration would have commensurate levels of known TTX-producing microbes