Microbiome of Tegula Snails

We assess potential microbiome bacterial contributions to thermal tolerance in the intertidal marine snails Tegula eiseni, Tegula funebralis, and Tegula gallina that co-occur in southern California but occupy different intertidal heights that vary in thermal stress exposure. 16S sequencing of the V4 region of individuals of each species exposed to control conditions (ambient temperature = 15 degrees C) or a single short duration 5.5-hour heat stress (maximum temperature = 34 degrees C) revealed distinct bacterial communities across species. Moreover, unique bacterial genera of the microbiome were significantly enriched (more abundant) in each Tegula species. Lutimonas, Polaribacter, and the exopolysaccharide (EPS)-producing bacteria Pelagicoccus were most abundant in T. gallina, the species that occupies the highest intertidal heights and thus experiences heat stress most frequently. These results suggest that microbiome-derived metabolites such as EPS could be contributing to the higher thermal tolerance of T. gallina. Overall, this study demonstrates that the bacterial microbiome should be considered when examining mechanisms of thermal tolerance in marine invertebrates.