Unraveling the predictive role of temperature in the gut microbiota of the sea urchin Echinometra sp. EZ across spatial and temporal gradients

Shifts in microbial communities represent a rapid response mechanism for
host organisms to respond to changes in environmental conditions.
Therefore, they are likely to be important in assisting the
acclimatization of hosts to seasonal temperature changes as well as to
variation in temperatures across a species’ range. The Persian/Arabian
Gulf is the world's warmest sea, with large seasonal fluctuations in
temperature (20℃ - 37℃) and is connected to the Gulf of Oman which
experiences more typical oceanic conditions (<32℃ in the summer).
This system is an informative model for understanding how symbiotic
microbial assemblages respond to thermal variation across temporal and
spatial scales. Here, we elucidate the role of temperature on the
microbial gut community of the sea
urchin Echinometra sp. EZ and identify
microbial taxa that are tightly correlated with the thermal environment.
We generated two independent datasets with a high degree of geographic and
temporal resolution. The results show that microbial communities vary
across thermally variable habitats, display temporal shifts that correlate
with temperature, and can become more disperse as temperatures rise. The
relative abundances of several ASVs significantly correlate with
temperature in both independent datasets despite the
>300 km distance between the furthest sites and the
extreme seasonal variations. Notably, over 50% of the temperature
predictive ASVs identified from the two datasets belonged to the family
Vibrionaceae. Together, our results identify temperature as a robust
predictor of community-level variation and highlight specific microbial
taxa putatively involved in the response to thermal environment.