Snapshot of the bacterial composition of two invertebrates Peltodoris
atromaculata and Petrosia ficiformis from the shallow hydrothermal
spring of Trapani
Abstract
The hydrothermal springs (HTSs) are unique environments characterised by
the emergence of geothermally heated groundwater that often releases
large amounts of dissolved minerals. Despite interest in HTSs, the
microbial composition of these sites remains largely under-explored,
particularly concerning the interactions between marine invertebrates
and microorganisms. As an example, the shallow HTSs of Trapani (West
coast of Sicily, Italy) maintain a constant temperature of 31 °C
throughout the year and two invertebrates and are inhabited by the
nudibranch Peltodoris atromaculata (P. atromaculata) and the sponge
Petrosia ficiformis (P. ficiformis). This study aimed to analyse the
bacterial communities associated with the sponge P. ficiformis and the
mantle and gut of P. atromaculata. Our results, based on Next-Generation
sequencing of the bacterial marker gene (16S rDNA), revealed that the
bacterial communities associated with the sponge P. ficiformis and the
mantle of P. atromaculata are strikingly similar, suggesting a shared
bacterial community, while also exhibiting distinct bacterial
differences. However, signatures of bacterial families were found in the
gut and mantle of P. atromaculata. These findings shed light on the
bacterial composition of the nudibranch P. atromaculata and the sponge
P. ficiformis, both considered bioindicators of environmental conditions
and highlight the importance of investigating the microbial biodiversity
in these peculiar environments to be preserved at every taxonomic level.
Additionally, to date, we have provided a brief introduction to
understanding the role of host-bacteria interactions in marine
invertebrates and these unique environments in shaping entire
communities.