Abstract Summary
Microbiota response within reef invertebrates potentially play a critical role in the holobionts environmental acclimation and ultimately the persistence of populations faced with future ocean acidification and warming. This study aimed to establish the microbial communities associated with early developmental stages of the GBR sponge, Carteriospongia foliascens and assess if vertical transmission of microbial symbionts from parents exposed to future climate conditions can be drivers of transgenerational acclimation in the early life history stages. Our results revealed a highly conserved microbial community structure across three critical points of early development of C. foliascens, indicating potential vertical acquisition of their microbial symbionts. In addition, intraspecific variation or ‘genotype effect’ was found to be a critical driver in shaping microbial assemblages present throughout the developmental stages of both ambient and experimental recruits and supports previous findings in which community stability has been seen despite stressful environmental conditions (i.e. salinity, temperature, eutrophication). The microbial similarities between experimental recruits were also found to be heavily influenced by the initial exposure of their parent sponge and highlights the potential implications on sponge population persistence via microbe mediated transgenerational acclimation. Although transplant treatments had a minimal effect on shifting community populations, we report that recruits subjected to high ocean acidification and warming conditions had higher relative abundance of Cyanobacteria than control groups which may mitigate thermal stress through higher energetic contribution to the host. Nevertheless, implications of variation in microbial community structure based on a host genotype effect must be taken into consideration for future conservation efforts and for this reason, our results highlight the necessity of considering genotype effect in which this effect can influence overall host physiology and in turn, its ability to acclimate quickly in the face of changing ocean parameters. With predicted impacts from OA and warming into the future, resolving the role of the microbial communities in facilitating acclimation and potential adaption to future conditions is currently a fundamental research focus and highlights the need for further exploration into host genotype and the implications on the interactions with its symbiotic microbiota.
