Impact of explantation techniques on the microbiota of the marine sponge Ecionemia alata

• Various sponge explantation methods produce similar impacts on sponge microbiota.
• Explanted clones have lower alpha and beta diversity than wildtype sponges.
• Explanted sponge microbiota not further phylogenetically clustered than wildtype.

Marine sponges host a diverse assemblage of microorganisms, but much remains unknown about the ecology of these hosts and their microbiota. Due to variable environmental conditions in most sponge habitats, a useful way to study these animals is under controlled conditions in an aquarium setting. It is unclear, however, to what degree the process of explanting a sponge and raising it ex situ can perturb the structure and diversity of the microbial community within the sponge. This study assesses the impact of several sponge explantation techniques on the microbial assemblages found in the New Zealand marine sponge Ecionemia alata. Results indicate that there are compositional changes to the community across treatments, but that most of these changes involve shifts in the relative abundance, rather than losses or gains, of certain bacterial taxa. Alpha and beta diversity of the sponge explant microbiota is lower relative to the wild type microbiota, but across the variety of ex situ establishment techniques, the results are statistically indistinguishable from each other. Finally, the potential for how these changes might relate to the use of sponges for experimentation is discussed.