Metagenome of sea anemone gastrovascular cavity
To establish field baselines, a microbiome sample was swabbed from each anemones gastrovascular cavity (GVC) (a non-lethal and repeatable technique) before the animal was removed from its substrate in the field. To determine how OA conditions (decreased seawater pH) affect microbial functional profile, a microbiome sample was swabbed from each anemones GVC on Days 0 and 20 of the experiment. Microbiome samples were collected by inserting a Puritan 15 cm sterile cotton tipped applicator with polystyrene handle (SKU# 25-806, Puritan Medical Products Company LLC, Guilford, ME, USA) into the GVC and twirling the applicator for 30 s, a standard microbiome sampling technique (Aagaard et al., 2013). The tip of the swab was inserted into a labeled ZymoBIOMICS ZR BashingBead Lysis Tube (Zymo Research, Irvine, CA, USA) and cut off using ethanol-sterilized scissors. The tube was capped and immediately flash frozen in liquid nitrogen. This process was repeated for all microbiome samples. For microbiome samples collected from anemones in experimental aquaria, the water was drained prior collection to reduce the contact between the swab and seawater or other surfaces.