Microsphere counts from incubation chambers of Oikopleura dioica prior to and following feeding incubations for experiment with artificial microspheres with two functionalized surfaces in three sizes

Cell surface properties can strongly mediate microbial interactions with predators in soil and host-pathogen systems. Yet, the role of microbial surface properties in avoiding or enhancing predation in the ocean remains a research frontier. Appendicularians are globally abundant marine suspension feeders that capture marine microorganisms in a complex mucous filtration system. We used artificial microspheres to test whether the surface properties of prey particles influenced selection by the appendicularian, O. dioica. Across microsphere sizes (0.5, 1, 2 and 3 µm) and concentrations (~103-106 particles ml-1), which were varied to represent realistic microbial communities, carboxylate- and amine-modified particles were handled differently by the appendicularians. The carboxylate-modified particles were enriched in the gut while the amine-modified particles were enriched in the mucous filters, leading to different particle fates. This dataset includes incubation chamber concentrations at the beginning and end of feeding incubations.