In laboratory culture experiments, calcified and decalcified coccolithophore cells were offered as prey to a phagotrophic predator, both in separate pure cultures with calcified or decalcified cells only, and in mixed cultures that contained both cell types. Overall, three experiments were conducted, each with a different coccolithophore species. The prey and predator concentrations were monitored over the course of each experiment by flow cytometry and microscopic counting.