Dataset: Grazing experiment 6: short term grazing

The phytoplankton Rhodomonas sp. CCMP 755 was grown semi-continuously in atmosphere controlled chambers at three different CO2 treatment concentrations; Ambient (400ppmv), Moderate (750ppmv), and High (1000ppmv).  Cultures were diluted daily starting day 4 with pre-equilibrated media containing f/50 nutrients.  On day 9 Rhodomonas cells from the treatments were fed to starved Coxliella sp. cells for 15, 30, and 45 minutes.  During each sampling time point, 20 ml of experiment volume was removed, fixed with 0.5% glutaraldehyde and stained with DAPI.  Samples were stored at 4° C for 12 hours to allow time for the DAPI to stain.  This volume was filtered onto a 10 µm pore size polycarbonate filter with, which was then put on a slide with immersion oil and kept frozen until evaluation.  Slides were evaluated under 400x using an epi-fluorescent microscope under blue-light excitation.  The first 100 microzooplankton on each slide were assessed for each replicate/treatment, and individual prey cells were counted in the grazer food vacuole.