English: Supplementary Movie 4 Loss of a single algal symbiont during high-light induced bleaching. A single polyp micropropagate was kept on the microscope stage under constant FASW flow, with temperature set to 24oC. Light intensity was set to 1500 µmol photons m-2 s-1, resulting in a slower bleaching response compared to the experiment shown in Supplementary Movie 3. Time lapse sequence was captured at 5 min intervals over a period of 12 h using a 10X objective (NA 0.3), with each frame composed of bright field (grey background), coral GFP (green) and algal chlorophyll (red). The sequence shows a single algal symbiont (denoted by red arrow in figure 4d) disappearing following an increase in chlorophyll fluorescence. Grey, snake like shadows in the background are the polyp's mesenterial filaments. Scale bar is given in Figure 4d. Frame-by-frame quantification of chlorophyll fluorescence from the disappearing algae and one neighboring algae is given in figure 4f.