Movie S1. Ciliary flow on a P. damicornis fragment. The video shows vortical ciliary flows traced out by 1-μm particles suspended in the seawater adjacent to the coral fragment. A slightly zoomed-in view of the same location is seen in Fig. S1B. The video was captured by dark-field microscopy using a 4× objective at ∼30 frames per second and is played back at real time.