Movie is playing at 60 frames per second (fps). n = 7 embryos between 13–14 hpf were set under the 100x/1.30 NA oil immersion objective lens on a Nikon Eclipse Ti-U inverted microscope at room temperature (26ºC). All images were taken with the dorsal roof of the Kupffer's vesicle (KV) facing the objective lens. Bright field images were recorded with a FASTCAM MC2 camera (Photron Europe, Limited) controlled with PFV (Photron FASTCAM Viewer) software