Movie S4.

The ciliated epithelium features two distinct microfluidic zones. Clip 1 is a close-up of the microparticle transport in the ex vivo light organ showing fast, directed transport in the vortical flow zone and, in contrast, slow, diffusion-like transport in the neighboring stagnation zone lined by short cilia. Clip 2 shows mucus and particles trapped in the stagnation zone being gently rocked by the motion of the short cilia.