Extended Data Fig. 1: Ciliary flame of the giant larvacean draws ambient seawater through a lattice of non-motile cilia and pumps it into the blood sinus.
A, The ciliated funnel (CF) in the giant larvacean B.stygius branches off the mouth cavity (M). B, Phase-contrast cross-section of entire ciliated funnel shows protective lattice of non-motile cilia in the funnel entry (opening to mouth cavity), ciliary flame, and connection to blood sinus with putative hemocytes (small arrows). The direction of the cilia-driven flow is inwards (large arrow), consistent with a multi-stage filtration system73. C, Cross-sectional confocal image of the ciliated funnel in B.stygius including the funnel entry and the ciliary flame. D, Close-up on the ciliary flame, showing an actin mesh (magenta) encasing the large ciliary flame (cyan) which is composed of multiple, tightly packed ciliary flame cells and connects to the blood sinus. E, Close-up on the lattice of non-motile cilia that project into the funnel entry. The morphology shown in A-E was confirmed in a minimum of 3 animals.
