Fig. 2

Aboral nervous system of V. multiformis. Immunofluorescent staining was performed with an anti-α-tubulin antibody to observe nervous systems of V. multiformis. a Positions of the following images in the animal are indicated. b, c Subepithelial neural-net-like structures of the peripheral (b) and central part (c) of the aboral surface. The arrowhead indicates the aboral organ. d-d’’ A series of images from external (d) to internal (d’’) focal planes of the aboral organ, stained with anti-α-tubulin antibody (green) and DAPI (magenta). The arrow indicates the cilia covering the internal organ, presumed to be dome cilia. The white and black arrowheads indicate the epithelial bulges and cilia surrounding these bulges, respectively. e A light microscopy image of the statolith of the living V. multiformis. f The schematic drawing of the aboral organ of V. multiformis reconstructed from immunofluorescent images and the pelagic ctenophore B. mikado (modified from Jokura and Inaba 2020 [29]) for comparison. The position of the statolith in V. multiformis is depicted based on that of B. mikado and other ctenophores. b, bulge; bc, balancer cells; cg, ciliated groove; dc, dome cilia; o; opening; s, statolith. Scale bar, 50 μm