Fig. 3

Muscular organization of V. multiformis. a A schematic representation indicating positions of the following images. b–g Muscular fibers of the body of V. multiformis were visualized by phalloidin staining. b Randomly oriented muscular fibers that were observed on aboral subepithelial layers. c High-magnification view of the crossing longitudinal fibers and circular muscle fibers on peripheral aboral surfaces. d Parallel bundles of muscle fibers run along the aboral organ (ao) (arrowheads). e Thin muscle fibers encircling the mouth openings (mo) on the oral subepithelial layers (arrowheads). f Radially elongated thicker fibers on the oral side (arrowheads indicating representative fibers). g Crossing of radial thick fibers (black arrowheads) and circular fibers (white arrowheads) observed on the oral side of the body. h, i High-magnification images of muscle fibers stained with phalloidin (green) and DAPI (magenta). Randomly oriented fibers on aboral surfaces (h) and striated thick fibers of radial muscle fibers on the oral side (i). Scale bar, 100 μm (b–g) or 20 μm (h and i)