Fig. 4

Polymorphic symmetry of internal organ arrangements in correlation with siphonoglyph number. a Summary of symmetries in the observed arrangements of gastric pouches alone (upper), those of gastric pouches and muscles (center), and those of gastric pouches, muscles, and siphonoglyphs (lower). The width and color of the lines indicate the number of samples and the symmetry type, respectively (red: bilateral symmetry, blue: biradial symmetry, gray: irregular). b, c External view (upper left), enlarged view around siphonoglyphs (lower left), horizontal section (upper right), and a schematic view of the corresponding arrangement (lower right). Black dashed arcs indicate siphonoglyphs. Representative individual with bilateral symmetry, a siphonoglyph, and 10 orange stripes (b). Representative individual with biradial symmetry, two siphonoglyphs, and 12 orange stripes (c). M3s are not shown. Scale bars, 500 μm. Gray dotted lines in A–C indicate symmetry planes. d Normalized frequency (%) of bilateral symmetry, biradial symmetry, and irregularity in monoglyphic (upper) and diglyphic (lower) individuals