Fig. 1

Intestinal epithelial cells of Paralvinella spp. and its EDS mapping. A: SEM micrograph of intestinal epithelial cells. Arrow and arrowhead indicate apical and basal side, respectively. B: EDS spectrum of a spherocrystal. C: EDS spectrum of non-spherocrystal position. D: SEM image of spherocrystals. E, F: EDS sulfur and iron mapping of the region shown in D