Fig. 1 in The metatrochophore of a deep-sea hydrothermal vent vestimentiferan (Polychaeta: Siboglinidae)

Fig. 1 Schematic drawings of metatrochophores of specimens #542 (a), #308 (b), #675 (c). Body composed of prostomium (p) containing brain (b) and apical organ (ao) in b; peristomium (pe), ring-like area including mouth and prototroch (pr); segment 1 (s1) with neutroch (nr), tentacles (te) with sensory organ (ste), and uncini; segment 2 (s2) with uncini; segment 3 (s3) in specimen b and c; white, transient digestive system with mouth, foregut (fg), midgut (mg), hindgut (hg), and anus (a); black, trophosome (tr); dark grey, mesoderm; medium grey, ectoderm; light grey, coelomic cavities