Fig. 12 Tentacles. a in The metatrochophore of a deep-sea hydrothermal vent vestimentiferan (Polychaeta: Siboglinidae)

Fig. 12 Tentacles. a Longitudinal ultrathin section of distal tentacle in specimen #675 with coelomic cavity (ct) surrounded by myoepithelial cells (mte), parts of prototroch (pr) ventral to tentacle; b–e series of ultrathin sections through region of connection between mesoderm of tentacles and first segment of specimen #308; arrows point to ECM of mesoderm; b epithelio-muscle cells (mu) surrounded by epidermis in tentacle; c solid mesoderm strand (mte) surrounded by epidermis in tentacle; d, e merging of mesoderm of first segment (m1) with mesoderm of tentacle (mte), foregut (fg)