Fig. 2

Three-dimensional (3D) reconstruction of the jaw apparatus of Histriobdella homari. The main jaw elements are indicated in different colors: maxillae and dorsal rod – yellow; dorsal rod flexors – blue; mandibles and mandibular shaft – orange; ventral carrier retractors – light green; ventral muscle bulb – olive; epithelial nuclei – gray; muscular nuclei – light orange. a. General view of the head with the intestine, maxillae, mandibles and muscles. Lateral view. b. Ventral pharyngeal organ (VPO) and jaws, dorsolateral view. c. Ventral pharyngeal organ and jaws, ventrolateral view. d. Detailed reconstruction of the VPO. Lateral view. Drf, dorsal rod flexor; dr, dorsal rod; en, epithelial cell nuclei in the ventral muscle bulb; i, intestine; m, mouth; md, mandible; mfb, transversal muscle fibers of the ventral bulb; mn, muscular nuclei of the ventral bulb; mx, maxillae; oe, esophagus; sh, mandibular shaft; t, tentacle; vb, ventral muscle bulb; vcr, ventral carrier retractor