Fig. 3

Electra posidoniae. Acetylated alpha-tubulin-lir in orange in all images. A Overview of few zooids. B Overview from the frontal side, showing alpha-tubulin-lir and f-actin (gray). Volume rendering. C Overview from the frontal side, showing alpha-tubulin-lir structures. Volume rendering. D Detail of the lophophoral base. Volume rendering. E Detail of the apertural area. Volume rendering. Abbreviations: abr – annular branch of the trifid neurite bundle, afn – abfrontal tentacle neurite bundle, caec – caecum cilia, cl – caecum ligament, cg – cerebral ganglion, CON – circumoral nerve ring, ctsn – compound tentacle sheath nerve, d – distal, izp – interzooidal pores, dtsn – direct tentacle sheath nerve, lb. – lophophoral base, lvn – laterovisceral neurite bundle, mvn – mediovisceral neurite bundle, o – operculum, opn – opercular nerve, opo – operculum occlusor, p – proximal, pbs – parietal branching site, pdi – parietodiaphragmatic muscle, pdin – parietodiaphragmatic nerve, php – pharyngeal nerve plexus, pm – parietal muscle, pmn – parietal muscle nerve, rm. – retractor muscle, sph – sphincter muscle, spn – sphincter nerve, tc – tentacle cilia, tfd – trifid neurite bundle, tm – tentacle muscle, white arrows indicate the position of duplicature bands