Fig. 4

Neuro-muscular system of the apertural area of Stephanella hina. Confocal laser scanning microscopy stacks based on acetylated alpha-tubulin labelling. Volume renderings, projections or optical slices. Acetylated alpha-tubulin in green LUT, f-actin in glow LUT. a Projection of a zooid with a retracted polypide showing duplicature bands and vestibular dilatators. b Thin neurite bundles traversing the duplicature bands and extending towards the conspicuous orificial cells. c Volume rendering of the orificial area of a zooid with a retracted polypide showing a closed vestibular area surrounded by stained gland cells. d Lateral view of a retracted zooid showing duplicature bands and vestibular dilatators. e Details of specific orificial cells. f Thin neurite bundles extending along the distal body wall towards the orificial cells. Abbreviations: bw – body wall, bwm – body wall musculature, bwp – body wall nervous plexus, db – duplicature band, dbn – duplicature band neurites, ds – diaphragmatic sphincter, gc – gland cell, or – orifice, osc – orificial (sensory?) cells, ti – tentacle innervation, tlm – tentacle sheath longitudinal muscles, vd – vestibular dilatators, vw – vestibular wall