Fig. 2

Organisation of the apical forebody region in Eudiplozoon nipponicum, with emphasis on glandular structures. A. General view of the forebody in the area of the mouth cavity, showing localisation of paired buccal suckers and GMO. Note the gland cell accumulations around this structure. CLSM, hydrochloric carmine staining in combination with transmission light. B. Detail of mouth opening with prominent buccal sucker and GMO connected to a canal. CLSM, transmission light. C. Histological section showing a lateral view of the forebody, with the muscular buccal sucker and several giant gland cells located below it. LM, MT. D-F. Forebody stained with hydrochloric carmine showing distribution of putative unicellular glands. Note the apically located circular structures in 2F. CLSM, output image not coloured. G. The apical part of the forebody with two symmetric groups of circular structures (encircled). CLSM, phalloidin-TRITC. H. Micrograph showing the mouth opening and a retracted collar with well-developed circular muscle fibres. CLSM, phalloidin-TRITC. I. Innervation of the collar and subjacent tegument. Note the paired nerve nodes (white rectangles) located at the base of the collar. CLSM, anti-α-tubulin-FITC. arrow – flame cell, arrowheads –internal canal attached to the GMO, asterisk – GMO, bs – buccal sucker, col – forebody collar, g – gland cells, lm – bundles of longitudinal muscle fibres, m – body wall musculature, p – parenchyma, pnf – peripheral nerve fibres subjacent to the tegument, white arrowheads – apical band of musculature, white arrows – muscle fibres arranged circularly around the border of the mouth opening, x – mouth opening