The main muscular organs in the forebody of Paradiplozoon homoion adults.

A) General view of the forebody. CLSM, phalloidin-TRITC. B-C) The forebody in median plane optical sectioning. Note the muscles forming thin trabeculae in the forebody apical part and the numerous cells with prominent nuclei located between the trabeculae (C). CLSM, phalloidin-TRITC (B) and phalloidin-TRITC/DAPI (C). D) Detail showing the pharynx muscle wall arrangement and the muscles controlling pharynx movement. CLSM, phalloidin-TRITC/DAPI. E-F) Various optical sections of the pharynx showing the transverse trabeculae and pharyngeal cell nuclei. G-H) Apical view of the pharynx. CLSM, Phalloidin-TRITC (E, H) and phalloidin-TRITC/DAPI (F, G). A-H are composite views created by flattening a series of optical sections. black arrowheads–muscles controlling the pharynx, black arrows–muscles controlling the buccal suckers, bs–buccal suckers, dm–diagonal muscles of the body wall, lm–longitudinal muscles of the body wall, ph–pharynx, pm–muscle fibres fixed perpendicularly to the tegument, um–U-shaped muscle bundle of a sucker, white arrowheads–two sensory structures localised in the area of the round projections, white arrows in E, F–trabeculae, white arrows in H–four round structures.