The image of the anterior body end of the turbellarian Microdalyellia picta (Rhabditophora, Platyhelminthes) showing the musculature and the nervous system of the pharynx stained with antibodies to alpha-tubulin. The pharynx of M. picta (pharynx doliiformis) is subdivided into two regions: the proximal interior region and the distal pharyngeal protrusion extending into the pharyngeal cavity. The pharyngeal protrusion is connected with the wall of the pharyngeal cavity along the juncture line. The image shows a ring-shaped nerve of the juncture line (nerve ring) and the longitudinal proximal nerves of the pharynx extending posteriorly from this nerve. The adjacent proximal nerves are interlinked by transverse nerves. A pair of proximal longitudinal nerves (ventro-lateral nerves) is more prominent than the other nerves. The distal longitudinal nerves extend anteriorly from the nerve ring of the juncture line. These nerves run inside the wall of the pharyngeal protrusion and terminate at its distal end, where they connect to the distal nerve ring of the protrusion (it is not visible in the image). The distal nerves are interlinked by numerous transverse nerves. The distal ring sends neurites towards the receptor cells of the pharyngeal papillae. The image also shows cilia of epidermal cells and of the terminal protonephridial cells.
Photo: A.A. Petrov