Ultrastructural changes in an unciliated sensory receptor during activation of the metacestode of Hymenolepis...

The fine structure of an unciliated sensory receptor of the metacestode of Hymenolepis microstoma is described. Each receptor contains a basal body inserted into an electron dense matrix; a terminal cilium is lacking. At this stage of development neurotubules were lacking, but rapidly appeared following excystation. It is suggested that neurotubules play a role in the functioning of the putative proprioceptor.