[A study on the tegument and sensory receptors of the scolex of a tetraphyllidean cestode plerocercoid, by transmission and scanning electron microscopy (author's transl)].

The ultrastructure of bothridia and the myzorhynchus of a tetraphyllidean cestode plerocercoid is described. Two types of microtriches occur on the tegument of these organs. On the bothridium, the microtriches are lanceolated whereas on the mizorhynchus, they are filamentous. Uniciliated sensory receptors, which consist of a basal bulb contaning one or two electron-dense collars, are observed especially on the bothridia and myzorhynchus. A papilla is also described on the tegument. According to the present study, it is suggested that the rostellum of cyclophyllidean cestodes and the myzorhynchus of the tetraphyllideans are homologous. Moreover, the role in the attachment and sensory perception of the myzorhynchus is revealed.