Studies on the embryogenesis of the tapeworm Shipleya inermis Fuhrmann, 1908 using transmission and scanning electron...

Scanning electron micrographs (SEM) are shown of the scolex, microtrichs, and the submucosal capsule formed by the worm. The course of development of the outer capsule and the outer envelope from the early preoncosphere to the mature oncosphere is followed by SEM and (in part) transmission electron microscopy. Three phases of development of the outer envelope (OE) were noted: (1) early preoncosphere with OE with a relative smooth outer surface, (2) the development of surface lamellae and (3) the formation of a dendritic area distal to the lamellae; all of the organelles appear to be secretory. Stereoscopic pairs of cryofractured developmental stages are used to aid understanding of the OE. Transmission electron micrographs are used to corroborate the SEM micrographs.