[Ultrastructural observation on the body wall of Pagumogonimus skrjabini].

This paper deals with the ultrastructure of the body wall of adult Pagumogonimus skrjabini by transmission electron microscopy. Infected crabs were collected from Siyen, Hubei Province, and adult worms were obtained from the lungs of experimentally infected dogs 90 days post-infection. The normal structure of body wall of the P. skrjabini is composed of tegument, tegument cell, muscle muscle cell and protoplasmic tubules, all of which form together syncytium. The tegument contains external plasma membrane, tegument matrix and basal plasma membrane. The cell coat in fine granules is distributed over the whole external plasma membrane surface. The tegument matrix contains various secretory bodies, vesicles and mitochondria. The tegument cell is irregular in shape. Golgi complex, ribosome, autolysosome are seen in the cytoplasm. There are two layers of muscle, the external circular muscle and the inner longitudinal muscle layers. The nucleus of immature muscle cell has many heterochromatins, while the nucleus of mature muscle cell is large and round in shape. Mitochondria and glycogen granules are transmitted from muscle cell proper to the muscle by protoplasmic tubules (Figs. 1 approximately 7).