This study was carried out to observe the chronological tegumental changes of juvenile C. sinensis using scanning and transmission electron microscopes (SEM and TEM). The subjected worms were the excysted metacercaria, and l day, 1 week, 2 week and 4 week old worms. By observation with SEM, the tegument of excysted metacercaria showed many transverse wrinkling or shallow rugae, especially remarkable in anterior half of body, i.e., anterior to ventral sucker. Many spines were arrayed on the whole body surface, and double or triple pointed on anterior half and single pointed on posterior half. The observed sensory papillae were composed of 3 types. The ciliated knob-like papillae (type A in Fujino's classification) were abundant on anterior half, especially around oral sucker. A few plate like elevated papillae (type B) were found on middle part and non-ciliated round swellings (type C papillae) were observed around ventral sucker. The tegumental surface of 1 day old worms showed deeper rugae, and the posterior body end was covered with cobble stone-like processes of distal cytoplasm. The spines protruded further and the spines on posterior half of body changed to scale-like ones. The tegument of 1 week old worms became velvety and the spines grew further in length, but the density decreased. The tegumental processes differentiated much finely in the 2 week and 4 week old specimens and the spines or sensory papillae decreased of their relative density. The basic tegumental structures, such as distal cytoplasm containing various granules, vesicles and spines, basement membrane complex, muscular layers and tegumental cells were also monitored in 1 week old worms by TEM.
parasitology-helminth-trematoda ; Clonorchis sinensis ; electron microscopy ; tegument

A transmission electron microscopic study was conducted in order to know basic tegumental structure of Cysticercus cellulosae which was obtained from the ventricles of human brain. In general, the electron microscopic appearance of the tegument resembled that of the body wall of adult and larval forms of other cestodes. The tegument both of the parenchymatous portion (scolex and spiral canal) and bladder portion consisted of such components , i.e., an outer vesicular layer with microtriches, and an inner fibrous layer. The subtegumental tissue below the fibrous layer was filled with muscle bundles and tegumental cells. The surface of the larva was covered by the microtriches of two distictly different types. The characteristic pyramid-shaped "tetrahedral" form was observed on the surface of the scolex portion, whereas the elongated, slender "filamentous" microtriches were distributed on the regions of the spiral canal and bladder portion. The tegumental and subtegumental tissues varied in thickenss from one region to the next. The possibility of application in making differential diagnosis from other larval cestodes and possible fuction of this larval tegument were discussed.
parasitology-helminth-cestoda ; Cysticercus celluosae ; Taenia solium ; tegument ; electronmicroscopy

A scanning electron microscopic study was performed to observe the tegumental surface of adult Fibricola seoulensis. The adult worms were collected from the small intestine of mice 5 days to 3 weeks after experimental infection with the metacercariae. The metacercariae were obtained from the viscera of the snakes, Natrix tigrina lateralis, by artificial digestion technique. The results were as follows: The tegument of anterior body was covered with cobblestone-like cytoplasmic processes and that of posterior body showed finger-like processes. The posterior body had 4-5 large transverse wrinklings which formed many discontinued shallow rugae. The entire surface of anterior body was regularly arranged with the spines of which tips diverged into 3 to 4 points. They were densely packed in anterior mid-median portion of dorsal surface where appeared a few spines indented upto 5 points. Farther laterally and posteriorly from this portion, the pointed spines were more sparse and became single tipped and extended to anterior one-third of posterior body. The posterior surface of oral sucker was armed with 50-60 spines having 2-3 tips and ventral sucker also covered with such spines. On anteriormost dorsal surface arranged 60-70 spade-shaped spines. The tribocytic organ was armed with many stout recurved pile-like spines arranged radially. There were 3 types of sensory papillae. The ciliated knob-like (Type I) papillae were almost bilaterally symmetrical in ventral and dorsal surfaces of anterior body, and abundant especially around bases of oral and ventral suckers, tribocytic organ, and in lateral margins of anterior body. About 24 non-ciliated round swellings (Type II) were observed around each lip of oral and ventral suckers. The plate-1ike elevated papilla without cilium (Type III) was found to distribute only in posterior body. These 3 types of papillae seem to be tangoreceptive and/or rheoreceptive in function when their morphology and distributions are considered.
parasitology-helminth-trematoda ; Fibricola seoulensis ; electron microscopy ; tegument ; mouse

This study was performed to observe the chronological changes in the tegumental structure of M. yokogawai using scanning electron microscope. The subjected worms were excysted metacercariae obtained from sweetfish, and 2-day, 1-week and 4-week old worms experimentally reared in albino rats. The results are as follows: The tegument of excysted metacercariae showed many transverse shallow rugae, which were more remarkable in posterior half body, i.e., posterior to ventral sucker. The whole surface was armed with many scale-like spines; 7-8 pointed ones on anterior body and 2-3 pointed on posterior body. The ciliated knob-like papillae (Type I) were abundant around oral and ventral suckers, which grouped 2, 3 or 4 in number in most cases. A few round swellings of tegument (Type II) were observed only on oral sucker. The tegumental surface of 2-day old worms showed deeper rugae, and the anterior half covered with knob-like processes of distal cytoplasm and the posterior half with cobblestone-like ones. Interspinous space became more wide and 9 pointed spines appeared on anterior dorsal surface. The sensory papillae enlarged but not changed in their distribution. The tegument of 1-week old worms revealed knob-like cytoplasmic processes in posterior half body and velvety ones around oral sucker. The scale-Iike spines of anterior half body changed remarkably to the slender ones of posterior body at the level of ventral sucker. In dorsal surface, the arrangement of the Type I papillae were bilaterally symmetrical. The tegument of 4-week old worms were finely differentiated and the posterior tegument covered with velvety cytoplasmic processes. The spines had remarkably grown in length and width but the density remained nearly unchanged. The papillae also became larger but their morphology and distribution were not different from younger worms. However, the round elevation of cytoplasmic ridges (Type III papilla) appeared bilaterally on inner wall of oral sucker, approximately 8 in number. From the above results, it is considered that the tegument of juvenile M. yokogawai continued to differentiate until 4 weeks after infection.
parasitology-helminth-trematoda ; Metagonimus yokogawai ; electronmicroscopy ; Plecoglossus altivelis ; tegument