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Korean J Parasitol > Volume 25(1):1987 > Article

Original Article
Korean J Parasitol. 1987 Jun;25(1):51-58. English.
Published online Mar 20, 1994.  http://dx.doi.org/10.3347/kjp.1987.25.1.51
Copyright © 1987 by The Korean Society for Parasitology
Scanning electron microscopical findings of Echinochasmus japonicus tegument
Soon Hyung Lee,Woon Mok Sohn and Sung Tae Hong
Department of Parasitology and Institute of Endemic Diseases, College of Medicine, Seoul National University, Seoul 110, Korea.

Tegumental ultrastructures of Echinochasmus japonicus were observed by scanning electron microscopy. The worms were recovered from albino rats which were experimentally infected with the metacercariae obtained from Pseudorasbora parva. Followings are summarized findings. The worms were minute and plumpy gourd-shaped with attenuated anterior and round posterior end. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. Head crown was armed with 24 collar spines which were embedded in cytoplasmic pockets. The spines were arranged in a row with an interruption at dorsomedian line, however, the 2nd and the 4th spines were outstretched more than others. Oral and ventral suckers were muscular with numerous type II sensory papillae, and genital pore opened between the two suckers. Tegumental spines were spade-shaped with broad base and pointed tip. They were compact in ventro-lateral tegument or dorsal surface of anterior body. The were not found between the two suckers and dorsal surface of posterior body. Two types of sensory papillae, uni-ciliated (Type I) and roundly swollen sensory papillae (Type II), were observed. The type I papillae were chiefly distributed on ventral surface of tegument and type II were on the lips of suckers. Arrangement of collar spines, shape and distribution of tegumental spines or sensory papillae are regarded as characteristic features of E. japonicus.


Fig. 1
Arrangement of collar spines of E. japonicus.

Fig. 1. Ventral view of 2-week old E. japonicus, OS; oral sucker, GP; genital pore, VS; ventral sucker, EP; excretory pore (×383).

Fig. 2. Dorso-lateral view of a 2-week old worm. Note the distribution of tegumental spines, concentrated on tegument of anterior body (×433).

Fig. 3. Dorso-lateral view of head portion. Note an interrupted portion of collar spines (arrow heads) (×1,360).

Fig. 4. Magnified collar spines which look like budding horns of a young stag (×3,490).

Fig. 5. Oral sucker (OS) with sensory papillae on its lip (p2: type II papillae (×2,600).

Fig. 6. Tegument between oral sucker and genital pore, showing wrinkled cytoplamic processes without a spine (×3,210).

Fig. 7. Type I sensory papillae (p1) in Fig.6 (×9,600).

Fig. 8. Genital pore (GP) with a cirrus (×3,210).

Fig. 9. Ventral sucker (VS) with a characteristic arrangement of spones and type II papillae (×2,000).

Fig. 10. Magnified cytoplasmic processes in the circled region of Fig.9 (×15,300).

*Scale unit is micrometer (µm).

Fig. 11. Tegumental spines of a 5 day old worm on ventrolateral surface of anterior body (×5,000).

Fig. 12. Tegumental spines of a 14-day old worm on same place of Fig.11 (×3,800).

Fig. 13. Tegumental spines of a 5-day old worm on dorso-median surface of anterior body (×4,000).

Fig. 14. Tegumental spines of a 14-day old worm on its dorsomedian surface of anterior body (×3,800).

Fig. 15. Dorso-posterior tegument of a 14-day old worm without a spine (×3,270).

Fig. 16. Magnified dorso-posterior tegument of a 14-day old worm (×9,800).

Fig. 17. Excretory pore of a 6-day old worm (×6,000).

Fig. 18. Excretory pore of a 14-day old worm with a few sensory papilae (×3,200).

*Scale unit is micrometer (µm).

1. Bennett CE. Scanning electron microscopy of Fasciola hepatica L. during growth and maturation in the mouse. J Parasitol 1975;61(5):892–898.
2. Chai JY, Hong SJ, Son DW, Lee SH, Seo BS. [Metacercariae of Echinochasmus japonicus encysted in a fresh water fish, Pseudorasbora parva, and their development in experimental mice]. Korean J Parasitol 1985;23(2):221–229.
3. Eom KS, Rim HJ, Jang DH. A Study On The Parasitic Helminths Of Domestic Duck(Anas Platyrhynchos Var. Domestica Linnaeus) In Korea. Korean J Parasitol 1984;22(2):215–221.
4. Erasmus DA. The host-parasite interface of Cyathocotyle bushiensis Khan, 1962 (Trematoda: Strigeoidea)l. II. Electron microscope studies of the tegument. J Parasitol 1967;53(4):703–714.
5. Fried B, Fujino T. Scanning electron microscopy of Echinostoma revolutum (Trematoda) during development in the chick embryo and the domestic chick. Int J Parasitol 1984;14(1):75–81.
6. Fujino T, Ishii Y, Cho DW. Surface ultrastructure of the tegument of Clonorchis sinensis newly excysted juveniles and adult worms. J Parasitol 1979;65(4):579–590.
7. Lee SH, Hong SJ, Chai JY, Hong ST, Seo BS. [Tegumental ultrastructures of Echinostoma hortense observed by scanning electron microscopy]. Korean J Parasitol 1986;24(1):63–70.
8. Lee SH, Hong ST, Seo BS. [A Study On The Fine Tegumental Structures Of The Metacercaria And Juvenile Stages Of Clonorchis Sinensis]. Korean J Parasitol 1982;20(2):123–132.
9. Lee SH, Seo BS, Chai JY, Hong SJ. [Study on Metagonimus yokogawai(Katsurada, 1912) in Korea VII. Electron microscopic observation on the tegumental structure]. Korean J Parasitol 1984;22(1):1–10.
10. Lumsden RD. Surface ultrastructure and cytochemistry of parasitic helminths. Exp Parasitol 1975;37(2):267–339.
11. Seo BS, Lee SH, Chai JY, Hong SJ. Studies on intestinal trematodes in Korea XX. Four cases of natural human infection by Echinochasmus japonicus. Korean J Parasitol 1985;23(2):214–220.
12. Seo BS, Lee SH, Chai JY, Hong ST, Hong SJ. [Studies on intestinal trematodes in Korea X. Scanning electron microscopic observation on the tegument of Fibricola seoulensis]. Korean J Parasitol 1984;22(1):21–29.
13. Smales LR, et al. J Helminth 1984;58:187–195.
14. Tanabe H. Nippon Byori Gakkai Kaishi 1926;16:295–296.
15. Ujiie N. . Taiwan Igakkai Zasshi 1936;35:535–546.
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