Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Development of the tegument ofechinococcus granulosus (Cestoda) protoscoleces during cystic diffentiation in vivo


During the first 4 days following infection, early tegumentary changes are confined to the protoscolex soma ofEchinococcus granulosus, the thick glycocalyx being lost and the blunt elevations, flattened. The Golgi complexes within the tegumentary cytons produce T2 vesicles that increase in number in the tegument from days 4 to 12, whereas T1 vesicles decline. Spineless, truncated microtriches develop at the somal surface, and the laminated layer starts to form around the developing cyst from days 20–40 onwards. T2 vesicles do not appear to be involved in its formation and decline in number. Two additional vesicle types participate in the production of the laminated layer: T4 vesciles contribute to the carbohydrate matrix, and ‘G’ vesicles form granular accumulations. Cystic differentiation is completed after 2–3 months, when the spined microtriches and rostellar hooks of the scolex are shed into the laminated layer and replaced by truncated microtriches. These ultrastructural changes are discussed with respect to parasite survival.

This is a preview of subscription content, log in to check access.


  1. Ali-Kahn Z, Siboo R (1980) Pathogenesis and host response in subcutaneous alveolar hydatidosis: I. Histogenesis of alveolar cysts and a qualitative analysis of the inflammatory infiltrates. Z Parasitenkd 62:241–254

  2. Annen J, Köhler P, Eckert J, Speck S (1980 Cytotoxic properties ofEchinococcus granulosus cyst fluid. In: Van den Bossche H (ed) The host invader interplay. Elsevier/North-Holland Amsterdam, pp 339–342

  3. Bortoletti G, Ferretti G (1973) Investigation on larval forms ofEchinococus granulosus with electron microscope. Riv Parasitol 34:89–110

  4. Bortoletti G, Ferretti G (1978) Ultrastructural aspects of fertile and sterile cysts ofEchinococcus granulosus developed in hosts of different species. Int J Parasitol 8:421–431

  5. Coltorti EA, Varela-Diaz VM (1975) Penetration of host IgG molecules into hydatid cysts. Z Parasitenkd 48:47–51

  6. Conder GA, Marchiondo AA, Williams F, Andersen FL (1983) Freeze-etch characterization of the teguments of three metacestodes:Echinococcus granulosus, Taenia crassiceps, andTaenia taeniaeformis. J Parasitol 69:539–548

  7. Dixon JB, Jenkins P, Allan D (1982)Immune recognition ofEchinococcus granulosus: I Parasite- activated, primary transformation by normal murine lymph node cells. Parasite Immunol 4:33–45

  8. Heath DD (1986) Immunobiology ofEchinococcus infections. In: Thompson RCA (ed). The biology ofEchinococcus and hydatid disease. Allen and Unwin, London, pp 164–182

  9. Hess E (1980) Ultrastructural study of the tetrathyridium ofMesocestoides corti Hoeppli, 1925: tegument and parenchyma. Z. Parasitenkd 61:135–159

  10. Jha RK, Smyth JD (1971) Ultrastructure of the rostellar tegument ofEchinococcus granulosus with special reference to the biogenesis of mitochondria. Int J Parasitol 1:169–177

  11. Lascano EF, Coltorti EA, Varela-Diaz VM (1975) Fine structure of the germinal membrane ofEchinococus granulosus cysts. J Parasitol 61:853–860

  12. Lopez-Campos JL, Linares J, Alonso J, Aneiros J, Diaz-Flores L (1978) Estudio de la capa laminada, membranas germinativas y tegumento del protoscolex delEchinococcus granulosus en su localisacion humana. Morphol Norm Patol 2:99–109

  13. Lumsden RD, Hildreth MB (1983) The fine structure of adult tapeworms. In: Arme C, Pappas P (eds) Biology of the Eucestoda. Academic Press, London, pp. 177–227

  14. Lumsden RD, Oaks JA, Mueller JF (1974) Brush border development in the tegument of the tapewormSpirometra mansonoides. J Parasitol 60:209–226

  15. Lumsden RD, Voge M, Sogandares-Bernal F (1982) The metacestode integument: fine structure, development, topochemistry and interaction with the host. In Flisser A, Willms K, Laclette JP, Larralde C, Ridaura C Beltran F (eds) Cysticercosis: present state of knowledge and perspectives. Academic Press. New York London, pp 307–361

  16. Morseth JD (1967) Fine structure of the hydatid cyst and protoscolex ofEchinococcus granulosus. J Parasitol 53:312–325

  17. Richards KS (1984)Echinococcus granulosus equinus: the histochemistry of the laminated layer of the hydatid cyst. Folia Histochem Cytobiol 22:21–32

  18. Richards KS, Arme C (1984) Maturation of the scolex'syncytium of the metacestode ofHymenolepis diminuta, with special reference to microthrix formation. Parasitology 88:341–349

  19. Richards KS, Arme C, Bridges JF (1983)Echinococcus granulosus equinus: an ultrastructural study of the laminated layer, including changes on incubating cysts in various media. Parasitology 86:399–405

  20. Richards KS, Arme C, Bridges JF (1984)Echinococcus granulosus equinus: variation in the germinal layer of murine hydatids and evidence of autophagy. Parasitology 89:35–47

  21. Rickard MD, Williams JF (1982) Hydatidosis/cysticercosis: Immune mechanisms and immunization against infection. Adv Parasitol 21:229–296

  22. Robinson RD, Arme C (1986)Echinococcus granulosus: effect of protoscoleces on murine macrophage activation. Hchminthologia 23:201–209

  23. Rogan MT (1987)Echinococcus granulosus: studies on the development of the metacestode tegument. PhD Thesis, University of Keele

  24. Rogan MT, Richards KS (1986) In vitro development of hydatid cysts from posterior bladders and ruptured brood capsules of equineEchinococcus granulosus. Parasitology 92:379–390

  25. Rogan MT, Richards KS (1987)Echinococcus granulosus: changes in the surface ultrastructure during protoscolex formation. Parasitology 94:359–367

  26. Sakamoto L, Sugimura M (1970) Electron microscopical observations on histogenesis of larvaEchinococcus multilocularis. Jpn J Vet Res 18:131–144

  27. Singh G, Lee RE (1979) Ultrastructure of the hydatid cyst. Arch Pathol Lab Med 103:459–462

  28. Smyth JD (1962) Studies on tapeworm physiology: X. Axenic cultivation of the hydatid organism,Echinococcus granulosus: establishment of a basic technique. Parasitology 52:441–457

  29. Smyth JD (1967) Studies on tapeworm physiology: XI. In vitro cultivation ofEchinococcus granulosus from the protoscolex to the strobilate stage. Parasitology 57:111–133

  30. Smuth JD (1979)Echinococcus granulosus andE. multilocularis: in vitro culture of the strobilar stages from protoscoleces. Angew Parasitol 20:137–147

  31. Smyth JD, Davies Z (1974) In vitro culture the strobilar stage ofEchinococcus granulosus (sheep strain): a review of basic problems and results. Int J Parasitol 4:631–644

  32. Timofeev VA, Kuperman BI (1972) Origin and formation of microtricha in Cestoda exemplified onTriaenophorus nodulosus-an electron-optic study. Dokl Akad Nauk SSSR 207:757–759

  33. Trimble JJ, Lumsden RD (1975) Cytochemical characterization of tegument membrane-associated carbohydrates inTaenia crassiceps larvae. J Parasitol 61:665–672

  34. Williams JF, Picone J, Engelkirk P (1980) Evasion of immunity by cestodes In: Van den Bossche H (ed) The host invader interplay. Elsevier/North-Holland, Amsterdam, pp 205–216

Download references

Author information

Correspondence to M. T. Rogan.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Rogan, M.T., Richards, K.S. Development of the tegument ofechinococcus granulosus (Cestoda) protoscoleces during cystic diffentiation in vivo. Parasitol Res 75, 299–306 (1989).

Download citation


  • Carbohydrate
  • Ultrastructural Change
  • Golgi Complex
  • Granular Accumulation
  • Laminate Layer