Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-26T03:19:24.688Z Has data issue: false hasContentIssue false
  • English
  • Français

Excystment of the Metacercariae of Echinoparyphium serratum (Trematoda: Echinostomatidae)

Published online by Cambridge University Press:  05 June 2009

M. J. Howell
M. J. Howell
Affiliation:
Australian National University, Canberra
Get access Rights & Permissions [Opens in a new window]

Extract

1. Metacercarial cysts of Echinoparyphium serratum occur in the pericardium of the snail Isidorella brazieri. Each cyst is surrounded by a nucleated, syncytial host capsule containing granules which are presumed to be melanin. The cyst wall consists of two layers and both contain acid and neutral mucopolysaccharide but little or no protein. No modification of the cyst wall coincident with the point of emergence of the metacercaria has been located.

2. Excystment of the metacercaria takes place in two main stages when pepsin is omitted from the initial pretreatment solution: stage I (emergence from the cyst wall through the escape aperture) is an active process (exogenous enzymes are not necessary), and a high percentage of specimens reaching this stage is dependent on the combined effects of a þH of 2, reducing conditions, elevated temperature (37–39°C) and sodium cholate. Temperature and sodium cholate are absolute requirements for this stage as is pretreatment of between þH 2 and 4 when sodium cholate is included with the reductant (sodium dithionite) rather than in the excystment medium with trypsin. The possibility that CO2 is involved has not been established.

Type
Research Article
Information
Journal of Helminthology , Volume 44 , Issue 1 , March 1970 , pp. 35 - 56
Copyright
Copyright © Cambridge University Press 1970

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Adams, J. E. and Martin, W. E., 1963.—“Life cycle of Himasthla rhigedana Dietz, 1909 (Trematoda: Echinostomatidae).” Trans. Am. microsc. Soc., 82, 1–0.CrossRefGoogle Scholar
Beaver, P. C., 1941.—“Studies on the life history of Euparyphium melts (Trematoda: Echinostomidae).” J. Parasit., 27, 35–44.CrossRefGoogle Scholar
Bisseru, B., 1967.—“Stages in the development of larval echinostomes recovered from schistosome transmitting molluscs in central Africa.” J. Helminth., 41, 89–108.CrossRefGoogle Scholar
Bogitsh, B. J., 1962.—“The chemical nature of metacercarial cysts. I. Histological and histochemical observations on the cyst of Posthodiplostomum minimum.” J. Parasit., 48, 55–60.CrossRefGoogle ScholarPubMed
Bullock, T. H., 1957.—“The trigger concept in biology.” In Physiological Triggers and Discontinuous Rate Processes, pp. 1–8. Ed. Bullock, T. H.. American Physiological Society, Washington.Google Scholar
Cheng, T. C., Shuster, C. N. and Anderson, A. H., 1960.—“A comparative study of the susceptibility and response of eight species of marine pelecypods to the trematode Himasthla quissetensis.” Trans. Am. microsc. Soe., 85, 284–295.CrossRefGoogle Scholar
Dixon, K. E., 1906.—“The physiology of excystment of the metacercaria of Fasciola hepatica L.” Parasitology, 56, 431–456.CrossRefGoogle Scholar
Erasmus, D. A., 1967.—“Histochemical observations on the structure and composition of the cyst wall enclosing the metacercaria of Cyathocotyle bushiensis Khan, 1962. (Strigeoidea: Trematoda).” J. Helminth., 41, 11–14.CrossRefGoogle Scholar
Erasmus, D. A., AND Bennett, L. J., 1965.—“A study of some of the factors affecting excystation in vitro of the metacercarial stages of Holostephanus liihei Szidat, 1936 and Cyathocotyle bushiensis Khan, 1962 (Strigeida: Trematoda).” J. Helminth., 39, 185–196.CrossRefGoogle Scholar
Howell, M. J., 1968a.—“The life-cycle of Echinoparyphium serratum sp. nov. (Digenea: Echinostomatidae).” Parasitology, 58, 573–582.CrossRefGoogle ScholarPubMed
Howell, M. J., 1968b.—“Excystment and in vitro cultivation of Echinoparyphium serratum.” Parasitology, 58, 583–597.CrossRefGoogle ScholarPubMed
Jackson, A. R. B., 1962.—“Excystation of Eimeria arloingi (Marotel, 1905): stimuli from the host sheep.” Nature, Lond., 194, 847–849.CrossRefGoogle Scholar
Krull, V. H. and Price, H. F., 1932.—“Studies on the life history of Diplodiscus temperatus Stafford from the frog.” Occ. Pap. Mus. Zool. Univ. Mich., no. 237, 38 pp.Google Scholar
Loomis, W. E., 1959.—“Feedback control of growth and differentiation. Carbon dioxide tension and related metabolic variables.” In Cell, Organisvi and Milieu, pp. 272–294. Ed. Rudnick, D.. Ronald Press, New York.Google Scholar
Mcdaniel, J. S., 1966.—“Excystment of Cryplocotyle lingua metacercariae.” Biol. Bull. mar. biol.Lab., Woods Hole, 130, 369–377.CrossRefGoogle ScholarPubMed
Macy, R. W., Berntzen, A. K. and Benz, M. 1968.—“In vitro excystation of Sphaeridiotrema globulus metacercariae, structure of cyst, and the relationship to host specificity.” J. Parasit., 54, 28–38.CrossRefGoogle ScholarPubMed
Mowry, R. W., 1963.—“The special value of methods that color both acidic and vicinal hydroxyl groups in the histochemical study of mucins. With revised directions for the colloidal iron stain, the use of Alcian blue G8X and their combinations with the periodic acid?—Schiff reaction.” Ann. N.Y. Acad. Sci., 106, 402–423.CrossRefGoogle Scholar
Patnaik, M. M. and Ray, S. K., 1966.—“A histopathologic study of Lymnaea auricularia var. rufescens infected with the larval stages of Echinostoma revolutum.” Jap. J. med. Sci. Biol., 19, 253–258.CrossRefGoogle Scholar
Pearse, A. G. E., 1961.—Histochemistry: Theoretical and Applied, 998 pp., 2nd ed.J. & A. Churchill Ltd., London.Google Scholar
Pike, A. W. and Erasmus, D. A., 1967.—“The formation, structure and histochemistry of the metacercarial cyst of three species of digenetic trematodes.” Parasitology, 57, 683–694.CrossRefGoogle ScholarPubMed
Rai, D. N. and Pande, B. P., 1967.—“On the metacercaria in Viviparus bengalensis (Lamarck) race mandiensis Kobelt and observations on an experimental infection with the echinostome form.” Z. ParasitKde, 28, 264–276.Google Scholar
Rogers, W. P., 1960.—“The physiology of infective processes of nematode parasites; the stimulus from the animal host.” Proc. R. Soc., B, 152, 367–386.Google ScholarPubMed
Rogers, W. P., 1966.—“The reversible inhibition of exsheathment in some parasitic nematodes.” Comp. Biochem. Physiol., 17, 1103–1110.CrossRefGoogle Scholar
Rogers, W. P., AND Sommerville, R. I., 1963.—“The infective stage of nematode parasites and its significance in parasitism.” In Advances in Parasitology (ed. Dawes, B.), 1, 109–177.CrossRefGoogle ScholarPubMed
Ždàrskà, Z., 1964.—“Method for obtaining metacercariae from cysts in vitro.” Čslkà. Parasit., 11, 343–345.Google Scholar