Hostname: page-component-77f85d65b8-7lfxl Total loading time: 0 Render date: 2026-04-18T18:06:57.363Z Has data issue: false hasContentIssue false
  • English
  • Français

Ultrastructure of the digestive and protonephridial systems of the metacercaria of Euclinostomum multicaecum

Published online by Cambridge University Press:  05 June 2009

P. Ramasamy ,
G.P. Brennan  and
K. Stalin
P. Ramasamy
Affiliation:
Department of Zoology, Life Sciences Building, University of Madras, Chennai 600025, India
G.P. Brennan*
Affiliation:
School of Biology and Biochemistry, The Queen's University of Belfast, Belfast, BT9 7BL, UK
K. Stalin
Affiliation:
Department of Zoology, Life Sciences Building, University of Madras, Chennai 600025, India
*
*Fax: 01232 236505 E-mail: g.brennan@qub.ac.uk
Get access Rights & Permissions [Opens in a new window]

Abstract

The structure of the digestive tract of Euclinostomum multicaecum (Digenea: Euclinostomatidae) is unusual, comprising several main lateral caeca which extend posteriorly and further divide, giving rise to numerous smaller branches which are widely distributed throughout the fluke. These multicaeca presumably promote nutrient absorption during rapid and prolonged feeding directly following excystment. The caecal wall consists of a syncytial gastrodermal epithelium, bearing loop-like lamellae which extend into the lumen and enclose spherical inclusion bodies and presumably also, increase the absorptive surface area. There was no evidence of endo- or exocytosis, nor were lysosomes, phagosomes or residual bodies observed. The gut caeca are supported by a fibrous basal lamina and an underlying layer of muscle fibres, while parenchymal cells occupy much of the extracellular space. The protonephridial system resembles that observed in other digeneans consisting of flame cells and collecting ducts which join to form a bladder that opens externally through a single excretory pore. The syncytial epithelium of the collecting ducts is elevated by numerous lamellae while the basal lamina is highly infolded. The luminal contents of these ducts comprise bar-shaped crystalline structures, lipid droplets and electron-dense inclusion bodies. The excretory system is supported by a network of muscle fibres and parenchymal cells.

Information

Type
Research Papers
Information
Journal of Helminthology , Volume 72 , Issue 3 , September 1998 , pp. 243 - 249
Copyright
Copyright © Cambridge University Press 1998

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.)

Article purchase

Temporarily unavailable

References

Bennett, C.E. (1977) Fasciola hepatica: development of excretory and parenchymal systems during migration in the mouse. Experimental Parasitology 41, 43–53.CrossRefGoogle ScholarPubMed
Bennett, C.E. & Threadgold, L.T. (1973) Electron microscope studies of Fasciola hepatica. XIII. Fine structure of the newly excysted juvenile. Experimental Parasitology 34, 85–99.CrossRefGoogle Scholar
Bock, D. (1989) Hatching mechanism of the metacercaria of Plagiorchis species 1 (Trematoda: Plagiorchiidae). Journal of Helminthology 63, 153–171.CrossRefGoogle Scholar
Dunn, T.S., Hanna, R.E.B. & Nizami, W.A. (1987) Ultra-structural and histochemical observations on the foregut and gut caeca of Gigantocotyle explanatum, Gastrothylax crumenifer and Srivastavaia indica (Trematoda: Paramphis-tomidae). International Journal for Parasitology 17, 1141–1152.CrossRefGoogle Scholar
Erasmus, D.A. (1972) The biology of trematodes. London, Edward Arnold.Google Scholar
Halton, D.W. (1982) An unusual structural organization to the gut of a digenetic trematode, Fellodistomum fellis. Parasitology 85, 3–60.CrossRefGoogle Scholar
Kawana, H. (1940) Study of the development of the excretory system of Fasciola hepatica L. with special reference to its first intermediate host in Central China. Journal of the Shanghai Science Institute 5, 13–34.Google Scholar
Lackie, A.M. (1975) The activation of infective stages of endoparasites of vertebrates. Biological Review 50, 285–323.CrossRefGoogle ScholarPubMed
Martin, W.E. & Bils, R.F. (1964) Trematode excretory concretions: formation and fine structure. Journal of Parasitology 50, 337–344.CrossRefGoogle ScholarPubMed
Mattison, R.G., Hanna, R.E.B. & Nizami, W.A. (1992a) Ultrastructure and histochemistry of the digestive tract of juvenile Paramphistomum epiclitum (Paramphistomidae: Digenea) during migration in Indian ruminants. International journal for Parasitology 22, 1089–1101.CrossRefGoogle ScholarPubMed
Mattison, R.G., Hanna, R.E.B. & Nizami, W.A. (1992b) Ultrastructure and histochemistry of the protonephridial system of juvenile Paramphistomum epiclitum and Fischoederius elongatus (Paramphistomidae: Digenea) during migration in Indian ruminants. International Journal for Parasitology 22, 1103–1115.CrossRefGoogle ScholarPubMed
Powell, E.C. (1977) Ultrastructural development of the excretory bladder in the early metacercariae of Ochetosoma aniarum (Leidy, 1891). Proceedings of the Helminthological Society of Washington 44, 136–141.Google Scholar
Smyth, J.D. (1994) An introduction to animal parasitology. 3rd edn.Cambridge, Hodder & Stoughton.Google Scholar
Smyth, J.D. & Halton, D.W. (1983) The physiology of trematodes. Cambridge, Cambridge University Press.Google Scholar
Sturkie, P.D. (1986) Avian physiology. New York, Cornell University Press.CrossRefGoogle Scholar
Sukhdeo, M.V.K. & Mettrick, D.F. (1986) The behaviour of juvenile Fasciola hepatica. Journal of Parasitology 72, 492–497.CrossRefGoogle ScholarPubMed
Threadgold, L.T. & Brennan, G.P. (1978) Fasciola hepatica: basal infolds and associated vacuoles of the tegument. Experimental Parasitology 46, 300–316.CrossRefGoogle ScholarPubMed
Tubangui, M.A. & Masilungan, V.A. (1935) Trematode parasites of Philippine vertebrates VII. Additional records of new species. The Philippine Journal of Science 58, 435–445.Google Scholar
Wilson, R.A. (1967) The protonephridial system in the miracidium of the liver fluke, Fasciola hepatica L. Comparative Biochemistry and Physiology 20, 337–342.CrossRefGoogle Scholar