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The tegument in Hemiuridae (Digenea: Hemiuroidea): structure and function in the adult

Published online by Cambridge University Press:  05 June 2009

B. F. Matthews
Affiliation:
Department of Biological Sciences, Plymouth Polytechnic, Drake Circus, Plymouth, Devon PL4 8AA, UK
R. A. Matthews
Affiliation:
Department of Biological Sciences, Plymouth Polytechnic, Drake Circus, Plymouth, Devon PL4 8AA, UK

Abstract

The teleost stomach, as a site of strong acid proteolytic digestion at pH 1–4, is a hostile environment rarely chosen as a habitat by parasites. Several Hemiuroidea have nevertheless invaded this niche, notably the Hemiuridae, a family in which the body is characterized by a retractile “tail”, or ecsoma. The structure and function of the latter has been studied in three hemiurid species, namely Hemiurus communis, Lecithochirium rufoviride and L. fusiforme, using ultrastructural, histochemical and autoradiographic techniques. Results indicate a clear demarcation between the function of the tegument covering the ecsoma and that of the rest of the body, or soma. No mitochondria have been observed in the ecsomal tegument, and intense acid phosphatase activity was detected in association with its outer plasma membrane. Uptake of 3H-tyrosine occurred within the excretory vesicle, which may serve for transport of nutrients forwards into the soma. In contrast, the thickened, dense somal tegument, with few mitochondria largely confined to ridges or plications in H. communis, showed neither phosphatase activity nor uptake of tyrosine. Glucose uptake was not detected in any part of the body. That the somal tegument serves not for absorption but for protection against both physico-chemical conditions and mechanical damage by prey entering the host's stomach is discussed.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1988

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References

Drury, R. A. B. & Wallington, E. A. (1967) Carleton's Histological Technique. Oxford University Press: New York/Toronto.Google Scholar
Dunn, T. S., Hanna, R. E. B. & Nizami, W. A. (1987) Ultrastructural and cytochemical observations on the tegument of three species of paramphistomes (Platyhelminthes: Digenea) from the Indian water buffalo,Bubalus bubalis. International Journal for Parasitology, 17, 11531161.CrossRefGoogle ScholarPubMed
Dunn, T. S., Nizami, W. A. & Hanna, R. E. B. (1985) Studies on the ultrastructure and histochemistry of the lymph system in three species of amphistome (Trematoda: Digenea) Gigantocotyle explanatum, Gastrothylax crumenifer and Srivastavaia indica from the Indian water buffalo Bubalus bubalis. Journal of Helminthology, 59, 118.CrossRefGoogle ScholarPubMed
Erasmus, D. A. (1972) The Biology of Trematodes. Edward Arnold: London.Google Scholar
Gallagher, S. S. E. & Threadgold, L. T. (1967) Electron microscope studies of Fasciola hepatica. The interrelationship of the parenchyma with other organ systems. Parasitology, 57, 627632.CrossRefGoogle Scholar
Gibson, D. I. & Bray, R. A. (1979) The Hemiuroidea: terminology, systematics, and evolution. Bulletin of the British Museum (Natural History): Zoology series, 36, 35146.CrossRefGoogle Scholar
Gibson, D. I. & Bray, R. A. (1986) The Hemiuridae (Digenea) of fishes from the north-east Atlantic. Bulletin of the British Museum (Natural History): Zoology series, 51, 1125.Google Scholar
Hanna, R. E. B. (1975) Fasciola hepatica: an electron microscope autoradiographic study of protein synthesis and secretion by gut cells in tissue slices. Experimental Parasitology, 38, 167180.CrossRefGoogle ScholarPubMed
Higgins, J. C. (1979) The role of the tegument of the metacercarial stage of Bucephalus haimeanus (Lacaze-Duthiers, 1854) in the absorption of particulate material and small molecules in solution. Parasitology, 78, 99106.CrossRefGoogle Scholar
Howells, R. E. (1969) Observations on the nephridial system of the cestode Moniezia expansa (Rud., 1805). Parasitology, 59, 449459.CrossRefGoogle ScholarPubMed
Isseroff, H. & Read, C. P. (1969) Studies on membrane transport—VI. Absorption of amino acids by fascioliid trematodes. Comparative Biochemistry and Physiology, 30, 11531159.CrossRefGoogle ScholarPubMed
Jahn, T. L. & Jahn, F. L. (1949) How to know the Protozoa. W. C. Brown: Dubuque, Iowa.Google Scholar
Johnson, A., Bhatti, I. & Kanemoto, N. (1971) Structure and function of the holdfast organ and lappets of Alaria marcianae (La Rue, 1917) (Trematoda: Diplostomatidae). Journal of Parasitology, 57, 235243.CrossRefGoogle Scholar
Kryvi, H. (1972) The ultrastructure of the external tegument of Derogenes varicus and Hemiurus communis (Trematoda). Norwegian Journal of Zoology, 20, 243254.Google Scholar
Lewis, P. R. & Knight, D. P. (1977) Staining methods for sectioned material. In: Practical Methods for Elecron Microscopy(editor, Glauert, A. M.), Vol. 5, pt. 1, 311 pp.Google Scholar
Mackenzie, K. & Gibson, D. I. (1970) Ecological studies on some parasites of plaice, Pleuronectes platessa (L.) and flounder Platichthys flesus (L.) Symposia of the British Society for Parasitology, 8, 142.Google Scholar
Pearse, A. G. E. (1968) Histochemistry: Theoretical and Applied, Vol. 1. Churchill Livingstone: London.Google Scholar
Pearse, A. G. E. (1972) Histochemistry: Theoretical and Applied, Vol. 2. Churchill Livingstone: London.Google Scholar
Reynolds, B. S. (1963) The use of lead citrate at high pH as an electron opaque stain in electron microscopy. Journal of Cell Biology, 17, 208212.CrossRefGoogle ScholarPubMed
Spurr, A. R. (1969) A low viscosity epoxy resin embedding medium for electron microscopy. Journal of Ultrastructure Research, 26, 3143.CrossRefGoogle ScholarPubMed
Threadgold, L. T. (1968) Electron microscope studies of Fasciola hepatica, VI. The ultrastructural localisation of phosphatases. Experimental Parasitology, 23, 264276.CrossRefGoogle ScholarPubMed
Threadgold, L. T. & Gallagher, S. S. E. (1966) Electron microscope studies of Fasciola hepatica 1. The ultrastructure and interrelationships of the parenchymal cells. Parasitology, 56, 299304.CrossRefGoogle Scholar
Young, J. Z. (1933) The preparation of isosonic solutions for use in experiments with fish. Pubblicazioni della Stazione zoologica di Napoli, 12, 425431.Google Scholar