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Unikaryon slaptonleyi sp.nov. (Microspora: Unikaryonidae) isolated from echinostome and strigeid larvae from Lymnaea peregra: observations on its morphology, transmission and pathogenicity

Published online by Cambridge University Press:  06 April 2009

Elizabeth U. Canning
Affiliation:
Department of Pure and Applied Biology, Imperial College, London SW7 2BB
Rosalind J. Barker
Affiliation:
Department of Pure and Applied Biology, Imperial College, London SW7 2BB
Jill C. Hammond
Affiliation:
Department of Pure and Applied Biology, Imperial College, London SW7 2BB
J. P. Nicholas
Affiliation:
Department of Pure and Applied Biology, Imperial College, London SW7 2BB

Summary

A microsporidium, isolated from echinostome and strigeid larval trematodes in Lymnaea peregra, is described as a new species Unikaryon slaptonleyi sp.nov. The nuclei isolated at all stages of development, the disporoblastic sporogony and development in contact with host cell cytoplasm are used to assign the species to the genus Unikaryon. The absence of a vacuolar membrane to isolate the meronts and stages of sporulation from the host cell cytoplasm differentiates this genus from Encephalitozoon. Spores are uninucleate, have 17–21 turns of the polar filament coil and measure 5·0 × 2·8/μm fresh. U. slaptonleyi was isolated from rediae and metacercariae of Echinoparyphium recurvatum and sporo-cysts and cercariae of an unidentified strigeid trematode in L. peregra. It was transmitted in the laboratory to unidentified echinostomes in L. peregra and to unidentified strigeids in Planorbis planorbis by feeding the spores to field-collected snails from which cercariae were already emerging. In these natural and experimental hyperinfections the snail tissues were lightly infected but, in the helminths, much of the parenchyma and germinal tissue was destroyed, so that few cercariae were released and most of those were distorted. Similar heavy infections were produced in Fasciola hepatica in Lymnaea truncatula, when spores were fed to the snails 14 days after miracidial penetration, but even high doses (106 spores/snail) produced only light infections in Schistosoma mansoni in Biomphalaria glabrata, in only 2 out of 9 snails. No infections were obtained in larvae producing xiphidiocercariae in P. planorbis although echinostomes became infected under the same conditions. Of a number of aquatic and terrestrial arthropods tested for susceptibility by feeding or by inoculation of spores into the haemocoele, only Pieris brassicae became infected. In a small proportion of pupae surviving from larvae which had been inoculated with spores at 3rd or 4th instar, there was clear evidence of spore replication.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

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References

REFERENCES

Canning, E. U. (1982). An evaluation of protozoal characteristics in relation to biological control of pests. In Parasites as Biological Control Agents (ed. Anderson, R. M. and Canning, E. U.). Parasitology 84 (4), 119–49.Google Scholar
Canning, E. U., Higby, G. C. & Nicholas, J. P. (1979). An experimental study of the effects of Nosema eurytremae (Microsporida: Nosematidae) on the liver fluke Fasciola hepatica. Parasitology 79, 381–92.CrossRefGoogle ScholarPubMed
Canning, E. U., Lai, P.-F. & Lib, K. J. (1974). Microsporidian parasite of trematode larvae from aquatic snails in West Malaysia. Journal of Protozoology 21, 1925.CrossRefGoogle ScholarPubMed
Canning, E. U. & Madhavi, R. (1977). Studies on two new species of Microsporida hyperparasitic in adult Allocreadium fasciatusi (Trematoda: Allocreadiidae). Parasitology 75, 293300.CrossRefGoogle Scholar
Canning, E. U. & Nicholas, J. P. (1974). Light and electron microscope observations on Unikaryon legeri (Microsporida, Nosematidae), a parasite of the metacerariae of Meigymno-phallus minutes in Cardium edule. Journal of Invertebrate Pathology 23, 92100.CrossRefGoogle Scholar
Canning, E. U., Olson, A. C. Jr. & Nicholas, J. P. (1983). The ultrastructure of Nosema lepocreadii Canning and Olson, 1979 (Microspore, Nosematidae) and its relevance to the generic diagnosis of Nosema Nageli, 1857. Journal of Parasitology (in the Press).CrossRefGoogle Scholar
Dollfus, R. P. (1912). Contribution a l'étude des trematodes marins des côtes du Boulonnais. Une métacercaire margaritigéne parasite de Donax villains da Costa. Mémoirs de la Société Zoologique de France 25, 85144.Google Scholar
Lai, P. F. & Canning, E. U. (1980). Infectivity of a microsporidium of mosquitoes (Nosema algerae) to larval stages of Schistosoma mansoni in Biomphalaria glabrata. International Journal for Parasitology 10, 293301.CrossRefGoogle ScholarPubMed
Mercer, I. D. (1966). The natural history of Slapton Ley Nature Reserve. 1. Introduction and morphological description. Field Studies 2, 385404.Google Scholar
Pilley, B. M., Canning, E. U. & Hammond, J. C. (1978). The use of a microinjection procedure for large scale production of the microsporidian Nosema eurytremae in Pieris brassicae. Journal of Invertebrate Pathology 32, 355–8.CrossRefGoogle Scholar
Sprague, V. & Vernick, S. H. (1971). The ultrastructure of Encephalitozoon cuniculi (Microsporida, Nosematidae) and its taxonomic significance. Journal of Protozoology 18, 560–9.CrossRefGoogle ScholarPubMed
Weidner, E. (1975). Interaction between Encephalitozoon cuniculi and macrophages. Zeitschrift für Parasitenkunde 47, 19.CrossRefGoogle ScholarPubMed