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Observations on the morphology of Toxocara pteropodis eggs

Published online by Cambridge University Press:  05 June 2009

Paul Prociv
Paul Prociv
Affiliation:
Department of Parasitology, The University of Queensland, St. Lucia, Queensland 4067, Australia
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Abstract

Fertile eggs of Toxocara pteropodis, passed in the faeces of juvenile flying-foxes, were ovoid to spheroid in shape with a diameter range of 80–110 µm. The shell was often seen to comprise 4 layers: a fine inner lipid layer, a thicker clear chitinous layer, an equally thick outer vitelline layer and a pitted outermost, proteinaceous uterine layer of variable thickness. Infertile eggs were less uniform in shape and generally did not have well-defined shell layers, the formation of which is triggered by sperm penetration of the oocyte. The eggs of this species are bulkier than those of related ascaridoids, apparently because of a thicker external coat which, while not providing mechanical strength, is thought to protect against desiccation. Scanning electron microscopical findings suggest that the outer layer is not applied directly by uterine cells, but forms by the gradual deposition of secretions in the uterine lumen, regardless of whether the oocyte has been fertilized.

Keywords

Toxocara pteropodisovamorphologyscanning electron microscopy
Type
Research Article
Information
Journal of Helminthology , Volume 64 , Issue 4 , December 1990 , pp. 271 - 277
Copyright
Copyright © Cambridge University Press 1990

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