Hostname: page-component-848d4c4894-4rdrl Total loading time: 0 Render date: 2024-06-27T14:14:02.261Z Has data issue: false hasContentIssue false
  • English
  • Français

The daily cercarial emission rhythm of Schistosoma margrebowiei with particular reference to dark period stimuli

Published online by Cambridge University Press:  05 June 2009

K. Raymond  and
A. J. Probert
K. Raymond
Affiliation:
School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, UK
A. J. Probert
Affiliation:
School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The cercariae of Schistosoma margrebowiei showed two peaks of emergence from Bulinus natalensis in a 12 h light/dark cycle. Peak emission occurred at 0700 h (one hour after the onset of light) and at 1900 h (one hour after the onset of darkness). Both peaks were of equal magnitude and were maintained during constant illumination indicating that the rhythm is innate. Delaying or advancing the timing of the dark period did not affect the timing of these two peaks. Following a five minute dark treatment elevation in cercarial output resulted irrespective of when the treatment was applied. Subjecting snails to various intensities of light only resulted in an elevation in output when a sudden change in intensity from 0 to 360 Lux or the reverse was applied. No response was seen to a gradual change in light intensity although the parasite could detect a change in light from 1 to 0 Lux. These responses appear to optimize the chances of host parasite contact.

Keywords

Schistosoma margrebowieiBulinus natalensiscercarial emergenceperiodicityTrematoda
Type
Research Papers
Information
Journal of Helminthology , Volume 65 , Issue 3 , September 1991 , pp. 159 - 168
Copyright
Copyright © Cambridge University Press 1991

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

Fryer, S. E. & Probert, A. J. (1988) The cercarial output from three Nigerian bulinids infected with two strains of Schistosoma haematobium. Journal of Helminthology, 62, 133–140.Google Scholar
Nojima, H. & Sato, A. (1978) The emergence of schistosome cercariae from the snails. 1. Hourly response of Schistosoma mansoni and Schistosoma haematobium and effect of light-cut on their emergence. Japanese Journal of Parasitology, 27, 197–213.Google Scholar
Nojima, H. & Sato, A. (1982) Schistsoma mansoni and Schistosoma haematobium: Emergence of schistosome cercariae from snails with darkness and illumination. Experimental Parasitology, 53, 189–198.Google Scholar
Pitchford, R. J. & Du Toit, J. F. (1976) The shedding pattern of three little known African schistosomes under outdoor conditions. Annals of Tropical Medicine and Parasitology, 70, 181–187.Google Scholar
Pitchford, R. J., Meyling, A. H., Meyling, J. and Du Toit, J. F. (1969) Cercarial shedding patterns of various schistosome species in the Transvaal. Annals of Tropical Medicine and Parasitology, 63, 359–371.Google Scholar
Raymond, K. & Probert, A. J. (1987) The effect of light on the production of cercariae of Schistosoma haematobium from Bulinus globosus. Journal of Helminthology, 61, 291–296.CrossRefGoogle ScholarPubMed
Théron, A. (1980) Mis en evidence de races chronobiologiques de Schistosoma mansoni, agent de la bilharziose, a partir des cinetiques d'emission cercarienne. Comptes Rendu de l'Academie des Sciences, Paris Serie D, 291, 279–282.Google Scholar
Théron, A. & Moné, H. (1986) Shedding patterns of Schistosoma mansoni, and Ribeiroia marini from a mixed infection of Biomphalaria glabrata. Journal of Helminthology, 60, 255–259.CrossRefGoogle ScholarPubMed
Willimas, C. L. & Gilbertson, D. E. (1983) Effects of alterations on the heartbeat rate and locomotor activity of Schistosoma mansoni infected Bipmphalaria glabrata on cercarial emergence. Journal of Parasitology, 69, 677–681.CrossRefGoogle Scholar