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The influence of some physico-chemical factors on the host-finding capacity of Fasciola hepatica miracidia

Published online by Cambridge University Press:  05 June 2009

Niels Ørnbjerg Christensen
Affiliation:
The Danish Agricultural and Veterinary Research Council Parasitological Research Group, Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Copenhagen V, Denmark
Peter Nansen
Affiliation:
The Danish Agricultural and Veterinary Research Council Parasitological Research Group, Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Copenhagen V, Denmark
Flemming Frandsen
Affiliation:
Danish Bilharziasis Laboratory, Jaegersborg Allé 1 D, DK-2920 Charlottenlund, Denmark

Abstract

A study was made on the host-finding capacity of Fasciola hepatica miracidia in relation to time, number of miracidia per snail, and several physico-chemical environmental factors. Specimens of Lymnaea truncatula were exposed to radiolabelled miracidia and the subsequent snail-bound radioactivity was used to measure the host-finding capacity of the larvae.

Maximum snail-bound radioactivity was achieved after 45–60 minutes exposure to miracidia in a volume of 80 ml water. The efficiency of the snail-location was unaltered up to a volume of 4.5 liters. A linear proportionality was demonstrated between the number of miracidia and the amount of radioactivity obtained in exposed snails. After 4 hours exposure snails placed in darkness took up the same amount of radioactivity as snails placed in bright illumination. Additional experiments showed that miracidia preferentially scan the lighted zone of a given environment, but if no snails are available in this zone, snails in shade are also effectively located.

The host-finding capacity was unaltered up to a salinity level of 3.79%. At 4.74% and 5.68% the snail-location proceeded at a slower rate, but the final levels reached after 3 hours were comparable to that obtained at low salinity. The over-all host-finding capacity was reduced at a salinity level of 7.58% and at 9.47% the capacity had ceased. The host-finding capacity was unaltered in the pH range 5.4 to 8.4, but it was reduced at pH 8.9. Further studies showed that the host-finding capacity was clearly inhibited in water with a high turbidity level.

Type
Reasearch Papers
Copyright
Copyright © Cambridge University Press 1978

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References

REFERENCES

Chernin, E. and Dunavan, C. A. (1962) The influence of host-parasite dispersion upon the capacity of Schistosoma mansoni miracidia to infect Australorbis glabratus. American Journal of tropical Medicine and Hygiene, 11, 445471.CrossRefGoogle ScholarPubMed
Chernin, E. and Perlstein, J. M. (1969) Further studies on the interference with the host-finding capacity of Schistosoma mansoni miracidia. The Journal of Parasitology, 55, 500508.CrossRefGoogle ScholarPubMed
Chernin, E. and Bower, C. (1971) Experimental transmission of Schistosoma mansoni in brackish waters. Parasitology, 63, 3136.CrossRefGoogle ScholarPubMed
Christensen, N. Ø., Nansen, P. and Frandsen, F. (1976a) The influence of temperature on the infectivity of Fasciola hepatica miracidia to Lymnaea truncatula. The Journal of Parasitology, 62, 698701.CrossRefGoogle ScholarPubMed
Christensen, N. Ø., Nansen, P. and Frandsen, F. (1976b) Molluscs interfering with the capacity of Fasciola hepatica miracidia to infect Lymnaea truncatula. Parasitology, 73, 161167.CrossRefGoogle ScholarPubMed
Jaeckel, S. (1950) Die Mollusken der Schlei. Archiv für Hydrobiologie, 44.Google Scholar
Nansen, P., Christensen, N. O. and Frandsen, F. (1976a) A technique for in vivo labelling of Fasciola hepatica miracidia with radioselenium. Zeitschrift für Parasitenkunde, 49, 7380.CrossRefGoogle ScholarPubMed
Nansen, P., Frandsen, F. and Christensen, N. O. (1976b) A study on snail location by Fasciola hepatica using radioisotopically labelled miracidia. Parasitology, 72, 163171.CrossRefGoogle Scholar
Over, H. J. (1967) Ecological biogeography of Lymnaea truncatula in the Netherlands. Thesis: University of Utrecht.Google Scholar
Rowcliffe, S. A. and Ollerenshaw, C. B. (1960) Observations on the bionomics of the egg of Fasciola hepatica. Annals of tropical Medicine and Parasitology, 54, 172181.CrossRefGoogle ScholarPubMed
Schermer, E. (1938) Süsswassermollusken im Brackwasser der Ostseeküste der Nordmark Heimat, Kiel 48.Google Scholar
Schiff, C. J. (1974) Seasonal factors influencing the location of Bulinus (Physopsis) globosus by miracidia of Schistosoma haematobium in nature. The Journal of Parasitology, 60, 578581.CrossRefGoogle Scholar
Styczynska-Jurewicz, E. (1965) The influence of a brackish environment on the development of eggs and viability of miracidia of Fasciola hepatica. Acta parasitologica polonica, 13, 483497.Google Scholar
Upatham, E. S. (1972) Effects of some physico-chemical factors on the infection of Biomphalaria glabrata (Say) by miracidia of Schistosoma mansoni Sambon in St. Lucia, West Indies. Journal of Helminthology, 46, 307315.CrossRefGoogle ScholarPubMed
Wilson, R. A. and Denison, J. (1970) Studies on the activity of the miracidium of the common liver fluke, Fasciola hepatica. Comparative Biochemistry and Physiology, 32, 301313.CrossRefGoogle ScholarPubMed