Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-24T11:29:16.705Z Has data issue: false hasContentIssue false

The influence of environmental temperature upon transmission of the cercariae of Echinostoma liei (Digenea: Echinostomatidae)

Published online by Cambridge University Press:  06 April 2009

N. A. Evans
Affiliation:
Department of Zoology, King's College London, Strand, London WC2R 2LS

Extract

The survival and infectivity characteristics of the cercariae of Echinostoma liei are described for 6 different water temperatures in the range 12–40 °C. Cercarial survival steadily decreased with increasing temperature, the maximum survival time falling from 75 h at 12 °C to approximately 8 h at 40 °C. Changes in environmental temperature affected the infectivity even of freshly emitted cercariae but their most noticeable effect was upon the rate at which infectivity diminished with increasing cercarial age. Infectivity rose from zero at 12 °C to a maximum at 30 °C before declining to a low level at 40 °C. The transmission efficiency of the cercariae at each temperature was calculated as the ratio of the instantaneous per capita rates of mortality and infection respectively. The efficiency of transmission was high between 19 and 30 °C, suggesting that cercariae are well adapted for transmission at water temperatures likely to be encountered in natural habitats.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1985

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

Anderson, R. M., Mercer, J. G., Wilson, R. A. & Carter, N. P. (1982). Transmission o. Schistosoma mansoni from man to snail: experimental studies of miracidial survival and infectivity in relation to larval age, water temperature, host size and host age. Parasitology 85, 339–60.CrossRefGoogle Scholar
Anderson, R. M. & Whitfield, P. J. (1975). Survival characteristics of the free-living cercarial population of the ectoparasitic digenea. Transversotrema patialense (Soparker, 1924). Parasitology 70, 295310.CrossRefGoogle Scholar
Christensen, N. Ø., Frandsen, F. & Roushdy, M. Z. (1980). The influence of environmental conditions and parasite-intermediate host-related factors on the transmission o. Echinostoma liei. Zeitschrift für Parasitenkunde 63, 4763.CrossRefGoogle Scholar
Demian, E. S. & Kamel, E. G. (1972). Growth and population dynamics o. Bulinus truncatus under semi-field conditions in Egypt. Proceedings of The Egyptian Academy of Science 25, 3760.Google Scholar
De Witt, W. B. (1955). Influence of temperature on penetration of snail hosts b. Schistosoma mansoni miracidia. Experimental Parasitology 4, 271–6.CrossRefGoogle Scholar
De Witt, W. B. (1965). Effects of temperature on penetration of mice by cercariae o. Schistosoma mansoni. American Journal of Tropical Medicine and Hygiene 14, 579–80.CrossRefGoogle Scholar
El Emam, M. A. & Madsen, H. (1982). The effect of temperature, darkness, starvation and various food types on growth, survival and reproduction of Helisoma duryi, Biomphalaria alexandrina and Bulinus truncatus (Gastropoda:Planorbidae). Hydrobiologia 88, 265–75.CrossRefGoogle Scholar
Evans, N. A. & Gordon, D. M. (1983). Experimental studies on the transmission dynamics of the cercariae o. Echinoparyphium recurvatum (Digenea: Echinostomatidae). Parasitology 87, 167–74.CrossRefGoogle Scholar
Gohar, H. A. F. & El Gindy, H. I. (1961). The ecology of Egyptian snail vectors of bilharziasis and fascioliasis. I. Physical factors. Proceedings of the Egyptian Academy of Science 15, 70–8.Google Scholar
Jeyarasasingham, U., Heyneman, D., Lim, H. K. & Mansour, N. (1972). Life-cycle of a new echinostome from Egypt. Echinostoma liei sp.nov. (Trematoda: Echinostomatidae). Parasitology 65, 203–22.CrossRefGoogle Scholar
Lawson, J. R. & Wilson, R. A. (1980). The survival of the cercariae o. Schistosoma mansoni in relation to water temperature and glycogen utilization. Parasitology 81, 337–48.CrossRefGoogle Scholar
May, R. M. & Anderson, R. M. (1978). Regulation and stability of host–parasite population interactions. II. Destabilizing processes. Journal of Animal Ecology 47, 249–68.CrossRefGoogle Scholar
Mousa, A. H. & El Hassan, A. A. A. (1972). The effect of water temperature on the snail intermediate hosts of schistosomiasis in Egypt. Journal of the Egyptian Medical Association 55, 148–65.Google ScholarPubMed
Prah, S. K. & James, C. (1977). The influence of physical factors on the survival and infectivity of miracidia of Schistosoma mansoni and S. haematobium. I. Effect of temperature and ultra-violet light. Journal of Helminthology 51, 7385.CrossRefGoogle ScholarPubMed
Purnell, R. E. (1966 a). Host-parasite relationships in schistosomiasis. I. The effect of temperature on the infection of Biomphalaria sudanica tanganyicensis with Schistosoma mansoni miracidia and of laboratory mice with Schistosoma mansoni cercariae. Annals of Tropical Medicine and Parasitology 60, 90–3.CrossRefGoogle ScholarPubMed
Purnell, R. E. (1966 b). Host–parasite relationships in schistosomiasis. III. The effect of temperature on the survival of Schistosoma mansoni miracidia and on the survival and infectivity of Schistosoma mansoni cercariae. Annals of Tropical Medicine and Parasitology 60, 182–6.CrossRefGoogle Scholar
Standen, O. D. (1952). Experimental infection o. Australorbis glabratus with Schistosoma mansoni. I. Individual and mass infection of snails and the relationship of infection to temperature and season. Annals of Tropical Medicine and Parasitology 46, 4856.CrossRefGoogle Scholar
Stirewalt, M. A. & Fregeau, W. A. (1965). Effect of selected experimental conditions on penetration and maturation o. Schistosoma mansoni in mice. I. Environmental. Experimental Parasitology 17, 168–79.CrossRefGoogle Scholar