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Pulsed transmission of Pseudodiplorchis americanus (Monogenea) between desert hosts (Scaphiopus couchii)

Published online by Cambridge University Press:  06 April 2009

R. C. Tinsley
Affiliation:
School of Biological Sciences, Queen Mary College, London University, Mile End Road, London E1 4NS
Helen C. Jackson
Affiliation:
School of Biological Sciences, Queen Mary College, London University, Mile End Road, London E1 4NS

Summary

Transmission of the monogenean Pseudodiplorchis americanus is restricted to the brief period when its host, the desert toad Scaphiopus couchii enters temporary water to breed. This study followed parasite recruitment into one host population in Arizona, USA, during the spawning season (July). Torrential rainfall triggered 3 successive assemblies. Amongst males, which may enter each assembly, the 3 pulses of invasion led to an approximate doubling of mean worm burdens at each exposure, culminating in 100% prevalence and a mean intensity of over 100 larvae/host. Females, which generally enter only one assembly, acquired a mean of about 40 larvae/host. Each exposure is limited to a maximum of 7 h by strictly nocturnal host activity, and the force of infection increased exponentially: around 10% of recruitment occurred in the first 3 h, and more than 30% in the last 1 h. Correlation of recruitment into males with parasite reproductive potential suggests that individual oncomiracidia had a 30% chance of invasion. Although invasion of the desert host relies on an aquatic infective stage, host behaviour ensures that targets are concentrated in space and time, and the parasite's annual reproductive output is synchronized with a period of host vulnerability totalling less than 24 h/year.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1988

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References

REFERENCES

Anderson, R. M. & Crombie, J. A. (1985). Experimental studies of age-intensity and age-prevalence profiles of infection: Schistosoma mansoni in snails and mice. In Ecology and Genetics of Host-Parasite Interactions, (ed. Rollinson, D. and Anderson, R. M.), pp. 111–45 Linnean Society Symposium Series No. 11.Google Scholar
Bundy, D. A. P. (1986). Epidemiological aspects of Trichuris and trichuriasis in Caribbean communities. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 706–18.CrossRefGoogle ScholarPubMed
Bundy, D. A. P., Cooper, E. S., Thompson, D. E., Anderson, R. A. & Didier, J. M. (1987). Agerelated prevalence and intensity of Trichuris trichiura infection in a St. Lucian community. Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 8594.CrossRefGoogle Scholar
Bundy, D. A. P., Cooper, E. S., Thompson, D. E., Didier, J. M. & Simmons, I. (1987). Epidemiology and population dynamics of Ascaris lumbricoides and Trichuris trichiura infection in the same community. Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 987–93.CrossRefGoogle ScholarPubMed
Elkins, D. B., Haswell-Elkins, M. & Anderson, R. M. (1988). The importance of host age and sex to patterns of reinfection with Ascaris lumbricoides following mass anthelmintic treatment in a South Indian fishing community. Parasitology 96, 171–84.CrossRefGoogle Scholar
Jackson, H. & Tinsley, R. C. (1988). The capacity for viable egg production by the monogenean Protopolystoma xenopodis in single and multiple infections. International Journal for Parasitology 18, 585–9.CrossRefGoogle Scholar
Margolis, L., Esch, G. W., Holmes, J. C., Kuris, A. M. & Schad, G. A. (1982). The use of ecological terms in parasitology. (Report of an ad hoc committee of the American Society of Parasitologists). Journal of Parasitology 68, 131–3.CrossRefGoogle Scholar
McClanahan, L. Jr (1967). Adaptations of the spadefoot toad, Scaphiopus couchi, to desert environments. Comparative Biochemistry and Physiology 20, 7399.CrossRefGoogle Scholar
Nawalinski, T., Schad, G. A. & Chowdhury, A. B. (1978). Population biology of hookworms in children in rural West Bengal. II. Acquisition and loss of hookworms. American Journal of Tropical Medicine and Hygiene 27, 1162–73.CrossRefGoogle ScholarPubMed
Ruibal, R., Tevis, L. Jr & Roig, V. (1969). The terrestrial ecology of the Spadefoot Toad Scaphiopus hammondii. Copeia 1969, 571–84.CrossRefGoogle Scholar
Smith, G. (1988). The population biology of the parasitic stages of Haemonchus contortus. Parasitology 96, 185–95.CrossRefGoogle ScholarPubMed
Tinsley, R. C. (1983). Ovoviviparity in platyhelminth life cycles. In The Reproductive Biology of Parasites. Symposia of the British Society for Parasitology, vol 20, (ed. Whitfield, P. J.). Parasitology 86 (4), 161–96.CrossRefGoogle Scholar
Tinsley, R. C. (1984). Pulsed parasite transmission between desert-adapted amphibians. Parasitology 89, vi.Google Scholar
Tinsley, R. C. & Earle, C. M. (1983). Invasion of vertebrate lungs by the polystomatid monogeneans Pseudodiplorchis americanus and Neodiplorchis scaphiopodis. Parasitology 86, 501–17.CrossRefGoogle Scholar
Tinsley, R. C. & Jackson, H. C. (1986). Intestinal migration in the life-cycle of Pseudodiplorchis americanus (Monogenea). Parasitology 93, 451–69.CrossRefGoogle Scholar
Warren, K. S. (1973). Regulation of the prevalence and intensity of schistosomiasis in man: immunology or ecology? Journal of Infectious Diseases 127, 595609.CrossRefGoogle ScholarPubMed
Wells, K. D. (1977). The social behaviour of anuran amphibians. Animal Behaviour 25, 666–93.CrossRefGoogle Scholar