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Temporal changes in aggregation: a laboratory study

Published online by Cambridge University Press:  06 April 2009

Marilyn E. Scott
Affiliation:
Department of Pure and Applied Biology, Imperial College, Prince Consort Road, London SW7 2BB

Extract

Changes in the variance to mean ratio and the parameter k of the negative binomial distribution were used to study temporal changes in the degree of aggregation of the monogenean parasite, Gyrodactylus turnbulli in free-running laboratory populations of the guppy, Poecilia reticulata. The parasite undergoes recurrent epidemic cycles in the host population under conditions of regular immigration of uninfected guppies. During the early phase of the epidemic, heterogeneity among fish together with direct reproduction are thought to contribute to the increasing degree of aggregation. During the increasing phase of the epidemic cycle, parasites become increasingly aggregated in the host population, presumably because of the direct reproduction of the parasite on the surface of a single host. As the peak prevalance and abundance are approached, the parasites become less aggregated with lowest clumping occurring during the declining phase of the cycle. This is thought to be a function of density-dependent death of infected hosts, and density-dependent reduction in parasite survival and reproduction on hosts that recover from infection. This study clearly indicates that the variance to mean ratio and the parameter k of the negative binomial distribution do not quantify the same aspect of the frequency distribution. It is suggested that the variance to mean ratio is a better measure when the prevalence and−or mean burden are changing and when the tail of the distribution is of particular interest, and that k may be a preferred parameter when the zero class or the lightly infected hosts are of primary interest.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1987

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References

Anderson, R. M. (1982). Parasite dispersion patterns: generative mechanisms and dynamic consequences. In Aspects of Parasitology (ed. Meerovitch, E.), pp. 140. Institute of Parasitology, McGill University.Google Scholar
Anderson, R. M. & Gordon, D. M. (1982). Processes influencing the distribution of parasite numbers within host populations with special emphasis on parasite-induced host mortalities. Parasitology 85, 373–98.CrossRefGoogle ScholarPubMed
Anscombe, F. J. (1950). Sampling theory of the negative binomial and logarithmic series distributions. Biometrika 37, 358–82.CrossRefGoogle ScholarPubMed
Bliss, C. I. & Fisher, R. A. (1953). Fitting the negative binomial distribution to biological data. Biometrics 9, 176200.CrossRefGoogle Scholar
Boswell, M. T. & Patil, G. P. (1970). Chance mechanisms generating the negative binomial distributions. In Random Counts in Models and Structures vol. 1, (ed. Patil, G. P.), pp. 322. The Penn State Statistics Series.Google Scholar
Bundy, D. A. P., Thompson, D. E., Golden, M. H. N., Cooper, E. S., Anderson, R. M. & Hart-land, P. S. E. (1985). Population distribution of Trichuris trichiura in a community of Jamaican children. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 232–7.CrossRefGoogle Scholar
Buxton, P. A. (1940). Studies on populations of head-lice (Pediculus humanus capitis: Anoplura). III. Material from South India. Parasitology 32, 296302.CrossRefGoogle Scholar
Crofton, H. D. (1971 a). A quantative approach to parasitism. Parasitology 62, 179–94.CrossRefGoogle Scholar
Crofton, H. D. (1971 b). A model of host–parasite relationships. Parasitology 63, 343–64.CrossRefGoogle Scholar
Croll, N. A. & Ghadirian, E. (1981). Wormy persons: contributions to the nature and patterns of overdispersion with Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus and Trichuris trichiura. Tropical and Geographical Medicine 33, 241–8.Google Scholar
Evans, N., Whitfield, P. J. & Dobson, A. P. (1981). Parasite utilization of a host community: the distribution and occurrence of metacercarial cysts of Echinoparyphium recurvatum (Digenea: Echinostomatidae) in seven species of mollusc at Harting Pond, Sussex. Parasitology 83, 112.CrossRefGoogle Scholar
Gordon, D. M. & Rau, M. E. (1982). Possible evidence for mortality induced by the parasite Apatemon gracilis in a population of brook sticklebacks Culaea inconstans. Parasitology 84, 41–7.CrossRefGoogle Scholar
Gordon, D. M. & Whitfield, P. J. (1985). Interactions of the cysticercoids of Hymenolepis diminuta and Raillietina cesticullus in their intermediate host, Tribolium confusum. Parasitology 90, 421–31.CrossRefGoogle ScholarPubMed
Kennedy, C. R. (1984). The use of frequency distributions in an attempt to detect host mortality induced by infection of diplostomatid metacercariae. Parasitology 89, 209–20.CrossRefGoogle Scholar
Kennedy, C. R. & Burroughs, R. (1981). The population biology of two species of eyefluke, Diplostomum gasterostei and Tylodelphys clavata in perch. Journal of Fish Biology 11, 619–33.CrossRefGoogle Scholar
Keymer, A. E. (1985). Experimental epidemiology: Nematospiroides dubius and the laboratory mouse. In Ecology and Genetics of Host–Parasite Interactions (ed. Rollinson, D. and Anderson, R. M.), pp. 5575. New York: Academic Press.Google Scholar
Keymer, A. E. & Anderson, R. M. (1979). The dynamics of infection of Tribolium confusum by Hymenolepis diminuta: the influence of infective stage density and spatial distribution. Parasitology 79, 195207.CrossRefGoogle ScholarPubMed
Lefkovitch, L. P. (1966). An index of spatial distribution. Research in Population Ecology 8, 8992.CrossRefGoogle Scholar
Lemly, A. D. & Esch, G. W. (1984). Population biology of the trematode Uvulifer ambloplitis (Hughes, 1927) in juvenile bluegill sunfish, Lepomis macrochirus, and largemouth bass, Micropterus salmoides. Journal of Parasitology 70, 466–74.CrossRefGoogle Scholar
Madhavi, R. & Anderson, R. M. (1985). Variability in the susceptibility of the fish host, Poecilia reticulata, to infection with Gyrodactylus bullatarudis (Monogenea). Parasitology 91, 531–44.CrossRefGoogle Scholar
Pence, D. B. & Windberg, L. A. (1984). Population dynamics across selected habitat variables of the helminth community in coyotes, Canis latrans, from South Texas. Journal of Parasitology 70, 735–46.CrossRefGoogle ScholarPubMed
Pennycuick, L. (1971). Frequency distributions of parasites in a population of three-spined sticklebacks, Gasterosteus aculeatus L., with particular reference to the negative binomial distribution. Parasitology 63, 389406.CrossRefGoogle Scholar
Pielou, E. C. (1969). An Introduction to Mathematical Ecology. New York: Wiley Interscience.Google Scholar
Pielou, E. C. (1974). Population and Community Ecology: Principles and Methods. New York: Gordon and Breach.Google Scholar
Schmid, W. D. & Robinson, E. D. Jr. (1972). The pattern of a host–parasite distribution. Journal of Parasitology 57, 907–10.CrossRefGoogle Scholar
Scott, M. E. (1982). Reproductive potential of Gyrodactylus bullatarudis (Monogenea) on guppies (Poecilia reticulata). Parasitology 85, 217–36.CrossRefGoogle Scholar
Scott, M. E. (1984). Helminth community in the belted kingfisher, Ceryle alcyon (L.), in southern Quebec. Canadian Journal of Zoology 62, 2679–81.CrossRefGoogle Scholar
Scott, M. E. (1985 a). Experimental epidemiology of Gyrodactylus bullatarudis (Monogenea) on guppies (Poecilia reticulata): short- and long-term studies. In Ecology and Genetics of Host–Parasite Interactions (ed. Rollinson, D. and Anderson, R. M.), pp. 2138. New York: Academic Press.Google Scholar
Scott, M. E. (1985 b). Dynamics of challenge infections of Gyrodactylus bullatarudis Turnbull (Monogenea) on guppies, Poecilia reticulata (Peters). Journal of Fish Diseases 8, 495503.CrossRefGoogle Scholar
Scott, M. E. & Anderson, R. M. (1984). The population dynamics of Gyrodactylus bullatarudis (Monogenea) within laboratory populations of the fish host Poecilia reticulata. Parasitology 89, 159–94.CrossRefGoogle ScholarPubMed
Scott, M. E. & Gibbs, H. C. (1986). Long-term population dynamics of pinworms (Syphacia obvelata and Aspiculuris tetraptera) in mice. Journal of Parasitology 72, (in the Press).CrossRefGoogle ScholarPubMed
Scott, M. E., McLaughlin, J. D. & Rau, M. E. (1979). Typhlocoelum cucumerinum Digenea: Cyclocoelidae): detailed analysis of distribution in wild ducks of southern Manitoba. Canadian Journal of Zoology 57, 2128–35.CrossRefGoogle Scholar
Scott, M. E. & Nokes, D. J. (1984). Temperature-dependent reproduction and survival of Gyrodactylus bullatarudis (Monogenea) on guppies (Poecilia reticulata). Parasitology 89, 221–7.CrossRefGoogle Scholar
Scott, M. E. & Robinson, M. A. (1984). Challenge infections of Gyrodactylus bullatarudis (Monogenea) on guppies, Poecilia reticulata (Peters), following treatment. Journal of Fish Biology 24, 581–6.CrossRefGoogle Scholar
Srivastava, L. P. & James, B. L. (1967). The morphology and occurrence of Gyrodactylus medius Kathariner, 1894 (Monogenoidea) from Onos mustelus (L.). Journal of Natural History 4, 481–9.CrossRefGoogle Scholar
Watkins, C. V. & Harvey, L. A. (1942). On the parasites of silver foxes on some farms in the South West. Parasitology 34, 155–79.CrossRefGoogle Scholar
Williams, C. B. (1964). Patterns in the Balance of Nature and Related Problems in Quantitative Ecology London: Academic Press.Google Scholar
Winfield, G. F. (1932). Quantitative studies on the rat nematode Heterakis spumosa (Schneider, 1866). American Journal of Hygiene 17, 168228.Google Scholar