Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T12:41:50.607Z Has data issue: false hasContentIssue false

The use of frequency distributions in an attempt to detect host mortality induced by infections of diplostomatid metacercariae

Published online by Cambridge University Press:  06 April 2009

C. R. Kennedy
Affiliation:
Department of Biological Sciences, The University, Exeter EX4 4PS

Summary

Following recent suggestions that a peaked host age–parasite abundance curve, concomitant with a decline in the degree of dispersion of parasites in the older age classes of hosts, can provide evidence of parasite-induced host mortality, the changes in mean abundance and over-dispersion of metacercarial stages of Diplostomum spathaceum, D. gasterostei, Tylodelphys clavata and T. podicipina in relation to fish age were studied in a field locality. The mean parasite burden of D. spathaceum, D. gasterostei and T. clavata increased with host age and the maximum mean burden was found in the oldest hosts. The variance to mean ratio also increased in D. gasterostei, but decreased in the oldest hosts in D. spathaceum and T. clavata. It is concluded that this decrease could be due to parasite-induced host mortality but could equally be due to death of parasites within the host or to changes in infection rate or could be a reflection of the small sample size of the oldest fish. The mean burden of T. podicipina declined gradually with host age, but the variance to mean ratio remained constant and it is concluded that this could be explained by death of the parasites within the host. None of these data or data from other localities provided clear and unambiguous evidence of host mortality induced by heavy infections of any of the four species, although they are consistent with such mortality and do not refute such a possibility. It is concluded that it may be just as difficult to detect and unequivocally demonstrate parasite-induced host mortality in metacercarial digenean–fish host systems as in any other parasite–host systems.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1984

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

Anderson, R. M. (1978). The regulation of host population growth by parasitic species. Parasitology 76, 119–57.CrossRefGoogle ScholarPubMed
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
Anderson, R. M. & May, R. M. (1978). Regulation and stability of host-parasite population interactions. I. Regulatory processes. Journal of Animal Ecology 47, 219–47.CrossRefGoogle Scholar
Bauer, O. N. (1962). Parasites of Freshwater Fish and the Biological Basis for their Control. Jerusalem: Israel Program for Scientific Translations.Google Scholar
Bottomley, P. E. & Woodiwiss, F. S. (1969). Progress report on the Trent River Authority investigation into the decline in fishing in some Midland canals. Proceedings of the 4th British Coarse Fish Conference 8392.Google Scholar
Brassard, P., Rau, M. E. & Curtis, M. A. (1982 a). Infection dynamics of Diplostomum spathaceum cercariae and parasite-induced mortality of fish hosts. Parasitology 85, 489–93.CrossRefGoogle Scholar
Brassard, P., Rau, M. E. & Curtis, M. A. (1982 b). Parasite-induced susceptibility to predation in diplostomiasis. Parasitology 85, 495501.CrossRefGoogle Scholar
Burrough, R. J. (1978). The population biology of two species of eyefluke, Diplostomum spathaceum and Tylodelphys clavata, in roach and rudd. Journal of Fish Biology 13, 1932.Google Scholar
Chappell, L. H. (1969). Parasites of the three-spined stickleback Gasterosteus aculeatus L. from a Yorkshire pond. II. Variation of the parasite fauna with sex and size of fish. Journal of Fish Biology 1, 339–47.CrossRefGoogle Scholar
Crowden, A. E. & Broom, D. M. (1980). Effects of the eyefluke, Diplostomum spathaceum, on the behaviour of dace (Leuciscus leuciscus). Animal Behaviour 28, 287–94.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
Kennedy, C. R. (1981 a). The establishment and population biology of the eye-fluke Tylodelphys podicipina (Digenea: Diplostomatidae) in perch. Parasitology 82, 245–55.Google Scholar
Kennedy, C. R. (1981 b). Long term studies on the population biology of two species of eyefluke, Diplostomum gasterostei and Tylodelphys clavata (Digenea: Diplostomatidae), concurrently infecting the eyes of perch, Perca fluviatilis. Journal of Fish Biology 19, 221–36.CrossRefGoogle Scholar
Kennedy, C. R. & Burrough, R. (1977). The population biology of two species of eyefluke, Diplostomum gasterostei and Tylodelphys clavata, in perch. Journal of Fish Biology 11, 619–33.CrossRefGoogle Scholar
Kennedy, C. R. & Burrough, R. J. (1978). Parasites of trout and perch in Malham Tarn. Field Studies 4, 617–29.Google Scholar
Larson, O. R. (1964). A study of the larval stages of a strigeoid fluke and the pathological conditions incurred by the fish host, Ictalurus melas (Raffinesque). Dissertation Abstracts 25, 2673.Google Scholar
Lopukhina, A. M., Strelkov, Y. A., Chernyshova, N. B. & Yunchis, O. N. (1973). The effect of parasites on abundance of young fish in natural water bodies. Verhandlungen der internationalen Vereinigung für theoretische und angewandte Limnologie 18, 1705–12.Google Scholar
May, R. M. & Anderson, R. M. (1978). Regulation and stability of host-parasite population interactions. II. Destabilising processes. Journal of Animal Ecology 47, 249–67.CrossRefGoogle Scholar
Pennycuick, L. (1971 a). Quantitative effects of three species of parasites on a population of three-spined sticklebacks, Gasterosteus aculeatus L. Journal of Zoology 165, 143–62.CrossRefGoogle Scholar
Pennycuick, L. (1971 b). 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.Google Scholar
Shariff, M., Richards, R. H. & Sommerville, C. (1980). The histopathology of acute and chronic infections of rainbow trout Salmo gairdneri Richardson with eye flukes, Diplostomum spp. Journal of Fish Diseases 3, 455–65.CrossRefGoogle Scholar
Shigin, A. A. (1964). On the length of life of Diplostomum spathaceum in the secondary host. Trudy Gelmintologicheskoi Laboratorii AN USSR 14, 262–72.Google Scholar
Sweeting, R. A. (1974). Investigations into natural and experimental infections of freshwater fish by the common eye fluke Diplostomum spathaceum Rud. Parasitology 69, 291300.CrossRefGoogle ScholarPubMed
Sweeting, R. A. & Powell, A. (1977). Mortalities of fish associated with eye flukes. Parasitology 76, XXXVIII.Google Scholar
Wootten, R. (1975). Observations on strigeid metacercariae in the eyes of fish from Hanningfield Reservoir, Essex, England. Journal of Helminthology 48, 7383.CrossRefGoogle Scholar