ISSN:
1095-8649
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
Changes in the size and composition of a population of the acanthocephalan Acanthocephalus clavula in eels, Anguilla anguilla, and flounders, Platichthys flesus, its definitive hosts, in a small river are described over a period of 4.5 years in the course of which the population underwent a steady and continuous decline. Parasite prevalence and abundance declined more rapidly initially and then more gradually, and during the period the frequency distribution changed from overdispersed to being close to random on most occasions. Throughout the whole period newly recruited parasites were found in eels, and adult females continued to mature and produce acanthors. Data on the distribution and occurrence of the intermediate host Asellus meridianus in the river suggested that in the latter part of the decline it was no longer possible for the parasite to complete its life cycle in some parts of the river, and the cause of the parasite population decline is believed to be the decrease in abundance of the intermediate host as a result of interspecific competition with a congeneric species. During this latter period, immigration of infected eels from another river in the catchment may have contributed to the maintenance of the parasites in the locality, but it is considered that the decline in the river was representative of what was happening in other parts of the catchment and that the whole parasite population in the catchment was declining for the same reason.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1095-8649.1984.tb04913.x
