Abstract
Transmission of parasites may be mediated by their habitat, consisting of abiotic and biotic components. I investigated the effect of 2 important habitat components in intertidal ecosystems, tidal level (abiotic) and density of upstream hosts (biotic), on the transmission of trematode cercariae to cockle (Cerastoderma edule) hosts. A field survey showed no general trend in metacercarial loads of cockles regarding tidal level but species-dependent reactions. Parasites originating from Littorina littorea (Himasthla elongata, Renicola roscovita) showed highest infection levels in the low intertidal while parasites originating from Hydrobia ulvae (H. continua, H. interrupta) showed highest infection levels in the mid-intertidal. This reflected the density of upstream hosts at both tidal levels and positive relationships between the density of upstream hosts and metacercarial load in cockles suggested the biotic habitat component to be the dominant factor in transmission. This was confirmed by a field experiment, manipulating tidal level and the density of infected upstream snail hosts. While tidal level had no significant effect on the number of metacercariae of H. elongata acquired by cockles, the effect of upstream host density was strong. In conclusion, although tidal level usually is a very important abiotic habitat component in intertidal ecosystems leading to conspicuous zonation patterns in free-living organisms, it seems of minor importance for trematode transmission. In contrast, the biotic component upstream host density is suggested to be the dominant predictor for trematode transmission to second intermediate hosts. Assessing the relative importance of abiotic and biotic habitat components in transmission is vital for the understanding of transmission processes in the field.
Publisher
Cambridge University Press (CUP)
Subject
Infectious Diseases,Animal Science and Zoology,Parasitology
Reference22 articles.
1. Grosholz, E. D. (1994).The effects of host genotype and spatial distribution on trematode parasitism in a bivalve population.Ecology 48,1514–1524.
2. Grazing on green algae by the periwinkleLittorina littorea in the Wadden Sea
3. Thieltges, D. W. and Reise, K. (2006 a).Spatial heterogeneity in parasite infections at different spatial scales in an intertidal bivalve.Oecologia (in the Press). DOI 10.1007/S00442-006-0557-2.
4. Sousa, W. P. and Grosholz, E. D. (1990).The influence of habitat structure on the transmission of parasites. In Habitat Structure: the Physical Arrangement of Objects in Space (ed. Bell, S. S. , McCoy, E. D. and Mushinsky, H. R. ), pp.300–324.Chapman and Hall,London.
5. Historical changes in the benthos of the Wadden Sea around the island of Sylt in the North Sea
Cited by
27 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献