Soil type and the distribution of Lymnaea truncatula

Habitat distribution of the snail Lymnea truncatula, the intermediate host of the liver fluke Fasciola hepatica, was related to a soil map in a part of Dyfed in South Wales. There was a close association with wet soils in general but, within these areas, habitats were concentrated in very wet localities of restricted size, such as ditches and seepages. Vegetation characteristic of these habitats is described. Soil maps could be a useful tool for the veterinary officer, agricultural adviser and research worker in identifying fluke-prone land.