A study on snail location byFasciola hepaticausing radioisotopically labelled miracidia

Abstract
A number of common freshwater molluscs were exposed toFasciola hepaticamiracidia labelledin vivowith radioselenium. Radioactivity was rapidly incorporated in all lymnaeid species tested (L. auricularia, L. columella, L. glabra, L. natalensis, L. palustris, L. pereger, L. stagnalis, L. tomentosaandL. truncatula) whereas no radioactivity could be demonstrated in non-lymnaeid pulmonate species (Aplexa hypnorum, Physa acuta, Physafontinalis, Anisus vortex, Gyraulus albusandPlanorbis planorbis) or in the prosobranchsValvata cristataandValvata piscinalis.However, the prosobranchsBithynia leachii, Bithynia tentaculataandPotamopyrgus jenkinsishowed a slow but significant uptake of radioactivity which was presumably explained by uptake of labelled miracidia through a ‘filter-feeding] mechanism.Sphaerium corneum, a true filter-feeder, showed a similar course of uptake of radioactivity.