to test the specificity of the assay, we used trematode species other than F. hepatica which had been found parasitizing Lymnaea sp., namely Coty-lurus sp., Echinoparyphium sp., Echinostoma sp., and some speciamens of Echinostomatidae of unknow genus.Uninfected laboratory-reared L. columella and L. viatrix were also tested using the same DNA isolation and PCR protocols as described above for field-collected samples