Abstract
The family Lymnaeidae is globally recognized for its role in the transmission of fasciolosis. This chapter thoroughly reviews the species of lymnaeid snails that have a proven or suspected role in the transmission of the liver flukes Fasciola hepatica and Fasciola gigantica. An outline of the differential roles of each major clade is presented with relation to the ecology of the species that helps to understand the epidemiological risks at different geographic levels. The chapter is accompanied by a detailed list of recorded prevalences either natural or experimental for 31 species of Lymnaeidae reviewed by country.