 In contrast, the anatomy of their reproductive tracts (including prostate, penis and preputium) is extremely homogeneous.Immunological, cytogenetical, enzyme electrophoresis studies, and DNA-based approaches have demonstrated extensive homoplasy in anatomical characters.Lymnaeidae are of major medical and veterinary importance since they act as vectors of parasites (helminths, mainly trematodes, e.g., "Fasciola" liver flukes) that severely affect human populations and livestock, and cause important economic losses.