Gyraulus laevis and G. parvus (Mollusca: Gastropoda), two distinct species

Lorencová et al. (2021) found by barcoding of Gyraulus laevis from Europe and G. parvus from Northern America that the tested gene fragments are similar and so the authors believed that both taxa are conspecific. However, they ignored anatomical and morphological differences which have to be considered because genetic data are not a priori higher weighted than morphology. Summarized we can say that Gyraulus parvus and G. laevis are distinct species, because,  (1) they differ in the vas deferens, (2) the penultimate whorl in G. parvus tends to be elevated (visible in the adults only), and (3) G. laevis occurs in shallow water of lakes and ponds, while G. parvus prefers (in Europe) artificial water bodies.