ABSTRACT
The genus Potamolithus Pilsbry, 1896PILSBRY, H.A. 1896. Notes on new species of Amnicolidae collected by Dr. Rush in Uruguay. The Nautilus, 10(8):86-89. (Gastropoda; Tateidae), has 31 species, 22 of which are distributed in Argentina in Del Plata basin, defining the Uruguay River and the Río de la Plata as a “hotspot” of diversity in freshwater gastropods. However, most of its species has been described only by conchology characters and a few has anatomical data, leading to the description of subspecies or morphs that overlap each other. Potamolithus lapidum some authors attribute four subspecies (with conchology data and anatomical partial data), but others include eight “morphs”. We give a start the study of Potamolithus lapidum elevating to Potamolithus lapidum supersulcatus Pilsbry, 1896PILSBRY, H.A. 1896. Notes on new species of Amnicolidae collected by Dr. Rush in Uruguay. The Nautilus, 10(8):86-89. to the category of species, of which only known partially conchology and radular characters. We provide data of: shell, pallial organs, head, foot, penis, radula, female and male reproductive system, nervous system and partial sequence of mitochondrial gene cytochrome c oxidase subunit I. A good description of species of the genus Potamolithus is necessary, because some species have been listed as vulnerable species and they inhabit rivers that are being modified by human activity and the presence of invasive bivalve Limnoperna fortunei.
KEY-WORDS:
Anatomy; COI; Conchology; Potamolithus lapidum; Vulnerable species
