Morphological and molecular data reveal the presence of exotic land snail species in Tierra del Fuego

In the present study, we report for the first time the presence of Vitrina pellucida and Arion silvaticus as invasive species in Isla Grande of Tierra del Fuego, Argentina. Additionally, our research confirmed the presence in the same region of Deroceras reticulatum a previously reported invasive species from continental Patagonia. Taxonomic identification was achieved through morphological and molecular analyses (ribosomal 5.8S-ITS2-28S region and 16S rRNAgene). The finding of V. pellucida constitutes the first record of Vitrinidae for South America. This species is already naturalized in southern Tierra del Fuego and invaded natural areas of the National Park but still with small populations. In the case of Arion silvaticus, we observed a comparable situation, as this species has not only been collected from urban areas but also from within the forests of the protected area. These exotic species of land snails are exclusively cold-adapted Pulmonates. Their feeding types and diets range from herbivores on fresh plant material to omnivorous, occasionally on dead animals. The native micro snail species, coexisting in the same habitats, due to their minimal dispersal capacity and probable dependence on particular microhabitats, are particularly vulnerable not only to anthropogenic disturbances but also to the impacts and activities of these exotic species. Given the tourist impact in the region, the introduction of V. pellucida and Arion silvaticus in Tierra del Fuego has most likely occurred through accidental transport in soil by tourists arriving on the island. Another possible pathway of introduction is plant transportation.