Use and application of iNaturalist on land snails from Argentina

Gastropods are a large and diverse taxonomic group, and South America has an impressive diversity of land snails. However, there are no accurate and complete lists or estimates of native species' richness in South America. The aim of this work is to evaluate the use of iNaturalist in Argentina for terrestrial gastropods and its potential to contribute to the knowledge of malacofauna. A search was performed for Argentina on 15 June 2024, filtering observations for terrestrial gastropods, yielding 3,758 records, of which about 10% were of interest for this work. Exotic species represented between 60-63% of the observations in iNaturalist, and native species represented between 37-40%, with post-validation and pre-validation respectively. The geographical distribution of exotic species was mostly concentrated in the urban areas of the capital cities, and the observations of native species were concentrated in a few provinces. It was possible to detect and expand the distribution area of exotic species such as Rumina decollata, Limacus flavus, Bradybaena similaris, Deroceras laeve, Deroceras reticulatum, Deroceras invadens, Arion intermedius, Milax gagates, Limax maximus, Vallonia pulchella, possibly Laevicaulis alte; native species such as Phyllocaulis soleiformis, Drymaeus poecilus, Drymaeus papyraceus. Potential species not recorded in Argentina were identified as Helix pomatia, Mesembrinus gereti. We also recorded species within the known range, potential new species not described by science, a possible case of accidental transfer of Mesembrinus interpunctus, and the prediction of the distribution of Megalobulimus lorentzianus was verified. Through the development of this study, we were able to demonstrate the relevance of citizen science in providing interesting contributions to the knowledge of terrestrial mollusks biodiversity in Argentina.