Review About the Biodiversity of Pill Clams (Bivalvia, Sphaeriidae) in the Confines of the World, the Argentinean Patagonia

This study aims at updating the diversity and distribution of Sphaeriidae in Argentine Patagonia, with a particular emphasis on the Santa Cruz Province. Samples were collected between 2015 and 2023 across diverse habitats, including rivers, lakes, lagoons, and Patagonian wetlands, and this was complemented by data obtained from a comprehensive literature review and a revision and improvement of major malacological collections. Both manual and sieve-based collection methods were used to obtain specimens from different habitats. From 121 records analyzed, 101 records were identified to species level, including four species of Pisidium and two of Sphaerium. Pisidium magellanicum and Pisidium patagonicum were the most frequently recorded species. Sphaerium patagonicum demonstrated the broadest distribution, ranging from northern Neuquén to southern Tierra del Fuego. Santa Cruz Province had the highest number of records (57), followed by Chubut (24), with Río Negro and Tierra del Fuego having the fewest records. We report the first record of Pisidium chilense in Neuquén Province, providing new evidence of its presence in Argentine Patagonia. These findings advance our knowledge of Sphaeriidae distribution in Patagonia and highlight gaps in coverage, particularly in less-sampled regions. Fil: Torres, Santiago Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Tecnológica Nacional. Facultad Regional Santa Cruz. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia de Santa Cruz; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica San Julián; Argentina Fil: de Lucia, Micaela. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina