Amphipod diversity in South American high-altitude peatlands: two novel Hyalella species supported by morphological and molecular evidence (Amphipoda, Hyalellidae)

The peatlands of the Puna and High Andes of northwestern Argentina harbor a poorly known diversity of freshwater amphipods of the genus Hyalella . Using an integrative taxonomic approach combining morphological and molecular evidence, we describe two new species, Hyalella portaesolis sp. nov . and Hyalella rodriguezi sp. nov . Molecular analyses based on the mitochondrial COI gene support the distinctiveness of both taxa and confirm the usefulness of this marker for species delimitation within South American Hyalellidae. We also provide ecological and distributional information for the new species, including habitat characteristics and the presence of epibionts. Additionally, we report other Hyalella species occurring in the study area, contributing to a better understanding of amphipod diversity in Andean peatlands. Our results highlight the high and still underestimated biodiversity of these unique wetlands and reinforce the importance of integrative studies for documenting and conserving freshwater fauna in a region increasingly affected by human activities.