What Are We Protecting? On the Silent Arrival of Anodonta cygnea to Spain.

Freshwater mussels play essential roles in ecosystem processes, such as water filtration and nutrient cycling, but, in the last decades, they have become increasingly threatened by habitat destruction, pollution, and the arrival of invasive species. In this study, a living population of the bivalve Anodonta cygnea is reported in Catalonia, Spain, based on molecular and morphological analyses. A comparison with A. anatina from a nearby population in southern France highlights the importance of using genetic tools to accurately distinguish between closely related freshwater mussel species. The introduction of A. cygnea likely reflects a recent range expansion, facilitated by human activities and environmental changes in the region. Its establishment in local ecosystems raises concerns about potential ecological impacts, including competition with native species and alteration of freshwater habitats. These findings underscore the critical need for effective monitoring and management strategies to mitigate the ecological risks associated with invasive species. This study emphasizes the importance of integrating molecular methods into conservation efforts to improve the understanding of species distributions and address the challenges posed by biodiversity loss in aquatic ecosystems.