Tracking the occurrence and global expansion of the non-native mollusk Corbicula largillierti (Bivalvia, Cyrenidae) in aquatic ecosystems

Corbicula largillierti is an invasive bivalve with significant socioeconomic and ecological impacts reported globally. However, a comprehensive review documenting its status, distribution, and expansion rate is lacking. This study aimed to investigate the global distribution and expansion of C. largillierti in aquatic ecosystems. A systematic literature review and field sampling were conducted in watersheds receiving water transfers from the São Francisco River Integration Project (PISF/Eastern Axis) in the semiarid region of Brazil. The findings showed 307 occurrence records for C. largillierti in 14 countries across four continents. However, its expansion rate varies between countries and continents, with the annual expansion rate being higher at local scales (12.54%) than at regional (5.39%) and global scales (1.38%). Its occurrence was particularly high in South America (n = 235), mainly in Brazil (n = 155) and Argentina (n = 75), where the number of records exceeds that reported worldwide. Additionally, we recorded the first occurrence of C. largillierti in the Pajeú River Watershed (n = 12), and the spread of this invasive mollusk in the Paraíba River Watershed (n = 75). These observations suggest that the PISF may have facilitated the introduction and dispersion of species in these watersheds. Taken together, our findings show that C. largillierti is an invasive species with continuous expansion worldwide, especially in South America. Our results emphasize the urgent need to enhance control and prevention measures in countries where the prevalence is higher, highlighting its potential negative impacts on local ecosystems.