The invasive Sinanodonta woodiana (Bivalvia: Unionidae) continues to spread in North Africa (Algeria): A new locality for an established population and further perspectives

Native to Eastern Asia, the Chinese Pond Mussel (Sinanodonta woodiana) (Mollusca: Bivalvia) is one of the most threatening invaders of freshwater habitats worldwide. Algerian waters are no exception. In 2023, the mussel was discovered in two locations, one of which is a protected area. Here, we report Babar Dam reservoir as a new site of its occurrence and the southernmost record of the species in the country. The present survey was conducted in May 2023 and included a set of live S. woodiana specimens in variable sizes (from 95.4 to 210.4 mm) and developmental stages (from 4 to 11 years old), which suggests that the species succeeded in establishing a sustainable population that can spread and colonise new territories. The possible pathway of introduction of the Chinese Pond Mussel and its occurrence in the whole country are discussed. Overall, the spread of S. woodiana in Algeria appears to be seriously underestimated and overlooked; it is crucial to establish a monitoring plan to manage the species’ progress and assess its impact on recipient ecosystems and indigenous communities.