First Detection Of Sinanodonta Woodiana In Lower Sizava River Basin (Czech Republic)

This article summarizes data on the presence of the freshwater mussel species (Unionidae, Bivalvia) at three locations in the Sazava River Basin (Bohemia, Czech Republic) with respect to the potential occurrence of invasive unionid bivalve the Chinese pond mussel (Sinanodonta woodiana). The Sazava river basin is one of the most valuable Central European habitats for large bivalve molluscs, the occurrence of S. woodiana was recorded in this area for the first time; together with a unique population of the specially protected species Anodonta cygnea at the same locality (Hubkovsky rybnik fish pond). The status of marsupia of duck mussel (Anodonta anatina) was checked and the species was found to be reproducing normally. The results demonstrate that S. woodiana is already reaching important localities with the occurrence of unionids in Central Bohemia. Even though no increased mortality of native species was observed in the localities, nor any negative effect on native fauna, we recommend monitoring of the future population development. Due to the close coexistence of endangered and invasive species and poor access to the sampling sites we conclude that potential attempts to eliminate the invasive species could have a negative impact on endangered freshwater mussel fauna.