Updated Information on the Habitat Distribution and Diversity of the Freshwater Malacofauna of Sarnena Gora Mountain (Bulgaria)

According to the recent research and the critical overview of the literature it can be summarized that a total of 13 species of freshwater snails and 6 species of mussels are known to occur in Sarnena Gora Mountain. The highest richness of freshwater molluscs species in the surveyed area were found in the medium sized rivers having microhabitats favorable for the aquatic molluscs such as fast flowing oligotrophic stretches combined with slow moving eutrophic parts and small floods on the banks. The species community of the freshwater molluscs known to live in the mountain studied was consisted mainly by some widely distributed species with Holarctic and Palearctic distributions, followed by the European species. Two local endemics were also registered in the mountain.