ECOLOGICAL RESEARCH OF ENDEMIC GASTROPOD SPECIES VALVATA HIRSUTECOSTATA FROM LAKE OHRID

Valvata hirsutecostata Polinski, 1929 is one of the many endemic species from Ohrid Lake Gastropods (subclass Prosobranchia). The main goal in our research was to follow the distribution and density of this endemic gastropod species. For that purpose we have undertaken sampling of benthic material from 6 different depth points using the methods of transects, on several different sites along the littoral region from Lake Ohrid. The results have pointed out to the following: In the locality Park, Kaneo and Pristanishte Valvata hirsutecostata was recorded only at 20 m depth on the muddy bottom covered with empty shells (shell zone). Specimens of Valvata hirsutecostata have not been recorded in other investigated depth points, where the habitat was sandy-stone, sandy-muddy, sandy bottom, submerse vegetation, muddy bottom, muddy bottom with vegetation and Chara belts.