Discovery of a remnant population of Ena montana (Draparnaud, 1801) at Beschissenberg (Hauset) in the Gueule Valley in the Entre-Vesdre-et-Meuse region, Belgium (Mollusca: Stylommatophora: Enidae)

We present the discovery of an isolated population of the Mountain Bulime, Ena
montana (Draparnaud, 1801), a species with a tendency for mountainous habitats, in the Gueule Valley at the Beschissenberg site in Hauset (Belgium). We hypothesize that this population is native and likely a remnant of an ancient population that was once widespread in the region but has since experienced significant fragmentation and loss of its habitat, namely forests on limestone soil. This population may have become isolated as early as the 18th century. This exceptional characteristic underscores the importance of efforts to protect this population. Additional research covering an area of 128 km² did not identify other Belgian populations in the region. However, another isolated population exists in Walheim (Germany), 9 km from Beschissenberg, and a potential population in Valkenburg (Netherlands) requires confirmation.