Eucobresia diaphana (Draparnaud, 1805) (Gastropoda, Pulmonata, Vitrinidae) in de Biesbosch

Since 1913 living specimens of Eucobresia diaphana (Draparmaud, 1805) have been found in various regions of the Netherlands. These regions include the Nijmegen area, several localities in the south of the province of Limburg and the Scheeken (a wet poplar forest in the municipality of Boxtel) in the National Landscape Het Groene Woud in the province of Noord-Brabant. In 1970 one empty shell was found in the Biesbosch National Park but it was assumed that it had been washed ashore. In 2008 there was a new record of an empty shell in the same area. This study presents the findings of three separate areas in the Biesbosch that were sampled on 4 April 2009. In addition to this sampling, one of the sampling areas was examined in detail (30 × 60 cm plot). Empty shells of E. diaphana were found in all three localities with living juvenile specimens in one of these areas. This article describes measurements, habitat and associated malacocoenosis. The Biesbosch, a freshwater tidal reserve, was already known as an area of importance for land molluscs; records of living specimens of E. diaphana indeed do confirm this.