Výsledky průzkumu měkkýšů (Mollusca: Gastropoda, Bivalvia) v okolí města Blatná v jihozápadních Čechách [Results of the faunistic survey of molluscs in the vicinity of Blatná town in south-western Bohemia]

Results of the faunistic survey on molluscs in the vicinity of the town of Blatná (south-western Bohemia, Czech Republic) are presented. This research was carried out in 2004–2007 at 28 sites complemented by other older unpublished records. Altogether 87 species (76 gastropods, 11 bivalves) have been recorded that the freshwater molluscs represented the most abundant ecological group in this region (about 40% of all species recorded). However, the rare species (e.g. Aplexa hypnorum, Physa fontinalis, Pisidium obtusale) have been found usually in small water bodies while the majority of common freshwater molluscs was recorded predominantly in large and mid-sized ponds. The snail Gyraulus acronicus is the rarest freshwater species found only at one locality. Important proportion of investigated malacofauna consisted of wetland and floodplain species with rare elements such as Vertigo antivertigo, V. substriata, Euconulus praticola or even V. angustior, the former being protected in the whole Europe. Occurrence of this endangered species in the studied region represents one of the most important clusters of its populations in Bohemia. Only several forest species have been recorded, the species Acanthinula aculeata and Vertigo pusilla are of particular importance. Unique are finds of the steppe species Chondrula tridens on old slacking walls in the town of Blatná.