| Description |
A faunistic survey of terrestrial and aquatic molluscs was conducted in the period 2018- 2021. Altogether, 47 sites were surveyed (35 for terrestrial gastropods and 12 for aquatic molluscs). In total, 91 species were recorded (75 terrestrial and 11 aquatic gastropods and 5 bivalves) of which 11 species are included in the IUCN Red List and one species in Annex II of the EU Habitats Directive (92/43/EEC). The majority of the terrestrial species richness are woodland dwellers (43 spp., 58%), including Aegopis verticillus (NT), Cochlodina orthostoma (NT), Sphyradium doliolum (NT), Vertigo alpestris (NT) and the most remarkable finding of Pagodulina pagodula (CR), occurring only at two sites in Czech Republic. The second most species-rich ecological group are euryvalent species (11 spp., 15%), followed by hygrophilous and wetland species (8 spp., 11% and 4 spp., 5%; respectively), silviphobic (4 spp., 5%) and xerophilous species (3 spp., 4%). The wetland species Vertigo angustior (VU, listed in Annex II of the EU Habitats Directive) was not recorded at a previously known site, however, it was discovered at a new site. Granaria frumentum (NT), Oxychilus inopinatus (NT), Pupilla triplicata (VU) and Truncatellina claustralis (VU) are open-habitat species of conservation importance, the latter two being associated with a remarkable habitat occurring in Podyjí NP – stone seas (rock debris). Fringes of some exposed stone seas are inhabited by unique gastropod assemblages combining calcicole forest and open-habitat species. Decline or presumed extinction of some open-habitat species recorded in the national park during a previous survey (Ložek & Vašátko 1997) is related to successional changes. Aquatic mollusc fauna consists predominantly of widespread species, with the occurrence of spring-dwelling Bythinella austriaca (NT) A faunistic survey of terrestrial and aquatic molluscs was conducted in the period 2018- 2021. Altogether, 47 sites were surveyed (35 for terrestrial gastropods and 12 for aquatic molluscs). In total, 91 species were recorded (75 terrestrial and 11 aquatic gastropods and 5 bivalves) of which 11 species are included in the IUCN Red List and one species in Annex II of the EU Habitats Directive (92/43/EEC). The majority of the terrestrial species richness are woodland dwellers (43 spp., 58%), including Aegopis verticillus (NT), Cochlodina orthostoma (NT), Sphyradium doliolum (NT), Vertigo alpestris (NT) and the most remarkable finding of Pagodulina pagodula (CR), occurring only at two sites in Czech Republic. The second most species-rich ecological group are euryvalent species (11 spp., 15%), followed by hygrophilous and wetland species (8 spp., 11% and 4 spp., 5%; respectively), silviphobic (4 spp., 5%) and xerophilous species (3 spp., 4%). The wetland species Vertigo angustior (VU, listed in Annex II of the EU Habitats Directive) was not recorded at a previously known site, however, it was discovered at a new site. Granaria frumentum (NT), Oxychilus inopinatus (NT), Pupilla triplicata (VU) and Truncatellina claustralis (VU) are open-habitat species of conservation importance, the latter two being associated with a remarkable habitat occurring in Podyjí NP – stone seas (rock debris). Fringes of some exposed stone seas are inhabited by unique gastropod assemblages combining calcicole forest and open-habitat species. Decline or presumed extinction of some open-habitat species recorded in the national park during a previous survey (Ložek & Vašátko 1997) is related to successional changes. Aquatic mollusc fauna consists predominantly of widespread species, with the occurrence of spring-dwelling Bythinella austriaca (NT) and regionally-important occurrence of Pisidium obtusale. Only two invasive species were recorded (Physa acuta, Potamopyrgus antipodarum) in the Dyje river.
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