Ranská jezírka – významná lokalita vodních měkkýšů na okraji Žďárských vrchů [Ranská jezírka – an important site of aquatic molluscs on the edge of the Žďárské vrchy]

Abstract

The Ranská jezírka are system of water bodies located in a forest complex on the western edge of the Žďárské vrchy PLA. These water bodies were created by flooding of depressions after surface mining of iron limonite ores. Currently, there are several larger and a number of smaller oligotrophic to mesotrophic pools covered with various types of littoral vegetation. Aquatic molluscs of this isolated and biologically interesting site were studied in 2023. In total, 15 species (6 gastropods and 9 bivalves) were found at 7 sites. Molluscan communities in water bodies with poorer vegetation were species-poor while water bodies more overgrown with littoral vegetation were inhabited by relatively species-richer communities. The rare and endangered bivalve Sphaerium nucleus was found. No non-native species were found.