Fauna of water mites (Acari, Hydrachnidia) in the stony littoral of water supply reservoirs in the Czech Republic
The article presents the results of a survey of the water mite fauna in 45 dam reservoirs in the Czech Republic that are sources of drinking wa-ter. In 37 reservoirs, the average seasonal concentration of chlorophyll a in water were lower than 20 µg/L, which indicates that most of these reservoirs have an oligotrophic to slightly mesotrophic character. Samples were taken with a hand plankton net in the stony littoral at a depth of 0.5–1.0 m at all localities; therefore, it is possible to compare findings from individual localities, although they do not represent quantitative data of water mites related to unit area or water volume. In total 1,356 water mites (849 adults, 507 nymphs) were caught and 34 species were recorded. Twelve species occurred in more than 15 % of the investigated reservoirs and accounted for 87.4 % of all individuals caught. These species show great locomotive activity, they are adapted for swimming/floating, and they commonly occur in the littoral fauna of European lakes.