The\u00a0study was created with the\u00a0support of\u00a0the\u00a0NCA for the\u00a0implementation of\u00a0the\u00a0Species Occurrence Database under a\u00a0contract for the\u00a0development of\u00a0the\u00a0work Diversity of\u00a0water mites in\u00a0water reservoirs of\u00a0the\u00a0Czech Republic <\/span>in\u00a02025.<\/span><\/p>\n Previous research on water mite fauna in\u00a0the\u00a0Czech Republic has focused mainly on ponds, running waters (especially streams), and springs; the\u00a0occurrence of\u00a0water mites in\u00a0dam reservoirs has received little attention, although there are 165\u00a0significant dam reservoirs in\u00a0the\u00a0country. Of\u00a0these, 47 are designated by Decree No. 137\/1999 Coll.\u00a0[1] for water-supply purposes and provide 50\u00a0% of\u00a0the\u00a0drinking water supply for the\u00a0population of\u00a0the\u00a0Czech Republic. The\u00a0management of\u00a0these water reservoirs and land-use practices within\u00a0their catchments are subject to protective regimes, not only to ensure a\u00a0sufficient volume of\u00a0stored water to meet supply demands, but above all to maintain\u00a0the\u00a0highest possible water quality. Protection zones of\u00a0water-supply sources (see\u00a0Act\u00a0No.\u00a0254\/2001\u00a0Coll., on waters and on amendments to certain\u00a0laws, as amended\u00a0[2]) and regulated agricultural management within\u00a0catchments (in\u00a0accordance with river basin\u00a0management plans under the\u00a0Water Framework Directive 60\/2000\/EC) strengthen the\u00a0provision of\u00a0high-quality raw water for water treatment. A\u00a0total of\u00a036 water reservoirs (Tab.\u00a01<\/span><\/em>) are located at elevations above 400\u00a0m a.s.l., and their inflows consist of\u00a0upper (headwater) sections of\u00a0watercourses, i.e.\u00a0catchments without significant sources of\u00a0pollution. For these reasons, water quality in\u00a0water reservoirs is significantly higher than in\u00a0multi-purpose reservoirs, ponds, and smaller standing waters. At the\u00a0same time, biomanipulation is applied in\u00a0these reservoirs through the\u00a0support of\u00a0so-called purpose-oriented fish stocking, with the\u00a0aim of\u00a0limiting phytoplankton development by influencing the\u00a0structure of\u00a0the\u00a0food web within\u00a0the\u00a0reservoir biocoenosis. Increased stocking of\u00a0predatory fish species affects the\u00a0food chain\u00a0by reducing the\u00a0abundance of\u00a0small fish species, which allows the\u00a0development of\u00a0larger zooplankton species (especially cladocera). Through their predatory activity on planktonic algae, these organisms can regulate phytoplankton biomass even under conditions of\u00a0elevated nutrient concentrations.<\/span><\/p>\n To date, only a\u00a0few isolated records exist on the\u00a0occurrence of\u00a0water mites in\u00a0dam reservoirs in\u00a0the\u00a0Czech Republic, mostly obtained as part of\u00a0hydrobiological research projects (e.g.\u00a0[3]). Similarly, in\u00a0other European countries, little attention has been paid to the\u00a0water mite fauna of\u00a0reservoirs; most information on standing waters comes from studies of\u00a0lakes and ponds.<\/span><\/p>\n The\u00a0aim of\u00a0this survey was to obtain\u00a0data on the\u00a0water mite fauna in\u00a0dam reservoirs in\u00a0the\u00a0Czech Republic, with a\u00a0focus on their occurrence in\u00a0the\u00a0littoral zone over the\u00a0stony surface of\u00a0the\u00a0dam embankment, i.e. in\u00a0that part of\u00a0the\u00a0reservoir which is connected to the\u00a0pelagic zone, is not overgrown with littoral vegetation, and has characteristics of\u00a0certain\u00a0lacustrine habitats, thus allowing comparison with findings of\u00a0water mites from European lakes.<\/span><\/p>\n The\u00a0distribution of\u00a0water reservoirs in\u00a0the\u00a0Czech Republic is shown in\u00a0the\u00a0map in\u00a0Fig.\u00a01. <\/span>A\u00a0list of\u00a0them is provided in\u00a0Tab.\u00a02<\/span>, which contains basic information on the\u00a0individual reservoirs from which water mite samples were collected in\u00a0August and September 2024. The\u00a0majority of\u00a0water reservoirs (80\u00a0%) are located at elevations above 400\u00a0m a.s.l.<\/span><\/p>\n <\/p>\n <\/p>\n Of\u00a0the\u00a0total of\u00a047 water reservoirs listed in\u00a0Decree No. 137\/1999 Coll.\u00a0[1], sampling was not carried out at Znojmo reservoir (which is essentially a\u00a0multipurpose reservoir with water-supply abstraction) or at Stavi\u0161t\u011b reservoir (access to the\u00a0dam was closed and it was not possible to obtain\u00a0a\u00a0sample from a\u00a0suitable location). Jeze\u0159\u00ed reservoir is also missing (it was drained in\u00a0the\u00a0given year), as is Myslivna reservoir, which, given its size, has more the\u00a0character of\u00a0a\u00a0pond. On the\u00a0other hand, sampling was carried out at Slezsk\u00e1 Harta reservoir, which serves as a\u00a0\u201cpre-reservoir\u201d for Kru\u017eberk reservoir, from which water is abstracted for supply purposes. A\u00a0sample was also taken from Kristi\u00e1nka water reservoir near Sv\u011btl\u00e1 nad S\u00e1zavou, which is a\u00a0permanent source for a\u00a0public water supply operated by Vodovody a\u00a0kanalizace Havl\u00ed\u010dk\u016fv Brod, a. s. In\u00a0total, water mite fauna samples were collected from 45 reservoirs; the\u00a0numerical designation of\u00a0the\u00a0sites\/reservoirs follows their order in\u00a0the\u00a0cited Decree, with the\u00a0two additional reservoirs assigned the\u00a0numbers 48 and 49 in\u00a0the\u00a0list.<\/span><\/p>\n Sampling sites were located in\u00a0the\u00a0littoral zone immediately adjacent to the\u00a0dam structures or over the\u00a0stony bottom at the\u00a0toe of\u00a0the\u00a0dams (geographical coordinates are given in\u00a0Tab.\u00a01<\/span><\/em>); examples of\u00a0several specific sites are shown in\u00a0Figs. 2\u20139<\/em><\/span>.<\/span><\/p>\n Tab.\u00a02<\/span><\/span><\/em> contains data on chlorophyll a<\/span>\u00a0concentrations in\u00a0the\u00a0individual reservoirs, which allow comparison of\u00a0their trophy, as the\u00a0quantity of\u00a0phytoplankton is an indicator of\u00a0nutrient loading in\u00a0water bodies. Mean values and ranges of\u00a0chlorophyll a<\/span>\u00a0concentrations are presented, based on samples collected at weekly intervals from April to September 2024. Typically, 9 to 11 values were determined over the\u00a0course of\u00a0the\u00a0season. Tab.<\/span>\u00a02<\/span><\/em> includes data on water transparency, also measured at weekly intervals during the\u00a0period from April to September. These data were provided by staff of\u00a0the\u00a0River Boards, state enterprises from ongoing long-term monitoring of\u00a0water quality in\u00a0all water reservoirs.<\/span><\/p>\n From water-level fluctuation data obtained from monitoring of\u00a0the\u00a0individual reservoirs (provided by the\u00a0respective River Board, state enterprise), it was confirmed for each site that the\u00a0sampling locations had been submerged for more than three months prior to sampling; thus, the\u00a0water mite fauna samples were collected from long-term submerged surfaces of\u00a0the\u00a0littoral zone. In\u00a0cases of\u00a0a\u00a0gradual long-term decrease in\u00a0water level by several metres, for example in\u00a0Horka reservoir (site No. 19), changes in\u00a0benthic community composition in\u00a0the\u00a0littoral zone cannot be ruled out.<\/span><\/p>\n For sampling water mite fauna, a\u00a0standard method was used involving the\u00a0collection of\u00a0organisms with a\u00a0plankton net mounted on a\u00a0pole; the\u00a0diameter of\u00a0the\u00a0circular opening was 30 cm and the\u00a0mesh size was 0.350\u00a0mm. Each sample was taken by sweeping the\u00a0net along the\u00a0dam face or over the\u00a0stony riprap at the\u00a0toe of\u00a0the\u00a0dam, with horizontal movement of\u00a0approximately 1.5\u00a0m and at depths of\u00a00.5\u20131.0\u00a0m below the\u00a0water surface for a\u00a0duration of\u00a0two minutes. Sampling sites were selected so that the\u00a0substrate (stony surfaces under the\u00a0open water column) was largely free of\u00a0vegetation and morphologically very similar (Figs. 2\u20139<\/span><\/em>).<\/span><\/p>\n This methodological approach does not provide an absolute quantification of\u00a0the\u00a0number of\u00a0individuals collected, i.e. in\u00a0relation to water volume or surface area; however, it allows comparison of\u00a0the\u00a0number of\u00a0water mites captured, the\u00a0frequency of\u00a0species present, and their occurrence within\u00a0the\u00a0same habitat (littoral over a\u00a0stony substrate). It therefore represents a\u00a0semi-quantitative method for assessing the\u00a0occurrence of\u00a0water mites at individual sites, making it possible to express the\u00a0relative abundance of\u00a0the\u00a0recorded species.<\/span><\/p>\n The\u00a0collected material, consisting of\u00a0detritus with zooplankton, meiobenthos (including water mites), macrozoobenthos, and larger phytoplankton species, was transferred from the\u00a0net into water in\u00a0a\u00a0plastic tray (30 \u00d7 50 cm). Water mites were picked out on site using a\u00a0pipette and fixed in\u00a0Koenike\u2019s\u00a0solution (a\u00a0mixture of\u00a0glacial acetic acid, glycerine, and distilled water\u00a0[4]). After the\u00a0completion of\u00a0sampling at the\u00a0end of\u00a0September 2024, the\u00a0individual water mite samples were sorted under a\u00a0stereomicroscope (at 10\u201350\u00d7 magnification), and both adult specimens and nymphs were counted. From the\u00a0adult specimens, already sorted to genus level, several individuals from each morphologically uniform group were selected for further preparation. After heating in\u00a0potassium hydroxide (30\u00a0%), during which the\u00a0chitinous body structures turn brown, the\u00a0homogeneous body contents are expelled from the\u00a0individual specimens under a\u00a0stereomicroscope; after rinsing in\u00a0water, the\u00a0specimens are transferred to glycerine. Subsequently, on a\u00a0microscope slide, the\u00a0organs necessary for species identification are prepared (mouthparts are separated, and in\u00a0some cases certain\u00a0legs). After embedding in\u00a0glycerine jelly and covering with a\u00a0coverslip, permanent slides of\u00a0adult specimens were prepared, suitable for microscopic identification to species level. These permanent preparations serve as reference material and allow the\u00a0acquisition of\u00a0photographic documentation. Glycerine jelly is a\u00a0historically well-established medium for zoological microscopic preparations and is still used today for preserving voucher material of\u00a0water mites, see\u00a0[5].<\/span><\/p>\n Immature stages of\u00a0water mites (nymphs) were, with few exceptions, not prepared, as their morphology generally does not allow reliable identification to species level.<\/span><\/p>\n Species identification of\u00a0water mites was based primarily on literature published in\u00a0the\u00a0last 10\u201312 years [6\u20138]; however, older identification keys are also useful for certain\u00a0more detailed information [4, 9].<\/span><\/p>\n Average chlorophyll a<\/span>\u00a0concentrations (Tab.\u00a02<\/span><\/em>) during the\u00a0growing season were below 10 \u00b5g\/L in\u00a026 reservoirs, while in\u00a011 reservoirs they ranged between 10 and 20 \u00b5g\/L. Only six reservoirs exceeded 20 \u00b5g\/L, in\u00a0three cases very substantially. These data indicate that the\u00a0sites are predominantly oligotrophic to slightly mesotrophic, which corresponds to the\u00a0requirements for water quality of\u00a0sources used for drinking water treatment. This is also reflected in\u00a0the\u00a0average values of\u00a0water transparency during the\u00a0summer (growing) period, which ranged between 2 and 3\u00a0m; only in\u00a0a\u00a0few cases were they less than 1\u00a0m.<\/span><\/p>\n A\u00a0total of\u00a01,356 water mites were recorded in\u00a045 water reservoirs, of\u00a0which 507 specimens (37.3\u00a0%) were immature stages (nymphs), for which identification to species level is uncertain\u00a0(Tab.\u00a03<\/span><\/em>). The\u00a0list of\u00a0water mite species in\u00a0Tab.\u00a03<\/span><\/em> is therefore based solely on the\u00a0identification of\u00a0849 adult individuals, whose occurrence and abundance were found at the\u00a0individual sites.<\/span><\/p>\n <\/p>\n The\u00a0numbers of\u00a0water mites vary considerably among individual sites, as does the\u00a0proportion of\u00a0immature stages (nymphs). Tab.\u00a04<\/span><\/em> presents data from sites with more than 40 water mites (adults and nymphs), i.e. more than 3 % of the total number of collected water mites. The highest numbers of water mites were found in Nov\u00e1 \u0158\u00ed\u0161e reservoir (site No. 40), Karolinka reservoir (site No. 34), and Husinec reservoir (site No. 8). By contrast, no water mites were found in Josef\u016fv D\u016fl reservoir (site No. 4), and\u00a0<\/span>only four nymphs were recorded in\u00a0Sou\u0161 reservoir (site No. 5) (only one was identified, belonging to the\u00a0genus Hydrochoreutes<\/span> Koch, 1837). The\u00a0likely cause is the\u00a0low pH values of\u00a0the\u00a0water in\u00a0these reservoirs (see Discussion). Only a\u00a0single water mite was also found in\u00a0Horka reservoir (site No. 19); a\u00a0probable reason may be the\u00a0long-term gradual but substantial decrease in\u00a0water level of\u00a0approximately 6\u20138\u00a0m (as\u00a0shown in\u00a0Fig.\u00a04<\/span><\/em>), which may have significantly reduced the\u00a0availability of\u00a0organisms necessary for the\u00a0development of\u00a0water mite larvae. A\u00a0total of\u00a034 water mite species were recorded across all 45 studied reservoirs. Twelve species dominated in\u00a0both occurrence and number of\u00a0individuals, accounting for 87.4\u00a0% of\u00a0all recorded adult water mites (Tab.\u00a05<\/span><\/em>). All these species possess numerous swimming setae on their legs, and Unionicola crassipes<\/span><\/em> (Mueller, 1776) as well as species of\u00a0the\u00a0genus Neumania<\/span><\/em> Lebert, 1879 are characterised by very long legs, as illustrated in\u00a0Microphotographs I\u2013L<\/span>. The\u00a0number of\u00a0species recorded in\u00a0individual reservoirs is given in\u00a0Tab.\u00a03<\/span><\/em>; the\u00a0highest numbers were found in\u00a0Vrchlice reservoir (site No. 3) and Nov\u00e1 \u0158\u00ed\u0161e reservoir (site\u00a0No.\u00a040), see Tab\u00a06<\/span>. Fourteen species occurred at only one site, while two to three species were recorded at three sites. These are species of\u00a0the\u00a0genera Arrenurus<\/span> <\/em>Dug\u00e8s, 1834, Limnesia<\/span><\/em> Koch, 1836, and Piona<\/span> <\/em>Koch, 1842, which otherwise commonly occur in\u00a0large numbers in\u00a0standing waters with macrophyte vegetation, especially in\u00a0ponds.<\/span><\/p>\n <\/p>\n <\/p>\n <\/p>\n Three recorded species expand the\u00a0list of\u00a0water mite species documented in\u00a0the\u00a0Czech Republic in\u00a0the\u00a0database of\u00a0the\u00a0Nature Conservation Agency of\u00a0the\u00a0Czech Republic. These are the\u00a0following species:<\/span><\/p>\n The\u00a0identification of\u00a0the\u00a0water mite designated as \u201cVicinaxonopsis<\/span><\/em> Cook, 1974\u201d remains unresolved. It belongs to the\u00a0subfamily Axonopsinae<\/span><\/em>, Viets, 1929. The\u00a0genus Vicinaxonopsis<\/span><\/em> has so far been described only from Bulgaria and Sardinia\u00a0[7]. Only a\u00a0single specimen (Microphotograph O<\/span><\/em>) was found in\u00a0Slu\u0161ovice reservoir (site No. 37, see Tab.<\/span>\u00a03<\/em>), and further clarification of\u00a0this record will therefore require repeated sampling at this site.<\/span><\/p>\n The\u00a0article also includes microphotographs of\u00a0water mite species that expand the\u00a0existing list of\u00a0species recorded in\u00a0the\u00a0Czech Republic by the\u00a0Nature Conservation Agency, as well as species most frequently occurring in\u00a0water reservoirs and species found only sporadically in\u00a0the\u00a0country (Microphotographs\u00a0A\u2013O<\/em>).<\/span><\/span><\/p>\n Water mite fauna in\u00a0dam reservoirs in\u00a0the\u00a0Czech Republic has not been studied in\u00a0detail to date, and available knowledge is therefore only fragmentary.<\/span><\/p>\n The\u00a0first data on the\u00a0occurrence of\u00a0water mites in\u00a0a\u00a0dam reservoir in\u00a0the\u00a0Czech Republic (then Czechoslovakia) were published in\u00a01960\u00a0[3] as part of\u00a0an extensive hydrobiological survey of\u00a0Sedlice reservoir on the\u00a0\u017delivka river. The\u00a0study was conducted at nine sites at depths of\u00a06\u20138\u00a0m using a\u00a0trap placed just above the\u00a0reservoir bottom. After a\u00a024-hour exposure, several dozen water mites were captured at each site. A\u00a0total of\u00a0six species were recorded, differing markedly from the\u00a0species composition of\u00a0water mites in\u00a0the\u00a0water reservoirs presented in\u00a0this study. Representatives of\u00a0the\u00a0genera Unionicola<\/span> <\/em>Haldeman, 1842 and Neumania<\/span><\/em> Lebert, 1879 were absent, while the\u00a0most abundant species were Piona coccinea<\/span><\/em> (Koch, 1836) and Hygrobates longipalpis<\/span><\/em> (Hermann, 1804). The\u00a0occurrence of\u00a0Lebertia fimbriata<\/span><\/em> Thor, 1899 is noteworthy, as this species was not found in\u00a0the\u00a0studied water reservoirs. Additional species recorded from the\u00a0genus Piona<\/span> <\/em>Koch, 1842 included Piona rotunda<\/span><\/em> (Kramer, 1870), now Piona rotundoides<\/span><\/em> (Thor, 1897), and Piona fallax<\/span><\/em> (Thon, 1899). This species, described by Thon from Munick\u00fd pond in\u00a0Czechoslovakia\u00a0[14], does not appear in\u00a0current hydrachnological literature and is not listed among the\u00a0synonyms of\u00a0existing species of\u00a0the\u00a0genus Piona<\/span><\/em> Koch, 1842. L\u00e1ska\u00a0[15] included Piona fallax<\/span><\/em> (Thon, 1899) in his list of water mites recorded in the Czech Republic, but it has not appeared in any subsequent studies on the water mite fauna of the country. Viets [16] also mentions this species in his 1955 publication and reports its\u00a0<\/span>occurrence in\u00a0Great Britain. Since the\u00a0cited record from Sedlice reservoir, however, the\u00a0species has not been recorded again; its existence therefore remains uncertain\u00a0and cannot be verified, as the\u00a0material from Sedlice reservoir is no longer available.<\/span><\/p>\n A\u00a0second record of\u00a0water mite occurrence from this region comes from Kn\u00edni\u010dky reservoir in\u00a0Moravia, where Hrab\u011b\u00a0[17] studied the\u00a0colonisation of\u00a0the\u00a0littoral zone and reservoir bottom. In\u00a0samples collected with a\u00a0plankton net at depths of\u00a0up to 1.5\u00a0m at eight sites, he recorded eight species of\u00a0water mites. The\u00a0most abundant species was Hygrobates longipalpis<\/span><\/em> (Hermann, 1804), but he also reported occasional occurrences of\u00a0Unionicola crassipes<\/span><\/em> (Mueller, 1776), Neumania limosa<\/span><\/em> (Koch, 1836), and Mideopsis orbicularis<\/span><\/em> (Mueller, 1776), which are among the\u00a0species with the\u00a0highest frequency of\u00a0occurrence in\u00a0the\u00a0water reservoirs studied here.<\/span><\/p>\n A\u00a0detailed study of\u00a0water mite fauna was published by Pun\u010doch\u00e1\u0159 and Hrb\u00e1\u010dek\u00a0[18] from Hubenov reservoir in\u00a0the\u00a0Bohemian-Moravian Highlands, where they described the\u00a0dominance of\u00a0Piona carnea<\/span><\/em> (Koch, 1836), which occurred in\u00a0the\u00a0plankton of\u00a0the\u00a0reservoir pelagic zone after the\u00a0reservoir was filled in\u00a01972. During the\u00a0first few years, the\u00a0fish stock consisted solely of\u00a0brown trout (Salmo trutta fario<\/span><\/em>), while large cladocerans of\u00a0the\u00a0genus Daphnia<\/span> dominated the\u00a0zooplankton and limited the\u00a0development of\u00a0phytoplankton biomass. Water transparency in\u00a0the\u00a0reservoir exceeded 9\u00a0m (the\u00a0maximum depth of\u00a0the\u00a0reservoir is 16\u00a0m). In\u00a0the\u00a0water mite fauna in\u00a0the\u00a0years 1976\u20131978, Piona carnea<\/span><\/em> (Koch, 1836) predominated (70\u201390\u00a0%); owing to the\u00a0dense swimming setae on its legs, it was able to move within\u00a0the\u00a0pelagic zone. Complementary species included Piona pusilla<\/span><\/em> (Neuman, 1875) and Piona rotundoides<\/span><\/em> (Thor, 1897), which accounted for 5\u201317\u00a0% of\u00a0the\u00a0water mite fauna. A\u00a0change in\u00a0fish stock, when trout were replaced due to disease by an ichthyofauna dominated by non-predatory fish, was accompanied by a\u00a0marked shift in\u00a0the\u00a0water mite assemblage: the\u00a0originally \u201ccomplementary species\u201d subsequently became dominant, and the\u00a0occurrence of\u00a0additional species increased, including Limnesia maculata<\/span><\/em> (Mueller, 1776) and Unionicola crassipes<\/span><\/em> (Mueller, 1776). Monitoring of\u00a0Hubenov reservoir is also included in\u00a0the\u00a0present study (site No. 45\u00a0\u2013 Tab.<\/span>\u00a01 <\/span><\/em>and 2<\/span><\/em>, Fig.\u00a02<\/span><\/em>). Its fish stock currently consists of\u00a0a\u00a0mixture of\u00a0species\u00a0[19], in\u00a0which predatory fish do not predominate, and the\u00a0water mite fauna is characterised by a\u00a0clear dominance of\u00a0Unionicola crassipes<\/span><\/em> (Mueller, 1776), see Tab.\u00a03<\/span><\/em>. A similar,\u00a0<\/span>unusual dominance of\u00a0the\u00a0water mite Piona limnetica<\/span> Biesiadka was described by Gliwicz and Biesiadka\u00a0[20] in\u00a0the\u00a0plankton of\u00a0a\u00a0dam reservoir in\u00a0Panama. As in\u00a0the\u00a0case of\u00a0Hubenov reservoir, the\u00a0main\u00a0reason was the\u00a0availability of\u00a0planktonic cladocerans as a\u00a0food source, together with suitable body morphology, as the\u00a0legs of\u00a0this species, with a\u00a0specific arrangement of\u00a0swimming setae, enable movement (swimming) in\u00a0open water outside the\u00a0littoral zone. Species of\u00a0the\u00a0genera Neumania<\/span><\/em> Lebert, 1879 and Unionicola<\/span><\/em> Haldeman, 1842 were present in\u00a0lower numbers in\u00a0this reservoir; their swimming setae also allow them to occur in\u00a0the\u00a0plankton.<\/span><\/p>\n Of\u00a0the\u00a034 water mite species recorded in\u00a0the\u00a0studied water-supply reservoirs, 12 species occurred at more than 10\u00a0% of\u00a0sites (Tab.\u00a05<\/span><\/em>). These are species characterised by pronounced locomotory activity in\u00a0the\u00a0pelagic zone.<\/span><\/p>\n With regard to the\u00a0occurrence and biology of\u00a0INTRODUCTION<\/h2>\n
Tab. 1. List and characteristics of water reservoirs (in order according to Decree No. 137\/1999 Coll. [1]) and date of water mites sampling in 2024<\/h5>\n
![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2026\/04\/Puncochar-tab-1-1.jpg\")
<\/a>\nSAMPLING SITES<\/h2>\n
Fig. 1. Location of investigated reservoirs in the Czech Republic, indicating the responsibility of the river basin administrators (River Boards, state enterprises) that manage the\u00a0reservoirs (Source:\u00a0Ministry of Agriculture, elaborated by Mgr. Monika St\u00e1dn\u00edkov\u00e1)<\/h6>\n
<\/a>\nTab. 2. List and additional characteristics of investigated water reservoirs (water transparency measured by Secchi disc, chlorophyll a<\/u> concentration, water level fluctuations; data\u00a0provided by colleagues of River Boards, state enterprises) and numbers of water mites found<\/h5>\n
<\/a>\n<\/a>\nFig. 2. Hubenov reservoir (site no. 45), view from the dam to the sampling site<\/h6>\n
<\/a><\/h6>\nFig. 3. P\u0159\u00edse\u010dnice reservoir (site no. 28), view of the dam and sampling site<\/h6>\n
<\/a><\/h6>\nFig. 4. Horka reservoir (site no. 19), view of the dam and sampling site<\/h6>\n
<\/a>\nFig. 5. Kru\u017eberk reservoir (site no. 31), view of the dam and sampling site<\/h6>\n
<\/a>\nFig. 6. Karolinka reservoir (site no. 34), view from the dam to the sampling site<\/h6>\n
<\/a>\nFig. 7. Mosti\u0161t\u011b reservoir (site no. 46), view of the dam and sampling site<\/h6>\n
<\/a>\nFig. 8. V\u00edr reservoir (site no. 43), view of the dam and sampling site<\/h6>\n
<\/a>\nFig. 9. Nov\u00e1 \u0158\u00ed\u0161e reservoir (site no. 40), view of the sampling site<\/h6>\n
METHODOLOGY<\/h2>\n
RESULTS<\/h2>\n
Tab. 3. Number of adults and nymphs of individual water mite species found in investigated reservoirs<\/h5>\n
<\/a>\nTab. 4. Number of adults and nymphs of individual water mite species found in investigated reservoirs<\/h5>\n
<\/a>\nTab. 5. Species of water mites with the highest abundance in all investigated reservoirs<\/h5>\n
<\/a>\nTab. 6. Reservoirs with the highest number of water mite species<\/h5>\n
<\/a>\n\n
\nThe\u00a0record of\u00a0this species in\u00a0Land\u0161tejn reservoir (site No. 41, see Tab.<\/span>\u00a03<\/em>) also represents a\u00a0species new to the\u00a0fauna of\u00a0the\u00a0Czech Republic, as it has not previously been reported in\u00a0published studies on water mites in\u00a0Czech waters.<\/span><\/li>\n
\nThis species has been recorded previously, and L\u00e1ska\u00a0[9] reports it as common throughout the\u00a0Czech Republic. It is among the\u00a0most frequently recorded species of\u00a0the\u00a0genus Arrenurus<\/span> Dug\u00e8s<\/em>, 1834 in\u00a0European water bodies, especially in\u00a0large lakes [10, 11].<\/span><\/li>\n
\nThis species is not new to the\u00a0fauna of\u00a0the\u00a0Czech Republic either; however, it\u00a0is reported as a\u00a0\u201crelatively rare species\u201d from submontane streams\u00a0[9]. It was found in\u00a0the\u00a0studied reservoirs but is common in\u00a0lakes [11, 12].<\/span><\/li>\nDISCUSSION<\/h2>\n