Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia
Water mites are the most diverse freshwater group of Acari and despite growing research interest in the ecology of this group, the environmental influences along longitudinal river gradients on their assemblages are still not fully understood. The objective of this study was to determine how physico...
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MDPI AG
2023-01-01
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| Online Access: | https://www.mdpi.com/1424-2818/15/2/139 |
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| author | Tia Žeželj Vidoša Ivana Pozojević Iva Vidaković Maoduš Zlatko Mihaljević |
| author_facet | Tia Žeželj Vidoša Ivana Pozojević Iva Vidaković Maoduš Zlatko Mihaljević |
| author_sort | Tia Žeželj Vidoša |
| collection | DOAJ |
| description | Water mites are the most diverse freshwater group of Acari and despite growing research interest in the ecology of this group, the environmental influences along longitudinal river gradients on their assemblages are still not fully understood. The objective of this study was to determine how physico-chemical water properties and hydromorphological alterations affect the composition and distribution of water mite assemblages along a longitudinal river gradient. Macroinvertebrate samples were collected from 20 study sites distributed longitudinally along the entire 106 km course of a lowland river (Bednja River) in the Pannonian Lowlands ecoregion of Croatia. At each site, 20 samples were collected with regard to microhabitat composition (+400 samples in total). In parallel with the sampling of macroinvertebrates at each site, the physico-chemical water properties were measured and the degree of hydromorphological alteration was assessed (European Standard EN 15843:2010). Both the number of taxa and water mite abundance were found to increase significantly with increasing distance from the source. However, the assemblages from the upper reaches and those from the lower reaches shared very few species, emphasizing the importance of species-level identification. Water mite species richness and diversity were not reduced with increased levels of variables associated with organic enrichment and eutrophication pressures. Similarly, hydromorphological alteration did not reduce either water mite abundance or species richness and was positively correlated with both. Furthermore, a correspondence analysis on water mite microhabitat preferences revealed that 32% of all species were positively associated with artificial microhabitats (technolithal). These positive associations may be the result of reduced competitive pressure from other larger invertebrates, as well as a possible preference for higher velocity, which usually occurs on smooth technolithal surfaces. A total of 22 different species of water mites were found during this study, 8 of which (or 36% of all species found) were recorded for the first time in Croatia. |
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| issn | 1424-2818 |
| language | English |
| last_indexed | 2024-03-11T08:56:47Z |
| publishDate | 2023-01-01 |
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| spelling | doaj.art-3a8774ca130c4b5b8b683bef91d7024d2023-11-16T20:03:36ZengMDPI AGDiversity1424-28182023-01-0115213910.3390/d15020139Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in CroatiaTia Žeželj Vidoša0Ivana Pozojević1Iva Vidaković Maoduš2Zlatko Mihaljević3Department of Biology, Faculty of Science, University of Zagreb, Zagreb 10000, CroatiaDepartment of Biology, Faculty of Science, University of Zagreb, Zagreb 10000, CroatiaElektroprojekt d.d., Civil and Architectural Engineering Department, Water Resources, Nature and Environmental Protection Section, Zagreb 10000, CroatiaDepartment of Biology, Faculty of Science, University of Zagreb, Zagreb 10000, CroatiaWater mites are the most diverse freshwater group of Acari and despite growing research interest in the ecology of this group, the environmental influences along longitudinal river gradients on their assemblages are still not fully understood. The objective of this study was to determine how physico-chemical water properties and hydromorphological alterations affect the composition and distribution of water mite assemblages along a longitudinal river gradient. Macroinvertebrate samples were collected from 20 study sites distributed longitudinally along the entire 106 km course of a lowland river (Bednja River) in the Pannonian Lowlands ecoregion of Croatia. At each site, 20 samples were collected with regard to microhabitat composition (+400 samples in total). In parallel with the sampling of macroinvertebrates at each site, the physico-chemical water properties were measured and the degree of hydromorphological alteration was assessed (European Standard EN 15843:2010). Both the number of taxa and water mite abundance were found to increase significantly with increasing distance from the source. However, the assemblages from the upper reaches and those from the lower reaches shared very few species, emphasizing the importance of species-level identification. Water mite species richness and diversity were not reduced with increased levels of variables associated with organic enrichment and eutrophication pressures. Similarly, hydromorphological alteration did not reduce either water mite abundance or species richness and was positively correlated with both. Furthermore, a correspondence analysis on water mite microhabitat preferences revealed that 32% of all species were positively associated with artificial microhabitats (technolithal). These positive associations may be the result of reduced competitive pressure from other larger invertebrates, as well as a possible preference for higher velocity, which usually occurs on smooth technolithal surfaces. A total of 22 different species of water mites were found during this study, 8 of which (or 36% of all species found) were recorded for the first time in Croatia.https://www.mdpi.com/1424-2818/15/2/139water miteslotic ecosystemhydromorphological alterationsanthropogenic stressors |
| spellingShingle | Tia Žeželj Vidoša Ivana Pozojević Iva Vidaković Maoduš Zlatko Mihaljević Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia Diversity water mites lotic ecosystem hydromorphological alterations anthropogenic stressors |
| title | Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia |
| title_full | Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia |
| title_fullStr | Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia |
| title_full_unstemmed | Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia |
| title_short | Longitudinal Changes in Diverse Assemblages of Water Mites (Hydrachnidia) along a Lowland River in Croatia |
| title_sort | longitudinal changes in diverse assemblages of water mites hydrachnidia along a lowland river in croatia |
| topic | water mites lotic ecosystem hydromorphological alterations anthropogenic stressors |
| url | https://www.mdpi.com/1424-2818/15/2/139 |
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