Water mites (Hydrachnidia) of temporary ponds of Western Siberia: do the composition and the structure of acarofauna change over a long period of time?

Temporary ponds are specific freshwater habitats in which the characteristic fauna of aquatic organisms i s formed. One of the large groups of invertebrates in temporary water bodies is water mites. In this work, water mites were studied in three different types of temporary ponds in the vicinity of the city of Tyumen, Wester n Siberia. The studies were carried out in two periods with a long time interval between them: in 2008-2010 an d 2018-2019. In total, 33 species of water mites from 7 families were identified in the studied ponds. All ponds were dominated by vernal mite species typical for this type of water bodies. Also, they were characterized b y similar seasonal dynamics of numbers. The species composition and the number of mites in different ponds varied, which is associated with different physicochemical parameters and the fauna of invertebrates, whic h served as food objects and hosts for the adults and larvae. Despite the small size and periodic drying of the ponds, the fauna of the mites inhabiting them has changed little over the long period of time that separates the studies. Only in one pond, which became permanent due to the rise of groundwater, significant changes in acarofauna were observed. Considering such constancy of the fauna of water mites of temporary ponds, they can be used as bioindicators of the ecological state of water bodies.