Environmental determinants of water mite (Acari: Hydrachnidia) distribution in the ancient Lake Skadar system

Abstract In comparison to Central Europe, the knowledge about water mites inhabiting the natural lakes of southern Europe is scarce. This is a first study focusing on the water mite species composition and zonation in a large Mediterranean lake, i.e. ancient Lake Skadar basin, and identifying the role of physical and chemical water parameters in their distribution. The Hydrachnidia community of Lake Skadar is composed of 53 species. The most diverse water mite assemblages were found in the littoral zone and in the sublacustrine springs. Our study revealed that water mites were most abundant in the deeper, open part of Lake Skadar. Typically sublacustrine species dominated in all zones and habitats of Lake Skadar. The rheobiontic and rheophilic species also had a substantial share, mainly in sublacustrine springs, but also in the open lake area. The unique feature of the Lake Skadar water mite community was an absence of many species typical for the vernal astatic waters and for the shallow phytolittoral zone, even if such habitats were present. We conclude that the structure of the water mite communities in Lake Skadar are associated with particular zones (sublacustrine springs, littoral, open lake area) of the lake and with local environmental conditions, predominantly temperature.