Remarks on fauna and population of oribatid mites (Acari: Oribatida) in Priazovsky National Wildlife Sanctuary (Southern Russia)

Abstract

This study is devoted to the faunal inventory and preliminary ecological analysis of oribatid mite communities in Priazovsky National Wildlife Sanctuary (Krasnodar Krai, Southern Russia), which is included into the Ramsar Convention ‘Kuban Delta’ Wetland of international importance. We sampled five major habitat types represented in the sanctuary and its environs: liman-reed beds, sandy coasts, elevated coasts, rice paddies, and a salt marsh. In total, 40 oribatid mite species were found. They belonged to 22 families. Most of the species were earlier met in the neighboring regions: Krasnodar Krai, Rostov region and Northern Caucasus. Few species however were found in Krasnodar Krai for the first time, e.g. Ghilarovizetes obtusus Shaldybina, 1969, which was earlier recorded only in the Central and Eastern Caucasus. The most species-rich habitats were liman-reed beds. In rice paddies, oribatid communities were rudimentary and represented only by very few species. The abundance of different oribatid ecomorphs was quite contrasting across the five habitat types. Soil-dwelling mites dominated in liman-reed beds possibly due to stable humidity of soil in this habitat type. The presence of aquatic mites in liman reed beds was also quite peculiar. In welldrained elevated coasts, non-specialized and surface-dwelling mites were the most numerous because of their better adaptation to drought. In sandy coasts and salt marshes, surface-dwelling mites prevailed. We conclude that salinity and rice-growing seem to reduce considerably abundance and diversity of oribatid mites in the study area. We further assume that the quite high similarity of oribatid fauna in Priazovsky National Wildlife Sanctuary with that in the surrounding regions suggests much closer biogeographic relationship of Kuban lowlands with other regions of North Caucasus, than one would expect.