Population of Soil-Dwelling Enchytraeids (Annelida, Clitellata, and Enchytraeidae) in the European Part of Russia

Enchytraeids are among the key organisms in the functioning of terrestrial ecosystems. Despite this, the fauna and population of enchytraeids of the European part of Russia (ER) have been studied rather poorly. Based on our collections gathered at 193 sites in the territory of the main biomes of European Russia in 2019–2023, 74 species of enchytraeids assigned to 15 genera were identified. The presence of tundra, boreal, nemoral, and desert faunal complexes of enchytraeids, as well as of a group of polyzonal species, was shown. From a faunal point of view, the Caucasus, which is inhabited by a group of species that are not found anywhere else in Russia, is distinguished in the European part of the country. Analysis of enchytraeid communities in various biomes of the European part at the species level would allow a more correct assessment of their role in detrital food webs and the functioning of ecosystems in general.