Tanasevitch A.V., Nekhaeva A.A. 2016. Spiders (Aranei) of the Kharaulakh Mountains and the Lena River lower reaches, northern Yakutia, Russia // Arthropoda Selecta. Vol.25. No.3: 307–326 [in English].
KEY WORDS: Arctic, typical tundra, chorology, checklist, Ust-Lensky Nature Reserve.
ABSTRACT. An analysis has been made of the two local araneofaunas: vicinities of Tyylaakh and Tiksi (northern Yakutia) situated in the subzone of typical tundra of the tundra zone. Peculiarities of spider distribution in the main zonal-landscape vegetation types were revealed. The fauna of intrazonal phytocenoses of local tundra is most rich (36 species) and specific (13%) but characterized by a small share of purely Arctic species (28%). Zonal groups are the second in the fauna richness (26 species) and contain the highest percentage of Arctic components (42%). In all types of communities, the fauna basically consists of the Arctic group species, such as arcto-alpine, arcto-boreal and arcto-boreo-montane (50–58%). Boreal species are rare and completely absent in zonal and azonal communities; polyzonal species are mainly represented in zonal and intrazonal habitats. Polytopic and petrophilous species were revealed, as well as species characteristic for certain types of vegetative aggregations. The Arctic Hilaira gertschi Holm, 1960 previously known in the Palearctic from Wrangel Island only (Chukotka Autonomous Okrug, Russia), was found for the first time in continental Siberia, in mountain tundra of the Kharaulakh Mountains. Agyneta bulavintsevi Tanasevitch, 2016, known only from Tiksi, was for the first time recorded from Vaygach Island (Arkhangelsk Area, Russia). Sciastes hyperboreus (Kulczyński, 1908) was restored in the genus Hilaira Simon, 1884, as Hilaira hyperborea Kulczyński, 1908, comb.revalid. A complete list of spiders is given for the Lena River lower reaches, the Kharaulakh Mountains and their vicinities (99 species); a separation was drawn between species from the forest biotopes of the Lena River Valley and those of lowland tundra. Each species is characterized by its range type and the zonal component.