The biodiversity of freshwater fauna of the Arctic Islands of the Russian Federation is currently poorly studied and to date
there are insufcient molecular genetic data concerning most of the taxa. This study presents the new data on species composition and distribution of freshwater benthic invertebrates in lakes of the Novaya Zemlya Archipelago and Vaigach Island
based on both the published and the original records. A total of 29 species of invertebrates in 4 classes and 14 orders were
found. Considering the published data, the list of species expands to 136 species. The copepod Mesocyclops leuckarti, the
pontoporeid amphipod Monoporeia afnis, the ostracod Leucocythere mirabilis, and the mollusk Euglesa globularis were
recorded for the frst time from the Novaya Zemlya Archipelago. The oligochaete Rhyacodrilus coccineus, the stonefy
Nemoura sahlbergi, the caddisfies Agrypnia obsoleta, Micrasema gelidum and Philarctus bergrothi were registered for the
frst time from Vaigach Island; P. bergrothi was also recorded for the frst time from Europe. The crane fy larvae of Tipula
(Arctotipula) were recorded as inhabitants of the bottom layer of Arctic lakes for the frst time. The obtained molecular data
are in accordance with the tabula rasa hypothesis that the invertebrate fauna of the Novaya Zemlya Archipelago and Vaigach
Island are the result of recent species immigration after the Last Glacial Maximum. Our data can be used in further ecological
studies and conservation management. The molecular data are of considerable interest for the taxonomy and biogeography
of the fauna of the Arctic islands during the Pleistocene.