First records of testate amoebae from the town of Ugolnye Kopi, Chukotka (Russian Arctic)

Abstract Testate amoebae are a useful group of species for biogeographic research. Recent knowledge of the distribution of testate amoebae in the Arctic is incomplete because of large geographic gaps in species distribution data. In this study, we present the first report of testate amoebae from the eastern part of Chukotka in the Russian Arctic, which may at least partially bridge the gap between Alaska and the studied regions of the Russian Arctic. Testate amoebae were collected from 11 waterbodies in the vicinity of the town of Ugolnye Kopi, which is located on the coast of Anadyr Bay in the Bering Sea. Testate amoebae were abundant and active in the studied water bodies, even in the extreme physical environment of Chukotka. The genus and species structure of testate amoebae have been described. We found clear differences in the species structure of the assemblages inhabiting the studied water bodies. Our results showed that most of the testate amoeba assemblages in this part of Chukotka were dominated by Centropyxis pontigulasiformis, which is a typical Arctic species, assemblages found in small water bodies show more affinity to those from Spitzbergen, and the assemblage dominated by Cucurbitella mespiliformis was not previously reported in the Arctic. These results highlight the limited knowledge of the abundance and diversity of testate amoebae over large areas of the globe.