Year: 2025, Number: 3, Pages: 5-15
Caloneis aerophila W. Bock is an under-studied diatom species previously recorded in Europe and North America, including the Arctic region. In the European part of Russia, it has been found in soils of the Polar Cis-Urals and Subpolar Urals. In Primorsky Krai, only empty valves of this species had been previously identifi ed in buried soils at the Steklyanukha archaeological site. A clone of C. aerophila was isolated from a soil sample collected in July 2021 in the Khasansky District of Primorsky Krai and identified using light and scanning electron microscopy. Morphometric data for C. aerophila were supplemented, with the lower limit of cell length refined; the ultrastructure of the striae was studied; and the structure of the epicingulum was described in detail. For the first time, a nucleotide sequence of the chloroplast DNA rbcL gene was obtained for this species. Phylogenetic analysis confi rmed that the genus Caloneis is not monophyletic and is closely related to species of the genus Pinnularia.