Drouetiella elegans (Oculatellaceae, Cyanobacteriota): A New Species of the Recently Established Genus from the Russian Arctic

The species diversity of the recently described genus Drouetiella (Oculatellaceae, Cyanobacteriota), including thin filamentous cyanobacteria, has been rapidly increasing due to the subsequent discovery of new-to-science species in the last several years. This study focuses on one more strain that was isolated from a small lake on the Chukotka Peninsula in the Russian Arctic and tested by an integrative approach. In the result of molecular phylogenetic analysis of the 16S rRNA gene and the 16S–23S ITS rRNA region, this strain was found in a separate clade in the genus Drouetiella. The strain is characterized by unique secondary structures of conserved regions D1–D1′, Box–B, V2, and V3 helices of the 16–23S ITS rRNA. Morphologically, the tested strain was distinct from other Drouetiella species by long cells in mature trichomes, absence of false branching, and hormogonia. Drouetiella elegans occurred in the plankton of a small lake and shared ecological similarities with some aquatic strains of Drouetiella lurida. We provide a taxonomic description of a new species, Drouetiella elegans sp. nov.