Salinity-Dependent Species Richness of Bacillariophyta in Hypersaline Environments

Abstract

Hypersaline habitats are among the most polyextreme habitats on Earth, but they contain a rather large diatom species diversity. A review of the diatom species’ richness was made on three scales: 1. a separate lake in Crimea; 2. all hypersaline waters in Crimea; and 3. the world totality as a whole. In total, 51 species were found in Lake Chersonesskoye during sampling from 2004 to 2018. In ten Crimean hypersaline lakes, 91 species were noted in total. All diatom species found in the studied hypersaline water bodies of the world belong to 458 species, which is 2.7% of the total number of known species of Bacillariophyta. In all three scales, the similarity of the species’ composition between water bodies as well as studied periods was not found. Most of all the identified species were found only in one of the studied water bodies, and only 59 species (13% of the total list) were found in more than three water bodies. An analysis showed that no more than 40% of the species that exist in hypersaline waters have been identified on a global scale. The diatom shell nanostructure from hypersaline waters has specific peculiarities that may be valuable for some technological applications. The knowledge of diatoms in hypersaline waters not only has pure scientific importance but also covers some needs of bio- and nanotechnologies.