Two New Species, <i>Mallomonas baicalensis</i> sp. nov. and <i>M. grachevii</i> sp. nov. (Synurales Chrysophyceae), Found under the Ice of Lake Baikal
2023
Anna Bessudova | Alena Firsova | Diana Hilkhanova | Mikhail Makarov | Maria Sakirko | Maria Bashenkhaeva | Igor Khanaev | Yulia Zakharova | Yelena Likhoshway
Two new species of silica-scaled chrysophytes (order Synurales) from the genus <i>Mallomonas</i> and sections <i>Striatae Mallomonas baicalensis</i> sp. nov. and <i>M. grachevii</i> sp. nov. found at the bottom surface of the ice of Lake Baikal, with a structure of siliceous scales, are described using electron microscopy. The main and unique distinctive feature of <i>M. baicalensis</i> is its dome with a long spine and the slightly asymmetrical shape of its scales, regardless of their position on the cell. We could not find the bristles, and if there are spines on the dome, we can assume that they may be missing. The main distinguishing feature of <i>M. grachevii</i> is the presence of a secondary layer on the shield except at the angle of the V-rib, in which an area without the secondary layer, a “window”, is present with numerous pores, and the first transverse rib closest to the dome is thickened. Among the <i>Mallomonas</i> species from the section <i>Striatae</i>, only <i>M. siveri</i> and <i>M. baicalensis</i> have a group of rimmed pores in the corner of the V-rib. As a result of our research, the number of <i>Mallomonas</i> species of the section <i>Striatae</i> found in Lake Baikal has increased to eight, of which, in addition to the new species, only one species is widespread, and the rest are rare, previously foundin oligotrophic/mountain water bodies.
显示更多 [+] 显示较少 [-]