Morphology of Chrysastrella paradoxa stomatocysts from the Subpolar Urals (Russia) with comments on related morphotypes

For many years Chrysastrella Chodat has been a cyst genus but recently it has been re-instated and re-defined. Currently, Chrysastrella contains Ochromonas-like flagellates including O. tuberculata Hibberd which was synonymized with the type species, Chrysastrella paradoxa Chodat. A mass development of stomatocysts, which we identified as Ch. paradoxa, was observed in a bog on the territory of “Yugyd va” National Park (the Subpolar Urals, Russia). The morphology of stomatocysts was studied by scanning electron microscopy and compared with previously described similar morphotypes. Stomatocysts #80 Hansen, #1 Wołowski & Płachno and #4 Bai & Chen seem to be identical to Chrysastrella paradoxa stomatocysts and we propose to reduce them to synonymy.