Light microscopy and phylogenetic analyses of Chlamydomonas species (volvocales, chlorophyceae). II. molecular phylogeny, secondary structure of ITS-2, cell morphology, and nomenclature of Microglena opisthopyren, and m. media, comb. nov.

Two species of Chlamydomonas Ehrenb. in the clade Monadinia, Chlamydomonas pseudomacrostigma L. Ş. Péterfi ex H. Ettl and C. media G. A. Klebs, were recently reported from Japan. However, several species in the clade were transferred to the genus Microglena Ehrenb. by different authors, and therefore the taxonomic treatment of these two species should be revisited. Here, their identifications were re-examined based on 18S rRNA gene phylogeny, secondary structure comparisons of ITS-2 rDNA, and vegetative cell morphology. Based on these comparisons, C. pseudomacrostigma and C. media were treated as a later synonym of Microglena opisthopyren (Skuja) Demchenko, Mikhailyuk & Pröschold and an earlier synonym of M. skujae Demchenko, Mikhailyuk & Pröschold, respectively. A new combination, Microglena media (G.A. Klebs) Nakada, comb. nov., is proposed for the latter.