title: Two New Freshwater Woloszynskioids Asulcocephalium miricentonis gen. et sp. nov. and Leiocephalium pseudosanguineum gen. et sp. nov. (Suessiaceae, Dinophyceae) Lacking an Apical Furrow Apparatus.
abstract: Two new woloszynskioid dinoflagellates, Asulcocephalium miricentonis gen. et sp. nov. and Leiocephalium pseudosanguineum gen. et sp. nov., are described from Japanese freshwater ponds on the basis of bright field and fluorescence light microscopy, scanning and transmission electron microscopy, and molecular phylogeny inferred from rDNA sequences. Asulcocephalium miricentonis has a spherical anterior nucleus and chloroplast with a pyrenoid penetrated by the cytoplasm. This species has 9-12 latitudinal series of amphiesmal vesicles (AVs), including an apparently large AV on the right ventral side of the epicone. Leiocephalium pseudosanguineum has a U-shaped nucleus in the epicone and chloroplasts without a pyrenoid. This species has at least 24 latitudinal series of AVs. The characteristic features of both species were brick-like material (type E) in the eyespot and the lack of an apical furrow. These features coincide with those of Polarella glacialis, but the two species differ in cell shape, number and arrangement of AVs, shape of resting cysts, and habitats; i.e., P. glacialis has been reported only from marine cold waters. Molecular phylogeny revealed that A. miricentonis and L. pseudosanguineum were positioned in the Suessiaceae and closely related to Piscinoodinium sp., but their relationship to Polarella and other reported taxa was not supported.
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Biological Institute, Section of Phycology, University of Copenhagen, Universitetsparken 4, DK-2100, Copenhagen K, Denmark.
authors.forename: Øjvind
authors.initials: Ø
authors.lastname: Moestrup
authors.affiliation: Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Jordan
authors.affiliation: Asian Natural Environmental Science Center, the University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan. Electronic address: iwataki@anesc.u-tokyo.ac.jp.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Iwataki
mesh_terms: D048028:DNA, Algal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004141:Dinoflagellida / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure*; D007564:Japan; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D048028:DNA, Algal; D004275:DNA, Ribosomal
keywords: Apical furrow; Asulcocephalium miricentonis; Leiocephalium pseudosanguineum; Suessiaceae.; dinoflagellate; eyespot