Morphology and phylogeny of the marine bipolar centric diatom <i>Pseudoleyanella lunata</i> (Cymatosiraceae) with special reference to the diatotepum

• NAKAMURA Noriaki

  Department of Biology, Tokyo Gakugei University

• YUASA Tomoko

  Department of Earth Science, Tokyo Gakugei University

• MAYAMA Shigeki

  Department of Biology, Tokyo Gakugei University

Bibliographic Information

Other Title

• 海産二極性中心珪藻<i>Pseudoleyanella lunata</i>におけるdiatotepumの観察を伴う形態学および系統学的研究

Abstract

Pseudoleyanella lunata Takano is a marine diatom with dorsiventral valves belonging to the family Cymatosiraceae. We studied the range of variation in valve morphology throughout the life cycle. We also observed the chloroplast division of this species. In large cells, the valves were narrowly lanceolate, slightly capitate at the apices, and asymmetrical with respect to the apical plane, i.e. with almost straight and convex margins on the ventral and dorsal sides, respectively. During cell size reduction, the valves gradually lost their dorsiventral nature, and eventually became almost circular. Although P. lunata was rectangular in girdle view in small cells, large vegetative cells, particularly those generated soon after auxosporulation, were slightly bent, as in Leyanella Hasle et al. However, in contrast to Leyanella, P. lunata lacked both pili and tubular processes at all stages of its life cycle. In phylogenetic analyses (SSU rDNA and rbcL), P. lunata was sister to Leyanella. We also observed the whole structure of the diatotepum which was a sheet-like structure underlying each theca. Under the transmission electron microscope, dot-like marks with high electron density were observed: their position and pattern corresponded to valve poroids. In addition, the diatotepum bore electron-dense lines corresponding to the internal sutures between the girdle bands.

Journal

• Diatom

  Diatom 32 (0), 1-10, 2016

  The Japanese Society of Diatomology

Keywords

• Cymatosiraceae
• diatotepum
• heterovalvy
• <i>Leyanella arenaria</i>
• <i>Pseudoleyanella lunata</i>

Details

• CRID: 1390001205501667584
• NII Article ID: 130006940873
• DOI: 10.11464/diatom.32.1
• ISSN: 21868565
• ISSN: 09119310
• Text Lang: ja
• Data Source:
  • JaLC
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed