MORPHOLOGY AND MOLECULAR PHYLOGENY OF ANKISTRODINIUM GEN. NOV. (DINOPHYCEAE), A NEW GENUS OF MARINE SAND-DWELLING DINOFLAGELLATES FORMERLY CLASSIFIED WITHIN AMPHIDINIUM

Authors

  • Mona Hoppenrath,

    1. Forschungsinstitut Senckenberg, Deutsches Zentrum für Marine Biodiversitätsforschung (DZMB), Südstrand 44, D-26382 Wilhelmshaven, Germany
      Departments of Zoology and Botany, University of British Columbia, Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Vancouver, BC V67 1Z4, Canada
    Search for more papers by this author
  • Shauna Murray,

    1. School of Biotechnology and Biomolecular Sciences, University of NSW, Sydney NSW 2052, Australia The Sydney Institute of Marine Sciences, Chowder Bay Road, Mosman, NSW 2088 Australia
    Search for more papers by this author
  • Sarah F. Sparmann,

    1. Departments of Zoology and Botany, University of British Columbia, Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Vancouver, BC V67 1Z4, Canada
    Search for more papers by this author
  • Brian S. Leander

    1. Departments of Zoology and Botany, University of British Columbia, Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Vancouver, BC V67 1Z4, Canada
    Search for more papers by this author

  • Received 17 August 2011. Accepted 12 February 2012.

Abstract

The classical athecate dinoflagellate genera (Amphidinium, Gymnodinium, Gyrodinium) have long been recognized to be polyphyletic. Amphidinium sensu lato is the most diverse of all marine benthic dinoflagellate genera; however, following the redefinition of this genus ∼100 species remain now of uncertain or unknown generic affiliation. In an effort to improve our taxonomic and phylogenetic understanding of one of these species, namely Amphidinium semilunatum, we re-investigated organisms from several distant sites around the world using light and scanning electron microscopy and molecular phylogenetic methods. Our results enabled us to describe this species within a new heterotrophic genus, Ankistrodinium. Cells of A. semilunatum were strongly laterally flattened, rounded-quadrangular to oval in lateral view, and possessed a small asymmetrical epicone. The sulcus was wide and characteristically deeply incised on the hypocone running around the antapex and reaching the dorsal side. The straight acrobase with hook-shaped end started at the sulcal extension and continued onto the epicone. The molecular phylogenetic results clearly showed that A. semilunatum is a distinct taxon and is only distantly related to species within the genus Amphidinium sensu stricto. The nearest sister group to Ankistrodinium could not be reliably determined.

Ancillary