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Ultrastructure and molecular phylogenetic position of a new marine sand-dwelling dinoflagellate from British Columbia, Canada: Pseudadenoides polypyrenoides sp. nov. (Dinophyceae)

posted on 13.04.2017, 09:30 by Mona Hoppenrath, Naoji Yubuki, Rowena Stern, Brian S. Leander

Two monospecific genera of marine benthic dinoflagellates, Adenoides and Pseudadenoides, have unusual thecal tabulation patterns (lack of cingular plates in the former; and no precingular plates and a complete posterior intercalary plate series in the latter) and are thus difficult to place within a phylogenetic framework. Although both genera share morphological similarities, they have not formed sister taxa in previous molecular phylogenetic analyses. We discovered and characterized a new species of Pseudadenoides, P. polypyrenoides sp. nov., at both the ultrastructural and molecular phylogenetic levels. Molecular phylogenetic analyses of SSU and LSU rDNA sequences demonstrated a close relationship between P. polypyrenoides sp. nov. and Pseudadenoides kofoidii, and Adenoides and Pseudadenoides formed sister taxa in phylogenetic trees inferred from LSU rDNA sequences. Comparisons of morphological traits, such as the apical pore complex (APC), demonstrated similarities between Adenoides, Pseudadenoides and several planktonic genera (e.g. Heterocapsa, Azadinium and Amphidoma). Molecular phylogenetic analyses of SSU and LSU rDNA sequences also demonstrated an undescribed species within Adenoides.


This work was supported by a scholarship to MH from the Deutsche Forschungsgemeinschaft (grant Ho3267/1-1) and by grants to BSL from the National Science and Engineering Research Council of Canada (NSERC 2014-05258) and the Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity. RS was also supported by the Canadian Barcode of Life Project.