Research Note: Molecular phylogenetic affiliations of Dissodinium pseudolunula, Pheopolykrikos hartmannii, Polykrikos cf. schwartzii and Polykrikos kofoidii to Gymnodinium sensu stricto species (Dinophyceae)

Partial large subunit ribosomal DNA (LSU rDNA) sequences of Dissodinium pseudolunula Swift ex Elbrächter et Drebes, Pheopolykrikos hartmannii (Zimmermann) Matsuoka et Fukuyo, Polykrikos cf. schwartzii Bütschli and Polykrikos kofoidii Chatton were analyzed to reveal their phylogenetic status. The four athecate dinoflagellate species fell within the clade of Gymnodinium sensu G. Hansen et Moestrup supported by high likelihood values without apparent phylogenetic relationships to neither Gymnodinium species nor each other. Their genetic affiliations to typical Gymnodinium species were morphologically supported by the loop-shaped apical grooves in Pheopolykrikos and Polykrikos species and the Gymnodinium -like motile stage at least once during pleomorphic life cycles in D. pseudolunula and Ph. hartmannii .