Gymnodinium smaydae n. sp., a New Planktonic Phototrophic Dinoflagellate from the Coastal Waters of Western Korea: Morphology and Molecular Characterization. (25th February 2014)

• Record Type: Journal Article
• Authors: Kang, Nam Seon; Jeong, Hae Jin; Moestrup, Øjvind; Lee, Sung Yeon; Lim, An Suk; Jang, Tae Young; Lee, Kyung Ha; Lee, Moo Joon; Jang, Se Hyeon; Potvin, Eric; Lee, Sook Kyung; Noh, Jae Hoon
• Is Part Of: Journal of eukaryotic microbiology. Volume 61:Number 2(2014:Mar./Apr.)
• Page Start: 182
• Page End: 203
• Publication Date: 2014-02-25
• Subjects: Protista -- Periodicals; Eukaryotic cells -- Periodicals; Microbiology -- Periodicals; 579.05
• DOI: 10.1111/jeu.12098
• Languages: English
• ISSNs: 1066-5234

Abstract

<abstract abstract-type="main" id="jeu12098-abs-0001"> <title>Abstract</title> <p>The marine phototrophic dinoflagellate <italic>Gymnodinium smaydae</italic> n. sp. is described from cells prepared for light, scanning, and transmission electron microscopy. Also, sequences of the small (SSU) and large subunits (LSU) and the internal transcribed spacer region (ITS1–5.8S–ITS2) of ribosomal DNA were analyzed. This newly isolated dinoflagellate possessed nuclear chambers, nuclear fibrous connective, an apical groove running in a counterclockwise direction around the apex, and a major accessory pigment peridinin, which are four key features for the genus <italic>Gymnodinium</italic>. The epicone was conical with a round apex, while the hypocone was ellipsoid. Cells growing photosynthetically were 6.3–10.9 μm long and 5.1–10.0 μm wide, and therefore smaller than any other <italic>Gymnodinium</italic> species so far reported except <italic>Gymnodinium nanum</italic>. Cells were covered with polygonal amphiesmal vesicles arranged in 11 horizontal rows, and the vesicles were smaller than those of the other <italic>Gymnodinium</italic> species. This dinoflagellate had a sharp and elongated ventral ridge reaching half way down the hypocone, unlike other <italic>Gymnodinium</italic> species. Moreover, displacement of the cingulum was 0.4–0.6 × cell length while in other known <italic>Gymnodinium</italic> species it is less than 0.3 × cell length. In addition, the new species possessed a peduncle, permanent chloroplasts, pyrenoids, trichocysts, pusule systems, and small knobs along the apical furrow, but it lacked an eyespot, nematocysts, and body scales. The sequence of the SSU, ITS1–5.8S–ITS2, and LSU rDNA region differed by 1.5–3.8%, 6.0–17.4%, and 9.1–17.5%, respectively, from those of the most closely related species. The phylogenetic trees demonstrated that the new species belonged to the <italic>Gymnodinium</italic> clade at the base of a clade consisting of <italic>Gymnodinium acidotum</italic>, <italic> Gymnodinium dorsalisulcum</italic>, <italic> Gymnodinium eucyaneum</italic>, etc. Based on morphological and molecular data, we suggest that the taxon represents a new species, <italic>Gymnodinium smaydae</italic> n. sp.</p> </abstract>