Gonyaulax whaseongensis sp. nov. (Gonyaulacales, Dinophyceae), a new phototrophic species from Korean coastal waters

Abstract

The planktonic phototrophic dinoflagellate Gonyaulax whaseongensis sp. nov., isolated from coastal waters of western Korea, was described from living and fixed cells under light and scanning electron microscopy, and its rDNA was sequenced. Gonyaulax whaseongensis had a plate formula of 2pr, 4′, 6′′, 6c, 6′′′, 1p, and 1′′′′ with S‐type ventral organization like the other species in the genus. However, this dinoflagellate had a narrow cingulum (ca. 2.6 μm), small displacement of the cingulum, slight overhang and steep angle between the ends of the cingulum, quadrangular sixth precingular plate, reticulated cell surface without longitudinal lines or ridges, and two unequal antapical spines, together which distinguish this from all other reported Gonyaulax species. In addition, the SSU and LSU rDNA sequences were 8%–12% and 11%–24%, respectively, different from those of Gonyaulax polygramma, Gonyaulax spinifera, Gonyaulax fragilis, Gonyaulax membranacea, and Gonyaulax digitale, the putatively closest related species in the phylogenetic analysis.

Cyst-theca relationships of Spiniferites bentorii, S. hyperacanthus, S. ramosus, S. scabratus and molecular phylogenetics of Spiniferites and Tectatodinium (Gonyaulacales, Dinophyceae)

“…However, other specimen identified as S. hyperacanthus from Japan by Matsuoka (1985) have similar sizes to our specimen (38.2-40.3 μm long and 34-38.5 μm wide; process length 12.0-18.5 μm). Spiniferites hyperacanthus from Tokyo Bay has been connected to the Gonyaulax spinifera complex (Matsuoka et al 2003), but here we demonstrate that the motile stages correspond to Gonyaulax whaseongensis, which is characterized by two unequal antapical spines, a quadrangular plate 6′′ and a ventral pore at the junction of plates 4′ and Q (Lim et al 2018). In addition, our cells show a dextral torsion, also reported in G. whaseongensis (Lim et al 2018), whereas in G. digitalis and G. spinifera there is a neutral torsion (Kofoid 1911).…”

“…Spiniferites hyperacanthus from Tokyo Bay has been connected to the Gonyaulax spinifera complex (Matsuoka et al 2003), but here we demonstrate that the motile stages correspond to Gonyaulax whaseongensis, which is characterized by two unequal antapical spines, a quadrangular plate 6′′ and a ventral pore at the junction of plates 4′ and Q (Lim et al 2018). In addition, our cells show a dextral torsion, also reported in G. whaseongensis (Lim et al 2018), whereas in G. digitalis and G. spinifera there is a neutral torsion (Kofoid 1911). Spiniferites hyperacanthus from Chinese coastal waters and G. whaseongensis also have identical molecular sequences, further indicating that they are conspecific.…”

“…Spiniferites hyperacanthus from Chinese coastal waters and G. whaseongensis also have identical molecular sequences, further indicating that they are conspecific. Our strain TIO260 produces cysts in culture spontaneously, but the Korean strain did not generate cysts in culture (Lim et al 2018), suggesting that this species might be heterothallic. Our strain was established from an assumed sexual resting cyst that produced daughter cells through meiosis (Elbrächter 2003) whereas the Korean strain is from a single, presumably vegetative cell (Lim et al 2018).…”

Unraveling the Gonyaulax baltica Species Complex: Cyst–theca Relationship of Impagidinium variaseptum, Spiniferites pseudodelicatus sp. nov. and S. ristingensis (Gonyaulacaceae, Dinophyceae), With Descriptions of Gonyaulax bohaiensis sp. nov, G. amoyensis sp. nov. and G. portimonensis sp. nov.

“…The thecal plates of Gonyaulax are often thick and ornamented by numerous reticulations to form ridges. Its plate tabulation has been interpreted as Po, Cp, *4 0 , 6 00 , 6c, ?s, 6 000 , 1p, 1 0000 (Dodge 1989, Lewis et al 1999, Carbonell-Moore and Mertens 2019) and now includes 77 recognized species (G omez 2012, Mertens et al 2015, Lim et al 2018, Gu et al 2021. The thecate morphology of Gonyaulax species is rather conservative and differs between species only in the cingular displacement and overhang, the shape of the sixth precingular plate, the position of the ventral pore, the plate ornamentation, the body size, the body shape, and the number and size of antapical spines (Dodge 1989, Lim et al 2018.…”

“…Its plate tabulation has been interpreted as Po, Cp, *4 0 , 6 00 , 6c, ?s, 6 000 , 1p, 1 0000 (Dodge 1989, Lewis et al 1999, Carbonell-Moore and Mertens 2019) and now includes 77 recognized species (G omez 2012, Mertens et al 2015, Lim et al 2018, Gu et al 2021. The thecate morphology of Gonyaulax species is rather conservative and differs between species only in the cingular displacement and overhang, the shape of the sixth precingular plate, the position of the ventral pore, the plate ornamentation, the body size, the body shape, and the number and size of antapical spines (Dodge 1989, Lim et al 2018. proposed to subdivide Gonyaulax into four subgenera (i.e., Gonyaulax, Fusigonyaulax, Steiniella, and Acanthogonyaulax based upon the general shape of the motile cells) but whether this is supported by molecular phylogenetics remains to be determined.…”