Ansanella granifera gen. et sp. nov. (Dinophyceae), a new dinoflagellate from the coastal waters of Korea

doi:2014.29.2.75

Algae > Volume 29(2); 2014 > Article

Algae 2014;29(2): 75-99. doi: https://doi.org/10.4490/algae.2014.29.2.075

Hae Jin Jeong¹^,2^,*, Se Hyeon Jang¹, Øjvind Moestrup³, Nam Seon Kang¹, Sung Yeon Lee¹, Éric Potvin¹ and Jae Hoon Noh⁴

¹School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea
²Advanced Institutes of Convergence Technology, Suwon 443-270, Korea
³Biological Institute, Section of Marine Biology, University of Copenhagen, Universitetsparken 4, DK-2100 Copenhagen K, Denmark
⁴Marine Resources Research Department, KIOST, Ansan 425-600, Korea

*Corresponding Author

Email: hjjeong@snu.ac.kr

ABSTRACT

A small dinoflagellate, Ansanella granifera gen. et sp. nov., was isolated from estuarine and marine waters, and examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. In addition, the identity of the sequences (3,663-bp product) of the small subunit (SSU), internal transcribed spacer (ITS) region (ITS1, 5.8S, ITS2), and D1-D3 large subunit (LSU) rDNA were determined. This newly isolated, thin-walled dinoflagellate has a type E eyespot and a single elongated apical vesicle, and it is closely related to species belonging to the family Suessiaceae. A. granifera has 10-14 horizontal rows of amphiesmal vesicles, comparable to Biecheleria spp. and Biecheleriopsis adriatica, but greater in number than in other species of the family Suessiaceae. Unlike Biecheleria spp. and B. adriatica, A. granifera has grana-like thylakoids. Further, A. granifera lacks a nuclear fibrous connective, which is present in B. adriatica. B. adriatica and A. granifera also show a morphological difference in the shape of the margin of the cingulum. In A. granifera, the cingular margin formed a zigzag line, and in B. adriatica a straight line, especially on the dorsal side of the cell. The episome is conical with a round apex, whereas the hyposome is trapezoidal. Cells growing photosynthetically are 10.0-15.0 μm long and 8.5-12.4 μm wide. The cingulum is descending, the two ends displaced about its own width. Cells of A. granifera contain 5-8 peripheral chloroplasts, stalked pyrenoids, and a pusule system, but lack nuclear envelope chambers, a nuclear fibrous connective, lamellar body, rhizocysts, and a peduncle. The main accessory pigment is peridinin. The SSU, ITS regions, and D1-D3 LSU rDNA sequences differ by 1.2-7.4%, >8.8%, and >2.5%, respectively, from those of the other known genera in the order Suessiales. Moreover, the SSU rDNA sequence differed by 1-2% from that of the three most closely related species, Polarella glacialis, Pelagodinium bei, and Protodinium simplex. In addition, the ITS1-5.8S-ITS2 rDNA sequence differed by 16-19% from that of the three most closely related species, Gymnodinium corii, Pr. simplex, and Pel. bei, and the LSU rDNA sequence differed by 3-4% from that of the three most closely related species, Protodinium sp. CCMP419, B. adriatica, and Gymnodinium sp. CCMP425. A. granifera had a 51-base pair fragment in domain D2 of the large subunit of ribosomal DNA, which is absent in the genus Biecheleria. In the phylogenetic tree based on the SSU and LSU sequences, A. granifera is located in the large clade of the family Suessiaceae, but it forms an independent clade.

Key words: new genus; new species; protist; Suessiaceae; Symbiodiniaceae; taxonomy; ultrastructure