Morphology, ultrastructure and molecular phylogeny of cyst-producing Caladoa arcachonensis gen. et sp. nov. (Peridiniales, Dinophyceae) from France and Indonesia
|Author(s)||Luo Zhaohe1, Mertens Kenneth2, Nezan Elisabeth2, Gu Li1, Pospelova Vera3, Thoha Hikmah4, Gu Haifeng1|
|Affiliation(s)||1 : Minist Nat Resources, Inst Oceanog 3, Xiamen 361005, Peoples R China.
2 : IFREMER, LER BO, Stn Biol Marine, Pl Croix,BP40537, F-29185 Concarneau, France.
3 : Univ Victoria, Sch Earth & Ocean Sci, OEASB A405,POB 1700 16 STN CSC, Victoria, BC V8W 2Y2, Canada.
4 : Indonesian Inst Sci, Res Ctr Oceanog, Jakarta 14430, Indonesia.
|Source||European Journal Of Phycology (0967-0262) (Taylor & Francis Ltd), 2019-04 , Vol. 54 , N. 2 , P. 235-248|
|WOS© Times Cited||11|
|Keyword(s)||Bysmatrum, cyst, dinoflagellate, eyespot, Peridiniales, plate overlap|
|Abstract||The dinoflagellate order Peridiniales encompasses several well circumscribed families. However, the family level of some genera, such as Bysmatrum and Vulcanodinium, has remained elusive for many years. Four Peridinium-like strains were established from the Atlantic coast of France and North Sulawesi, Indonesia through cyst germination or isolation of single cells. The cyst-theca relationship was established on specimens from the French Atlantic. Their morphologies were examined using light, scanning and transmission electron microscopy. The cells were characterized by a much larger epitheca relative to the hypotheca, a large anterior sulcal (Sa) plate deeply intruding the epitheca and a small first anterior intercalary plate. The plate formula was identified as Po, cp, X, 4 ', 3a, 7 '', 6C, 5S, 5 ''', 2 '''', shared by Apocalathium, Chimonodinium, Fusiperidinium and Scrippsiella of the family Thoracosphaeraceae but the configuration of Sa plate and anterior intercalary plates is different. Transmission electron microscopy showed that the eyespot was located within a chloroplast comprising two rows of lipid globules and thus belongs to type A. All four strains were classified within a new genus Caladoa as C. arcachonensis gen. et sp. nov. Small subunit ribosomal DNA (SSU rDNA), partial large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer ribosomal DNA (ITS rDNA) sequences were obtained from all strains. Genetic distance based on ITS rDNA sequences between French and Indonesian strains reached 0.17, suggesting cryptic speciation in C. arcachonensis. The maximum likelihood and Bayesian inference analysis based on concatenated data from SSU and LSU rDNA sequences revealed that Caladoa is monophyletic and closest to Bysmatrum. Our results supported that Caladoa and Bysmatrum are members of the order Peridiniales but their family level remains to be determined. Our results also support that Vulcanodinium is closest to the family Peridiniaceae.|