Pentaplacodinium saltonense gen. et sp. nov. (Dinophyceae) and its relationship to the cyst-defined genus Operculodinium and yessotoxin-producing Protoceratium reticulatum

trains of a dinoflagellate from the Salton Sea, previously identified as Protoceratium reticulatum and yessotoxin producing, have been reexamined morphologically and genetically and Pentaplacodinium saltonense n. gen. et sp. is erected to accommodate this species. Pentaplacodinium saltonense differs from Protoceratium reticulatum (Claparède et Lachmann 1859) Bütschli 1885 in the number of precingular plates (five vs. six), cingular displacement (two widths vs. one), and distinct cyst morphology. Incubation experiments (excystment and encystment) show that the resting cyst of Pentaplacodinium saltonense is morphologically most similar to the cyst-defined species Operculodinium israelianum (Rossignol, 1962) Wall (1967) and O. psilatum Wall (1967). Collections of comparative material from around the globe (including Protoceratium reticulatum and the genus Ceratocorys) and single cell PCR were used to clarify molecular phylogenies. Variable regions in the LSU (three new sequences), SSU (12 new sequences) and intergenic ITS 1–2 (14 new sequences) were obtained. These show that Pentaplacodinium saltonense and Protoceratium reticulatum form two distinct clades. Pentaplacodinium saltonense forms a monophyletic clade with several unidentified strains from Malaysia. LSU and SSU rDNA sequences of three species of Ceratocorys (C. armata, C. gourreti, C. horrida) from the Mediterranean and several other unidentified strains from Malaysia form a well-supported sister clade. The unique phylogenetic position of an unidentified strain from Hawaii is also documented and requires further examination. In addition, based on the V9 SSU topology (bootstrap values >80%), specimens from Elands Bay (South Africa), originally described as Gonyaulax grindleyi by Reinecke (1967), cluster with Protoceratium reticulatum. The known range of Pentaplacodinium saltonense is tropical to subtropical, and its cyst is recorded as a fossil in upper Cenozoic sediments. Protoceratium reticulatum and Pentaplacodinium saltonense seem to inhabit different niches: motile stages of these dinoflagellates have not been found in the same plankton sample.

Keyword(s)

Pentaplacodinium, Protoceratium, Precingular plates, Salton Sea, Ceratocorys, Operculodinium, Cribroperidinioideae

Full Text

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Publisher's official version
2110 Mo
Appendix A. Supplementary data
3209 Ko
Author's final draft
711 Mo
How to cite
Mertens Kenneth, Carbonell-Moore Maria Consuelo, Pospeloya Vera, Head Martin J., Highfield Andrea, Schroeder Declan, Gu Haifeng, Andree Karl B., Fernandez Margarita, Yamaguchi Aika, Takano Yoshihito, Matsuoka Kazumi, Nezan Elisabeth, Bilien Gwenael, Okolodkov Yuri, Koike Kazuhiko, Hoppenrath Mona, Pfaff Maya, Pitcher Grant, Al-Muftah Abdulrahman, Rochon Andre, Lim Po Teen, Leaw Chui Pin, Lim Zhen Fei, Ellegaard Marianne (2018). Pentaplacodinium saltonense gen. et sp. nov. (Dinophyceae) and its relationship to the cyst-defined genus Operculodinium and yessotoxin-producing Protoceratium reticulatum. Harmful Algae. 71. 57-77. https://doi.org/10.1016/j.hal.2017.12.003, https://archimer.ifremer.fr/doc/00416/52756/

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