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ABSTRACT
We establish the cyst-theca relationship of the dinoflagellate cyst species Trinovantedinium pallidifulvum Matsuoka Citation1987 based on germination experiments of specimens isolated from the Gulf of Mexico. We show that the motile stage is a new species, designated as Protoperidinium louisianensis. We also determine its phylogenetic position based on single-cell polymerase chain reaction (PCR) of a single cell germinated from the Gulf of Mexico cysts. To further refine the phylogeny, we determined the large subunit (LSU) sequence through single-cell PCR of the cyst Selenopemphix undulata isolated from Brentwood Bay (Saanich Inlet, BC, Canada). The phylogeny shows that P. louisianensis is closest to P. shanghaiense, the motile stage of T. applanatum, and is consistent with the monophyly of the genus Trinovantedinium. Selenopemphix undulata belongs to a different clade than Selenopemphix quanta (alleged cyst of P. conicum), suggesting that the genus Selenopemphix is polyphyletic. Trinovantedinium pallidifulvum is widely distributed with occurrences in the Gulf of Mexico, the North Atlantic, the northeast Pacific and southeast Asia. In addition, we illustrate the two other extant species, Trinovantedinium applanatum and Trinovantedinium variabile, and two morphotypes of Trinovantedinium. Geochemical analyses of the cyst wall of T. pallidifulvum indicate the presence of amide groups in agreement with other heterotrophic dinoflagellate species, although the cyst wall of T. pallidifulvum also includes some unique features.
Acknowledgements
Kenneth Neil Mertens is a postdoctoral researcher of FWO Belgium. Martin J. Head is acknowledged for advice on the genus Trinovantedinium. Anna Godhe is thanked for providing a sample from the Kattegat. Evelyne Goubert is thanked for providing a sample from La Vilaine Bay, and Jean-Pierre Debenay for samples from the Vie River estuary. We acknowledge the Scripps Institution of Oceanography (SIO) Geological Collections and, in particular, Alex Hangsterfer for sediment samples from the Bay of Bengal. Pieter R. Gurdebeke is thanked for providing a nice specimen of Trinovantedinium variabile. KNM and AMP thank Anne de Vernal for letting us use the equipment to conduct germination experiments at Geotop. Sofia Ribeiro is thanked for the loan of slides from Portugal. GJMV acknowledges support by the German Science Foundation (Heisenberg fellowship VE486/2). AMP and VP acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC). Support for ship time for Gulf of Mexico specimens was provided by the National Oceanic and Atmospheric Administration, Center for Sponsored Coastal Ocean Research, under awards NA06OP0528 and NA09NOS4780204 to Louisiana Universities Marine Consortium, and awards NA06OP0529 and NA09NOS4780230 to Louisiana State University. The crew of the R/V Pelican is thanked for assistance with sample collection. Martin J. Head and an anonymous reviewer are thanked for remarks that significantly improved the manuscript.
Supplemental data for this article can be accessed here.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Kenneth Neil Mertens
KENNETH NEIL MERTENS is a permanent researcher at Ifremer, LER BO, Concarneau, France. He received his PhD in 2009 from Ghent University. His research interests are the taxonomy, evolution, phylogeny and biogeography of dinoflagellates, and the palaeoceanographical application of dinoflagellate cysts, particularly in the Quaternary and Neogene.
Haifeng Gu
HAIFENG GU is a professor at Third Institute of Oceanography, China. He received his PhD in 2007 from Ocean University of China. His research interests are the taxonomy and evolution of dinoflagellates.
Yoshihito Takano
YOSHIHITO TAKANO is a postdoctoral researcher at National Research Institute of Fisheries Science, Fisheries Research Agency, Yokohama, Japan. He received his PhD in 2006 from Hokkaido University. His research interests are the taxonomy and evolution of dinoflagellates.
Andrea M. Price
ANDREA PRICE is a PhD candidate in the Department of Geography at McGill University. She received her BSc Honours and MSc in earth and ocean sciences at the University of Victoria. Her main research interests include using dinoflagellate cysts as indicators of water quality in North American estuaries, the seasonality of cyst production and the use of cysts in Quaternary palaeoceanographic studies.
Vera Pospelova
VERA POSPELOVA is an associate professor at the School of Earth and Ocean Sciences (SEOS), University of Victoria. She received her Honours BSc in geology from Novosibirsk University (Russia) and PhD in physical geography from McGill University (Canada). Vera's research interests include: taxonomy of late Quaternary dinoflagellate cysts; cyst production, ecology and seasonal dynamics in coastal waters; applications of dinoflagellate cysts as indicators of water quality conditions, with an emphasis on the pollution and eutrophication in North American estuaries; and palaeoceanographic reconstructions using sedimentary archives.
Kara Bogus
KARA BOGUS is a staff scientist with the International Ocean Discovery Program (IODP) at Texas A&M University (College Station, Texas, USA). She earned her PhD (marine geosciences) from the University of Bremen (Bremen, Germany). Her research interests include using organic-walled dinoflagellate cysts in palaeoceanographic studies, cyst wall chemical composition and its application to both environmental reconstructions and diagenesis of sedimentary organic carbon.
Gerard J. M. Versteegh
GERARD VERSTEEGH combines organic geochemistry, palynology and pala-eobotany to assess organic matter degradation, and, through this, to elucidate present and past environment and evolution. In 1995 he received his PhD in biology at Utrecht University on palynology and the onset of Northern Hemisphere glaciations. He expanded his expertise with organic geochemistry at the Netherlands Institute for Sea Research. At the Université de Lille 1, France, he was an invited professor in 2007 and 2008, and obtained a prestigious Heisenberg Fellowship from the German Science Foundation in 2009. Currently he is at the Alfred Wegener Institute in Bremerhaven and the Centre for Marine Environmental Research, Bremen University. His interests include the macromolecular composition of palynomorphs, selective degradation of organic matter, the Palaeozoic terrestrialisation, (sub)recent Mediterranean environmental change, proxy development, lipids, acritarchs and dinoflagellates.
Fabienne Marret
FABIENNE MARRET is a micropalaeontologist by training, with research interest in the field of Quaternary palaeoceanography and palaeoecology. She received her PhD in 1994 from the University of Bordeaux, France. She studies marine sediments from around the world to interpret past environmental changes, based on vegetation tracers (pollen grains) and sea-surface conditions (dinoflagellate cysts). She is particularly interested in the causes of abrupt climate changes in the past, from the tropics to the poles.
R. Eugene Turner
R. EUGENE TURNER is a faculty member at Louisiana State University. He received his PhD in 1974 from the University of Georgia, USA. His research interests include coastal oceanography and wetlands.
Nancy N. Rabalais
NANCY RABALAIS is executive director and professor of the Louisiana Universities Marine Consortium in Chauvin, Louisiana. Since the mid-1980s, Rabalais has been the driving force behind identifying and characterising the dynamics of the large hypoxic region in the Gulf of Mexico, which receives excess nutrients from the Mississippi River. She serves on numerous boards and panels for federal agencies and national organisations. She has received numerous awards, most recently the John D. & Catherine T. MacArthur ‘Genius’ Award (2012). She graduated with a PhD from the University of Texas in 1983.
Kazumi Matsuoka
KAZUMI MATSUOKA is a professor emeritus at Nagasaki University. Although retired since 2013, he continues scientific research on fossil and modern dinoflagellates – in particular, cyst-motile form relationships of both naked and thecate dinoflagellates.