Consulta: creatorFacets:"Mertens, Kenneth"
Registros recuperados: 34
Data/hora: 11/06/2024 12:26:28

A review of rare and less well known extant marine organic-walled dinoflagellate cyst taxa of the orders Gonyaulacales and Suessiales from the Northern Hemisphere
Provedor de dados: 5
Autores: Limoges, Audrey; Van Nieuwenhove, Nicolas; Head, Martin J.; Mertens, Kenneth; Pospelova, Vera; Rochon, André.
Dinoflagellate resting cysts with rare exception produce the only discrete link between the biology of extant dinoflagellate species and their fossil record. The geological preservability of such cysts allows them to be used for quantitative paleoecological reconstructions, especially in the Quaternary, and for biostratigraphy and the calibration of molecular clocks with the geological record. This contribution reviews and updates the taxonomy of 27 uncommon dinoflagellate cyst species and morphotypes belonging to the orders Gonyaulacales and Suessiales with occurrences in upper Quaternary marine sediments of the Northern Hemisphere. Comparative descriptions and illustrations are provided along with the biological affinity of each taxon where known and...
Tipo: Text
Palavras-chave: Dinoflagellate cysts; Gonyaulacales; Suessiales; Marine sediment; Quaternary.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00593/70487/68626.pdf

Description and phylogenetic position of     Plagiolemma distortum     sp. nov., a new raphid diatom (Bacillariophyceae) from French coastal waters
Provedor de dados: 5
Autores: Nezan, Elisabeth; Bilien, Gwenael; Boulben, Sylviane; Mertens, Kenneth; Chomerat, Nicolas.
A new marine raphid diatom, Plagiolemma distortum Nézan, sp. nov. is described from plankton samples from the Atlantic Ocean, south Brittany (north-western France), where it was regularly observed, but never in high abundances. Cells have an unusual and complex shape under light microscopy (LM) depending on their position and orientation. The two valves are highly vaulted and narrow in width (transapical axis). Cells contain four complexly lobed plastids and a variable number of refractive granules without particular localization. In addition, capsules containing motile cells were observed. Ultrastructural details of the frustules were investigated using scanning electron microscopy (SEM). The girdle bands are simple. Each valve possesses a sigmoid raphe...
Tipo: Text
Palavras-chave: Capsules; Habitat; Molecular phylogeny; Plastids; Raphid diatom; Video.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00441/55235/56797.pdf

Taxonomic Re-Investigation and Geochemical Characterization of Reid’s (1974) Species of     Spiniferites     from Holotype and Topotype Material
Provedor de dados: 5
Autores: Gurdebeke, Pieter R.; Mertens, Kenneth; Bogus, Kara; Marret, Fabienne; Chomerat, Nicolas; Vrielinck, Henk; Louwye, Stephen.
The genus Spiniferites currently encompasses 142 dinoflagellate cyst species. Some Spiniferites species are difficult to identify because of an incomplete or doubtful description, and/or substandard iconography. This study re-describes and re-illustrates the Spiniferites holotypes first described by Reid in 1974 Reid PC. 1974. Gonyaulacacean dinoflagellate cysts from the British Isles. Nova Hedwigia. 25:579–637. [Google Scholar]. It also discusses topotype material from surface sediments recovered from British estuaries, and attempts to provide further constraints on the classification of species in this genus using the geochemical characterization of their cyst walls. Reid described four new Spiniferites species: Spiniferites belerius, Spiniferites...
Tipo: Text
Palavras-chave: Dinoflagellate cyst; Redescription; Taxonomy; Geochemistry; Cyst wall composition; FTIR; Dinosporin.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58306/60847.pdf

A review of rare, poorly known, and morphologically problematic extant marine organic-walled dinoflagellate cyst taxa of the orders Gymnodiniales and Peridiniales from the Northern Hemisphere
Provedor de dados: 5
Autores: Mertens, Kenneth; Gu, Haifeng; Gurdebeke, Pieter R.; Takano, Yoshihito; Clarke, Dave; Aydin, Hilal; Li, Zhen; Pospelova, Vera; Shin, Hyeon Ho; Li, Zhun; Matsuoka, Kazumi; Head, Martin J.
Dinoflagellates are a major component of the modern plankton. Of the 2192 species of marine free-living dinoflagellates presently described, an increasing number are being shown to produce resting cysts (probably hypnozygotes) within their life cycle. With rare exception, only the resting cysts fossilize, so they are of central importance in tracing the history of dinoflagellates through geological time. Cysts of many of the more common dinoflagellate species have distinctive morphologies allowing their geographic and stratigraphic occurrences to be traced. An ever-increasing number of taxa are also being shown to produce distinctive cysts, potentially increasing our knowledge of the diverse representation of dinoflagellates through time. Here the...
Tipo: Text
Palavras-chave: Archaeperidinium; Diplopsalis; Dubridinium; Echinidinium; Gymnodinium; Lejeunecysta; Protoperidinium.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00512/62333/66593.pdf

The cyst-theca relationship of the dinoflagellate cyst Trinovantedinium pallidifulvum, with erection of Protoperidinium lousianensis sp nov and their phylogenetic position within the Conica group
Provedor de dados: 5
Autores: Mertens, Kenneth; Gu, Haifeng; Takano, Yoshihito; Price, Andrea M.; Pospelova, Vera; Bogus, Kara; Versteegh, Gerard J. M.; Marret, Fabienne; Turner, R. Eugene; Rabalais, Nancy N.; Matsuoka, Kazumi.
We establish the cyst-theca relationship of the dinoflagellate cyst species Trinovantedinium pallidifulvum Matsuoka 1987 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...
Tipo: Text
Palavras-chave: Micro-FTIR; Selenopemphix undulata; Wadden Sea; Lake Saroma; Saanich Inlet; Gulf of Mexico.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00385/49609/50120.pdf

Cyst-Theca Relationship and Phylogenetic Position of     Impagidinium caspienense     Incubated from Caspian Sea Surface Sediments: Relation to     Gonyaulax baltica     and Evidence for Heterospory within Gonyaulacoid Dinoflagellates
Provedor de dados: 5
Autores: Mertens, Kenneth; Takano, Yoshihito; Gu, Haifeng; Bagheri, Siamak; Pospelova, Vera; Pienkowski, Anna J.; Leroy, Suzanne A. G.; Matsuoka, Kazumi.
We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other...
Tipo: Text
Palavras-chave: Ataxiodinium choane; Baltic Sea; Impagidinium pallidum; Pyxidinopsis psilata; Salinity; Spiniferites belerius; Spiniferites ramosus.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00382/49326/49703.pdf

Dinoflagellate fossils: Geological and biological applications
Provedor de dados: 5
Autores: Penaud, Aurelie; Hardy, William; Lambert, Clement; Marret, Fabienne; Masure, Edwige; Seryais, Thomas; Siano, Raffaele; Wary, Melanie; Mertens, Kenneth.
Dinoflagellates are part of the marine plankton and about 200 species produce a cyst (dinocyst) during their life cycle, these organic-walled sexually-produced cysts being fossilizable in sediments for hundreds of millions of years. Over the past 40–50 years, dinocysts have led to major advances on Mesozoic-Cenozoic research, in terms of biostratigraphy and paleogeogeography. Dinocyst taxonomy has then been continuously revised, with the tabulation being the main morphological link between living dinoflagellates and fossilized cysts. Over the Quaternary, and based on the principle of uniformitarianism (i.e. species ecology did not change through time), relationships between modern assemblages and present-day environmental factors controlling their...
Tipo: Text
Palavras-chave: Dinoflagellate; Cyst-motile stage relationship; Modern dinocyst distribution; Paleoecology; Biostratigraphy; Ancient DNA.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00463/57476/59749.pdf

Reconstructing marine productivity of the Cariaco Basin during marine isotope stages 3 and 4 using organic-walled dinoflagellate cysts
Provedor de dados: 5
Autores: Gonzalez, Catalina; Dupont, Lydie M.; Mertens, Kenneth; Wefer, Gerold.
An organic-walled dinoflagellate cyst analysis was carried out on sediment core MD03-2622, retrieved from the Cariaco Basin. The core comprises the 73-30 ka interval. Down core changes in cyst abundance, accumulation rate, and composition of cyst assemblages were used to identify climatic and oceanographic changes at orbital and millennial time scales in this near-equatorial seasonal upwelling area. Throughout the sequence, dinoflagellate cyst assemblages were dominated by heterotrophic dinocysts (mainly Brigantedinium spp.), with the exception of four autotrophic-dominated (mainly Spiniferites ramosus) intervals around 58, 53, 46, and 37 ka. At orbital time scales, changes in the dinoflagellate productivity seem to follow low-latitude insolation, with the...
Tipo: Text
Ano: 2008
URL: https://archimer.ifremer.fr/doc/00237/34805/33327.pdf

Additional observations of     Spiniferites alaskensis     from topotype material
Provedor de dados: 5
Autores: Marret, Fabienne; Mertens, Kenneth.
Here we present new observations of Spiniferites alaskensis, a relatively rare species described from the Eemian of the Gulf of Alaska. We show that the species shows a gonyaulacacean tabulation: Po, 4´, 6´´, 6c,? s, 6´´´, 1p, 1´´´´. The surface is finely granulate to scabrate. The species bears characteristic processes: these are exclusively gonal, membranous, perforated and end distally in platforms with stumpy ends. We provide more detail as how this species compares to closely related species belonging to the genus Spiniferites.
Tipo: Text
Palavras-chave: Gulf of Alaska; Chorate; Spiniferites; Processes; Eemian; ODP.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58307/60848.pdf

Cyst-motile stage relationship and molecular phylogeny of a new freshwater dinoflagellate Gymnodinium plasticum from Plastic Lake, Canada
Provedor de dados: 5
Autores: Wang, Na; Luo, Zhaohe; Mertens, Kenneth; Mccarthy, Francine M. G.; Gu, Li; Gu, Haifeng.
The dinophyceaen genus Gymnodinium was established with the freshwater species G. fuscum as type. According to Thessen et al. (2012), there are 268 species, with the majority marine species. In recently published molecular phylogenies based on ribosomal DNA sequences, Gymnodinium is polyphyletic. Here, a new freshwater Gymnodinium species, G. plasticum, is described from Plastic Lake, Ontario, Canada. Two strains were established by incubating single cysts, and their morphology was examined with light microscopy and scanning electron microscopy. The cyst had a rounded epicyst and hypocyst with a wide cingulum and smooth surface. Vegetative cells were characterized by an elongated nucleus running vertically and a deep sulcal intrusion. The apical structure...
Tipo: Text
Palavras-chave: Apical structure complex; Cyst; Gymnodiniales sensu stricto; Gymnodinium fuscum.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00406/51731/53727.pdf

Attributing   Ceratocorys, Pentaplacodinium   and   Protoceratium   to Protoceratiaceae (Dinophyceae), with descriptions of   Ceratocorys malayensis sp. nov   . and   Pentaplacodinium usupianum sp. nov
Provedor de dados: 5
Autores: Luo, Zhaohe; Lim, Zhen Fei; Mertens, Kenneth; Krock, Bernd; Teng, Sing Tung; Tan, Toh Hii; Leaw, Chui Pin; Lim, Po Teen; Gu, Haifeng.
The gonyaulacean family Protoceratiaceae is characterised by five precingular plates. It currently encompasses the type genus Ceratocorys and the fossil genus Atopodinium. Fourteen strains of Ceratocorys, Pentaplacodinium, and Protoceratium were established from Malaysian and Hawaiian waters, and their morphologies were examined using light and scanning electron microscopy. Two new species, Ceratocorys malayensis sp. nov. and Pentaplacodinium usupianum sp. nov., were described from Malaysian waters. They share a Kofoidean plate formula of Po, Pt, 3ʹ, 1a, 6ʹʹ, 6C, 6S, 5ʹʹʹ, 1p, 1ʹʹʹʹ. Ceratocorys malayensis has a short first apical plate (1ʹ) with no direct contact with the anterior sulcal plate (Sa) whereas Pentaplacodinium usupianum had a...
Tipo: Text
Palavras-chave: Ceratocoryaceae; Gonyaulacaceae; Molecular phylogeny; Protoceratium reticulatum; Yessotoxin.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00589/70143/68109.pdf

Late Quaternary climatic and oceanographic changes in the Northeast Pacific as recorded by dinoflagellate cysts from Guaymas Basin, Gulf of California (Mexico)
Provedor de dados: 5
Autores: Price, Andrea M.; Mertens, Kenneth; Pospelova, Vera; Pedersen, Thomas F.; Ganeshram, Raja S.
A high-resolution record of organic-walled dinoflagellate cyst production in Guaymas Basin, Gulf of California (Mexico) reveals a complex paleoceanographic history over the last similar to 40 ka. Guaymas Basin is an excellent location to perform high resolution studies of changes in late Quaternary climate and paleo-productivity because it is characterized by high primary productivity, high sedimentation rates, and low oxygen bottom waters. These factors contribute to the deposition and preservation of laminated sediments throughout large portions of the core MD02-2515. In this study, we document dinoflagellate cyst production at a centennial to millennial scale throughout the late Quaternary. Based on the cyst assemblages, three dinoflagellate cyst zones...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00262/37306/35718.pdf

Pentaplacodinium saltonense gen. et sp. nov. (Dinophyceae) and its relationship to the cyst-defined genus Operculodinium and yessotoxin-producing Protoceratium reticulatum
Provedor de dados: 5
Autores: 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.
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)....
Tipo: Text
Palavras-chave: Pentaplacodinium; Protoceratium; Precingular plates; Salton Sea; Ceratocorys; Operculodinium; Cribroperidinioideae.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00416/52756/53852.pdf

Adding new pieces to the Azadinium (Dinophyceae) diversity and biogeography puzzle: Non-toxigenic Azadinium zhuanum sp. nov. from China, toxigenic A. poporum from the Mediterranean, and a non-toxigenic A. dalianense from the French Atlantic
Provedor de dados: 5
Autores: Luo, Zhaohe; Krock, Bernd; Mertens, Kenneth; Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Tillmann, Urban; Gu, Haifeng.
The marine planktonic dinophyceaen genus Azadinium is a primary source of azaspiracids, but due to their small size its diversity may be underestimated and information on its biogeography is still limited. A new Azadinium species, A. zhuanum was obtained from the East China Sea and Yellow Sea of China by incubating surface sediments. Five strains were established by isolating single germinated cells and their morphology was examined with light microscopy and scanning electron microscopy. Azadinium zhuanum was characterized by a plate pattern of Po, cp, X, 4′, 2a, 6′′, 6C, 5S, 6′′′, 2′′′′, by a distinct ventral pore at the junction of Po, the first and fourth apical plates, and a conspicuous antapical spine. Moreover, Azadinium poporum was obtained for the...
Tipo: Text
Palavras-chave: Azadinium; Azaspiracid; AZA-2; AZA-2 phosphate; Biogeography; China; French Atlantic; Mediterranean Sea.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49765/51155.pdf

Should Gonyaulax hyalina and Gonyaulax fragilis (Dinophyceae) remain two different taxa?
Provedor de dados: 5
Autores: Carbonell-moore, M. Consuelo; Mertens, Kenneth.
Escalera et al. (2018. Phycologia 57: 453–464) concluded that Gonyaulax hyalina and G. fragilis were the same species. Here, the morphologies of G. hyalina and G. fragilis were restudied in field samples from different parts of the World Ocean. Results showed that Escalera et al. did not observe G. fragilis, as all strains used in their study belong to one species, G. hyalina. In consequence, it is hereby proposed that the two taxa remain as separate species until further genetic studies are carried out. Additionally, the interpretation of the anterior sulcal plate as unique within gonyaulacoids is considered here inaccurate, as the plate pattern of both species is similar to other species of Gonyaulax, e.g. G. polygramma. We also show that both species...
Tipo: Text
Palavras-chave: Anterior sulcal plate; Gonyaulax polygramma; Misidentification.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00516/62786/67616.pdf

Prorocentrum shikokuense Hada and P. donghaiense Lu are junior synonyms of P. obtusidens Schiller, but not of P. dentatum Stein (Prorocentrales, Dinophyceae)
Provedor de dados: 5
Autores: Shin, Hyeon Ho; Li, Zhun; Mertens, Kenneth; Seo, Min Ho; Gu, Haifeng; Lim, Weol Ae; Yoon, Yang Ho; Soh, Ho Young; Matsuoka, Kazumi.
In Japanese, Chinese and Korean coastal waters, recurrent blooms of a small, elongate Prorocentrum species have been observed in recent years. In previous studies, this species has been respectively identified as P. shikokuense, P. donghaiense and P. dentatum, despite morphological similarity and identical rDNA sequences. To resolve the confusion, morphological features, including the architectural details of the periflagellar area, were examined and ribosomal DNA (rDNA) sequences were obtained from specimens collected from the East China Sea and Korean coast, and a strain established in the waters off the Canary Islands of Spain. In addition, the descriptions of the three species and allied species were reviewed. Morphological observations and a phylogeny...
Tipo: Text
Palavras-chave: Morphology; Periflagellar area; RDNA; Prorocentrum veloi; P. monacense.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00566/67839/69555.pdf

First record of resting cysts of the benthic dinoflagellate     Prorocentrum leve     in a natural reservoir in Gujan-Mestras, Gironde, France
Provedor de dados: 5
Autores: Mertens, Kenneth; Gu, Haifeng; Pospelova, Vera; Chomerat, Nicolas; Nezan, Elisabeth; Gurdebeke, Pieter; Bogus, Kara; Vrielinck, Henk; Rumebe, Myriam; Meteigner, Claire.
The resting cysts of the benthic dinoflagellate Prorocentrum leve from a natural reservoir in Gujan-Mestras (Gironde, France) were described in this study. The incubated urn-shaped cysts gave rise to cells of Prorocentrum leve. Morphological observations through light microscopy and scanning electron microscopy, particularly of the periflagellar platelets, combined with large subunit ribosomal DNA sequences obtained through single-cell analysis confirm their affinity to the species Prorocentrum leve. The cysts are characterized by a specific shape and the presence of an anterior plug. This is the first conclusive evidence for fossilizable resting stages within the Prorocentrales, one of the major orders within the Dinophyceae. Palynological treatments show...
Tipo: Text
Palavras-chave: Cellulosic; Micro-FTIR; Palynology; Prorocentrales; Resting stage.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00398/50971/51728.pdf

Taxonomic revision of     Spiniferites elongatus     (the resting stage of     Gonyaulax elongata     ) based on morphological and molecular analyses
Provedor de dados: 5
Autores: Van Nieuwenhove, Nicolas; Potvin, Eric; Heikkila, Maija; Pospelova, Vera; Mertens, Kenneth; Masure, Edwige; Kucharska, Malgorzata; Yang, Eun Jin; Chomerat, Nicolas; Zajaczkowski, Marek.
We restudied the morphological complex comprising the cyst-based species Spiniferites elongatus/Spiniferites frigidus/Rottnestia amphicavata. We reviewed existing studies, and acquired new morphometric measurements of recent cysts from across the Northern Hemisphere, scanning electron microscopy (SEM) observations of cysts from Barents Sea surface sediments, and genetic analyses of cysts from the Beaufort Sea. The measurements suggest that populations and morphospecies cannot be distinguished based on morphometric criteria. Furthermore, sequential sediment trap samples from Hudson Bay reveal that morphological variation can occur at the same location over a few weeks, arguing against a uniform morphological response to environmental parameters. The SEM...
Tipo: Text
Palavras-chave: Single-cell PCR; Spiniferites ellipsoideus; Spiniferites frigidus; Rottnestia amphicavata; Morphologic variability; Taxonomy.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58305/60846.pdf

Morpho-molecular diversity and phylogeny of     Bysmatrum     (Dinophyceae) from the South China Sea and France
Provedor de dados: 5
Autores: Luo, Zhaohe; Lim, Zhen Fei; Mertens, Kenneth; Gurdebeke, Pieter; Bogus, Kara; Carbonell-moore, Maria Consuelo; Vrielinck, Henk; Leaw, Chui Pin; Lim, Po Teen; Chomerat, Nicolas; Li, Xintian; Gu, Haifeng.
The dinoflagellate genus Bysmatrum encompasses five epibenthic or tide-pool species and has been characterized by separated anterior intercalary plates. In the present study, we obtained six strains of Bysmatrum from the South China Sea and French Atlantic coast by isolating single cells/cysts from plankton and sediment samples. All strains were examined with light microscopy and scanning electron microscopy. Based on morphological observations, three strains were identified as Bysmatrum subsalsum, characterized by the elongated and rectangular first and a hexagonal second anterior intercalary plate. They differ from each other in the number of sulcal lists and the configuration of the first anterior intercalary plate. One strain was identified as...
Tipo: Text
Palavras-chave: Benthic dinoflagellate; Biogeography; Bysmatrum granulosum; Bysmatrum gregarium; Bysmatrum subsalsum; Eyespot; Molecular phylogeny.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00450/56188/57872.pdf

The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition
Provedor de dados: 5
Autores: Gurdebeke, Pieter R.; Mertens, Kenneth; Takano, Yoshihito; Yamaguchi, Aika; Bogus, Kara; Dunthorn, Micah; Matsuoka, Kazumi; Vrielinck, Henk; Louwye, Stephen.
Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens...
Tipo: Text
Palavras-chave: Acritarch; Ciliate cyst; FTIR; LSU-SSU rDNA; Prostomatida; Taxonomy.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00468/57970/64186.pdf

An overview and brief description of common marine organic-walled dinoflagellate cyst taxa occurring in surface sediments of the Northern Hemisphere
Provedor de dados: 5
Autores: Van Nieuwenhove, Nicolas; Head, Martin J.; Limoges, Audrey; Pospelova, Vera; Mertens, Kenneth; Matthiessen, Jens; De Schepper, Stijn; De Vernal, Anne; Eynaud, Frédérique; Londeix, Laurent; Marret, Fabienne; Penaud, Aurélie; Radi, Taoufik; Rochon, André.
Organic-walled resting cysts of planktonic dinoflagellates occur commonly in modern marine sediment where they represent, with rare exceptions, the only geologically preservable part of the life cycle. Although many species do not produce fossilizable resting cysts, upper Quaternary sediments contain a diverse cyst record that is used frequently for paleoenvironmental reconstruction and stratigraphic analysis. Reconstructions of past sea-surface conditions rely on an understanding of the distributions of dinoflagellate cysts in modern sediments linked to their respective environmental parameters, underpinned by sound taxonomy and standardized nomenclature. Stratigraphic studies additionally require knowledge of morphological details to distinguish extant...
Tipo: Text
Palavras-chave: Dinoflagellate cysts; Marine; Quaternary; Gymnodiniales; Gonyaulacales; Peridiniales.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00606/71817/70324.pdf

Identification key for Pliocene and Quaternary   Spiniferites   taxa bearing intergonal processes based on observations from estuarine and coastal environments
Provedor de dados: 5
Autores: Limoges, Audrey; Londeix, Laurent; Mertens, Kenneth; Rochon, Andre; Pospelova, Vera; Cuellar, Tomasa; De Vernal, Anne.
The use of dinoflagellate cyst assemblages as a tool for palaeo-environmental reconstructions strongly relies on the robustness of cyst identification and existing information on the distribution of the different species. To this purpose, we propose a functional key for the identification of Pliocene and Quaternary Spiniferites bearing intergonal processes and depict the range of morphological variation of the different species on the basis of new observations from estuarine and coastal regions. Accordingly, the description of Spiniferites mirabilis is emended to include the new subspecies Spiniferites mirabilis subsp. serratus. We also report the occasional presence of intergonal processes in Spiniferites bentorii and Spiniferites belerius. This key aims...
Tipo: Text
Palavras-chave: Dinoflagellate cyst; Taxonomy; Description; Morphological variability; Emendations.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58308/60849.pdf

The dinoflagellate cyst genera     Achomosphaera     Evitt 1963 and     Spiniferites     Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
Provedor de dados: 5
Autores: Mertens, Kenneth; Van Nieuwenhove, Nicolas; Gurdebeke, Pieter R.; Aydin, Hilal; Bogus, Kara; Bringue, Manuel; Dale, Barrie; De Schepper, Stijn; De Vernal, Anne; Ellegaard, Marianne; Grothe, Arjen; Gu, Haifeng; Head, Martin J.; Heikkila, Maija; Limoges, Audrey; Londeix, Laurent; Louwye, Stephen; Marret, Fabienne; Masure, Edwige; Matsuoka, Kazumi; Mudie, Peta J.; Penaud, Aurelie; Pospelova, Vera; Price, Andrea Michelle; Ribeiro, Sofia; Rochon, Andre; Sangiorgi, Francesca; Schreck, Michael; Torres, Vladimir; Uzar, Serdar; Versteegh, Gerard J. M.; Warny, Sophie; Zonneveld, Karin.
We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al. 1973) Londeix et al. 2009, Spiniferites? rubinus (Rossignol 1962 ex Rossignol 1964) Sarjeant 1970, and Thalassiphora balcanica...
Tipo: Text
Palavras-chave: Spiniferites; Achomosphaera; Hafniasphaera; Rottnestia; Pterocysta.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58304/60844.pdf

Reclassification of Gonyaulax verior (Gonyaulacales, Dinophyceae) as   Sourniaea diacantha gen. et comb. nov.
Provedor de dados: 5
Autores: Zhang, Wei; Li, Zhun; Mertens, Kenneth; Derrien, Amelie; Pospelova, Vera; Carbonell-moore, M. Consuelo; Bagheri, Siamak; Matsuoka, Kazumi; Shin, Hyeon Ho; Gu, Haifeng.
Gonyaulax verior was initially described as Amylax diacantha from Belgian coastal waters a century ago but its detailed morphology needed restudy. Here, we established nine strains of G. verior by germinating cysts or isolating cells from localities from the European Atlantic to the Caspian Sea and the Pacific Ocean. Both cyst and thecal morphology were examined by light and scanning electron microscopy. SSU, LSU and/or ITS-5.8S rRNA gene sequences were obtained from all strains. Cells of G. verior have a plate formula of Po, 4′, 2a, 6-7′′, 6C, 6S, 6′′′, 1p, 1′′′′ with an L-type ventral organisation, characterised by two either straight or curved antapical horns of variable length. Cysts of G. verior are oval, smooth and contain one or two yellow...
Tipo: Text
Palavras-chave: Amylax diacantha; Cysts; Dinoflagellate; Gonyaulax longispina; Molecular phylogeny.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00621/73347/72625.pdf

Reconstructing salinity changes and environmental influence on dinoflagellate cysts in the central Baltic Sea since the late 19th century
Provedor de dados: 5
Autores: Sildever, Sirje; Ribeiro, Sofia; Mertens, Kenneth; Andersen, Thorbjørn Joest; Moros, Matthias; Kuijpers, Antoon.
We present a record of dinoflagellate cyst assemblage composition, abundance, and morphology from the central Baltic Sea, spanning from the late 19th to the early 21st century. Environmental time-series were analyzed in relation to changes in community structure and diversity as inferred from the sediment record, and average summer sea surface salinity (SSS) was reconstructed based on the average process length of Protoceratium reticulatum resting cysts. The reconstructed summer SSS was compared to instrumental data for a critical evaluation of this approach. The most abundant species in this record were P. reticulatum and Biecheleria baltica, and on average ten taxa were identified per sample. The cyst record of B. baltica indicated that although this...
Tipo: Text
Palavras-chave: Baltic Sea; Biecheleria baltica; Dinoflagellate cysts; Environmental change; Protoceratium reticulatum; Sea-surface salinity; Sediment core records.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00481/59300/61994.pdf

Projet de Sciences Participatives. HERMIONA II, 1 - Protocoles
Provedor de dados: 5
Autores: Le Bec, Claude; Nezan, Elisabeth; Mertens, Kenneth; Terre Terrillon, Aouregan; Baudrier, Jerome; Even, Francoise.
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58279/60807.pdf

Atlas of modern dinoflagellate cyst distributions in the Black Sea Corridor: From Aegean to Aral Seas, including Marmara, Black, Azov and Caspian Seas
Provedor de dados: 5
Autores: Mudie, Peta J.; Marret, Fabienne; Mertens, Kenneth; Shumilovskikh, Lyudmila; Leroy, Suzanne A. G.
We present the first comprehensive taxonomic and environmental study of dinoflagellate cysts in 185 surface sediment samples from the Black Sea Corridor (BSC) which is a series of marine basins extending from the Aegean to the Aral Seas (including Marmara, Black, Azov and Caspian Seas). For decades, these low-salinity, semi-enclosed or endorheic basins have experienced large-scale changes because of intensive agriculture and industrialisation, with consequent eutrophication and increased algal blooms. The BSC atlas data provide a baseline for improved understanding of linkages between surface water conditions and dinoflagellate cyst (dinocyst) distribution, diversity and morphological variations. By cross-reference to dinocyst occurrences in sediment cores...
Tipo: Text
Palavras-chave: Phytoplankton; Harmful algae; Biodiversity; Paleoceanography; Surface samples.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00387/49824/50408.pdf

Discovery of a New Clade Nested Within the Genus Alexandrium (Dinophyceae): Morpho-molecular Characterization of Centrodinium punctatum (Cleve) F.J.R. Taylor
Provedor de dados: 5
Autores: Li, Zhun; Mertens, Kenneth; Nézan, Elisabeth; Chomérat, Nicolas; Bilien, Gwenael; Iwataki, Mitsunori; Shin, Hyeon Ho.
Investigation of phytoplankton from East China Sea of the Pacific Ocean, offshore Réunion Island of the Indian Ocean, and the French Atlantic coast revealed a species of poorly known armored fusiform dinoflagellate. To clarify this species, morphology and phylogeny based on mitochondrial and nuclear protein gene sequence (Cox1, Cob and Hsp90) concatenated with the SSU, ITS region and LSU rDNA sequences were analysed. Epifluorescence and scanning electron microscopy observations revealed that the nucleus of the specimen was elongated, sausage-shaped and located equatorially on the left lateral side of the cell, and that the plate formula is Po, 3′, 1a, 6″, 6C, 8S, 5‴, 1p, 2′‴. These morphological features indicate that the species can be assigned to...
Tipo: Text
Palavras-chave: Fusiform dinoflagellate; Centrodinium; Alexandrium; Morphology; Phylogeny.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00483/59496/62364.pdf

Micro-algues des claires ostréicoles de Charente Maritime : focus sur les producteurs potentiels de toxines DSP, PSP et ASP et toxines émergentes (palytoxines, pinnatoxine...)
Provedor de dados: 5
Autores: Mertens, Kenneth; Chomerat, Nicolas; Nezan, Elisabeth; Bruneau, Audrey; Le Bec, Claude.
Les inspections vétérinaires de la Commission Européenne ayant signifié à la France son constat d'une absence de réserau de surveillance sur les claires ostréicoles, la DGAL a mandaté l'Ifremer afin de réaliser un premier diagnostic sur le phytoplancton. Cette commande de la DGAL place l'Ifremer LERBO comme prestataire de service et spécialiste des micro-algues. Les claires ostréicoles étant hors du domaine public maritime, une concertation avec le Comité Régional de la Conchyliculture de Poitou-Charentes, la DGAL et la DDTM 17 en juin 2018 a permis de proposer six claires, réparties entre l'île de Ré et l'île d'Oléron et pouvant être échantillonnées. L'objectif est de faire un état des lieux de la présence ou de l'absence de cellules de phytoplancton...
Tipo: Text
Palavras-chave: Charentes; Claire; Phytoplancton; Micro-algue; Toxine.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59731/62828.pdf

Huia caspica     gen. &amp; comb. nov., a dinoflagellate species that recently crossed the marine-freshwater boundary
Provedor de dados: 5
Autores: Gu, Haifeng; Mertens, Kenneth; Liu, Tingting.
The dinoflagellate subfamily Diplopsalidoideae encompasses 11 genera whose plate patterns show a large diversity. In a recently published molecular phylogeny (Liu et al. 2015) some of these genera (e.g. Diplopsalis, Diplopelta) are polyphyletic, suggesting that further subdivision of these genera is needed. Here we established the cyst-theca relationship of Diplopsalis caspica by incubating cysts collected from the East China Sea. Cells of D. caspica display a plate formula of Po, X, 3′, 1a, 6″, 3c+t, ?4s, 5″′, 1″″, characterized by a small, parallelogrammic anterior intercalary plate (1a) located in the middle of the dorsal part of the epitheca. The cysts are spherical and smooth-walled with a theropylic archeopyle. In addition, we obtained four large...
Tipo: Text
Palavras-chave: Cyst-theca relationship; Diplopsalioideans; Diplopsalis caspica; Glenodinium caspica; LSU rDNA.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00351/46221/47476.pdf

Morphology, ultrastructure and molecular phylogeny of     Wangodinium sinense     gen. et sp. nov. (Gymnodiniales, Dinophyceae) and revisiting of     Gymnodinium dorsalisulcum     and     Gymnodinium impudicum
Provedor de dados: 5
Autores: Luo, Zhaohe; Hu, Zhangxi; Tang, Yingzhong; Mertens, Kenneth; Leaw, Chui Pin; Lim, Po Teen; Teng, Sing Tung; Wang, Lei; Gu, Haifeng.
The genus Gymnodinium includes many morphologically similar species, but molecular phylogenies show that it is polyphyletic. Eight strains of Gymnodinium impudicum, Gymnodinium dorsalisulcum and a novel Gymnodinium‐like species from Chinese and Malaysian waters and the Mediterranean Sea were established. All of these strains were examined with LM, SEM and TEM. SSU, LSU and internal transcribed spacers rDNA sequences were obtained. A new genus, Wangodinium, was erected to incorporate strains with a loop‐shaped apical structure complex (ASC) comprising two rows of amphiesmal vesicles, here referred to as a new type of ASC. The chloroplasts of Wangodinium sinense are enveloped by two membranes. Pigment analysis shows that peridinin is the main accessory...
Tipo: Text
Palavras-chave: Apical structure complex; Cyst; Dinoflagellate; Lepidodinium; Nuclear chambers; Pigment; Pyrenoid; Ultrastructure.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56610/58307.pdf

Taxonomic revision, phylogeny, and cyst wall composition of the dinoflagellate cyst genus     Votadinium     Reid (Dinophyceae, Peridiniales, Protoperidiniaceae)
Provedor de dados: 5
Autores: Gurdebeke, Pieter R.; Mertens, Kenneth; Pospelova, Vera; Matsuoka, Kazumi; Li, Zhen; Gribble, Kristin E.; Gu, Haifeng; Bogus, Kara; Vrielinck, Henk; Louwye, Stephen.
The taxonomy of the dinoflagellate cyst-based genus Votadinium has been in need of revision. This was accomplished here by integrating morphology, LSU rDNA sequences, and cyst wall composition analyses through micro-Fourier transform infrared spectroscopy. Three new species, Votadinium pontifossatum, V. rhomboideum and V. reidii, were described as cyst stages of Protoperidinium paraoblongum, P. quadrioblongum, and P. steidingerae, respectively. A previously undescribed type of ornamentation was reported for V. pontifossatum. A fourth new species was assigned to V. concavum. Furthermore, Lejeunecysta psilodora Benedek (=Lejeunecysta psuchra Matsuoka), was re-described as V. psilodora and the holotype re-illustrated, as was done for the holotype of V....
Tipo: Text
Palavras-chave: Taxonomy; Dual nomenclature; Dinocyst; Ornamentation; Micro-FTIR; Cyst wall composition; Sporopollenin.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00480/59214/62622.pdf

Introduction to     Spiniferites     Mantell 1850 special issue
Provedor de dados: 5
Autores: Mertens, Kenneth; Carbonell-moore, Consuelo.
The first chapter of this special issue introduces the proceedings of two workshops concerning the cystbased genus Spiniferites Mantell 1850. The historical background of the cyst-based genus Spiniferites, its closely related genera and the theca-based genus Gonyaulax Diesing 1866 is presented here
Tipo: Text
Palavras-chave: Spiniferites; Achomosphaera; Nematosphaeropsis; Gonyaulax.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58303/60843.pdf

Morphology, ultrastructure and molecular phylogeny of cyst-producing Caladoa arcachonensis gen. et sp. nov. (Peridiniales, Dinophyceae) from France and Indonesia
Provedor de dados: 5
Autores: Luo, Zhaohe; Mertens, Kenneth; Nezan, Elisabeth; Gu, Li; Pospelova, Vera; Thoha, Hikmah; Gu, Haifeng.
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...
Tipo: Text
Palavras-chave: Bysmatrum; Cyst; Dinoflagellate; Eyespot; Peridiniales; Plate overlap.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00489/60112/63564.pdf