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| Registros recuperados: 34 | |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34805/33327.pdf |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00262/37306/35718.pdf |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Registros recuperados: 34 | |
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