|
|
|
| Registros recuperados: 34 | |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
| Registros recuperados: 34 | |
|
|
|
