Consulta: creatorFacets:"Pospelova, Vera"
Registros recuperados: 14
Data/hora: 09/06/2024 04:46:46

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

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

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

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

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

Cryptic diversity within the harmful dinoflagellate Akashiwo sanguinea in coastal Chinese waters is related to differentiated ecological niches
Provedor de dados: 5
Autores: Luo, Zhaohe; Yang, Weidong; Leaw, Chui Pin; Pospelova, Vera; Bilien, Gwenael; Liow, Guat Ru; Lim, Po Teen; Gu, Haifeng.
Blooms of the harmful dinoflagellate Akashiwo sanguinea are responsible for the mass mortality of fish and invertebrates in coastal waters. This cosmopolitan species includes several genetically differentiated clades. Four clonal cultures were established by isolating single cells from Xiamen Harbour (the East China Sea) for morphological and genetic analyses. The cultures displayed identical morphology but were genetically different, thus revealing presence of cryptic diversity in the study area. New details of the apical structure complex of Akashiwo sanguinea were also found. To investigate whether the observed cryptic diversity was related to environmental differentiation, 634 cells were obtained from seasonal water samples collected from 2008 to 2012....
Tipo: Text
Palavras-chave: Biogeography; Cryptic species; Gymnodinium sanguineum; Seasonal occurrence; Speciation.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49771/50355.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

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