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Peter A. Siver - One of the best experts on this subject based on the ideXlab platform.

  • Surviving the marine environment: two new species of Mallomonas (Synurophyceae)
    Phycologia, 2019
    Co-Authors: Minseok Jeong, Jong Im Kim, Peter A. Siver, Han Soon Kim, Woongghi Shin
    Abstract:

    The genus Mallomonas consists of single-celled flagellates covered with siliceous scales and bristles and is well known in freshwater environments. Two new marine Mallomonas species were collected ...

  • Mallomonas aperturae sp. nov. (Synurophyceae) reveals that the complex cell architecture observed on modern synurophytes was well established by the middle Eocene
    Phycologia, 2018
    Co-Authors: Peter A. Siver
    Abstract:

    Abstract Mallomonas, the largest genus within the class Synurophyceae, consists of unicellular, flagellated, heterokont organisms each with an external cell covering comprised of species-specific overlapping siliceous scales. Most species also possess bristles, which are elongated needle-like siliceous structures that radiate out from the scale coat. A new fossil species, Mallomonas aperturae, is described from the middle Eocene Giraffe Pipe locality situated near the Arctic Circle in northern Canada. The new species possesses uniquely sculptured tripartite scales, each possessing a well-developed V-rib, dome and anterior wing-like extensions. The most unique feature is a large and elongated opening along the posterior side of the dome, a structure known only on scales of the modern species, Mallomonas paludosa (Synurophyceae). It is proposed that the opening on the dome may provide a means for securing bristles to the scales and aiding in bristle rotation. Remarkably, remains of cells with scales still i...

  • Mallomonas bronchartiana compere revisited two new species described from asia
    Cryptogamie Algologie, 2017
    Co-Authors: Evgeniy Gusev, Peter A. Siver, Woongghi Shin
    Abstract:

    Abstract Species from the Mallomonas bronchartiana complex were examined using material from Vietnam, the U.S.A. and South Korea. The original description of Mallomonas bronchartiana is expanded and descriptions of two new taxa, M. pseudobronchartiana and M. velari, are given. All taxa possess body scales that are large, broad, with an asymmetrically-placed posterior rim, an internal honeycomb reticulation, and are covered externally with a layer containing papillae. A distinct V-rib is lacking on Mallomonas bronchartiana scales. Scales of M. pseudobronchartiana have a thin V-shaped rib situated on the scale surface, while the V-rib of M. velari is formed from an upward folding of the surface of the scale. Scales of Mallomonas velari are also easily separated from the other species by the presence of a large forward projecting wing. The positions of all three taxa within the genus are discussed, and placement in section Quadratae is proposed. The distributions and habitat conditions of each species are su...

  • Phylogeny of the genus Mallomonas (Synurophyceae) and descriptions of five new species on the basis of morphological evidence
    Phycologia, 2013
    Co-Authors: Woongghi Shin, Peter A. Siver, Han Soon Kim, Robert A Andersen
    Abstract:

    Jo B.Y., Shin W., Kim H.S., Siver P.A. and Andersen R.A. 2013. Phylogeny of the genus Mallomonas (Synurophyceae) and descriptions five new species on the basis of morphological evidence. Phycologia...

  • fossil species of Mallomonas from an eocene maar lake with recessed dome structures early attempts at securing bristles to the cell covering
    Nova Hedwigia, 2012
    Co-Authors: Peter A. Siver, Anne Marie Lott
    Abstract:

    The genus Mallomonas, the largest within the Class Synurophyceae, consists of motile, unicellular, freshwater heterokonts that are covered with an outer layer of overlapping siliceous scales. The scales are flat, circular to oval structures with taxonomically distinct designs. In addition to scales, the cell coverings of most Mallomonas species contain a second siliceous component known as a bristle. Bristles are composed of a long thin shaft and a flattened proximal foot. The foot of the bristle is fastened under the distal end of a scale in such a way as to allow the shaft to radiate out from the cell and rotate on its axis. For many species, the distal scale margin is distinctly raised, forming a hollow space that secures the bristle foot, and an inverted U-shaped opening from which the shaft emerges. This structure is called the dome. We describe three fossil species of Mallomonas from an Arctic Eocene maar lake that contain domes that are recessed to varying degrees back from the distal scale margin. This design is not known in the modern flora and we hypothesize that it represents an early attempt at securing bristles to the scale coat.

Evgeniy Gusev - One of the best experts on this subject based on the ideXlab platform.

  • Mallomonas loricata sp nov synurales chrysophyceae a new tropical species from section planae
    Phytotaxa, 2021
    Co-Authors: Evgeniy Gusev, Natalia Shkurina, Maxim Kulikovskiy
    Abstract:

    A new species, Mallomonas loricata sp. nov., is described from Vietnam based on silica-scale morphology studied using transmission and scanning electron microscopy. The species belongs to section Planae and has similar morphology to species from the Mallomonas matvienkoae complex. The new species is characterized by obovoid scales with a thick secondary layer with internal reticulation that covers almost whole surface of the scale. Scales of Mallomonas loricata were found at twenty-four localities of eight provinces in northern, central and southern areas of Vietnam. Scales of this new species have also been previously reported from Singapore and Malaysia. The distribution and habitat conditions of the new species are summarized.

  • two new species of genus Mallomonas from swamp localities in vietnam
    Phytotaxa, 2020
    Co-Authors: Evgeniy Gusev, Maxim Kulikovskiy
    Abstract:

    Two new species, Mallomonas punctostriata sp. nov. and Mallomonas collucata sp. nov., are described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. Both species inhabits swamp areas. Mallomonas punctostriata belongs to section Striatae. Its scales have unique transverse rows, consisting of papillae, resembling transverse ribs of members of section Striatae. Mallomonas collucata belongs to section Annulatae. This species has small scales with hexagonal reticulation on the shield. Mallomonas punctostriata was found in Phu Quoc Island (Kien Giang Province) and Cam Ranh Peninsula (Khanh Hoa Province). Mallomonas collucata has been observed only in one site on Phu Quoc Island.

  • Mallomonas lamii sp nov synurales chrysophyceae a new species bearing large scales described from the tropics
    Phytotaxa, 2019
    Co-Authors: Evgeniy Gusev, Pavel V Kulizin, Elena E Guseva, Natalia Shkurina, Maxim Kulikovskiy
    Abstract:

    A new species Mallomonas lamii sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopies. The species belongs to the Mallomonas matvienkoae complex and is characterized by large oval scales with a thick secondary layer with internal reticulation that covers the distal one-third of the scale. The scale morphology of Mallomonas lamii is very similar to that of the fossil taxon M. pleuriforamen. Scales of Mallomonas lamii were found at thirteen localities from six provinces in central and southern areas of Vietnam. The distributions and habitat conditions of the new species are summarized.

  • Mallomonas minuscula sp nov synurales chrysophyceae a new member in the section torquatae from vietnam
    Fottea, 2019
    Co-Authors: Evgeniy Gusev, Elena E Guseva, Elena Kezlya, Maxim Kulikovskiy
    Abstract:

    Mallomonas minuscula sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. This species belongs to the Mallomonas mangofera complex and is characterized by small scales with large polygonal papillae on the shield, raised wide arms on the anterior submarginal rib with small papillae, and a small "window" in the angle of the posterior submarginal rib. Scales of Mallomonas minuscula were found in nine localities from six provinces of Central and Southern Vietnam. The distributions and habitat conditions of the new species are summarized.

  • Mallomonas gusakovii sp nov chrysophyceae synurales a new species from phu quoc island vietnam
    Phytotaxa, 2019
    Co-Authors: Evgeniy Gusev, Dmitry A Kapustin, Elena E Guseva, Nikita A Martynenko, Maxim Kulikovskiy
    Abstract:

    Mallomonas gusakovii sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. This species belongs to section Quadratae and is characterized by large and broad scales of three types with an internal reticulation, V-shaped rib and a forward projecting wing. Different types of the V-shaped rib in taxa from section Quadratae are discussed. Scales of Mallomonas gusakovii were found only in two sites in Phu Quoc Island, Southern Vietnam.

Maxim Kulikovskiy - One of the best experts on this subject based on the ideXlab platform.

  • Mallomonas loricata sp nov synurales chrysophyceae a new tropical species from section planae
    Phytotaxa, 2021
    Co-Authors: Evgeniy Gusev, Natalia Shkurina, Maxim Kulikovskiy
    Abstract:

    A new species, Mallomonas loricata sp. nov., is described from Vietnam based on silica-scale morphology studied using transmission and scanning electron microscopy. The species belongs to section Planae and has similar morphology to species from the Mallomonas matvienkoae complex. The new species is characterized by obovoid scales with a thick secondary layer with internal reticulation that covers almost whole surface of the scale. Scales of Mallomonas loricata were found at twenty-four localities of eight provinces in northern, central and southern areas of Vietnam. Scales of this new species have also been previously reported from Singapore and Malaysia. The distribution and habitat conditions of the new species are summarized.

  • two new species of genus Mallomonas from swamp localities in vietnam
    Phytotaxa, 2020
    Co-Authors: Evgeniy Gusev, Maxim Kulikovskiy
    Abstract:

    Two new species, Mallomonas punctostriata sp. nov. and Mallomonas collucata sp. nov., are described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. Both species inhabits swamp areas. Mallomonas punctostriata belongs to section Striatae. Its scales have unique transverse rows, consisting of papillae, resembling transverse ribs of members of section Striatae. Mallomonas collucata belongs to section Annulatae. This species has small scales with hexagonal reticulation on the shield. Mallomonas punctostriata was found in Phu Quoc Island (Kien Giang Province) and Cam Ranh Peninsula (Khanh Hoa Province). Mallomonas collucata has been observed only in one site on Phu Quoc Island.

  • Mallomonas lamii sp nov synurales chrysophyceae a new species bearing large scales described from the tropics
    Phytotaxa, 2019
    Co-Authors: Evgeniy Gusev, Pavel V Kulizin, Elena E Guseva, Natalia Shkurina, Maxim Kulikovskiy
    Abstract:

    A new species Mallomonas lamii sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopies. The species belongs to the Mallomonas matvienkoae complex and is characterized by large oval scales with a thick secondary layer with internal reticulation that covers the distal one-third of the scale. The scale morphology of Mallomonas lamii is very similar to that of the fossil taxon M. pleuriforamen. Scales of Mallomonas lamii were found at thirteen localities from six provinces in central and southern areas of Vietnam. The distributions and habitat conditions of the new species are summarized.

  • Mallomonas minuscula sp nov synurales chrysophyceae a new member in the section torquatae from vietnam
    Fottea, 2019
    Co-Authors: Evgeniy Gusev, Elena E Guseva, Elena Kezlya, Maxim Kulikovskiy
    Abstract:

    Mallomonas minuscula sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. This species belongs to the Mallomonas mangofera complex and is characterized by small scales with large polygonal papillae on the shield, raised wide arms on the anterior submarginal rib with small papillae, and a small "window" in the angle of the posterior submarginal rib. Scales of Mallomonas minuscula were found in nine localities from six provinces of Central and Southern Vietnam. The distributions and habitat conditions of the new species are summarized.

  • Mallomonas gusakovii sp nov chrysophyceae synurales a new species from phu quoc island vietnam
    Phytotaxa, 2019
    Co-Authors: Evgeniy Gusev, Dmitry A Kapustin, Elena E Guseva, Nikita A Martynenko, Maxim Kulikovskiy
    Abstract:

    Mallomonas gusakovii sp. nov. is described from Vietnam based on silica-scale morphology studied by means of transmission and scanning electron microscopy. This species belongs to section Quadratae and is characterized by large and broad scales of three types with an internal reticulation, V-shaped rib and a forward projecting wing. Different types of the V-shaped rib in taxa from section Quadratae are discussed. Scales of Mallomonas gusakovii were found only in two sites in Phu Quoc Island, Southern Vietnam.

Han Soon Kim - One of the best experts on this subject based on the ideXlab platform.

  • Surviving the marine environment: two new species of Mallomonas (Synurophyceae)
    Phycologia, 2019
    Co-Authors: Minseok Jeong, Jong Im Kim, Peter A. Siver, Han Soon Kim, Woongghi Shin
    Abstract:

    The genus Mallomonas consists of single-celled flagellates covered with siliceous scales and bristles and is well known in freshwater environments. Two new marine Mallomonas species were collected ...

  • Growth characteristics of bloom forming Mallomonas elongata (Synurophyceae) based on silicate and light intensity
    2016
    Co-Authors: Han Soon Kim, Kyung Lak Lee
    Abstract:

    A dominant planktonic bloom-forming species, Mallomonas elongata was isolated from a small shallow eutrophic pond. The growth characteristics of this species on variable silicate concentrations and light intensities were investi-gated in laboratory unialgal cultures. In culture condition of 15°C, the maximum population growth and the highest growth rate of M. elongata occurred at a light intensity of 80 μmol m-2 s-1, and in culture condition of 18°C, it exhibited the maximum population growth and the highest growth rates at a light intensity of 50 μmol m-2 s-1. Silicate concentration had no effect on the population growth and growth rate of M. elongata. Key Words: bloom forming species; growth rate; light intensity; Mallomonas elongata; silicate; unialgal cultur

  • Phylogeny of the genus Mallomonas (Synurophyceae) and descriptions of five new species on the basis of morphological evidence
    Phycologia, 2013
    Co-Authors: Woongghi Shin, Peter A. Siver, Han Soon Kim, Robert A Andersen
    Abstract:

    Jo B.Y., Shin W., Kim H.S., Siver P.A. and Andersen R.A. 2013. Phylogeny of the genus Mallomonas (Synurophyceae) and descriptions five new species on the basis of morphological evidence. Phycologia...

  • growth characteristics of two bloom forming synurophytes Mallomonas elongata and synura petersenii at different nitrate and phosphate concentrations
    Nordic Journal of Botany, 2012
    Co-Authors: Kyung Lak Lee, Jin Hee Kim, Hosung Yoon, Han Soon Kim
    Abstract:

    Two dominant planktonic bloom-forming algal species in a small shallow eutrophic pond were identified as Mallomonas elongata and Synura petersenii by electron microscopy. Their growth requirements were investigated as uni-algal cultures in a laboratory study. The maximum population growth and maximum growth rate of M. elongata occurred at concentrations of 24 μM nitrate (NO3) and 5 μM phosphate (PO4) at a temperature of 15°C and a pH of 6. Synura petersenii grew maximally and exhibited the highest growth rate at a NO3 concentration of 24 μM and a PO4 concentration of 2 μM. Mallomonas elongata and S. petersenii had similar nutrient requirements for optimum growth, suggesting that the biomass of these two species can be controlled by nutrient gradients.

  • studies on ultrastructure and three gene phylogeny of the genus Mallomonas synurophyceae 1
    Journal of Phycology, 2011
    Co-Authors: Woongghi Shin, Han Soon Kim, Sung Min Boo, Peter A. Siver
    Abstract:

    The genus Mallomonas, a common and often abundant member of the planktic community in many freshwater habitats worldwide, consists of 180 species divided into 19 sections and 23 series. Classification of species is based largely on ultrastructural characteristics of the siliceous scales and bristles that collectively form a highly organized covering over the cell. However, the relative importance of the different siliceous features of the scales, such as the dome, V rib, and secondary structures, as well as the different types of scales, in understanding the evolution and phylogeny of the genus is little known. In this study, we investigated the scale and bristle ultrastructure, along with sequences of three genes, for 19 isolates (18 species) of Mallomonas (18 isolates were from Korean habitats). The isolates represented nine of the 19 sections. Sequences for both the nuclear SSU and LSU rDNA and plastid LSU of RUBISCO (rbcL) genes for each of the 19 Mallomonas isolates and four outgroups were determined. Bayesian and maximum-likelihood (ML) analyses of the data revealed that Mallomonas consists of two strongly supported clades. Mallomonas bangladeshica (E. Takah. et T. Hayak.) Siver et A. P. Wolfe was at the base of the first clade that included taxa from the sections Planae and Heterospinae, both of which lack a V rib on the shield of the scales. Our results indicated that the sections Planae and Heterospinae should be combined. The second clade, with Mallomonas insignis Penard and Mallomonas punctifera Korshikov at the base, contained taxa from the sections Mallomonas, Striatae, Akrokomae, Annulatae, Torquatae, Punctiferae, and Insignes, all of which have V ribs or well-developed marginal ribs on the scales. Sister relationships between Mallomonas and Striatae were strongly supported, but interrelations among the remaining sections were not resolved, probably due to inclusion of too few species. Our results suggest that the current classification of the genus Mallomonas at the section level will require some revision. Additional species will need to be added in future analyses.

Yvonne Němcova - One of the best experts on this subject based on the ideXlab platform.

  • Two new species of Mallomonas (Chrysophyceae: Synurales): Mallomonas temonis and Mallomonas divida
    2016
    Co-Authors: Yvonne Němcova, Jana Kreidlova
    Abstract:

    This paper describes two new species of Mallomonas. Mallomonas temonis was identified in the Table Mountai

  • Two new species of Mallomonas (Chrysophyceae: Synurales): Mallomonas
    2013
    Co-Authors: Yvonne Němcova, Jana Kreidlova
    Abstract:

    This paper describes two new species of Mallomonas. Mallomonas temonis was identified in the Table Mountai

  • two new species of Mallomonas chrysophyceae synurales Mallomonas temonis and Mallomonas divida
    Phytotaxa, 2013
    Co-Authors: Yvonne Němcova, Jana Kreidlova
    Abstract:

    This paper describes two new species of Mallomonas . Mallomonas temonis was identified in the Table Mountain Plateau, South Africa; Mallomonas divida was identified in Aquitaine, France. The descriptions are based on silica-scale morphology studied by means of transmission and scanning electron microscopy. Mallomonas temonis belongs to the section Heterospinae . A scale is surrounded by a submarginal rib connected at lateral parts by a strong, more or less transversal rib. Mallomonas divida belongs to the section Torquatae . The shield of scales is covered by regularly arranged, delicate papillae and marked by one or several rows of more distinctive papillae.

  • Mallomonas solea ferrea and Mallomonas siveri chrysophyceae synurophyceae two new taxa from the western cape south africa
    Nova Hedwigia, 2011
    Co-Authors: Yvonne Němcova, Petr Bulant, Jorgen Kristiansen
    Abstract:

    Abstract: Two new species, Mallomonas solea-ferrea and M. siveri, are described based on both transmission and scanning electron microscopy from the Western Cape (South Africa). Mallomonas solea-ferrea is located in the section Torquatae, with typical collar scales bearing a smooth, curved bristle, rhomboid body scales, and rear scales with a diminutive spine. The shield of the body scales is covered with delicate papillae and a secondary reticulum where each mesh encloses approximately six pores. The proximal-most reticulation forms a depression in the shape of a horseshoe. The most similar taxon to M. solea-ferrea is the nominal variety of M. pumilio. Mallomonas siveri belongs to the section Striatae. All scales of the cell coat have a smooth dome and possess a sharply terminated, slightly curved bristle. The scales of M. siveri are most similar to those of M. striata since they possess the special groups of pores posteriorly on the shield. However, in M. siveri, the V-rib arms are continuous with the anterior submarginal ribs, and both flanges are smooth.

  • Geometric morphometric analyses of silica-scale variation in four Mallomonas species (Synurophyceae, Stramenopiles)
    Nordic Journal of Botany, 2008
    Co-Authors: Martina Pichrtova, Yvonne Němcova
    Abstract:

    The tools of geometric morphometrics (GM) were used to examine morphological variation of silica-scales in four Mallomonas species (M. calceolus, M. kalinae, M. flora and M. striata). Relative warps analysis revealed the main trends in morphological variation to be associated with the width, length and shape of the V-rib, while the proximal border region was found to be more stable. Almost all of the scales investigated were successfully differentiated and assigned to an individual species by means of multivariate statistics, the classification experiments were done in a pairwise manner. Geometric morphometric based analyses did not corroborate the classification of these species into traditionally defined sections. M. kalinae and M. striata were found to be the most similar, although they are classified into different sections of the genus, while M. kalinae and M. calceolus that are both traditionally classified as belonging to the section Papillosae, proved to be the most dissimilar species pair. The genus Mallomonas (Synurophyceae, Stramenopila) comprises unicellular freshwater flagellates. One of the main distinctive features of this genus is the presence of bilaterally symmetric and heteropolar scales forming a scale case around the cell. The ultrastructure of silica scales and bristles is crucial for species determination, and the taxonomy of Mallomonas is based almost exclusively on it. Since the middle of the 20th century, about 150 species and infraspecific taxa have been described. Scale morphology is species-specific and a single scale will usually suffice for making a species determination. Taxa with narrow ecological optimum may be considered valuable bioindicators of both recent and historical environments (Siver 1995, Smol 1995, Siver and Marsicano 1996). The genus Mallomonas is traditionally divided into