Three new araphid diatoms (Bacillariophyta) from the Maritime Antarctic Region

Phytotaxa ◽  
2014 ◽  
Vol 167 (3) ◽  
pp. 256 ◽  
Author(s):  
BART VAN DE VIJVER ◽  
EDUARDO A. MORALES ◽  
KATEŘINA KOPALOVÁ
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
New Taxa ◽  
Maritime Antarctic ◽  
Antarctic Region ◽  
Diatom Flora ◽  
Ecological Preferences ◽  
The Antarctic ◽  
Scanning Electron

A revision of taxa from the genus Staurosira and Staurosirella from the Maritime Antarctic Region, formerly identified as Staurosirella (Fragilaria) pinnata and Fragilaria alpestris, resulted in the description of three new taxa: Staurosira pottiezii Van de Vijver sp. nov., Staurosirella antarctica Van de Vijver & E.Morales sp. nov. and S. frigida Van de Vijver & E.Morales sp. nov. Detailed light (LM) and scanning electron microscope (SEM) observations are used to better characterize the morphology and ultrastructure of these three new taxa. Comparisons with similar taxa and the ecological preferences of each species are added. The revision of these species confirmed the endemic nature of the Antarctic diatom flora. 

Two new Gomphonema species (Bacillariophyta) from the Maritime Antarctic Region

Phytotaxa ◽  
2016 ◽  
Vol 269 (3) ◽  
pp. 209 ◽  
Author(s):  
BART VAN DE VIJVER ◽  
KATEŘINA KOPALOVÁ ◽  
RALITSA ZIDAROVA ◽  
J. PATRICK KOCIOLEK
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Maritime Antarctic ◽  
Antarctic Region ◽  
Diatom Flora ◽  
Ecological Preferences ◽  
The Antarctic ◽  
Scanning Electron

Two new diatom taxa belonging to the genus Gomphonema were recorded during a survey of the Maritime Antarctic freshwater and limno-terrestrial diatom flora: Gomphonema jamesrossense sp. nov. and G.maritimo-antarcticum sp. nov. Detailed light (LM) and scanning electron microscope (SEM) observations are used to characterize the morphology and ultrastructure of the two new Gomphonema taxa. Comparisons with similar taxa and the ecological preferences of each species are added. The revision of these species confirmed the endemic nature of the Antarctic diatom flora.

Three new Craticula species (Bacillariophyta) from the Maritime Antarctic Region

Phytotaxa ◽  
2015 ◽  
Vol 213 (1) ◽  
pp. 35 ◽  
Author(s):  
Bart Van de Vijver ◽  
Katerina Kopalova ◽  
Ralitsa Zidarova
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
New Taxa ◽  
Taxonomic Revision ◽  
Maritime Antarctic ◽  
Antarctic Region ◽  
Diatom Flora ◽  
South Georgia ◽  
The Antarctic ◽  
Scanning Electron

Three new diatom taxa belonging to the genus Craticula were found during the ongoing taxonomic revision of the Antarctic freshwater and limno-terrestrial diatom flora: Craticula australis, sp. nov., C. obaesa, sp. nov and C. petradeblockiana, sp. nov. Detailed light and scanning electron microscope observations are used to better characterize the morphology and ultrastructure of these three new taxa. A fourth Craticula taxon, formerly identified as Navicula megacuspidata, described from South Georgia, is transferred to the genus Craticula and its taxonomy is briefly discussed. Comparisons with similar taxa and the ecological preferences of each species are added. The revision of these species confirms once again the endemic nature of the Antarctic diatom flora.

scholarly journals Four Achnanthidium species (Bacillariophyta) formerly identified as Achnanthidium minutissimum from the Antarctic Region

2014 ◽  
Author(s):  
Bart Van de Vijver ◽  
Kateřina Kopalová
Keyword(s):  
New Taxa ◽  
Taxonomic Revision ◽  
Antarctic Region ◽  
Diatom Flora ◽  
Electron Microscopical ◽  
Morphological Differences ◽  
The Antarctic ◽  
Scanning Electron

Four taxa belonging to the complex of species around Achnanthidium minutissimum were found during the ongoing taxonomic revision of the Antarctic freshwater and limno-terrestrial diatom flora. Two taxa were previously described as Achnanthidium lailae and A. sieminskae. Two others were formerly identified as A. minutissimum but detailed light and scanning electron microscopical observations revealed sufficient morphological differences compared to the type of A. minutissimum, to justify their separation and description as new taxa: Achnanthidium indistinctum and A. maritimo-antarcticum. The morphology and ecology of all four taxa are discussed comparing the species with morphologically similar taxa. The biogeographical consequences of the splitting of the former A. minutissimum complex in the Antarctic Region are discussed.

Luticola puchalskiana, a new small terrestrial Luticola species (Bacillariophyceae) from the Maritime Antarctic Region

Phytotaxa ◽  
2020 ◽  
Vol 450 (1) ◽  
pp. 85-94
Author(s):  
NATALIA KOCHMAN-KĘDZIORA ◽  
RALITSA ZIDAROVA ◽  
TERESA NOGA ◽  
MARIA OLECH ◽  
BART VAN DE VIJVER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Analysis ◽  
New Taxon ◽  
Maritime Antarctic ◽  
Antarctic Region ◽  
Diatom Flora ◽  
Terrestrial Habitats ◽  
Two Populations ◽  
Scanning Electron

During a survey of the terrestrial diatom flora of the Maritime Antarctic Region, an unknown Luticola taxon that could not be identified using the currently available literature was observed on two islands of the South Shetland Archipelago. After a detailed morphological analysis and comparison, the unknown taxon is described as Luticola puchalskiana sp. nov. The new species can be separated from other Luticola species based on its valve dimensions, stria density and the shape of both central and terminal raphe endings. Two populations of the new taxon were observed in samples collected from terrestrial habitats. The morphology of Luticola puchalskiana is elaborately described and illustrated using both light and scanning electron microscopy observations. A comparison is made with a large number of other morphologically similar Luticola species from the entire (sub)Antarctic Region.

Lacuneolimna gen. nov., Lacuneolimna zalokariae comb. nov. and Lacuneolimna novagallia spec. nov. (Bacillariophyceae) from the French Guiana diatom freshwater flora

Phytotaxa ◽  
2015 ◽  
Vol 231 (1) ◽  
pp. 19 ◽  
Author(s):  
Loïc Tudesque ◽  
René Le Cohu ◽  
Michel Coste ◽  
Horst Lange-Bertalot
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
New Taxa ◽  
French Guiana ◽  
New Genus ◽  
Freshwater Diatoms ◽  
Diatom Genus ◽  
Scanning Electron

The freshwater diatoms of the French Guiana have received little attention so far. A new diatom genus, Lacuneolimna, based on the species Eolimna zalokariae, is described from a small rainforest stream. Numerous ultrastructural features differ from the genus Eolimna, notably the pluriseriate striae lying between relief-like elevated virgae and depressed externally. In addition, another species new to science, L. novagallia, belonging to this new genus, was discovered in the same place. Detailed light and scanning electron microscope observations are used to characterize the morphology and the ultrastructure of these two new taxa.

scholarly journals Early Cretaceous striate tricolpate pollen from the Borehole Mersa Matruh 1, North West Desert, Egypt

1988 ◽  
Vol 7 (2) ◽  
pp. 201-215 ◽  
Author(s):  
James H. J. Penny
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
New Taxa ◽  
Early Cretaceous ◽  
North West ◽  
Sem Study ◽  
Stratigraphic Ranges ◽  
Scanning Electron

Abstract. Striate tricolpate pollen has been recovered from Early Cretaceous samples of the borehole Mersa Matruh 1 in the N.W. Desert of Egypt. Scanning Electron Microscope (SEM) study has revealed fine details of their exine scupture, on the basis of which four new taxa, STRIOTRI-OVAL, STRIOTRI-SMOOTHMUR, STRIOTRI-SEGMUR and STRIORET-SMOOTH, are distinguished. The stratigraphic ranges of these are discussed and they are compared with other published species. They are among the oldest striate tricolpate pollen yet described, appearing in sediments of Early Aptian age, slightly predating the first reliable records of reticulate tricolpates in the sequence studied. The lack of earlier reticulate grains is attributed to possible sample failure. There is evidence that the true first appearance of tricoplate pollen in Egypt may be late Barrenian.

A basal chalcidoid (Insecta: Hymenoptera) from the earliest Cretaceous or latest Jurassic of Mongolia

2004 ◽  
Vol 35 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Donald Quicke ◽  
Hasan Basibuyuk ◽  
Alexandr Rasnitsyn
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
New Taxa ◽  
Fore Wing ◽  
Wing Venation ◽  
Wing Vein ◽  
Environmental Chamber ◽  
Sister Clade ◽  
Basal Group ◽  
Scanning Electron

AbstractKhutelchalcis gobiensis gen. et sp. n. (Khutelchalcididae fam. n.), based on a tiny impression fossil collected from the lowermost Cretaceous or uppermost Jurassic deposits of Khutel-Khara in East Mongolia, was studied using an environmental chamber scanning electron microscope. Character analysis suggests that the fossil belongs to a putative basal group of the Chalcidoidea. The greatly reduced wing venation, apparent presence of multiporous plate sensillae with long aperture on the flagellomeres, and a high antennal insertion all suggest that the new taxa is related to the Chalcidoidea. The angulation of fore wing vein Cu at the M+Cu fork is similar to that of Jurassic Jurapriidae, Cretaceous Serphitidae as well as various chalcidoids. This character might be a synapomorphy for Chalcidoidea + Serphitoidea (including Mymarommatidae) + Jurapriidae, which in turn are possibly a sister clade to Platygastroidea. The small size of this species is discussed in relation to conflicting scenarios concerning the plesiomorphic biology of the chalcidoid+proctotrupoid linage. Mymarommatidae and Serphitidae are combined in a single superfamily, Serphitoidea Brues, 1937 (= Mymarommatoidea Debauche, 1948, syn. nov.).

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Sign in / Sign up

Export Citation Format

Share Document