Micro- and Nanostructures of Calcareous Foraminiferal Tests: Insight from Representatives of Miliolida, Rotaliida and Lagenida

2018 ◽  
Vol 48 (2) ◽  
pp. 142-155 ◽  
Author(s):  
Zofia Dubicka ◽  
Krzysztof Owocki ◽  
Michał Gloc
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fiber Bundles ◽  
Calcite Crystal ◽  
Crystal Fiber ◽  
Phylogenetic Reconstructions ◽  
Inner Surface ◽  
Molecular Phylogenetic ◽  
Scanning Electron ◽  
Taxonomic System

Abstract The test structures of Lagenida, Rotaliida, and Miliolida (Foraminifera) are described at an unprecedented scale of resolution. Observations using conventional and field-emission scanning electron microscopy revealed distinct micro- and nanoscale differences in the textural compositions of these three main groups of calcifying foraminifers, consistent with recent molecular phylogenetic reconstructions and a higher-level taxonomic system. The rotaliid test is entirely composed of roughly spherical primary carbonate nanograins, up to 100 nm in diameter, which merge into micrometer-sized irregular aggregates. The miliolid test is made up of two morphologically different primary crystallites. Arbitrarily arranged needle-shaped elements (up to 1 µm in length and 200 nm in width) make up the bulk of the test, including the inside of the wall (porcelain) and mineralized inner surface (intrados) (ca. 100 nm in thickness). Roughly spherical nanograins (up to 50 nm in diameter) form more or less regularly arranged polygons of an outer lamina (extrados), which is ca. 200 nm in thickness. By contrast, the lagenid test texture is characterized by much larger crystals than in other calcifying foraminifers. At moderate magnification, lagenid tests display a fibrous texture composed of fiber bundles (tens of μm in length and several μm in width) that are oriented perpendicular to test surfaces and taper towards the ends when in contact with another lamina. At higher magnification, each bundle constitutes a single calcite crystal with an inner pore extending along the entire length of the crystal/fiber. We measured test hardness using the nanoindentation method. This is the first application of this technique in microfossils. We found that Cretaceous Lagenida tests were more resistant to mechanical stress than Rotaliida tests. These comparative strengths may be linked to internal test microstructure and play a role in determining habitats in which these taxa can live.

Scanning electron microscopy of the operculum of Garra lamta (Hamilton) (Cyprinidae:Cypriniformes), an Indian hill stream fish

2010 ◽  
Vol 58 (3) ◽  
pp. 182 ◽  
Author(s):  
Swati Mittal ◽  
Usha Kumari ◽  
Pinky Tripathi ◽  
Ajay Kumar Mittal
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Epithelial Cells ◽  
Goblet Cells ◽  
Stream Fish ◽  
Male And Female ◽  
Fish Breeding ◽  
Inner Surface ◽  
Garra Lamta ◽  
Scanning Electron

The surface architecture of the epidermis on the outer surface of the operculum (OE) and the epithelium on the inner surface of the operculum (EISO) of Garra lamta was examined by scanning electron microscopy. The surface appeared smooth on the OE and wavy on the EISO. A wavy epithelium is considered to facilitate an increase in its stretchability, during the expansion of the branchial chamber. The OE and the EISO were covered by a mosaic pavement of epithelial cells with characteristic patterns of microridges and microbridges. Interspersed between the epithelial cells were mucous goblet cell pores, which were not significantly different in number in the OE and the EISO. Nevertheless, their surface area in the EISO was significantly higher than in the OE. This could be an adaptation to secrete higher amounts of mucus on the EISO for keeping the branchial chamber lining clean, avoiding clogging, the increased slipperiness reducing friction from water flow and increased efficiency in protecting against microbial attachments. Rounded bulges on the OE and the EISO were associated with mucous goblet cells. The absence of the taste buds in the EISO, in contrast to the OE, suggests that their function in the branchial chamber may not be of much significance in this fish. Breeding tubercles on the OE are believed to facilitate better contact between the male and female during breeding.

scholarly journals Balantidium grimi n. sp. (Ciliophora, Litostomatea), a new species inhabiting the rectum of the frog Quasipaa spinosa from Lishui, China

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 29 ◽  
Author(s):  
Weishan Zhao ◽  
Can Li ◽  
Dong Zhang ◽  
Runqiu Wang ◽  
Yingzhen Zheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Analysis ◽  
New Species ◽  
Body Shape ◽  
Ssu Rdna ◽  
The Body ◽  
Molecular Phylogenetic ◽  
A New Species ◽  
Scanning Electron

Balantidium grimi n. sp. is described from the rectum of the frog Quasipaa spinosa (Amphibia, Dicroglossidae) from Lishui, Zhejiang Province, China. The new species is described by both light microscopy (LM) and scanning electron microscopy (SEM), and a molecular phylogenetic analysis is also presented. This species has unique morphological features in that the body shape is somewhat flattened and the vestibulum is “V”-shaped, occupying nearly 3/8 to 4/7 of the body length. Only one contractile vacuole, situated at the posterior body, was observed. The phylogenetic analysis based on SSU-rDNA indicates that B. grimi groups together with B. duodeni and B. entozoon. In addition, the genus Balantidium is clearly polyphyletic.

Fe-Sem Observations on the Microfibrillar Orientation in the Secondary Wall of Tracheids

IAWA Journal ◽  
1991 ◽  
Vol 12 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Hisashi Abe ◽  
Jun Ohtani ◽  
Kazumi Fukazawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Secondary Wall ◽  
Abies Sachalinensis ◽  
Clockwise Direction ◽  
Inner Surface ◽  
Scanning Electron

Field emission scanning electron microscopy was used to observe the inner surfaces of the developing secondary walls of earlywood tracheids of Abies sachalinensis Masters. Microfibrillar orientation in the secondary wall, as seen from the lumen side, changed in a clockwise direction from the outermost S1 to the middle of the S2 and from there counter-clockwise to the innermost S3. Sometimes microfibrils oriented in a steep S-helix were observed in the S3 layer. Lamellae showing different microfibrillar orientations in wall layers other than the S2 were observed beneath newly deposited microfibrils on the inner surface of the developing wall. Furthermore, on the inner surface of the wall forming the S12, S23 and S3, lamellae with microfibrils closely aligned at the same angle as one another and lacking spaces were not observed. These observations suggest that in layers other than the S2 most lamellae are not composed of closely spaced microfibrils.

scholarly journals Taxonomic significance of pollen morphology in Succisa and Succisella

2019 ◽  
Vol 55 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Zoya M. Tsymbalyuk ◽  
Sergei L. Mosyakin ◽  
Lyudmila M. Nitsenko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Polar View ◽  
Taxonomic Significance ◽  
Oblate Spheroidal ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic ◽  
Scanning Electron

Abstract Pollen morphology of representatives of the genera Succisa and Succisella in the flora of Ukraine was studied using light and scanning electron microscopy. Pollen grains in both taxa were tricolpate, prolate, rarely oblate-spheroidal or spheroidal; large-sized. Their outline in polar view was subcircular, rarely trilobate, in equatorial view elliptical or rarely circular. Colpi short, of variable width, margins irregular with distinct, narrow margo, and blunt or acute ends. Exine sculpture was echinate-microechinate. The revealed characteristics of pollen grains are taxonomically significant at the generic and specific levels, and they can be used in pollen analysis. Palynomorphological data are consistent with the results of recent molecular phylogenetic studies. Data on pollen morphology also confirm taxonomic circumscription of Succiseae V. Mayer & Ehrend. Pollen grains in Succiseae are characterized by a tricolpate aperture type, which was probably ancestral in Dipsacaceae s. str.

Bone Resorption in Human Cholesteatoma: Morphological Study with Scanning Electron Microscopy

1995 ◽  
Vol 104 (6) ◽  
pp. 463-468 ◽  
Author(s):  
Yoshihumi Uno ◽  
Ryusuke Satto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bone Resorption ◽  
Bone Destruction ◽  
Collagen Fibrils ◽  
Fiber Bundles ◽  
Morphological Evidence ◽  
Middle Ear Surgery ◽  
Organic Substances ◽  
Scanning Electron

The detailed mechanism of bone resorption in cholesteatoma was investigated by means of eroded ossicles obtained during middle ear surgery for cholesteatoma. In the light microscopic study, multinucleate osteoclasts with ruffled borders were found in contact with the eroded bone, which appeared to be osteoclastic lacunae. Scanning electron microscopy revealed the lacunae to be many absorption bays, 30 to 100 μm in diameter, clustered on the surface of eroded areas. Numerous cone-shaped stubs of digested collagen fiber bundles, consisting of scores of collagen fibrils and degenerated extracellular organic substances, were visible at higher magnification on the bottom of the absorption bay. The pattern of fusion and twining of the disarranged collagen fibrils at the top of the partly digested fiber bundles was clearly rendered by the alkali-water maceration method for scanning electron microscopy. We infer from the morphological evidence that osteoclastic resorption may be one of the major mechanisms of bone destruction in cholesteatoma, and that demineralization and degeneration of extracellular organic substances precede disruption of collagen fibrils at the front of bone resorption.

Morphological and genetic characterization of Pterygodermatites (Paucipectines) zygodontomis (Nematoda: Rictulariidae) from Necromys lasiurus (Rodentia: Sigmodontinae) from Uberlândia, Brazil

2017 ◽  
Vol 92 (5) ◽  
pp. 618-629 ◽  
Author(s):  
N.A. Costa ◽  
R.O. Simões ◽  
R.V. Vilela ◽  
J.G.R. Souza ◽  
S.T. Cardoso ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Genetic Characterization ◽  
The Body ◽  
Oral Aperture ◽  
Minas Gerais State ◽  
Molecular Phylogenetic ◽  
I Gene ◽  
Scanning Electron

AbstractPterygodermatites (Paucipectines) zygodontomis, a nematode parasite of the small intestine of the rodent Necromys lasiurus, from Uberlândia, Minas Gerais state, Brazil, was analysed by light and scanning electron microscopy. Additionally, phylogenies were inferred from the mitochondrially encoded cytochrome c oxidase I gene (MT-CO1). Details of the helminth surface, such as the oral aperture, cephalic papillae, papillae in the posterior region of the body and longitudinal cuticular elements represented by spine-like projections and fans are presented, adding new taxonomic details. Molecular phylogenetic analysis, based on the MT-CO1, demonstrated that P. (P.) zygodontomis and Pterygodermatites (Paucipectines) jaegerskioldi form a unique evolutionary unit in accordance with the subgenus Paucipectines and corroborated their occurrence in cricetid and didelphid hosts.

scholarly journals Teunia rosae sp. nov. and Teunia rudbeckiae sp. nov. (Cryptococcaceae, Tremellales), two novel basidiomycetous yeast species isolated from flowers

2020 ◽  
Vol 70 (10) ◽  
pp. 5394-5400
Author(s):  
Gui-Shuang Wang ◽  
Yu Zhou ◽  
Lu Xue ◽  
Ai-Hua Li ◽  
Wangmu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Analysis ◽  
Yeast Species ◽  
Novel Species ◽  
Its Region ◽  
Basidiomycetous Yeast ◽  
Yeast Strains ◽  
Molecular Phylogenetic ◽  
Scanning Electron

Three yeast strains isolated from three flower samples were identified as representing two novel species of Teunia based on molecular phylogenetic analysis and phenotypic comparisons. Strains 12A8 and 21S4 with pink cream colonies and subglobose to globose cells had identical sequences in the ITS and LSU D1/D2 regions, which differed from strain X54 with cream colonies and ovoid to ellipsoidal cells by 6 nt substitutions (1 %) and 9 nt mismatches (1.5 %) in the D1/D2 domains and ITS region, respectively. They could also be distinguished from each other in assimilation of glucitol and salicin, growth at 28 °C and cell fibrillar appendages under scanning electron microscopy. The three strains differed from known species of Teunia by more than 8 nt (1.3 %) and 30 nt (5 %) in the D1/D2 domains and ITS region, respectively. Therefore, the names Teunia rudbeckiae sp. nov. (Holotype CGMCC 2.5840, Mycobank MB 835892) and Teunia rosae sp. nov. (Holotype CGMCC 2.5830, MycoBank MB 835891) are proposed to accommodate strain X54, and strains 12A8 and 21S4, respectively.

Scanning Electron Microscopy and Etiological Studies of Teat Cup Inflations for Mastitis Control

1980 ◽  
Vol 43 (3) ◽  
pp. 205-207 ◽  
Author(s):  
DANIEL O. NOORLANDER ◽  
RICHARD HECKMANN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Inner Surface ◽  
Mastitis Control ◽  
Scanning Electron

Scanning electron microscopy was utilized in evaluating inner surfaces of rubber and silastic® teat cup inflations. New inflations and inflations subjected to 1000 and 5000 or more milkings were examined. Cracks and depressions appeared in new rubber inflations and increased in width (from 1.0 μm to 15.0 μm) with use. No cracks were visible in the silastic® product. Bacteria appeared to be present in the cracks of the inner surface of used rubber inflations but were not present in silastic ®.

Sign in / Sign up

Export Citation Format

Share Document