Resolving the confusion between two fossil freshwater diatoms from Otago, New Zealand: Encyonema jordanii and Encyonema jordaniforme (Cymbellaceae, Bacillariophyta)

Phytotaxa ◽  
2019 ◽  
Vol 394 (4) ◽  
pp. 231 ◽  
Author(s):  
MARGARET A. HARPER ◽  
BART VAN DE VIJVER ◽  
UWE KAULFUSS ◽  
DAPHNE E. LEE
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Morphological Features ◽  
The Past ◽  
Freshwater Diatoms ◽  
History Of ◽  
Pennate Diatoms ◽  
Scanning Electron

Encyonema jordanii and E. jordaniforme are two freshwater pennate diatoms from Otago, New Zealand which have been misidentified in the past. The first is of uncertain age, while E. jordaniforme, dominant in a Konservat-Lagerstätte diatomite from Foulden Maar near Middlemarch, South Island, New Zealand, is dated as earliest Miocene in age (23 Ma). The two species are similar in appearance as both are swollen at their centres. However, E. jordanii is constricted near its wide ends, which are ventrally deflected near their tips, whereas E. jordaniforme has more acute apices and less strongly radiating central striae. Both species are illustrated with light and scanning electron microscopy observations which highlight the main morphological features that can be used to separate the two species. A brief history of the taxonomy and description of both species is added.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Oospore dimensions and wall ornamentation in Chara braunii

Biologia ◽  
2008 ◽  
Vol 63 (4) ◽  
Author(s):  
Patrycja Boszke ◽  
Mariusz Pełechaty ◽  
Andrzej Pukacz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Local Population ◽  
Polar Axis ◽  
Morphological Features ◽  
Cylindrical Shape ◽  
Reproductive Structures ◽  
Equatorial Diameter ◽  
Variable Character ◽  
Scanning Electron

AbstractMorphological features of oospores of a rarely noted species Chara braunii Gmel. were examined in a local population (fishpond near Tuplice village, Ziemia Lubuska region, mid-western Poland). The largest polar axis (LPA, length), largest equatorial diameter (LED, width), isopolarity index (ISI = LPA/LED* 100), and the number of ridges and width of fossa of 90 oospores were measured. Additionally, the oospore wall ornamentation pattern was examined by means of scanning electron microscopy (SEM). As a result, a cylindrical shape and the lack of so-called “shoulder” were found. Oospore length and width ranged between 466.8–600.1 µm and 250.1–366.7 µm, respectively, with the ISI index values between 148 and 213. The number of ridges was 8–10 and the width of fossa varied between 50.0 and 66.7 µm. The oospore width appeared to be the most changeable feature, whereas, by contrast, the number of ridges was the least variable character. Wall ornamentation can be described as tuberculate and a ribbon was present on the ridges. As a comparative material for the study performed, 9 oospores from Professor Izabela Dąmbska’s Collection of Charophytes of Poland were measured. It was evidenced that variation ranges of most of the features of Chara braunii oospores from Tuplice fishpond are similar to those of Professor Dąmbska’s herbarium materials and to data reported by authors from other countries as well. The morphology of reproductive structures does not follow the variation of thalli characteristics.

Aggregate Rays in New Zealand Nothofagus Blume (Fagaceae) Stem Wood and their Influence on Vessel Distribution

IAWA Journal ◽  
1987 ◽  
Vol 8 (1) ◽  
pp. 53-57 ◽  
Author(s):  
T. M. Middleton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Composite Structures ◽  
Growth Ring ◽  
Stem Wood ◽  
Scanning Electron

Aggregate rays occur in the stem wood of Nothofagus solandri var. cliffortioides (Hook. f.) Poole (mountain beech), N. solandri var. solandri (Hook. f.) Gerst. (black beech), N. truncata (Col.) Ckn. (hard beech), and N. fusca (Hook. f.) Gerst. (red beech), but not in N. menziesii (Hook. f.) Gerst. (silver beech). The composite structures visible in transversely sawn wood consist of groups of narrow xylem rays separated by fibres; vessels are frequently absent. The influence of aggregate rays on vessei distribution was studied using scanning electron microscopy and tested statistically. Indented growth ring boundaries are associated with the presence of aggregate rays. Aggregate rays occur in saplings. In larger trees aggregate rays taper out beyond 6 cm from the stem centre.

scholarly journals Range extension of the invasive Potamopyrgus antipodarum (Gray, 1843) (Gastropoda, Tateidae) in Chile, and a summary of its distribution in the country

Check List ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 621-626 ◽  
Author(s):  
Gonzalo A. Collado ◽  
Carmen G. Fuentealba
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
South America ◽  
River Basin ◽  
Dna Barcode ◽  
Potamopyrgus Antipodarum ◽  
Range Extension ◽  
First Time ◽  
Scanning Electron

The New Zealand mudsnail Potamopyrgus antipodarum (Gray, 1843) has been considered as one of the most invasive mollusks worldwide and recently was listed among the 50 most damaging species in Europe. In the present paper, we report for the first time the presence of P. antipodarum in the Maule river basin, Chile. The identity of the species was based on anatomical microdissections, scanning electron microscopy comparisons, and DNA barcode analysis. This finding constitutes the southernmost record of the species until now in this country and South America.

A comparative study of the morphology, chemical composition and weathering of rhyolitic and andesitic glass

Clay Minerals ◽  
1980 ◽  
Vol 15 (2) ◽  
pp. 165-173 ◽  
Author(s):  
J. H. Kirkman ◽  
W. J. McHardy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Chemical Composition ◽  
Electron Probe ◽  
Volcanic Glass ◽  
Chemical Activity ◽  
Rapid Rate ◽  
Bonding Characteristics ◽  
Scanning Electron

AbstractThe morphology of volcanic glass particles in rhyolitic and andesitic tephra of central North Island and Taranaki areas of New Zealand has been studied by scanning electron microscopy. Electron probe analyses of the glasses are compared with those of the clays to which they weather. Loss of silica characterizes the weathering of both glasses. The rapid rate of weathering of andesitic glass is attributed to its occurrence as fine, soft microlites and extensive substitution of Al for Si in the structure. Rhyolitic glass weathers more slowly because it occurs as hard and brittle particles containing relatively little alumina. It is suggested that the structure, chemical composition and chemical activity of allophane is governed largely by the chemical composition and bonding characteristics of the parent glass.

scholarly journals Natural infection by Procyrnea uncinipenis (Nematoda, Habronematidae), a parasite from rheas, an autoctone bird from South America, in emus Dromaius novaehollandiae, a ratite from New Zealand

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicole Brand Ederli ◽  
Samira Salim Mello Gallo ◽  
Francisco Carlos Rodrigues de Oliveira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Gastrointestinal Tract ◽  
Natural Infection ◽  
State University ◽  
Dromaius Novaehollandiae ◽  
The City ◽  
Janeiro State ◽  
Scanning Electron

Abstract The present study reports a natural infection of emus, Dromaius novaehollandiae, by the nematode Procyrnea uncinipenis. Five adult emus from a scientific breeding farm at North Fluminense State University located in the city of Campos dos Goytacazes, Rio de Janeiro state, Brazil were necropsied, and their gastrointestinal tract were collected and examined for the presence of parasites from October 2013 to November 2015. Two of the five (40%) emus necropsied were infected with nematodes, and a portion of the nematodes were processed for light microscopy. In addition, two other nematodes (a male and a female) were prepared for scanning electron microscopy. In a female bird, one nematode was collected in the proventriculus and two nematodes in the gizzard and in the male bird four nematodes were collected in the gizzard. The morphological and morphometric analyzes allowed to identify the nematodes as P. uncinipenis, this being the first report of an infection by P. uncinipenis in emus. Therefore, we infer that these emus were naturally infected by nematodes that were considered specific to rheas.

New data on the morphology of Comephoronema oschmarini (Nematoda, Cystidicolidae), a little-known gastrointestinal parasite of Lota lota (Teleostei) in Palaearctic Eurasia

2007 ◽  
Vol 52 (2) ◽  
Author(s):  
František Moravec ◽  
Vladimíra Hanzelová ◽  
Daniel Gerdeaux
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Features ◽  
Valid Species ◽  
Lake Geneva ◽  
Gastrointestinal Parasite ◽  
Intensity Of Infection ◽  
Lota Lota ◽  
Scanning Electron

AbstractThe nematode Comephoronema oschmarini Trofimenko, 1974 (Cystidicolidae) was found in the stomach of the burbot Lota lota (Linnaeus) of Lake Geneva, Savoy, France, collected on 23 March 2000 [prevalence 60% (3/5); intensity of infection 2–66 (mean 35)]. This material made it possible to study in detail the morphology of this so far little-known parasite, using both light and scanning electron microscopy (the latter not previously used for this species). The SEM examination showed taxonomically important morphological features, not previously reported, including the presence of distinct terminal pseudolabial projections (protuberances), four submedian labia, four bilobed submedian sublabia, and only four cephalic papillae. Deirids were found to be bifurcated. A description of the true arrangement of the two last pairs of minute caudal papillae and phasmids in the male is given. Species of Compehoronema Layman, 1933 are considered to be closely related to those of Ascarophis van Beneden, 1871. A key to valid species of Comephoronema is provided.

A re-description of Fragilaria fonticola Hustedt and its varieties, with three new combinations and one new species from India

Phytotaxa ◽  
2020 ◽  
Vol 453 (3) ◽  
pp. 179-198
Author(s):  
ANBUKKARASU VIGNESHWARAN ◽  
CARLOS E. WETZEL ◽  
DAVID M. WILLIAMS ◽  
BALASUBRAMANIAN KARTHICK
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
River Basin ◽  
Western Ghats ◽  
Morphological Features ◽  
New Combinations ◽  
One New Species ◽  
Scanning Electron

Tabularia (Kützing) D.M. Williams & Round has received some attention since its separation from Synedra. The present study investigates Fragilaria fonticola Hustedt and its varieties based on the analysis of the type materials. The combinations were proposed as Tabularia fonticola (Hustedt) C.E. Wetzel & D.M. Williams comb. nov. (≡ Fragilaria fonticola Hustedt), Tabularia angusta (Hustedt) C.E. Wetzel & D.M. Williams comb. nov. et stat. nov. (≡ Fragilaria fonticola var. angusta Hustedt), Tabularia chandolensis (Gandhi) A. Vigneshwaran, D.M. Williams & B. Karthick comb. nov. (≡ Synedra chandolensis Gandhi) and the new species, Tabularia koynensis sp. nov. is also described from the Koyna River basin, Western Ghats, India. The detailed morphological features were analysed under light and scanning electron microscopy. Tabularia koynensis has linear valves outline with square to rounded ends. Striae short, radiate towards ends. This new species compared with T. sinensis, T. fasciculata, T. tabulata, T. kobayasii and Fragilaria longissima, which differ in size, valve shape, striae density and ultrastructure.

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