Two new Stauroneis species (Bacillariophyta, Stauroneidaceae) from midwestern karstic Brazilian formations

Phytotaxa ◽  
2018 ◽  
Vol 358 (3) ◽  
pp. 265 ◽  
Author(s):  
EDUARDO A. TUSSET ◽  
PRISCILA I. TREMARIN ◽  
THELMA A.V. LUDWIG

The morphology of three Stauroneis species from midwestern karstic Brazilian formations was illustrated under light and electron microscopy. Two new Stauroneis are described and compared with similar species in the genus. Stauroneis cavalcantei Tremarin, Tusset & T. Ludwig is characterized by lanceolate valves with subtly protracted apices, and S. karstica Tusset, Tremarin & T. Ludwig by rhombic-lanceolate valves with attenuate to acutely-rounded apices, reduced pseudosepta, bow-tie-shaped stauros, and areolae depressed along prominent longitudinal-oriented apical ribs. Stauroneis alabamae is a scarcely known species and unprecedented scanning electron microscopy illustrations are provided.

Phytotaxa ◽  
2021 ◽  
Vol 494 (2) ◽  
pp. 208-218
Author(s):  
DMITRY CHUDAEV ◽  
INGRID JÜTTNER ◽  
ZLATKO LEVKOV

This is the first detailed taxonomic study of the genus Navicula in the Krasnodar Territory of the Caucasus region, Russia. During the study of the genus in waterbodies of the Adegoy River valley 15 taxa were recorded. Two species, N. adegoyensis sp. nov. and N. pseudocryptofallax sp. nov., are described as new to science. Their morphology is studied by light and scanning electron microscopy, and comparisons with morphologically similar species are provided. The use of the name N. avenacea for N. lanceolata sensu auct. is discussed. Navicula diversity was higher in the Adegoy River than in pools elsewhere in the river valley.


Phytotaxa ◽  
2021 ◽  
Vol 508 (2) ◽  
Author(s):  
DMITRY CHUDAEV ◽  
INGRID JÜTTNER ◽  
BART VAN DE VIJVER

During a survey of the diatom flora of the Adegoy River (Krasnodar Territory, Russia), an unknown Fragilaria species (Bacillariophyta) was found that could not be identified using the currently available literature and here we describe it as a new species. The morphology of Fragilaria irregularis sp. nov. was studied using light and scanning electron microscopy and compared to similar species including Fragilaria deformis, F. rinoi, F. septentrionalis and Fragilariforma bicapitata. It differed from these taxa in several characters. Most observed valves showed an irregular striation pattern, a feature not observed in other species. Other important differences include valve outline (linear with parallel margins) and stria density (7–14 in 10 µm, lower compared to all other species). The new taxon has a linear valve outline with parallel to weakly convex margins, subcapitate apices and a very irregular, coarse striation pattern.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dorothea Pinotsi ◽  
Simona Rodighiero ◽  
Silvia Campioni ◽  
Gabor Csucs

Abstract A number of new Correlative Light and Electron Microscopy approaches have been developed over the past years, offering the opportunity to combine the specificity and bio-compatibility of light microscopy with the high resolution achieved in electron microscopy. More recently, these approaches have taken one step further and also super-resolution light microscopy was combined with transmission or scanning electron microscopy. This combination usually requires moving the specimen between different imaging systems, an expensive set-up and relatively complicated imaging workflows. Here we present a way to overcome these difficulties by exploiting a commercially available wide-field fluorescence microscope integrated in the specimen chamber of a Scanning Electron Microscope (SEM) to perform correlative LM/EM studies. Super-resolution light microscopy was achieved by using a recently developed algorithm - the Super-Resolution Radial Fluctuations (SRRF) - to improve the resolution of diffraction limited fluorescent images. With this combination of hardware/software it is possible to obtain correlative super-resolution light and scanning electron microscopy images in an easy and fast way. The imaging workflow is described and demonstrated on fluorescently labelled amyloid fibrils, fibrillar protein aggregates linked to the onset of multiple neurodegenerative diseases, revealing information about their polymorphism.


Phytotaxa ◽  
2014 ◽  
Vol 170 (3) ◽  
pp. 155 ◽  
Author(s):  
RALITSA ZIDAROVA ◽  
ZLATKO LEVKOV ◽  
BART VAN DE VIJVER

The paper describes four new Luticola taxa from the South Shetland Archipelago, Antarctica:  Luticola neglecta sp. nov., L. bogaertsiana sp. nov., L. contii sp. nov. and L. olegsakharovii sp. nov. All new taxa are studied using both light and scanning electron microscopy and compared to other morphologically similar species from (sub-)Antarctica and elsewhere in the world. Data on their ecology and biogeography are added. 


Phytotaxa ◽  
2014 ◽  
Vol 184 (4) ◽  
pp. 208 ◽  
Author(s):  
Priscila Izabel Tremarin ◽  
Thelma Ludwig ◽  
Lezilda Torgan

Examination of samples from different aquatic environments from Brazil revealed the presence of a new Aulacoseira species. Aulacoseira veraluciae Tremarin, Torgan & T. Ludwig is described and illustrated with light and scanning electron microscopy, and its morphology compared with that of similar species, such as A. muzzanensis (Meister) Krammer, A. granulata (Ehrenberg) Simonsen and A. agassizii (Ostenfeld) Simonsen. The new species is characterized mainly by the straight pervalvar rows of areolae, morphology of the linking spines, shape and position of the rimoportulae on the valve mantle, deepness and thickness of the ringleiste.


2016 ◽  
Vol 130 (1) ◽  
pp. 278-291 ◽  
Author(s):  
Matthew R. G. Russell ◽  
Thomas R. Lerner ◽  
Jemima J. Burden ◽  
David O. Nkwe ◽  
Annegret Pelchen-Matthews ◽  
...  

1974 ◽  
Vol 22 (4) ◽  
pp. 647 ◽  
Author(s):  
JJ Mott ◽  
PW Tynan

The anatomy of the hull directly over the embryo was examined by light and electron microscopy in long-term dormant and non-dormant grains of A. contorta. A lipid-containing layer was noted, covering the surface of the inner epidermis of the hull, and examination by scanning electron microscopy showed that although the layer was intact in all dormant grain examined, it was fractured in non-dormant grain. A definitive statement on the function of these cracks is not possible, but they appear to be an anatomical change leading to increased gas permeability of the hull of non-dormant grains.


Phytotaxa ◽  
2017 ◽  
Vol 308 (2) ◽  
pp. 249 ◽  
Author(s):  
ZHONGYAN ZHANG ◽  
PATRICK RIOUAL ◽  
YUMEI PENG ◽  
XIAOPING YANG ◽  
ZHANGDONG JIN ◽  
...  

This paper describes a new Cymbella species from an alpine lake in the Pamir Mountains, NW China, with the aid of light and scanning electron microscopy and morphometric analyses. The morphology of the new species, named Cymbella pamirensis, is discussed and compared to similar species. The main morphometric features distinguishing Cymbella pamirensis from similar species of Cymbella are the outline and size of the valves. Cymbella pamirensis has been observed in surface sediment and core samples from Lake Sate Baile Dikuli, an alkaline, mesotrophic lake of the Pamir Mountains.


Phytotaxa ◽  
2015 ◽  
Vol 236 (3) ◽  
pp. 257 ◽  
Author(s):  
Wei Zhang ◽  
Yan Ling Li ◽  
J Patrick Kociolek ◽  
Rui Lei Zhang ◽  
Li Qing Wang

During a survey of freshwater diatoms from streams in the west region of the Tianmu Mountains, Zhejiang Province, China, a new Oricymba species, Oricymba tianmuensis sp. nov. has been recorded. A detailed morphology description of O. tianmuensis is presented, based on light and scanning electron microscopy. Oricymba tianmuensis sp. nov. is characterized by a ridge along the valve face typical of the genus, as well as a linear-lanceolate, symmetrical or slightly dorsiventral outline with a gibbous central portion gradually tapering or nearly paralleling towards the bluntly cuneate poles, a distinct rhombic-lanceolate asymmetric central area with a distinct stigma on the ventral side of the central nodule, a slightly lateral raphe with widened proximal endings and strongly deflected distal endings, and weakly radiate striae. Morphological features of the taxon are compared with similar species, and the biogeography of the genus is summarized.


Phytotaxa ◽  
2014 ◽  
Vol 186 (2) ◽  
pp. 61 ◽  
Author(s):  
YUMEI PENG

A new medium-sized species of Hippodonta (Bacillariophyceae) is described from Lake Qinghai, China. The morphology and ultrastructure of Hippodonta qinghainensis sp. nov. are described using light and scanning electron microscopy. This new species is compared with similar species of Hippodonta using conventional and geometric morphometric analyses. Hippodonta qinghainensis can be separated from the other species of Hippodonta by a unique combination of characters that include an elliptic-lanceolate to rhombic-lanceolate valve shape, non protracted apices, the absence of fascia, relatively coarse, uniseriate striae and the presence of two rows of lineolae around the valves apices.


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