scholarly journals Integrative description of Macrobiotus canaricus sp. nov. with notes on M. recens (Eutardigrada: Macrobiotidae)

2018 ◽  
Author(s):  
Daniel Stec ◽  
Łukasz Krzywański ◽  
Łukasz Michalczyk
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Molecular Markers ◽  
18S Rrna ◽  
28S Rrna ◽  
Mitochondrial Coi ◽  
Internal Surfaces ◽  
Morphometric Analyses ◽  
Taxonomic Methods ◽  
Scanning Electron

In this paper we describe Macrobiotus canaricus sp. nov., a new tardigrade species of the Macrobiotus hufelandi group from the Canary Islands. Moreover, with the use of DNA sequencing, we confirm that Macrobiotus recens Cuénot, 1932 represents the hufelandi group, even though eggs laid by this species do not exhibit the typical hufelandi group morphology. Our study is based on both classical taxonomic methods that include morphological and morphometric analyses conducted with the use of light and scanning electron microscopy, and on the analysis of nucleotide sequences of four molecular markers (three nuclear: 18S rRNA, 28S rRNA, ITS-2, and one mitochondrial: COI). Our analyses revealed that M. canaricus sp. nov. is most similar to Macrobiotus almadai Fontoura et al., 2008 from the Archipelago of the Azores, from which it differs by the absence of granulation patches on the external and internal surfaces of legs I–III as well as by the absence of a cuticular pore in the centre of the external patch on legs I–III. Molecular sequences allowed us to pinpoint the phylogenetic positions of M. canaricus sp. nov. and M. recens within the M. hufelandi group.

scholarly journals Integrative taxonomy identifies two new tardigrade species (Eutardigrada: Macrobiotidae) from Greenland

2020 ◽  
Author(s):  
Daniel Stec ◽  
Denis T. Tumanov ◽  
Reinhardt Møbjerg Kristensen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Integrative Taxonomy ◽  
Morphological Data ◽  
28S Rrna ◽  
Mitochondrial Coi ◽  
Morphometric Analyses ◽  
Taxonomic Methods ◽  
Two Populations ◽  
Scanning Electron

In this paper we describe Macrobiotus engbergi sp. nov. and Tenuibiotus zandrae sp. nov. from Greenland. Our study has involved both classical taxonomic methods, which include morphological and morphometric analyses conducted with the use of light and scanning electron microscopy, and genetic analysis based on four molecular markers (three nuclear: 18S rRNA, 28S rRNA, ITS-2, and one mitochondrial: COI). Moreover, we re-examined the type series of Tenuibiotus voronkovi (Tumanov, 2007) as well as the original sample where the species was found and we provide new morphological data from light and scanning electron microscopy which enabled us to amend its description. Finally, we also analysed slides with animals and egg of two populations from Nordaustlandet and Edgeøya (archipelago of Svalbard, Norway) designated as T. voronkovi within its recent redescription. The results and comparisons presented in our study question the validity of this designation. 

scholarly journals Integrative description of a new Tunisian tardigrade species, Macrobiotus azzunae sp. nov. (Eutardigrada, Macrobiotidae, hufelandi group)

2021 ◽  
Vol 758 ◽  
Author(s):  
Jamila Ben Marnissi ◽  
Michele Cesari ◽  
Lorena Rebecchi ◽  
Roberto Bertolani
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
18S Rrna ◽  
Integrated Approach ◽  
Molecular Data ◽  
28S Rrna ◽  
Considerable Potential ◽  
Mitochondrial Coi ◽  
Taxonomic Approach ◽  
Scanning Electron

In this paper a new tardigrade species, Macrobiotus azzunae sp. nov., from Tunisia, is described. An integrative taxonomic approach was applied by combining morphological, morphometric and molecular data. In particular, light and scanning electron microscopy observations, and four genetic markers, three nuclear (18S rRNA, 28S rRNA and ITS-2) and one mitochondrial (COI) were used. The analysis showed that M. azzunae sp. nov. belongs to the Macrobiotus hufelandi group and is most similar to Macrobiotus sandrae Bertolani & Rebecchi, 1993. It differs from M. sandrae by a more pronounced constriction of the first macroplacoid (hardly visible in M. sandrae) and for the eggshell shape, with thinner wires of the reticulum and meshes around the processes larger than the inter-process meshes in M. azzunae sp. nov., while all meshes are similar in size in M. sandrae. The species is gonochoristic. With this discovery, there are 33 species of tardigrades identified in Tunisia, all non-marine. This result, compared with nearby Sicily, where more research has been conducted, indicates that there is a considerable potential for identification of new species. Further research will be most informative if multiple habitats are explored and if carried out with an integrated approach as done in this present work.

Mesobiotus datanlanicus sp. nov., a new tardigrade species (Macrobiotidae: Mesobiotus harmsworthi group) from Lâm Đồng Province in Vietnam

Zootaxa ◽  
2019 ◽  
Vol 4679 (1) ◽  
pp. 164-180 ◽  
Author(s):  
DANIEL STEC
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
18S Rrna ◽  
Integrative Taxonomy ◽  
28S Rrna ◽  
Morphometric Analyses ◽  
The Status ◽  
A New Species ◽  
Scanning Electron

A new species of the Mesobiotus harmsworthi group is described from Datanla Waterfall amusement park in Lâm Đồng Province, Vietnam. An integrative taxonomy approach was applied, by combining morphological and morphometric analyses using light contract microscopy (LCM)) and scanning electron microscopy (SEM) with genetic analysis (18S rRNA, 28S rRNA, ITS-2 and COI markers), to cross-verify the status of the newly discovered population as a new species. By the presence of fully developed areolation around egg processes bases and well developed oral cavity armature (OCA), with all three bands of teeth visible under (LCM), the new species, Mesobiotus datanlanicus sp. nov., is most similar to seven taxa from the harmsworthi complex: M. barbarae (Kaczmarek, Michalczyk & Degma, 2007), M. hieronimi (Pilato & Claxton, 1988), M. insanis Mapalo, Stec, Mirano-Bascos & Michalczyk, 2017, M. neuquensis (Rossi, Claps & Ardohain, 2009), M. nuragicus (Pilato & Sperlinga, 1975), M. pseudoliviae (Pilato & Binda, 1996), M. pseudonuragicus (Pilato, Binda, & Lisi, 2004), but differs from them mainly by some specific characters of the egg and adult morphology as well as by morphometrics. 

Hippodonta fujiannensis sp. nov. (Bacillariophyceae), a new epipsammic diatom from the low intertidal zone, Fujian Province, China

Phytotaxa ◽  
2017 ◽  
Vol 295 (1) ◽  
pp. 77 ◽  
Author(s):  
LONG ZHAO ◽  
JIANDONG SUN ◽  
YAHUI GAO ◽  
JUNRONG LIANG ◽  
LIN SUN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Marine Environment ◽  
Intertidal Zone ◽  
Fujian Province ◽  
Single Row ◽  
Valve Morphology ◽  
Morphometric Analyses ◽  
Scanning Electron

Hippodonta fujiannensis sp. nov., a new small-sized species of Hippodonta (Bacillariophyceae), was described from the low intertidal zone, Fujian Province, China. The morphology and ultrastructure were investigated by light and scanning electron microscopy, which revealed the following results: 1) valves asymmetrical, elliptic-lanceolate to rhombic-lanceolate with non-protracted apices; 2) raphe filiform, with teardrop-shaped and closely spaced central endings; 3) striae uniseriate, evenly spaced throughout the whole valve; 4) single row of lineolae around the valve apices. In particular, this new species is characterized by its dissymmetrical valves with one special column of lineolae which is close to the raphe and positioned perpendicular to the remaining lineolae of the striae, on only one side of the valves. Hippodonta fujiannensis is epipsammic and inhabits the marine environment. Conventional morphometric analyses were employed to elucidate the differences between this new species and several taxa similar in valve morphology, and the results are discussed.

Cymbella pamirensis sp. nov. (Bacillariophyceae) from an alpine lake in the Pamir Mountains, Northwestern China

Phytotaxa ◽  
2017 ◽  
Vol 308 (2) ◽  
pp. 249 ◽  
Author(s):  
ZHONGYAN ZHANG ◽  
PATRICK RIOUAL ◽  
YUMEI PENG ◽  
XIAOPING YANG ◽  
ZHANGDONG JIN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Alpine Lake ◽  
Similar Species ◽  
Nw China ◽  
Morphometric Analyses ◽  
Morphometric Features ◽  
Pamir Mountains ◽  
Scanning Electron

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.

Morphology and ultrastructure of Hippodonta qinghainensis sp. nov. (Bacillariophyceae), a new diatom from Lake Qinghai, China

Phytotaxa ◽  
2014 ◽  
Vol 186 (2) ◽  
pp. 61 ◽  
Author(s):  
YUMEI PENG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
The Other ◽  
Similar Species ◽  
Unique Combination ◽  
Lake Qinghai ◽  
Geometric Morphometric ◽  
Morphometric Analyses ◽  
Scanning Electron

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.

Critical Point Drying of Freeze-Fractured Tissue For Scanning Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 452-453 ◽  
Author(s):  
Walter J. Humphreys ◽  
Ben O. Spurlock ◽  
Janet S. Johnson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Tension ◽  
Plastic Deformation ◽  
Critical Point ◽  
Crystal Formation ◽  
Exposed Surface ◽  
Internal Surfaces ◽  
Critical Point Drying ◽  
Scanning Electron

The critical point method eliminates distortion that might have been caused by surface tension during drying of specimens being prepared for scanning electron microscopy. Such preparations can be made rapidly and routinely, and the structural fidelity of surfaces of cells and tissues thus prepared is excellent. But attempts to look inside the tissues or cells with the scanning electron microscope have been less successful. Critical point dried tissue can be broken or cut, and the exposed surface viewed. But plastic deformation of the exposed surface structures caused by the cutting or breaking severely limits the usefulness of this approach. Plastic deformation is minimized when tissue is freeze-fractured to expose internal surfaces, and the water (ice) can be sublimed away from small fragments of tissue without surface tension distortion by freeze-drying the specimen in a vacuum. But freeze damage, resulting mainly from ice crystal formation, is very difficult to avoid.

scholarly journals Campomanesia adamantium and Campomanesia pubesncens are distinct species? Use of palynology and molecular markers in taxonomy

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Érica Virgínia Estêfane de Jesus Amaral ◽  
Juliana de Fátima Sales ◽  
Edésio Fialho dos Reis ◽  
Christiano Peres Coelho ◽  
Evaristo Mauro de Castro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Molecular Markers ◽  
Plant Breeding ◽  
Plant Material ◽  
Morphological Variability ◽  
Distinct Species ◽  
Plant Taxonomy ◽  
Taxonomic Description ◽  
Scanning Electron

Abstract The species Campomanesia adamantium and C. pubescens present a great morphological variability, with the existence of morphotypes and the indication of a possible hybridization process occurring between them. Thus, the aim of this study was to characterize the Campomanesia adamantium species and morphotypes of species Campomanesia pubescens through palynological reviews and with the use of molecular markers to assist the taxonomic description of the species. The plant material was collected in the experimental field of Federal University of Jataí, in bloom of 2014, and analyzes were performed in the Morphology Laboratory of Plant Taxonomy and in the Laboratory of Genetics and Plant Breeding belonging to the same institution. Analysis of scanning electron microscopy was performed at the Federal University of Lavras. Important information was found that reinforce the possibility of cross between Campomanesia adamantium and Campomanesia pubescens, generating morphotypes intermediaries, indicating a possible hybridisation process. It can be concluded that Campomanesia adamantium is farthest from the morphotype 2 from Campomanesia pubescens, and morphotypes 1 and 3 are intermediate between them, possibly being hybrids.

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