Free-living marine planktonic unarmoured dinoflagellates from the Gulf of Mexico and the Mexican Pacific

2015 ◽  
Vol 58 (1) ◽  
Author(s):  
Sergio Escobar-Morales ◽  
David U. Hernández-Becerril
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gulf Of Mexico ◽  
Species Composition ◽  
New Records ◽  
Morphological Characters ◽  
Phylogenetic Group ◽  
Free Living ◽  
Mexican Pacific ◽  
Scanning Electron

AbstractThe so-called unarmoured dinoflagellates are not a “natural” (phylogenetic) group but they lack thecal plates, share fragility and possess relatively few morphological characters that can be positively identified. This study depicts the species composition of unarmoured dinoflagellates collected from sites along the coasts of the Gulf of Mexico and the Mexican Pacific and includes their descriptions and illustrations. We identified a total of 25 species belonging to 13 genera and six families that were studied through various techniques using light and scanning electron microscopy. Seven new records for the Mexican Pacific are annotated here that include

Taxonomic application of macro and micro morphological characters of seeds in Astragalus L. (Galegeae, Fabaceae) in India

Phytotaxa ◽  
2021 ◽  
Vol 502 (2) ◽  
pp. 191-207
Author(s):  
SHIVANI KASHYAP ◽  
CHANDAN KUMAR SAHU ◽  
ROHIT KUMAR VERMA ◽  
LAL BABU CHAUDHARY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Seed Coat ◽  
Morphological Plasticity ◽  
Morphological Characters ◽  
Individual Species ◽  
Large Size ◽  
The Individual ◽  
Scanning Electron

Due to large size and enormous morphological plasticity, the taxonomy of the genus Astragalus is very complex and challenging. The identification and grouping of species chiefly based on macromorphological characters become sometimes difficult in the genus. In the present study, the micromorphology of the seeds of 30 species belonging to 14 sections of Astragalus from India has been examined applying scanning electron microscopy (SEM) along with light microscopy (LM) to evaluate their role in identification and classification. Attention was paid to colour, shape, size and surface of seeds. The overall size of the seeds ranges from 1.5–3.2 × 0.8–2.2 mm. The shape of the seeds is cordiform, deltoid, mitiform, orbicular, ovoid and reniform. The colour of seeds varies from brown to blackish-brown to black. Papillose, reticulate, ribbed, rugulate and stellate patterns were observed on the seed coat surface (spermoderm) among different species. The study reveals that the seed coat ornamentations have evolved differently among species and do not support the subgeneric and sectional divisions of the genus. However, they add an additional feature to the individual species, which may help in identification in combination with other macro-morphological features.

scholarly journals ELECTRON MICROSCOPIC STUDIES OF SOME ANTICANCER PLANTS POLLEN GRAINS

2021 ◽  
Vol 9 (10) ◽  
pp. 1386-1393
Author(s):  
Jayshree Sandesh Thaware ◽  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Electron Microscopic ◽  
Plant Parts ◽  
Morphological Studies ◽  
Datura Metel ◽  
Scanning Electron

Pollen is appropriately referred by some as Golden dust extremely valuable on account of their tremendous applications in science, industries and public health. No other plant part even though extremely tiny in size is packed with so much information and power. Similar to other plant parts, pollen characters are so varied that the classification system of plants can be built up entirely on the basis of pollen morphology.Palynology is the distinct branch of biology that deals with the dispersed microscopic tiny living and fossil entities including pollen grains, spores, algal and fungal fragments and others. An important aspect of Palynology is the Pollen morphology. The importance of Palynology in taxonomic and phylogenetic consideration of plants is well known. The changes occurring through hybridization and years of cultivation are reflected in pollen morphology. The scope and interest in the study of pollen morphology have widened with the advent of Scanning Electron Microscopy (SEM) and with regards to unipalynous taxa particularly the understanding of finer morphology is of fundamental importance. SEM gives a correct understanding of exine surface as the electron photographs of the surface replica of the exine provides the exact picture of the ornamentation pattern. The variation in the pollen morphological characters helps in the classification of plant taxa and their assessment of their phylogenetic relationship. In the present investigation, the pollen morphological studies were carried out of some ethnomedicinal plants like Catharanthus roseus, Allamanda cathartica, Datura metel, Brassica juncea, Raphanus sativus and Cleome viscosa pollen grains by Scanning electron microscopy. All that they possess anticancer characteristics in common.

scholarly journals Foliar trichomes of Croton L. (Euphorbiaceae: Crotonoideae) from China and its taxonomic implications

2013 ◽  
Vol 20 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Huan-Fang Liu ◽  
Yun-Fei Deng ◽  
Jing-Ping Liao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Species Identification ◽  
Morphological Characters ◽  
Plant Taxon ◽  
Taxonomic Implications ◽  
Sectional Classification ◽  
Trichome Types ◽  
Trichome Morphology ◽  
Scanning Electron

Foliar trichomes of 21 species of the genus Croton L. from China have been examined using stereomicroscopy and scanning electron microscopy. Five trichome types characterized by their morphology are identified, viz., stellate, lepidote, simple, dendritic and appressed-rosulate. Only stellate trichome is observed in most species, with only six species that are found to maintain two or three trichome types. Trichome types and density are useful for species identification and sectional classification for Chinese species. Based on the trichome types and other morphological characters, 21 Chinese species are proposed to be placed in five sections. Croton crassifolius belongs to sect. Andrichnia; C. cascarilloides belongs to sect. Monguia; C. mangelong, C. kongensis, C. laevigatus and C. laniflorus belong to sect. Argyrocroton; C. lauioides, C. howii and C. damayeshu belong to sect. Adenophylli. The remaining Chinese Croton species might be placed into sect. Croton. A key for Chinese Croton species based on trichome morphology is provided.DOI: http://dx.doi.org/10.3329/bjpt.v20i1.15468Bangladesh J. Plant Taxon. 20(1): 85-94, 2013 (June)

scholarly journals Mericarp morphology of the tribe Selineae (Apiaceae, Apioideae) and its taxonomic implications in Korea

2018 ◽  
Vol 25 (2) ◽  
pp. 175-186 ◽  
Author(s):  
Changyoung Lee ◽  
Jinki Kim ◽  
Ashwini M. Darshetkar ◽  
Ritesh Kumar Choudhary ◽  
Sang-Hong Park ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Characters ◽  
Surface Pattern ◽  
Taxonomic Implications ◽  
Scanning Electron

Mericarp morphology of 24 taxa belonging to nine genera of the tribe Selineae (Family: Apiaceae) in Korea was studied by Scanning Electron Microscopy. UPGMA and NMDS analyses were performed based on 12 morphological characters. The mericarp surface characters like mericarp shape, rib number and shape, surface pattern, surface appendages and mericarp symmetry proved useful in distinguishing the genera of the tribe Selineae.

Revised taxonomy and redescription of two species of the Peripatidae (Onychophora) from Brazil: a step towards consistent terminology of morphological characters

Zootaxa ◽  
2010 ◽  
Vol 2493 (1) ◽  
pp. 16 ◽  
Author(s):  
IVO DE SENA OLIVEIRA ◽  
ALFREDO HANNEMANN WIELOCH ◽  
GEORG MAYER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
Morphological Characters ◽  
Type Material ◽  
Taxon Sampling ◽  
The Caribbean ◽  
Dermal Papillae ◽  
Scanning Electron

Based on the supposed quadrangular shape of the basal pieces of dorsal primary papillae, several species of the “Caribbean group” of the neotropical Peripatidae, including Macroperipatus acacioi and M. machadoi, were assigned to Macroperipatus. So far, the quadrangular shape of dermal papillae was confirmed only for M. torquatus, the type species of the genus. Previous observations revealed that the putatively quadrangular shape reported from other species of the “Caribbean group” might be a fixation artefact. Hence, detailed reinvestigations of all putative Macroperipatus species are required to clarify their taxonomy. In the present study, two species of the “Caribbean group”, M. acacioi and M. machadoi, are analyzed and redescribed, based on type material and topotype specimens collected at the corresponding type localities. The original descriptions of both species are complemented with data obtained from scanning electron microscopy, in addition to conventional morphological methods. The quadrangular bases of primary papillae are shown to be absent from M. acacioi and M. machadoi, thus suggesting that these two species are not closely related to M. torquatus. The new data instead suggest that these two species are representatives of Epiperipatus: E. acacioi comb. nov. and E. machadoi comb. nov.. The present study highlights the use of scanning electron microscopy for clarifying the taxonomy and phylogeny of the neotropical Peripatidae. It also reveals gaps in taxon sampling and problems regarding the ambiguous terminology of morphological characters used for describing the anatomy of peripatids. An attempt is made towards a consistent terminology for species (re)descriptions and studies of onychophoran anatomy and phylogeny.

scholarly journals Use of different SEM techniques in the study of Tyrophagus putrescentiae (Acari: Acaridae) in Costa Rica

2013 ◽  
Vol 5 (2) ◽  
pp. 201-208
Author(s):  
Pamela Murillo ◽  
Hugo Aguilar ◽  
Ethel Sanchez
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Costa Rica ◽  
Morphological Characters ◽  
Morphological Description ◽  
Tyrophagus Putrescentiae ◽  
Viable Option ◽  
Efficient Procedure ◽  
Advantages And Disadvantages ◽  
Scanning Electron

Scanning electron microscopy (SEM) has been used as a tool to facilitate the morphological description of mites and to complement the information obtained from the light microscope. Unfortunately, several of SEM techniques used for soft-bodied mites such as Tyrophagus, have in many cases not shown the desired results. This investigation sought to develop an efficient procedure for preparing specimens of T. putrescentiae for SEM so that its major morphological characters could be observed and photographed. This species is the most important contaminant of tissue culture laboratories in Costa Rica. Seven methods were used to process the samples. The evaluated treatments showed differences in their ability to preserve the morphological structures of the specimens. The advantages and disadvantages of each treatment are discussed.  Mites processed using ethanol were the most viable option with method 3 being the procedure that showed the best results; this technique also reduced the time and costs of processing the specimens.KEY WORDSAcari, Acaridae, Tyrophagus putrescentiae, Scanning Electron Microscopy (SEM), SEM techniques

New diagnostic characters for Amphiodia and Ophiophragmus (Amphiuridae, Ophiuroidea, Echinodermata)

2020 ◽  
Vol 100 (5) ◽  
pp. 759-781
Author(s):  
Gisella C.S. Chagas ◽  
Renata A.S. Alitto ◽  
Helena Serrano ◽  
Gabriela Granadier ◽  
Pablo D.B. Guilherme ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Records ◽  
External Morphology ◽  
Diagnostic Characters ◽  
Comparative Analyses ◽  
Phylogenetic Studies ◽  
New Information ◽  
Taxonomic Studies ◽  
Scanning Electron

AbstractThe genera Ophiophragmus and Amphiodia are amphiurids that are considered taxonomically difficult due to their great resemblance, few diagnostic characters and synonymy problems. Our aim is to redescribe the species using scanning electron microscopy and morphometry of diagnostic structures, and to provide new information for the identification of these Ophiuroidea. Five Amphiodia spp. and six Ophiophragmus spp. recorded in Brazil were rigorously redescribed. The descriptions include new diagnostic characters derived from external morphology, arm microstructures and morphometry. We also provided comparative analyses of species with shared characters such as Amphiodia riisei and Amphiodia trychna. The geographic and bathymetric distributions of the studied species were updated, and new records are provided. All the information presented may be used in taxonomic, ecological and phylogenetic studies, helping to fill gaps in the knowledge of the biodiversity, ecology and evolution of these Ophiuroidea. Conclusively, all the tools applied here assisted in the identification of genera and species and could be useful in other taxonomic studies of Echinodermata.

scholarly journals Diatoms of the genus Gomphonema Ehr. (Bacillariophyceae) from a karstic stream in the Krakowsko-Częstochowska Upland

2011 ◽  
Vol 72 (3) ◽  
pp. 213-220 ◽  
Author(s):  
Agata Wojtal
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Characters ◽  
Diatom Flora ◽  
Ecological Requirements ◽  
Floristic Study ◽  
Photographic Documentation ◽  
First Time ◽  
Scanning Electron

<p>This paper presents the results of a floristic study focusing on taxa representing the genus <em>Gomphonema </em>in Kobylanka stream, situated ca 30 km NW of Kraków. Species belonging to the genus <em>Gomphonema </em>Ehr. were very frequently observed diatom taxa in the material studied. Amongst 272 diatom taxa recorded in the studied material, 13 belong to this genus. Some of them are widespread and often found in Poland; others such as <em>Gomphonema micropus </em>Kutz. and <em>G. sarcophagus </em>Greg. are rarely or for the first time reported from the Kraków-Częstochowa Upland. <em>G. brebissonii </em>Reichardt, <em>G. lagerheimii </em>A. Cl. and <em>G. parallelistriatum </em>Lange-Bert. and Reichardt are new to the Polish flora.</p><p>Identification of the diatom flora was based on light (LM) and scanning electron microscopy (SEM). Morphological characters and dimensions of frustules were measured for all taxa reported. Ecological requirements, remarks on distribution, and photographic documentation are also given.</p>

Centric diatoms from paleolakes of the Baikal rift zone, Russia

2019 ◽  
pp. 279-284
Author(s):  
Marina V. Usoltseva ◽  
Lyubov А. Titova ◽  
Abdulmonem Hassan ◽  
Irina S. Chuvashova ◽  
Sergei V. Rasskazov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Species Composition ◽  
Rift Zone ◽  
Baikal Rift Zone ◽  
Centric Diatoms ◽  
Scanning Electron

Using light and scanning electron microscopy centric diatoms were investigated from paleolakes of the Barguzin, Tunkinskaya valleys and Vitim Plateau. Representatives of Aulacoseira, Actinocyclus, Alveolophora, Pseudoaulacoseira and Concentrodiscus were common and widespread. The greatest similarity in species composition of diatoms was found between the paleo-lakes of the Barguzin Valley and the Vitim Plateau.

Molecular and morphological studies identify a new genus within the Heterolepismatinae (Zygentoma: Lepismatidae)

Zootaxa ◽  
2021 ◽  
Vol 5030 (1) ◽  
pp. 1-118
Author(s):  
GRAEME B. SMITH ◽  
ANDREW MITCHELL ◽  
RAFAEL MOLERO-BALTANÁS
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Anterior Margin ◽  
New Genus ◽  
Sequence Data ◽  
Morphological Characters ◽  
Type Series ◽  
Morphological Studies ◽  
Molecular Studies ◽  
Scanning Electron

Molecular studies using COI and 28S sequence data strongly identify a clade within the Heterolepismatinae distinct from the majority of species so far sequenced. The independence of the clade is supported by several morphological characters including a glabrous anterior margin to the frons, large trapezoidal thoracic sternites, tarsal trichobothria, long, conical parameres which in some species consist of two segments, and the presence of triangular or rounded subrectangular scales on the femora, tibia and clypeus. This clade is described as a new genus Visma n. gen. containing ten new species V. advenum n. sp., V. bingara n. sp., V. brayi n. sp., V. bundjalung n. sp., V. brigalowsum n. sp., V. capricornia n. sp., V. pallidum n. sp., V. powellheueri n. sp., V. tenebrosum n. sp. and V. xanthorrhoea n. sp.. Heterolepisma stilivarians Silvestri, 1908 is redescribed from the holotype and transferred to the new genus. The remaining H. stilivarians type series is found to be different to the holotype and removed from the type series. It is considered possible that H. annectens Silvestri, 1924 may also belong to this genus. Scanning electron microscopy of scale shape and rib-spacing is shown to be a useful tool to separate at least some species of the genus and considered to have greater potential if well preserved material is available.  

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