Comparative Morphology of the North American Species of Spinitectus (Nematoda: Spirurida) Analyzed by Scanning Electron Microscopy

1982 ◽  
Vol 101 (2) ◽  
pp. 126 ◽  
Author(s):  
Reid Jilek ◽  
John L. Crites
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
Comparative Morphology ◽  
North American Species ◽  
The North ◽  
Scanning Electron

Scanning electron microscopy of basidiospores of species of Strobilomycetaceae

1971 ◽  
Vol 49 (8) ◽  
pp. 1259-1261 ◽  
Author(s):  
Larry F. Grand ◽  
Royall T. Moore
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
North American Species ◽  
Surface Features ◽  
The Family ◽  
Similarities And Differences ◽  
Scanning Electron

Basidiospores of 13 North American species of Strobilomycetaceae were examined by scanning electron microscopy. Similarities and differences of surface features among species are discussed in relation to their possible role in the taxonomy of the family.

Reduced Seed Germination after Pappus Removal in the North American Dandelion (Taraxacum officinale; Asteraceae)

Weed Science ◽  
2010 ◽  
Vol 58 (4) ◽  
pp. 420-425 ◽  
Author(s):  
Alison N. Hale ◽  
Samantha M. Imfeld ◽  
Chloé E. Hart ◽  
Kevin M. Gribbins ◽  
Jay A. Yoder ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Relative Humidity ◽  
North American ◽  
Taraxacum Officinale ◽  
Water Entry ◽  
Laboratory Rearing ◽  
The North ◽  
Fungal Association ◽  
Scanning Electron

This study examined seed ultrastructure in relation to germination of North American dandelion seeds. Based on laboratory rearing observations, it was thought that the design of the pappus acts as a conduit facilitating water entry into the seed. It was hypothesized that seeds without a pappus would yield fewer seedlings and require more time to germinate than seeds with an intact pappus. Seed ultrastructure was investigated using scanning electron microscopy, while relative humidity and fungal association were explored as factors that may confer an advantage to intact seeds. Results indicate that germination for seeds lacking a pappus is 31% lower than control seeds (with an intact pappus) and that the seeds lacking a pappus require more time to germinate. Relative humidity did not differentially affect germination, and while a fungus Cladosporium cladosporioides was recovered internally, its presence neither enhanced germination nor decreased time to germination when tested by antimycotic removal. Electron micrographs revealed that (1) the pappus is hollow and (2) the pericarp of the fruit fuses with and partially encloses the pappus. Fusion of the pappus with the fruit suggests that this structure acts as a device to regulate seed hydration.

Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters

Zootaxa ◽  
2020 ◽  
Vol 4789 (2) ◽  
pp. 348-370 ◽  
Author(s):  
GIULIA SCARPARO ◽  
ROBERT WOLTON ◽  
MARCO MOLFINI ◽  
LUIGI CAO PINNA ◽  
ANDREA DI GIULIO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sibling Species ◽  
Comparative Morphology ◽  
Immature Stages ◽  
Outward Appearance ◽  
Diagnostic Features ◽  
Diagnostic Characters ◽  
Ant Nests ◽  
Scanning Electron

Hoverflies (Diptera: Syrphidae) of the genus Microdon Meigen have larvae that live in ant nests where they are predatory on ant larvae. Reflecting the exceptional challenges of this very specialized lifestyle, Microdon eggs, larvae and puparia are highly distinctive in their morphology. Detailed descriptions of these immature stages is, however, lacking for all but a very few species, and much of this has been limited through the sole use of light microscopes. Here, using Scanning Electron Microscopy (SEM), we present detailed, comparative descriptions of the immature stages of three European Microdon species: M. analis, M. devius and M. myrmicae. Given that many adult Microdon species are very similar to each other in their outward appearance, we demonstrate that the morphology of their immature stages can improve our understanding of the phylogeny of the genus. We also discuss how particular adaptations of the immature morphology may allow their myrmecophilous life within ant nests. In this paper new diagnostic features are also presented to distinguish M. myrmicae from its sibling species M. mutabilis—the two are morphologically indistinguishable as adults. 

Isoetes × marensis, a new interspecific hybrid from western Canada

1995 ◽  
Vol 73 (9) ◽  
pp. 1345-1353 ◽  
Author(s):  
Donald M. Britton ◽  
Daniel F. Brunton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Key Words ◽  
North American ◽  
Interspecific Hybrid ◽  
Western Canada ◽  
Hybrid Plants ◽  
Surface Ornamentation ◽  
Scanning Electron

A new interspecific hybrid in Isoetes, I. maritima Underw. × I. howellii Engelm., is delineated and described from the Shuswap Highlands region of British Columbia by means of cytology and scanning electron microscopy of spores. Isoetes × marensis D.M. Britton and D.F. Brunton, hyb.nov. is the name proposed for this taxon. It is triploid (3x; 2n = 33) and is believed to produce only sterile and (or) aborted spores. Hybrid plants have polymorphic spores that demonstrate size and surface ornamentation features intermediate between those of the putative parents. Three populations were examined, each growing with both of the putative parents in silt and sand among granite cobble over clay along an emergent lakeshore. Isoetes × marensis is the first described North American hybrid involving an amphibious Isoetes. It is expected to be a rare taxon owing to the restricted sympatric area of the putative parents and their tendency to occupy different habitats. Key words: Isoetes, Isoetes howellii, Isoetes maritima, hybrid, British Columbia.

scholarly journals Taxonomic synthesis of the eastern North American millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae), utilizing high-detail ultraviolet fluorescence imaging

2019 ◽  
Vol 187 (1) ◽  
pp. 117-142 ◽  
Author(s):  
Petra Sierwald ◽  
Derek A Hennen ◽  
Xavier J Zahnle ◽  
Stephanie Ware ◽  
Paul E Marek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluorescence Imaging ◽  
North American ◽  
Type Material ◽  
High Quality ◽  
Subjective Synonym ◽  
Scanning Electron

Abstract The species of the eastern North American millipede genus Pseudopolydesmus are reviewed. Synonyms and comprehensive literature citations are provided for each of the eight recognized species. Diagnostic morphology of the genus, including clarification of male gonopod terminology, is reviewed and defined using scanning electron microscopy and high-quality macrophotographic images, including those in which ultraviolet fluorescence was induced to produce detailed images of morphological structures. Based on the examination of available type material, the following eight species are recognized: (1) Pseudopolydesmus erasus; (2) Pseudopolydesmus canadensis; (3) Pseudopolydesmus collinus; (4) Pseudopolydesmus pinetorum; (5) Pseudopolydesmus minor; (6) Pseudopolydesmus caddo; (7) Pseudopolydesmus paludicolus; and (8) Pseudopolydesmus serratus. The species names Polydesmus neoterus and Polydesmus euthetus are here placed as junior subjective synonyms of Ps. minor (both syn. nov.), and Polydesmus natchitoches is placed as a junior subjective synonym of Ps. pinetorum (syn. nov.).

Observations on North American Gomphoneis. III. Gomphoneis septa comb.nov.

1986 ◽  
Vol 64 (11) ◽  
pp. 2764-2768 ◽  
Author(s):  
J. P. Kociolek ◽  
E. F. Stoermer ◽  
L. L. Bahls
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
Size Range ◽  
Taxonomic Position ◽  
Apical Pore ◽  
Close Relationship ◽  
Ultrastructural Characteristics ◽  
Scanning Electron

The valvar ultrastructure of the diatom Gomphonema septum Mogh. was investigated with scanning electron microscopy and is discussed with regard to the taxonomic position of this species. Ultrastructural features include striae composed of double rows of puncta, presence of a narrow axial plate which is responsible for the image of longitudinal lines, and apical pore fields composed of pores dissimilar in appearance from the puncta. These and other ultrastructural characteristics point to a close relationship between G. septum and members of the genus Gomphoneis. A transfer of Gomphonema septum to Gomphoneis is proposed. Information supplemental to previous observations on the size range and variability of this species is presented.

scholarly journals Studies on the genus Setaria Viborg, 1795 in South Africa. III. Setaria thwaitei Mönnig, 1933

2004 ◽  
Vol 71 (2) ◽  
Author(s):  
R. Watermeyer ◽  
J. Boomker ◽  
J.F. Putterill
Keyword(s):  
Electron Microscopy ◽  
South Africa ◽  
Scanning Electron Microscopy ◽  
Original Description ◽  
Valid Species ◽  
The North ◽  
Roan Antelope ◽  
Hippotragus Equinus ◽  
North And South ◽  
Scanning Electron

Mönnig (1933) described Setaria thwaitei from a sable antelope, Hippotragus niger, the type host, as well as from roan antelope, Hippotragus equinus, and waterbuck, Kobus ellipsiprymnus. Yeh (1959) considered Setaria thwaitei to be synonym of Setaria hornbyi. Material collected from roan antelopes, sable antelopes and gemsbuck, Oryx gazella, from several localities in the north and south of South Africa, together with Mönnig's (1933) material, were re-examined. Measurements of the adult worms obtained in this study were compared with those in the original description of the species. Scanning electron microscopy of the anterior and posterior regions of the female worms confirmed S. thwaitei as a valid species.

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