Biological Notes on Eupera cubensis (Bivalvia: Sphaeriidae) from Kansas

1976 ◽  
Vol 33 (7) ◽  
pp. 1652-1656 ◽  
Author(s):  
G. L. Mackie ◽  
D. G. Huggins
Keyword(s):  
Root Systems ◽  
Range Extension ◽  
North Central ◽  
Older Parents ◽  
Stage Of Development ◽  
Water Willow ◽  
Scanning Electron

The occurrence of Eupera cubensis (Prime) in Kansas represents a north central range extension. The species appears to be more common in root systems of the water willow, Justicia americana, than in riffle areas or backwater areas. Scanning electron photographs are given to illustrate important shell characteristics. The generative performance of E. cubensis appears to increase with increasing age up to 3 yr, with as many as 64 larvae, all in the same stage of development, in larger (older) parents.

scholarly journals Anatomía de la semilla de Tigridia pavonia (Iridaceae)

2017 ◽  
pp. 66
Author(s):  
Aída Carrillo-Ocampo ◽  
E.M. Engleman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Thin Layer ◽  
Cell Walls ◽  
Histochemical Staining ◽  
Stage Of Development ◽  
Scanning Electron

With methods of light microscopy, histochemical staining and scanning electron microscopy, it was found that the ovule in the seed of Tigridia pavonia (Iridaceae) is anatropous, bitegmic, and crassinucellate. During development, the exotegmen is crushed and the endotegmen persists with tannins in the lumens and in the walls, which also react positively for lignin. The exotesta contains tannins and its outer walls are convex, thickened, and cuticularized. The mesotesta has multiple layers, accumulates abundant lipids, and forms a bulge in the chalaza. The cell walls of the endotesta collapse and accumulate tannins. In the chalaza, a hypostasal cushion contains tannins in the lumens and in the walls, which also react positively for lignin. At the micropylar end of the seed there is an operculum which consists of: a) a slightly crushed exotegmen, b) an endotegmen with cuticular thickenings that are concentric with respect to the micropyle, c) hemispherical deposists of cutin on the anticlinal walls of the endotegmen, and c) a thin layer of endosperm that covers the radicle. During its cellular stage of development, the endosperm has conspicuous transfer walls at the chalazal end next to the nucella. The embryo is small and has a conical cotyledon.

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.

scholarly journals A Range Extension for the Rock Vole, Microtus chrotorrhinus, in Labrador

2005 ◽  
Vol 119 (3) ◽  
pp. 412 ◽  
Author(s):  
Sarah W. Lansing
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Range Extension ◽  
Southern Coast ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Southern Island

Rock Voles (Microtus chrotorrhinus) were previously documented only from the southern coast of Labrador and the Strait of Belle Isle south of Hamilton Inlet. During two field seasons in 2000 and 2001, both in July, six Rock Vole specimens were collected on Southern Island, off the north-central coast of Labrador, extending the range of the subspecies Microtus chrotorrhinus ravus approximately 250 km to the central Labrador coast north of Hamilton Inlet. Rock Voles were trapped primarily in stunted Black Spruce (Picea mariana) forest and areas associated with rocks, thick brush, and water.

scholarly journals SEM studies on the leaf indumentum of six Melastomataceae species from Brazilian Cerrado

Rodriguésia ◽  
2011 ◽  
Vol 62 (1) ◽  
pp. 203-212 ◽  
Author(s):  
Camilla Rozindo Dias Milanez ◽  
Silvia Rodrigues Machado
Keyword(s):  
Mixed Type ◽  
Complex Structures ◽  
Brazilian Cerrado ◽  
Stage Of Development ◽  
Different Types ◽  
Young Leaves ◽  
Microscopy Techniques ◽  
First Time ◽  
Scanning Electron ◽  
Glandular Portion

Abstract The wide diversity of their trichomes, which vary from simple unicellular to very complex structures, is a remarkable characteristic in Melastomataceae. This paper characterizes the leaf indumentum of Miconia albicans (Sw.) Triana, M. chamissois Naudin, M. fallax DC., M. ligustroides (DC.) Naudin, Microlepis oleaefolia (DC.) Triana and Rhynchanthera dichotoma DC., typical species from Brazilian cerrado. Samples collected from the median third of young and mature leaf blades were processed following the usual scanning electron microscopy techniques (SEM). We observed ten morphological types of trichomes and four of emergences. With five different types, four of which are reported for the first time, Rhynchanthera dichotoma is the species that presents the most diverse indumenta. A mixed type of trichome formed by a glandular and a branched non-glandular portion called "lateral-gland" was observed in M. ligustroides. Such non-glandular portion presents different degrees of development. A correlation is suggested between the stage of development of the non-glandular portion and the exposition to light of these "lateral gland" on young leaves.

scholarly journals Range extension of Wallace’s Striped Racer, Wallaceophis gujaratensis (Squamata: Colubridae), in north-central Gujarat, India

2020 ◽  
Vol 27 (1) ◽  
pp. 83
Author(s):  
Jaydeep Maheta ◽  
Vishal Varma ◽  
Shruti Patel ◽  
Zala Atulsinh
Keyword(s):  
Range Extension ◽  
North Central

Taking a closer look: an SEM review of Levinsenia species (Polychaeta: Paraonidae) reported from California

Zootaxa ◽  
2020 ◽  
Vol 4751 (2) ◽  
pp. 256-275
Author(s):  
LAWRENCE L. LOVELL ◽  
KIRK FITZHUGH
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Light Microscope ◽  
Molecular Phylogenetics ◽  
Range Extension ◽  
Sensory Organ ◽  
The Status ◽  
A New Species ◽  
Scanning Electron

Scanning electron (SEM) and light microscope examinations of members of Levinsenia Mesnil, 1897, species from California yielded a new species, new characters, emended name and range extension for L. kirbyorum Lovell, 2002. Specimens of L. gracilis (Tauber, 1879) from Sweden, Iceland, and California were compared and could not be distinguished on the basis of morphology. Two other Californian species, L. multibranchiata (Hartman, 1957) and L. oculata (Hartman, 1957), were also examined. SEM revealed features previously undescribed for the genus. Additional prostomial ciliary bundles, dorsal transverse ciliary branchial connections, notopodial sensory pores, and neurochaetal fascicle configurations. Levinsenia barwicki n.sp. possessing a terminal sensory organ, 4-8 leaf-like ciliate branchiae, and recurved neurochaete with distal hood is described More SEM work is necessary to confirm if these features are present among other members of Levinsenia and other Paraonidae genera. The status of Levinsenia according to the phylogenetic analysis performed by Langeneck et al. (2019, Molecular Phylogenetics and Evolution, 136, 1-13) is discussed. 

Morphology and morphogenesis of synnemata of Ceratocystis ulmi

1978 ◽  
Vol 56 (16) ◽  
pp. 1909-1914 ◽  
Author(s):  
Yasuyuki Hiratsuka ◽  
Shozo Takai
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Initial Formation ◽  
Conidium Production ◽  
Stage Of Development ◽  
Transmission Electron ◽  
Scanning Electron

Morphology and morphogenesis of synnemata of Ceratocystis ulmi were observed under a scanning electron microscope and a transmission electron microscope. Synnematal development in C. ulmi can be divided into four stages: (1) synnema initial formation, (2) stalk development, (3) conidiophore formation, and (4) conidium production. Observations on each stage of development are described and illustrated.

In-situ compression of high performance polymeric and related fibers within the Scanning Electron Microscope

1990 ◽  
Vol 48 (4) ◽  
pp. 544-545
Author(s):  
Var L. St. Jeor ◽  
C. C. Chau ◽  
Mark Thomsen
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Brittle Failure ◽  
High Performance ◽  
Kink Band ◽  
Compressive Failure ◽  
Polymeric Fibers ◽  
Band Formation ◽  
Stage Of Development ◽  
Scanning Electron

A large portion of the interest currently given high performance polymer fibers stems from their potential use in composite construction. Although many of these fibers display good tensile properties, compressive strength is a major concern. There are many studies which have observed the compressive failure morphology of polymeric fibers. These studies usually involve the postmortem observation of samples which have failed, either partly or completely, following compressive strain. Observations have included such events as kink band formation, brittle failure and other modes as well. But to our knowledge these failure modes have not been recorded, in process, using the scanning electron microscope (SEM). In this article we introduce a technique which allows observation of compressive failure within the SEM, or using light microscopy (LM), in process. We also present some results unique to this procedure. This technique allows us to follow this "process" of compressive failure including both it's initiation and the more advanced stages of failure. Since the compressive failure of polymeric fibers is a process rather than an instantaneous event we have been able to record this process of failure, in it's various stages, in relatively high resolution SEM micrographs. Our methodology involves the use of relatively low accelerating voltages to minimize charging artifacts associated with damaged areas of the fiber. This induced damage can disrupt the 3 - 5nm sputter coating used to prevent such artifact resulting in uncoated fiber being exposed to the electron beam. This technique also lends itself readily to video recording. We have observed compressive failure processes for Kevlar 49®, Spectra 1000®, Hercules AS-4® carbon and various experimental fibers such as Polybenzobisoxazole (PBO). Our observations have included such modes of failure as kink band formation, delamination, buckling and brittle failure. It is noted that some of these processes occur simultaneously in any given fiber, and with the exception of brittle failure, these processes can be recorded at every stage of development visible to the SEM.

Decision Making within Plant Root Systems

1996 ◽  
Author(s):  
Yoav Waisel ◽  
Bobbie McMichael ◽  
Amram Eshel
Keyword(s):  
Root System ◽  
System Architecture ◽  
Plant Root ◽  
Lateral Roots ◽  
Root Systems ◽  
Root System Architecture ◽  
Growth Patterns ◽  
Soil Conditions ◽  
Stage Of Development ◽  
Root Types

Architecture of a root system is the expression of the potential of various root types to branch, to grow and to coordinate with other plant organs, under the specific limitations of the environmental conditions. The present investigation has proven the following points. 1) Genotypes with different types of root systems were identified. The growth patterns of their roots and the distribution of laterals along their main axes were recorded. 2) The patterns of development of the root systems of four cotton genotypes, throughout the entire life cycle of the plants, were described, even at such a late stage of development when the total length of the roots exceeded two kilometers. To the best of our knowledge, this is the first time that an analysis of this type is accomplished. 3) The development of root systems under restrictive soil conditions were compared with those that have developed under the non-restrictive conditions of aeroponics. Results indicate that in the absence of the mechanical impedance of the soil, cotton plants develop single roots that reach the length of 6 m, and have a total root length of 2000 m. Thus, root growth is strongly inhibited by the soil, with some root types being inhibited more than others. 4) One of the important decisions, in constructing an operational root system architecture of mature plants, is the shift of the balance between various root fractions in favor of the very fine roots. 5) Root system architecture is determined, in part, by the sites of initiation of the lateral roots. This is determined genetically by the number of xylem archs and by the totuosity of the stele. Selection for such traits should be sought.

A morphological examination of Frustulia (Bacillariophyceae) from the Ocala National Forest, Florida, USA

2004 ◽  
Vol 82 (5) ◽  
pp. 629-644 ◽  
Author(s):  
Peter A Siver ◽  
George Baskette
Keyword(s):  
Morphological Characters ◽  
Algal Community ◽  
National Forest ◽  
Morphological Examination ◽  
North Central ◽  
Central Florida ◽  
Emended Description ◽  
Components Analysis ◽  
Scanning Electron ◽  
Shape And Size

The genus Frustulia was found to be an abundant and important component of the attached algal community in a suite of dilute, poorly buffered, and acidic ponds situated in the Ocala National Forest in north-central Florida. Six species were found in the study, including Frustulia krammeri Lange-Bertalot & Metzeltin, Frustulia saxonica Raben horst, Frustulia crassinervia (Brébisson) Lange-Bertalot & Krammer, Frustulia pseudomagaliesmontana Camburn & Charles, Frustulia bahlsii Edlund & Brant, and a newly described taxon, Frustulia trochus Siver & Baskette sp. nov. In addition, an emended description is provided for F. pseudomagaliesmontana. Each species was studied in detail with both light and scanning electron microscopy, and the importance of specific morphological characters was also examined with principal components analysis. In addition to valve shape and size, striae density and areolae density, the structure of the helictoglossae, raphe fissures, and areolae were all found to be useful and important characters in distinguishing among species. Three distinct types of helictoglossae, referred to as linear, rolled tongue, and hoop shaped, are discussed. Taxa with linear or rolled-tongue-shaped helictoglossae also had T-shaped raphe fissures and circular hymen coverings. Taxa with hoop-shaped helictoglossae had teardrop-shaped raphe fissures and rectangular hymen coverings. K-cluster analysis was used to examine the distinction between F. krammeri and F. saxonica relative to the historical separation of F. rhomboides from F. saxonica.Key words: acidic ponds, Florida, Frustulia, Frustulia trochus, new species, Ocala National Forest.

Sign in / Sign up

Export Citation Format

Share Document