scholarly journals Histological Variation in Plethodontid Digital Surfaces [University of Findlay]

Author(s):  
Megan Pasternak ◽  
Justin Rheubert

Despite numerous investigations into the morphology and function of toe pads in many species, most notably anurans and geckonids, there is relatively little knowledge on salamander digit morphology. To date, toe morphology in salamanders has been limited to Desmognathus fuscus, Ambystoma maculatum, Bolitoglossa sp., and Aneides aeneus. The limited studies to date have shown variation inter- and intra-specifically but have not investigated numerous taxa within a given family which may provide deeper insights into the causes of variation (phylogenetic vs ecological pressures). Therefore, to test hypotheses concerning the presence of variation in the ventral digital surface of plethodontid salamanders, we plan to use various microscopy methodologies to view the ventral surface of the digital tips of three species from three different genera within the Plethodontidae: Desmognathus, Eurycea, and Plethodon. Toe pads will be characterized grossly using scanning electron microscopy, histologically using light microscopy, and ultrastructurally using transmission electron microscopy. Preliminary results suggest that all three species investigated display enlarged surfaces. Surface morphology (assessed via scanning electron microscopy) varies between species at a gross level concerning the shape and overall orientation of the enlarged surface. Surface morphologies include a well-developed circular pad (D. fuscus), a well-developed oval pad (P. cinereus), and a poorly developed circular pad (E. cirrigera). Furthermore, surface morphology appears to vary at the cellular level as well, with Desmognathus having polygonal squamous cells with microprojections and Eurycea having polygonal cells with nanopillars in a honeycomb arrangement. These differences may be attributed to differences in habitat preference as the three species tested include a terrestrial, semi-aquatic, and aquatic dwelling species. However, further investigation including light microscopy and enhanced scanning electron microscopy are needed. Further understanding of the morphological variation will aid in our understanding of ecomorphology and understanding of morphological evolution in amphibians.

Parasitology ◽  
1980 ◽  
Vol 81 (2) ◽  
pp. 423-431 ◽  
Author(s):  
V. R. Parshad ◽  
D. W. T. Crompton ◽  
Jean Martin

SUMMARYThe surface morphology of fixed ovarian balls from female Moniliformis dubius, aged 12, 18, 26, 28, 42, 77, 105 and 118 days, has been examined by means of scanning electron microscopy. The appearance of the surface has been found to be variable between ovarian balls from worms of the same and different ages. Some parts of the surface are seen to possess micro-projections, cavities and ridges while other parts have the appearance of an irregular meshwork of fibres. Various protruding features have been observed to extend from the surfaces of the ovarian balls taken from the inseminated female worms. In most cases, the surfaces of the protruding features differ in appearance from the surrounding surfaces of the ovarian balls. Some of these features have been assumed to represent growing zygotes and developing eggs covered by the supporting syncytium of the ovarian ball. Single or several thread-like structures have been observed in association with the surfaces of ovarian balls taken from the inseminated female worms. At present, the thread-like structures are believed to be portions of spermatozoa. By means of light microscopy, preliminary observations have been made on what is considered to be the division process of ovarian balls taken from uninseminated and inseminated worms varying in age from 7 to 98 days.


1992 ◽  
Vol 6 (1) ◽  
pp. 65-69
Author(s):  
Denise Pinheiro Da Costa ◽  
Raul Dodsworth Machado

Scanning electron microscopy and light microscopy were used to elucidate the morphology of Metzgeria conjutata Lindb. and confirm the presence of 2 rows of epidermal cells on the dorsal surface, (21-3) rows on the ventral surface, midrib with cells in (3-51-6) tiers; hirsute, short hairs, straight on the thallus-margin and on the ventral surface of midrib; marginal hairs paired, single or in groups of three; male branches globose or subglobose; female involucres obovate and hirsute at the margin, calyptra fleshy, pyriform to club-shaped, hirsute on the outer surface, hairs long and straight.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
D. Johnson ◽  
P. Moriearty

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.


Author(s):  
D.R. Hill ◽  
J.R. McCurry ◽  
L.P. Elliott ◽  
G. Howard

Germination of Euonymous americanus in the laboratory has previously been unsuccessful. Ability to germinate Euonymous americanus. commonly known as the american strawberry bush, is important in that it represents a valuable food source for the white-tailed deer. Utilizing the knowledge that its seeds spend a period of time in the rumin fluid of deer during their dormant stage, we were successful in initiating germination. After a three month drying period, the seeds were placed in 25 ml of buffered rumin fluid, pH 8 at 40°C for 48 hrs anaerobically. They were then allowed to dry at room temperature for 24 hrs, placed on moistened filter paper and enclosed within an environmental chamber. Approximately four weeks later germination was detected and verified by scanning electron microscopy; light microscopy provided inadequate resolution. An important point to note in this procedure is that scarification, which was thought to be vital for germination, proved to be unnecessary for successful germination to occur. It is believed that germination was propagated by the secretion of enzymes or prescence of acids produced by microorganisms found in the rumin fluid since sterilized rumin failed to bring about germination.


Author(s):  
P. Evers ◽  
C. Schutte ◽  
C. D. Dettman

S.rodhaini (Brumpt 1931) is a parasite of East African rodents which may possibly hybridize with the human schistosome S. mansoni. The adult male at maturity measures approximately 3mm long and possesses both oral and ventral suckers and a marked gynaecophoric canal. The oral sucker is surrounded by a ring of sensory receptors with a large number of inwardly-pointing spines set into deep sockets occupying the bulk of the ventral surface of the sucker. Numbers of scattered sensory receptors are found on both dorsal and ventral surfaces of the head (Fig. 1) together with two conspicuous rows of receptors situated symmetrically on each side of the midline. One row extends along the dorsal surface of the head midway between the dorsal midline and the lateral margin.


2009 ◽  
Vol 18 (2) ◽  
pp. 191-195
Author(s):  
E.V. Soldatenko

The radula morphology and the anatomy of the copulatory apparatus in Kolhymorbis angarensis were examined using light microscopy, scanning electron microscopy (SEM) and histological methods. Kolhymorbis angarensis was shown to have the stylet and the penial sac with a glandular appendage (flagellum), the characteristics, previously unknown for any species of this genus. The significance of these findings for the taxonomy of the genus is discussed.


2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>


Author(s):  
Christina V. Haden ◽  
Donald A. Jordan ◽  
Pamela M. Norris

A novel and inexpensive bucky gel electrode has been investigated for use as the electrode substrate for deposition of polypyrrole. The electroactive polymer membrane was successfully deposited and the surface morphology studied using scanning electron microscopy. Given the properties of the bucky gel electrode and its ability to conduct ions, this work establishes the first step towards a semi-solid ion-gating system to be used in further applications.


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