scholarly journals THE FINE STRUCTURE OF GIARDIA MURIS

1966 ◽  
Vol 29 (2) ◽  
pp. 317-332 ◽  
Author(s):  
Daniel S. Friend
Keyword(s):  
Fine Structure ◽  
Osmium Tetroxide ◽  
Smooth Endoplasmic Reticulum ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Cell Periphery ◽  
Adhesive Disc ◽  
Medial Surfaces ◽  
Dorsal Portion ◽  
Giardia Muris

Giardia is a noninvasive intestinal zooflagellate. This electron microscope study demonstrates the fine structure of the trophozoite of Giardia muris in the lumen of the duodenum of the mouse as it appears after combined glutaraldehyde and acrolein fixation and osmium tetroxide postfixation. Giardia muris is of teardrop shape, rounded anteriorly, with a convex dorsal surface and a concave ventral one. The anterior two-thirds of the ventral surface is modified to form an adhesive disc. The adhesive disc is divided into 2 lobes whose medial surfaces form the median groove. The marginal grooves are the spaces between the lateral crests of the adhesive disc and a protruding portion of the peripheral cytoplasm. The organism has 2 nuclei, 1 dorsal to each lobe of the adhesive disc. Between the anterior poles of the nuclei, basal bodies give rise to 8 paired flagella. The median body, unique to Giardia, is situated between the posterior poles of the nuclei. The cytoplasm contains 300-A granules that resemble particulate glycogen, 150- to 200-A granules that resemble ribosomes, and fusiform clefts. The dorsal portion of the cell periphery is occupied by a linear array of flattened vacuoles, some of which contain clusters of dense particles. The ventrolateral cytoplasm is composed of regularly packed coarse and fine filaments which extend as a striated flange around the adhesive disc. The adhesive disc is composed of a layer of microtubules which are joined to the cytoplasm by regularly spaced fibrous ribbons. The plasma membrane covers the ventral and lateral surfaces of the disc. The median body consists of an oval aggregate of curved microtubules. Microtubules extend ventrally from the median body to lie alongside the caudal flagella. The intracytoplasmic portions of the caudal, lateral, and anterior flagella course considerable distances, accompanied by hollow filaments adjacent to their outer doublets. The intracytoplasmic portions of the anterior flagella are accompanied also by finely granular rodlike bodies. No structures identifiable as mitochondria, smooth endoplasmic reticulum, the Golgi complex, lysosomes, or axostyles are recognized.

scholarly journals THE FINE STRUCTURE OF THE ELECTRIC ORGAN OF TORPEDO MARMORATA

1965 ◽  
Vol 24 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Michael N. Sheridan
Keyword(s):  
Fine Structure ◽  
Connective Tissue ◽  
Basement Membrane ◽  
Intercellular Space ◽  
Electric Organ ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Nerve Fibers ◽  
Nerve Endings ◽  
Torpedo Marmorata

The fine structure of the electric organ of the fish Torpedo marmorata has been examined after osmium tetroxide or potassium permanganate fixation, acetone dehydration, and Araldite embedment. This organ consists of stacks of electroplaques which possess a dorsal noninnervated and a ventral richly innervated surface. Both surfaces are covered with a thin basement membrane. A tubular membranous network whose lumen is continuous with the extracellular space occupies the dorsal third of the electroplaque. Nerve endings, separated from the ventral surface of the electroplaque by a thin basement membrane, contain synaptic vesicles (diameter 300 to 1200 A), mitochondria, and electron-opaque granules (diameter 300 A). Projections from the nerve endings occupy the lumina of the finger-like invaginations of the ventral surface. The cytoplasm of the electroplaques contains the usual organelles. A "cellular cuff" surrounds most of the nerve fibers in the intercellular space, and is separated from the nerve fibre and its Schwann cell by a space containing connective tissue fibrils. The connective tissue fibrils and fibroblasts in the intercellular space are primarily associated with the dorsal surface of the electroplaque.

scholarly journals Attachment devices and the tarsal gland of the bug Coreus marginatus (Hemiptera: Coreidae)

Zoomorphology ◽  
2021 ◽  
Vol 140 (1) ◽  
pp. 85-102
Author(s):  
Manuela Rebora ◽  
Gianandrea Salerno ◽  
Silvana Piersanti ◽  
Elena V. Gorb ◽  
Stanislav N. Gorb
Keyword(s):  
Fine Structure ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Hydraulic Pressure ◽  
Capillary Suction ◽  
Gland Cells ◽  
Tarsal Gland ◽  
Fluid Production ◽  
Adhesive Fluid ◽  
Attachment Devices

AbstractThe present ultrastructural investigation using scanning and transmission electron microscopy as well as light and fluorescence microscopy describes in detail the attachment devices and tarsal gland of the bug Coreus marginatus (L.) (Hemiptera: Coreidae). In particular, the fine structure of pulvilli reveals a ventral surface rich with pore channels, consistent with fluid emission, and a folded dorsal surface, which could be useful to enhance the pulvillus contact area during attachment to the substrate. The detailed description of the tarsal gland cells, whose structure is coherent with an active secretory function, allows us to consider the tarsal gland as the plausible candidate for the adhesive fluid production. Scolopidia strictly adhering to the gland cells are also described. On the basis of the fine structure of the tarsal gland, we hypothesise a fluid emission mechanism based on changes of the hydraulic pressure inside the gland, due to the unguitractor tendon movements. This mechanism could provide the fluid release based on compression of the pad and capillary suction, as demonstrated in other insects. The data here reported can contribute to understanding of insect adhesive fluid production, emission and control of its transport.

The Ultrastructure of Myocardial Cells in Normal and Cardiac Lethal Mutant Mexican Axolotls, (Ambystoma Mexicanum)

1970 ◽  
Vol 28 ◽  
pp. 62-63
Author(s):  
Larry F. Lemanski ◽  
Eldridge M. Bertke ◽  
J. T. Justus
Keyword(s):  
Fine Structure ◽  
Heart Development ◽  
Osmium Tetroxide ◽  
Picric Acid ◽  
Ambystoma Mexicanum ◽  
Recessive Mutation ◽  
Acid Mixture ◽  
Myocardial Cells ◽  
Lethal Mutant ◽  
Mexican Axolotl

A recessive mutation has been recently described in the Mexican Axolotl, Ambystoma mexicanum; in which the heart forms structurally, but does not contract (Humphrey, 1968. Anat. Rec. 160:475). In this study, the fine structure of myocardial cells from normal (+/+; +/c) and cardiac lethal mutant (c/c) embryos at Harrison's stage 40 was compared. The hearts were fixed in a 0.1 M phosphate buffered formaldehyde-glutaraldehyde-picric acid-styphnic acid mixture and were post fixed in 0.1 M s-collidine buffered 1% osmium tetroxide. A detailed study of heart development in normal and mutant embryos from stages 25-46 will be described elsewhere.

Scanning electron microscopy of the integument of schistosoma rodhaini

1986 ◽  
Vol 44 ◽  
pp. 132-133
Author(s):  
P. Evers ◽  
C. Schutte ◽  
C. D. Dettman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Oral Sucker ◽  
Adult Male ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Sensory Receptors ◽  
East African ◽  
Dorsal Midline ◽  
Scanning Electron

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.

The larval stages of the celery fly (Acidia heraclei L.) and of the braconid Adelura apii (Curtis), with notes upon an associated parasitic yeast-like fungus

Parasitology ◽  
1943 ◽  
Vol 35 (1-2) ◽  
pp. 27-36 ◽  
Author(s):  
D. Keilin ◽  
P. Tate
Keyword(s):  
Dorsal Surface ◽  
Ventral Surface ◽  
Host Larva ◽  
Yeast Cells ◽  
Stage Larva ◽  
Normal Type ◽  
Abortive Infection ◽  
Unique Case ◽  
Larval Stages ◽  
Adult Females

The larval stages of the celery fly, Acidia heraclei, have been described, and it is shown that this larva agrees with other biontophagous dipterous larvae in having the pharynx devoid of ventral ridges. The transparency of the larvae permits the internal anatomy to be seen clearly in the living larva, and by this means the structure of the perispiracular glands is clearly revealed.The braconid Adelura apii occurs as a parasite of Acidia heraclei larvae, and its first. stage larva is described in detail. This larva is densely hairy, has a long, curved, hairy, tail-like appendage and, by the more rapid growth of the ventral surface, it develops a dorsal curvature which obscures the true orientation so that the true dorsal surface appears externally to be ventral. In these respects the first stage larva of Adelura apii resembles that of A. gahani described by de la Baume-Pluvinel. The later larval stages of A. apii, of which there are at least two, are naked, lack the tail-like appendage and do not differ from the normal type of parasitic hymenopterous larvae.A yeast-like fungus occurs as a parasite in the blood of Acidia heraclei larvae. It is always found associated with existing or abortive infection of the larvae with Adelura apii. Dense mycelial masses sometimes occur in the gut of A. apii pupae and are probably derived from the yeast cells parasitic in the host larvae. It is suggested that this is a unique case of a fungus parasitic in a host larva (Acidia heraclei) undergoing part of its development in a parasitic braconid (Adelura apii), adult females of which transmit the fungus to the host larva during oviposition.

A new species of Glyptothorax (Teleostei: Sisoridae) from the Brahmaputra River basin, Arunachal Pradesh, India

Zootaxa ◽  
2021 ◽  
Vol 5023 (2) ◽  
pp. 239-250
Author(s):  
LAISHRAM KOSYGIN ◽  
PRATIMA SINGH ◽  
SHIBANANDA RATH
Keyword(s):  
River Basin ◽  
Indian Subcontinent ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Northeast India ◽  
Arunachal Pradesh ◽  
Brahmaputra River ◽  
Body Depth ◽  
Pectoral Spine ◽  
Pelvic Fin

Glyptothorax rupiri, a new sisorid catfish, is described from the Brahmaputra River basin in Arunachal Pradesh, northeast India. It differs from its congeners in the Indian subcontinent by the following combination of characters: the presence of plicae on the ventral surface of the pectoral spine and first pelvic-fin ray; a posteriorly serrated dorsal-fin spine, its length 11.3–12.2% SL; body depth at anus 11.2–13.4% SL; a thoracic adhesive apparatus longer than broad, with a V-shaped median depression which opens posteriorly; an arrow-shaped anterior nuchal plate element; adipose-fin base length 10.9–12.6% SL; nasal barbel not reaching anterior orbital margin; 14–18 serrae on posterior margin of the pectoral-fin spine; body with two longitudinal pale-cream stripes; densely tuberculated skin; and the presence of numerous tubercles on the dorsal surface of pectoral and pelvic-fin rays.  

A New Delphinium-Infesting Aphid (Homoptera: Aphididae)

1958 ◽  
Vol 90 (11) ◽  
pp. 690-692 ◽  
Author(s):  
W. R. Richards
Keyword(s):  
Dorsal Surface ◽  
Ventral Surface ◽  
Apical Segment ◽  
Basal Diameter ◽  
Viviparous Female ◽  
Fourth Segment ◽  
Small Tubercle ◽  
Small Primary ◽  
Basal Portion ◽  
Large Primary

Apterous Viviparous FemaleHolotype.–Dorsum of head with six blunt or slightly clavate setae. Frontal tubercles well developed, smooth, diverging, each with one long, (blunt seta on dorsal surface and one or two on ventral surface. Antenna about as long as body, third segment expanded just distad of base to almost twice its basal diameter; 56 small, tubercle-like, secondary sensoria scattered along whole length of one third segment, 60 on other; one fourth segment with four secondary sensoria, the other with five; a single, large, primary sensorium near apex of each fifth segment, and one large one and five or six adjacent smaller ones near apices of basal portion of sixth segment; each small primary sensorium on sixth segment with a central papilla; all primary sensoria lacking marginal, cilia-like fimbriations. Antennal setae distinctly capitate and about equal in length to basal diameter of third segment. Lengths of antenna1 segments as follows: III, 0.85 mm.; IV, 0.4 mm.; V, 0.3 mm.; VI, 0.15-0.85 mm. Rostrum reaching slightly beyond middle coxae; apical segment 0.13 mm. long, with 17 slender pointed setae in addition to usual apical ones.

scholarly journals Giardia muris and Giardia duodenalis groups: ultrastructural differences between the trophozoites

1989 ◽  
Vol 31 (4) ◽  
pp. 242-247 ◽  
Author(s):  
Maria Inês L. Sogayar ◽  
Elisa Aparecida Gregório
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Giardia Duodenalis ◽  
Dorsal Surface ◽  
Distal Extremity ◽  
Transmission Electron ◽  
Marginal Plate ◽  
Marginal Plates ◽  
Giardia Muris ◽  
Rats And Mice

Trophozoites of the Giardia muris group from hamsters, domestic rats and mice and of the Giardia duodenalis group from hamsters and domestic rats were examined by transmission electron microscopy. The basic ultrastructure of the trophozoites was similar. Differences were shown in the morphology of the ventrolateral flange of the trophozoites of Giardia muris and Giardia duodenalis groups. Marginal plates are less developed in the species of the Giardia duodenalis group. In this group, the distal extremity of the lateral flange is short and thick and the marginal plate does not penetrate into the distal extremity of the flange. In the Giardia muris group, the ventro-lateral flange is well developed and narrow and the marginal plate penetrates the distal extremity of the flange. The osmiophilic lamella, which accompanies the dorsal surface of the marginal plate is seen only in the Giardia muris group.

scholarly journals Tongue papillae morphology of brown-throated sloth Bradypus variegatus (SCHINZ, 1825)

2014 ◽  
Vol 66 (5) ◽  
pp. 1479-1486 ◽  
Author(s):  
D.M. Martins ◽  
L.L. Pinheiro ◽  
V.C. Ferreira ◽  
A.M. Costa ◽  
A.R. Lima ◽  
...  
Keyword(s):  
Dorsal Surface ◽  
Ventral Surface ◽  
Simple Type ◽  
Morphological Aspect ◽  
Fungiform Papilla ◽  
Wild Mammals ◽  
Deep Groove ◽  
Vallate Papillae ◽  
Filiform Papillae ◽  
Bradypus Variegatus

The Bradypusvariegatus inhabits the forests of South America and feeds from leaves, branches and sprouts from different plants. Due to its diet and the lack of literature on the morphological aspect of Xenarthras, five Bradypusvariegatus tongues from animals which died from natural causes were evaluated, and they came from Pará State Museum Emílio Goeldi and were donated to the Laboratory of Animal Morphological Research (LaPMA) from UFRA, for revealing the different types of papillae and epithelial-connective tissue. Macroscopically, the tongues presented elongated shape, rounded apex, body, root, median sulcus in the root's apex, and two vallate papillae. The mucous membrane of the tongue revealed a keratinized stratified pavement epithelium, while the ventral surface of the tongue was thin and smooth, not provided with any type of papillae. However, the dorsal surface of the tongue was irregular with the presence of three types of papillae: filiform, fungiform and vallate papillae. The filiform papillae found were of a simple type, presenting a rounded base, irregularly distributed with a larger concentration and development on the tongue's apex and body. The fungiform papilla showed a practically smooth surface with irregular format, with the presence of gustatory pores; these were found all over the dorsal surface, with larger concentration at the rostral part of the apex. Only two vallate papillae were observed disposed in the root of the tongue, surrounded by a deep groove, and revealing several taste buds. The tongues from Bradypusvariegatus presented gustatory papillae similar to the ones described for other Xenarthras species and wild mammals.

scholarly journals The fine structure produced in cells by primary fixatives 2. Potassium dichromate

1965 ◽  
Vol s3-106 (73) ◽  
pp. 15-21
Author(s):  
JOHN R. BAKER
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Membrane ◽  
Osmium Tetroxide ◽  
Potassium Dichromate ◽  
Potassium Dichromate Solution ◽  
Zymogen Granules ◽  
Mouse Pancreas

The exocrine cells of the mouse pancreas were fixed in potassium dichromate solution, embedded in araldite or other suitable medium, and examined by electron microscopy. Almost every part of these cells is seriously distorted or destroyed by this fixative. The ergastoplasm is generally unrecognizable, the mitochondria and zymogen granules are seldom visible, and no sign of the plasma membrane, microvilli, or Golgi apparatus is seen. The contents of the nucleus are profoundly rearranged. It is seen to contain a large, dark, irregularly shaped, finely granular object; the evidence suggests that this consists of coagulated histone. The sole constituent of the cell that is well fixed is the inner nuclear membrane. The destructive properties of potassium dichromate are much mitigated when it is mixed in suitable proportions with osmium tetroxide or formaldehyde.

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