scholarly journals Redescription of Female Laelaps nuttalli Hirst, 1915 (Acari: Dermanyssoidea: Laelapidae) with Emphasis on Its Gnathosoma, Sense Organs and Pulvilli

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ashraf Ahmed M. E. Montasser

The present scanning electron microscopic (SEM) study includes the redescription of female Laelaps nuttalli with emphasis on its gnathosoma and pulvilli which were rarely described in superfamily Dermanyssoidea. Chaetotaxy of dorsal shield revealed 40 pairs of setae, 22 on prosoma and 18 on opisthosoma. Epigynial plate carried 4 pairs of setae. Gnathosoma consisted of long basis capituli carrying median hypostome and 2 lateral pedipalps. Hypostome had dorsal labrum of 2 lobes covered with minute papillae, 2 lateral 3-segmented chelicerae, and ventral labium carrying 2 median lobes with laciniae and 2 lateral club-like lobes. Function of labrum papillae might be chemosensory while labium lobules might be mechanical, preventing solid material from entering the oral cavity. Palpal and foreleg tarsal organs comprised 10 and 15 sensilla, respectively. Sensilla of palpal organ were mostly chemoreceptors while those of tarsal organ were probably mechanoreceptors. Each pulvillus terminated with 2 medioventral claws and integumental folds beside longitudinal folds.

2000 ◽  
Vol 52 (5) ◽  
pp. 445-453 ◽  
Author(s):  
E.-N. Emmanouil-Nikoloussp ◽  
M. Goret-Nicaise ◽  
Ch. Foroglou ◽  
E. Katsarma ◽  
A. Dhem ◽  
...  

1997 ◽  
Vol 3 (S2) ◽  
pp. 113-114
Author(s):  
C. Baker ◽  
E.D. Green

The large eggs of Haematopinus phacochoeri are found attached to the long dorsal mane bristles of the diurnal warthog. The eggs are generally exposed to great environmental stresses such as excessive sunlight and temperature as well as the occasional plunge under water or mud during grooming. This investigation was therefore undertaken to determine how the eggs of H. phococoeri are adapted to tolerate the various environmental changes it is constantly exposed to. To our knowledge no other SEM study on the eggs of this species has been performed.Specimens still attached to the bristles were fixed in 70% ethanol, dehydrated and ultrasonically cleaned. Some eggs were longitudinally sectioned with a razor blade to expose the chorionic layers. The eggs were critical point dried in liquid CO2, mounted and viewed by means of a Leica Stereoscan 420 scanning electron microscope.The general structure of the shell consists of two layers of chorion, i.e. the endo-and exochorion. These two layers are attached at the pre-formed line of weakness at the operculum and again near the hydropyle. Elsewhere these two layers are completely separated by the respiratory layer.


2006 ◽  
Vol 53 (2) ◽  
pp. 95-103
Author(s):  
Jovan Vojinovic ◽  
Radoje Stevanovic ◽  
Slobodanka Hrvacanin

In the article are presented results of SEM study of pathological dentinogenesis on the human and dogs tooth in the different formative stages. The pathological dentinogenesis take place in the genetically predetermined way no matter of type of an irritation. The structure of pathological dentin depends upon the level of irritation and its duration. Lower level irritation produce the secretion of tubular dentine with irregular tubular direction, higher irritation stronger irregularities. Strong irritations damage odonoblastes, and they are replaced by undifferentiated cells. Lower level of differentiation produce more irregular dentine. New cells momentarily starts secretion, at the beginning the atubular dentine, and latter tubules arrear. The odontoblasts are very resistant cells, so even under of very strong irritants some of them could survive and continue formatting individual tubules detected within amorphous dentinal tissue. The resistance of odontoblasts is limited, specially when irritations are long enough exhausting formative potential of cells. Excreted dentinal tissue becomes more and more irregular. These biological facts should be consider in the therapy of puplodentinal complex. Therapy have to preserve conditions for undisturbed recovery of damaged odontoblasts, or new undifferentiated cells. In the other words biological principles insist on the preservation of conditions for the normal expression of formative cells genetically tasks.


2017 ◽  
Vol 6 (5) ◽  
pp. 178-185
Author(s):  
M. S. Sharma ◽  
K. C. Sharma

An attempt to study the adhesive organ of Garra gotyla gotyla inhabiting hill streams of Aravalli region has been made using scanning electron micro-scope. The results were compared with that of scanning electron microscop-ic studies of the adhesive organ of G. gotyla gotyla of the Himalayan region. The SEM study reveals that the upper fringed lip (UFL)and the lower lip or the posterior free labial fold (PFLF) bears short stub shaped tubercles (ST). These tubercles in turn bear numerous spines (S). The tubercles are covered with squamous epithelium (SE) indicating that spines are modified squamous epithelial cells. The margins of stub-shaped tubercles bear smaller spines; their size increases from margin to the centre. The surface ultrastructure of the adhesive disc of G. gotyla gotyla revealed the presence of hexagonal epithelial cells with elevated cell boundaries. Each spine is attached to callous pad with a broad base. The spines are used for anchorage to the substratum so that fish can scrap food even in fast current of water. Tubercles are used by fish for protection against mechanical injuries. Further these may be taxo-nomically used for conspecific recognition. Cumulative action of tubercles and mucus enables the fish to make firm hold on the substratum.


1980 ◽  
Vol 94 (9) ◽  
pp. 985-992 ◽  
Author(s):  
R. F. E. Gray ◽  
R. P. E. Barton ◽  
J. L. W. Wright ◽  
P. N. Dilly ◽  
R. F. Moss

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