scholarly journals Surface ultrastructure of the adult and juvenile stages of the trematode Astiotrema impletum (Looss, 1899) Looss 1900 (incertae sedis) from the Nile puffer, Tetraodon lineatus Linnaeus, 1758

2021 ◽  
Vol 58 (2) ◽  
pp. 188-195
Author(s):  
S. G. Abd El-Kareem ◽  
M. H. Ibraheem

Summary A scanning electron microscope study was performed on the surface of the trematode Astiotrema impletum (Looss, 1899) Looss 1900 from the Nile puffer, Tetraodon lineatus Linnaeus, 1758 (Syn. Tetraodon fahaka) for the first time. Adult A. impletum have a markedly large, sub-terminal oral sucker and a small ventral sucker. As with most trematodes, tegumental spines are concentrated anteriorly and are absent just anterior the ventral sucker. Spines have serrated tips on a short, tongue–shaped body. At the level of the ventral sucker the base of each spine exhibits a three bulbous-like structure that can be partially or completely withdrawn into the tegument. Sensory papillae are concentrated around the oral and ventral suckers and genital pores. Papillae are conical or knob-like, either ciliated or non-ciliated; some are protruded and others are embedded inside the tegument. In the juvenile stage, spines are smaller, less well-developed and tightly packed. The cytoplasmic processes of the posterior quarter of body show brain-like velvety appearance on the adult and small cobblestone-like on the juvenile.

2008 ◽  
Vol 45 (3) ◽  
pp. 109-113 ◽  
Author(s):  
I. Hodová ◽  
V. Baruš ◽  
V. Tukač

AbstractMorphological features of adult specimens of Ascaridia hermaphrodita and A. platyceri (Nematoda: Ascaridida), parasitizing parrots (Psittaciformes), were studied for the first time using scanning electron microscopy. The morphology of A. hermaphrodita, the type species of Ascaridia, coincides fully with the generic diagnosis. The shape of the labial inner structure (two spoon-like projections), cervical alae and spicule with cuticular wings were typical for this species. A. hermaphrodita has been found in the Czech Republic for the first time in a new host, Amazona pretrei, from Brazil. The morphology of Ascaridia platyceri does not correspond with the generic diagnosis in all aspects, as some variation was found, mainly in the presence of interlabia, small teeth in the inner ribbon of the lips and long lateral alae. These morphological characteristics in other species of Ascaridia are discussed. The generic diagnosis is to include the statement “interlabia very rarely present”.


Author(s):  
P. Dayanandan ◽  
P. B. Kaufman

A three dimensional appreciation of the guard cell morphology coupled with ultrastjuctural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.


Author(s):  
V.K. Berry

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.


1987 ◽  
Vol 41 (6) ◽  
pp. 1238-1243
Author(s):  
Yohichiroh Soh ◽  
Junroh Tahara ◽  
Takashi Hayashikawa ◽  
Masatoshi Hitaka ◽  
Kohzoh Kubota ◽  
...  

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