Fasciola hepatica: surfaces involved in movement of miracidia and cercariae

2001 ◽  
Vol 75 (1) ◽  
pp. 1-5 ◽  
Author(s):  
C.E. Bennett

Rapid freezing and substitution with fixative prior to scanning electron microscopy was used to demonstrate the pattern of beat and recovery of the cilia of free swimming miracidia ofFasciola hepatica. There were stages of dexioplectic metachronal co-ordination and the power stroke was approximately 15° anticlockwise from the anterior–posterior axis. Around the circumference of the body of the miracidia there were approximately 12 metachronal waves of power and recovery. Free-swimming cercariae were recorded by time-lapse photography and, after conventional fixation, by scanning electron microscopy. Cercarial tail-beats were to the posterior of the body in the lateral plane at a rate of 8 Hz. The tail has paired lateral ridges positioned to act as leading edges. There is an array of 32 sensory papillae on the mid-ventral surface of the tail. The tegument of the most distal part of the tail is described: it is free of sensory endings and the surface shows a spiral pattern.

2018 ◽  
Vol 10 (1) ◽  
pp. 347-351
Author(s):  
Kommu Sudhakar ◽  
G.S.S. Murthy ◽  
Udaya Kumar. M ◽  
Narasimha Reddy. Y ◽  
Lakshman. M ◽  
...  

The present study was undertaken to investigate the detailed morphological features along with morphometry of different structures of Schistosoma spindale (Adult flukes) which were recovered by a perfusion technique and visualized by Scanning Electron Microscopy (SEM). The length of spines on the oral sucker and ventral suckers were 2.6 µm and 2.5 µm, respectively. The measured width of aspinose area beneath the ventral sucker, rim of the ventral sucker and tegumental papillae were 5.4, 22.5 µm and 3 µm, respectively. Males have a welldefined gynaecophoric canal, originating just below the ventral sucker and extending up to the posterior end of the body, continued as a marked conical projection. The ventral surface of the oral sucker was completely covered with numerous spines. The ventral sucker was pedunculated, round, thick-rimmed and the inner side contained numerously pointed spines directed towards the center of the ventral sucker. The tegument surface of S. spindale showed ridged layers with large uniciliated and pit like papillae which were recorded more in posterior end. Thus, Scanning Electron microscopy (SEM) provided indepth ultrastructural morphological details of Schistosoma spindale which was in accordance with that of previous studies, would be applicable for its differentiation with other species (S. mansoni, S. bovis, S. haematobium, S. japonicum).


2011 ◽  
Vol 20 (4) ◽  
pp. 342-346 ◽  
Author(s):  
Maria Clara Pamplona-Basilio ◽  
Helene Santos Barbosa ◽  
Simone Chinicz Cohen

Gotocotyla acanthura (Parona & Perugia, 1896) Meserve, 1938 collected from the gills of Pomatomus saltatrix from the coast of the state of Rio de Janeiro state was analyzed using scanning electron microscopy (SEM). The study demonstrated the presence of a buccal cavity, a genital atrium on the ventral surface and a muscular structure on the dorsal surface at the level of the body constriction. An elongated haptor with 80 to 120 pedunculated clamps symmetrically distributed in two rows, with rib-like thickenings and a curved lappet bearing a pair of hooks at the posterior extremity of the body were also observed. The cirrus could be seen protruding from the genital atrium, armed with pectinate spines along its length and presenting up to eight pointed spines around the genital atrium.


1981 ◽  
Vol 59 (10) ◽  
pp. 1941-1946 ◽  
Author(s):  
D. K. Cone ◽  
M. Beverley-Burton

The tegumental surface of Benedenia sp. (Monogenea: Capsalidae), a skin-dwelling parasite of Haemulon sciurus (blue-striped grunt) from coastal waters of Bermuda, was examined using scanning electron microscopy. The dorsal surface of the body and haptor is covered with comparatively long, flexible microvilli (2 to 3 μm in length; density 5/μm2), and the ventral surface of the body is covered with short, stubby microvilli (0.5 μm in length; density 10/μm2). The surface of the two anterior adhesive discs has three transverse zones which differ morphologically: the anterior region has a reticulate texture with uniciliated structures arising from some of the elevated ridges; the middle zone has a dense mat of short microvilli with scattered uniciliated structures, each of which is surrounded by a collar of shorter protuberances; the posterior zone is smooth and lacks ciliated structures. The ventral surface of the haptor is also smooth with the bare extremities of the accessory sclerites and the anterior and posterior hamuli protruding. The surface topography of Benedenia sp. is compared with that of other monogeneans.


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.


Author(s):  
Nancy R. Wallace ◽  
Craig C. Freudenrich ◽  
Karl Wilbur ◽  
Peter Ingram ◽  
Ann LeFurgey

The morphology of balanomorph barnacles during metamorphosis from the cyprid larval stage to the juvenile has been examined by light microscopy and scanning electron microscopy (SEM). The free-swimming cyprid attaches to a substrate, rotates 90° in the vertical plane, molts, and assumes the adult shape. The resulting metamorph is clad in soft cuticle and has an adult-like appearance with a mantle cavity, thorax with cirri, and incipient shell plates. At some time during the development from cyprid to juvenile, the barnacle begins to mineralize its shell, but it is not known whether calcification occurs before, during, or after ecdysis. To examine this issue, electron probe x-ray microanalysis (EPXMA) was used to detect calcium in cyprids and juveniles at various times during metamorphosis.Laboratory-raised, free-swimming cyprid larvae were allowed to settle on plastic coverslips in culture dishes of seawater. The cyprids were observed with a dissecting microscope, cryopreserved in liquid nitrogen-cooled liquid propane at various times (0-24 h) during metamorphosis, freeze dried, rotary carbon-coated, and examined with scanning electron microscopy (SEM). EPXMA dot maps were obtained in parallel for qualitative assessment of calcium and other elements in the carapace, wall, and opercular plates.


1972 ◽  
Vol 3 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Christine Dahl

AbstractA method for preparation of alcohol-preserved culicid larvae for Scanning Electron Microscope (SEM) studies is described. It is based on dehydration by ethanol-xylol and fast evaporation of xylol in +8o° C. for ten minutes. For taxonomic studies such as examination of pecten teeth, comb scales and microtrichiae in magnifications up to 6oooX the method is suitable. For studies of receptor structures on hair-tufts and microstructures of the body integument alcohol preserved material is less satisfactory. The microstructure of the comb scales is figured and their function discussed. Differences in the ultrastructure of the abdominal hair-tufts are pointed out.


2010 ◽  
Vol 55 (No. 6) ◽  
pp. 275-280 ◽  
Author(s):  
NS Kim ◽  
HC Kim ◽  
C. Sim ◽  
JR Ji ◽  
NS Kim ◽  
...  

In March 2010, a 3.5-month-old Korean native calf was anatomized and two nematode worms were detected in the thoracic cavity. The worms were identified and classified by light and scanning electron microscopy on the basis of features at the anterior and posterior parts of the worms. The worms were female Setaria digitata and Setaria marshalli and numerous eggs which contained microfilaria were detected in the uterus of both species. The body lengths of the S. digitata and S. marshalli were 78 mm and 117 mm, respectively. Mosquitoes act as the vector for Setaria nematodes but these are inactivated in winter in Korea. Therefore, we concluded that this case represented setariasis with congenital infection occurring during the summer prenatal stage of life.


Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 29 ◽  
Author(s):  
Weishan Zhao ◽  
Can Li ◽  
Dong Zhang ◽  
Runqiu Wang ◽  
Yingzhen Zheng ◽  
...  

Balantidium grimi n. sp. is described from the rectum of the frog Quasipaa spinosa (Amphibia, Dicroglossidae) from Lishui, Zhejiang Province, China. The new species is described by both light microscopy (LM) and scanning electron microscopy (SEM), and a molecular phylogenetic analysis is also presented. This species has unique morphological features in that the body shape is somewhat flattened and the vestibulum is “V”-shaped, occupying nearly 3/8 to 4/7 of the body length. Only one contractile vacuole, situated at the posterior body, was observed. The phylogenetic analysis based on SSU-rDNA indicates that B. grimi groups together with B. duodeni and B. entozoon. In addition, the genus Balantidium is clearly polyphyletic.


2011 ◽  
Vol 295-297 ◽  
pp. 869-872
Author(s):  
Qing Shan Li ◽  
Xin Wang ◽  
Jun Liu ◽  
Guang Zhong Xing

Six-ring Rock is widely used as containers of water and additives to produce health care products. In this paper, the composition and microstructure of Six-ring Rock have been investigated by using scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, x-ray diffraction and other technologies. Results show that Six-ring Rock is composed of CaMg(CO3)2, SiO2 and KAlSi3O8. Fe atoms exist in CaMg(CO3)2 by replacing Mg atoms. Six-ring Rock shows nano-size lamellar and acerose microstructures on the surface, and nano-size monocrystals in the body. Six-ring Rock is a natural nano structure mineral.


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