Scanning Electron Microscope Observations on Adult Schistosoma japonicum

Abstract

The integumental surfaces of critical point dried adult Schistosoma japonicum were studied by scanning electron microscopy. There are no bosses or spines on the dorsal surface of the male, which is ridged and presents a spongy appearance. Many spines cover the inner surface of the oral sucker and extend to the pharyngeal opening. The oral sucker shows a rim with spines of variable size and sharpness inward and outward from the rim. The ventral sucker possesses many spines which are smaller than in the oral sucker. The lining of the gynecophoric canal is roughened by minute spines. The integument of the female is ridged and pitted and possesses fewer spines than in the oral sucker, the ventral sucker, and the gynecophoric canal of the male. Anterior to the acetabulum, the integumental surfaces are devoid of spines. However, in the other areas, spines are equally distributed except for the vicinity of the excretory pore.

Morphological study of adult male worms of Schistosoma mansoni Sambon, 1907 by confocal laser scanning microscopy

“…The surface topography of adult schistosomes has been exhaustively visualized in a number of scanning electron microscope (SEM) studies (Miller et al 1972, Hockley 1973, Kuntz et al 1976, Sakamoto & Ishii 1977, McLaren 1980, which also showed tegumental alterations after schistosomicides treatment (Kohn et al 1982, Magalhães Filho 1987 or after incubation in various media (Kalapothakis et al 1988). Recently, we have demonstrated that the far anterior region of the gynaecophoric canal is spiness, the right side of the gynaecophoric canal presents a greater amount of tubercles compared to the other in which the spines prevailed.…”

Ultrastructural study on morphology of Schistosoma spindale by Scanning electron microscopy (SEM)

“…An aspinose area is present below the lower border of the rim which is followed by an area of blunt spines. In S. mansoni, the extremity of the ventral sucker presented two spiny regions and some sensorial papillae distributed between the two rows of spines (Machado-Silva et al, 1997) whereas in S. japonicum it possesses spines smaller than the oral sucker (Sakamoto et al, 1977). The tegument of S. spindale showed ridged layers and pit-like papillae which are more in the posterior part.…”

“…Machado-Silva et al (1997) also reported that the anterior border of the oral sucker of S. mansoni presented an area covered by several small sharp spines whereas the present morphological study of S. spindale revealed that the rim of oral sucker does not contain any spines while the ventral surface contains numerous spines which are directed downward into the oral aperture. In S. haematobium, the oral sucker has spines directed towards the oesophagus (Kuntz et al, 1976) and in case of S. japonicum it shows a rim with spines of variable size and sharpness (Sakamoto et al, 1977). Regarding the ventral sucker of S. spindale, the rim contains sharp and pointed spines.…”

“…The tegument of S. haematobium is moderately rough (Kuntz et al, 1976), where as in case of S. japonicum there were no spines and tegumental ridges were compact and regular with sensory papillae in the middle of the integumentum (Yang et al, 2012). The lining of gynaecophoric canal in S. spindale consists of thick, evenly arranged transverse ridges and numerous papillae and in S. haematobium the surface of canal possesses irregular ridging with scattered pits (Kuntz et al, 1976) and the surface of the canal is ridged and covered with small, irregularly arranged spines (Skelly and Wilson, 2006) and in S. japonicum, irregularly directed spines is distributed inside the gynaecophoric canal (Sakamoto et al, 1977). The posterior part of the male worm ends in wide conical projection, and similar findings were observed by Agrawal (2000).…”

Transmission electron microscopy of presumed sensory receptors in the forebody papillae of Crepidostomum metoecus (Digenea: Allocreadiidae)

“…by Bennett 1975b, Sakamoto and Ishii 1977, Bakke 1978, Font and Wittrock 1980, Crites and Jilek 1981, Žďárská et al 1983, 1988, Žďárská and Soboleva 1990. With TEM, the structure of the papillae of adult digeneans was studied by Bennett (1975a) in Fasciola hepatica Linnaeus, 1758; Edwards et al (1977) in Philophthalmus megalurus (Cort, 1914);Fujino et al (1979) in Clonorchis sinensis (Cobbold, 1875); Hoole and Mitchell (1981) in Gorgoderina vitelliloba (Olson, 1876);Dunn et al (1987) in three species of paramphistomes, and Žďárská (1993) in Brachylaimus aequans (Looss, 1899).…”