Scanning electron microscopic study of the tegumental surface of adult Schistosoma sinensium.

The SEM study of tegumental surface of adult Schistosoma sinensium reveals that the male tegument lacks tubercles or bosses; instead it is corrugated with small pits or perforated ridges. On the dorsal surface, spines are present whose number and size progressively increase towards the posterior end of the body. In addition, there are three types of papillae interspersed among the ridges and spines. The first type of papillae has crater-like holes surrounded by a circular doughnut-shaped elevation; some are ciliated and others are non-ciliated. They are generally found on the dorsal and ventral surfaces. The second is sensory papillae which are hemispherical in shape bearing apical cilia. They are found to be concentrated around the oral sucker and on the posterior end of the worm. The third is fungiform papillae without cilia which are found on the posterior end. There are short spines present on the tegument lining the gynecophoral canal of the male worm. The tegument of the female S. sinensium is corrugated with ridges on the ventral surface. Small spines are present on the anterior portion of the dorsal surface. They become larger and increased in number towards the posterior end of the worm. The three types of papillae are present but they are much fewer and less developed than those in the male worm.

Microtopography of the surface of adult Schistosoma japonicum-like (Malaysian) as observed by scanning electron microscopy.

The surface of adult Schistosoma japonicum-like (Malaysian) was studied by scanning electron microscopy. The basic pattern of surface microtopography is similar to other strains of S. japonicum as previously reported. However, among male member there are some unique differences in the types, number and distribution of surface papillae and morphology of ridges. Three kinds of papillae were observed: (1) the large fungiform papillae (3.5-4 micron in diameter, most without cilia) are more numerous than in other strains of S. japonicum, they concentrate on the lateral aspect of the anterior and middle parts close to the edge of the gynecophoral canal, and on the dorso-lateral aspect of the posterior part towards the tail tip; (2) the small hemispherical papillae (1.5-2 micron in diameter, all bearing cilia) are especially numerous in the suckers, the gynecophoral canal and parts of the tegument around the suckers and close to the tail tip; on the rest of the surface they are evenly distributed; (3) the cratered papillae (3-4 micron in diameter, about half having cilia) are more numerous than on other strains, they concentrate on the lateral aspect of the middle part and on the edges of the gynecophoral canal. The surface ridges (about 0.2-0.3 micron in width) are tall, highly branching and perforated; they are most developed in the middle part. Spines were observed only in the suckers and the gynecophoral canals. In contrast to the male, the female has numerous spines on all parts of the surface except the most anterior, where a large number of long cilia were observed. All three kinds of papillae were present; fungiform papillae are more numerous than in females of other strains; they concentrate on the latero-dorsal aspect of middle and posterior parts, and around the excretory pore. Ridges are much less developed than in the male and are prominent only in the middle part.

Scanning electron microscopy of the tegumental surface of adult Schistosoma spindale.

The tegumental surfaces of adult male and female of Schistosoma spindale were studied by scanning electron microscopy. In general, the body surface of the male appears to be fairly uniform from anterior end to posterior end. It is characterized by the presence of transverse ridges and papillae of various types. These papillae are distributed fairly regularly over the whole body surface of the worm. The tegument lining the gynecophoral canal of the male worm is covered with numerous spines interspersed with papillae, some without cilia and some with crater-like holes in the centres and apical cilia. The tegument of the female worm is covered with smooth and perforated ridges and sensory bulbs with apical nodules.

Scanning electron microscope studies of anesthetized Tricula aperta, vector of mekong Schistosoma.

Nembutal, menthol, Ketaset, and Curarine were used to anesthetize beta race of Tricula aperta snails in preparation for study by scanning electron microscopy. The snails remained sensitive to the glutaraldehyde fixative in low level anesthesia of nembutal, menthol and Ketaset. Snails were also sensitive to Curarine and retracted into their shells. The best relaxations were obtained by initial anesthesia with nembutal or menthol followed by curarine. Snails relaxed by this procedure showed relatively little reaction to the fixative solution and remained extended outside their shells. The surface ultrastructure of the snails was well preserved, showing microvillate, secretory, and ciliated sensory cells. The mucoid secretions remained on the surface of cilia on the body and foot of the snails as spherical granules. There were two types of ciliated cells: (1) Those with few short cilia showing 1-3 microns above the microvilli of surrounding cells and (2) Those with numerous cilia up to 10 microns long. Results of transmission electron microscopic studies of these snails show no disruption of the ultrastructure of the surface cells.

Scanning electron microscopy of adult Schistosoma incognitum.

The integumental surfaces of adult Schistosoma incognitum were studied by scanning electron microscopy. The anterior part of the male which bears oral and ventral suckers is spongy in appearance due to the presence of ridges, while the middle and posterior parts are covered with numerous bosses with variable numbers of spines. Surfaces between bosses possess tegumental papillae. Bosses disappear at the edge of the gynecophoral canal which is composed of ridges. They are replaced by variable forms of papillae. The lining of the gynecophoral canal is composed of ridges and papillae, free of spines, with small number of sensory bulbs. The female tegument is relatively smooth and appears to be pitted with minute spines around the oral and ventral suckers. The posterior end of the body, in the vicinity of the excretory pore, is composed of prominent anteriorly directed spines with trabeculae and sensory bulbs.

Scanning and transmission electronmicroscopy of Mekong Schistosoma eggs and adults.

Eggs and adult males and females of Mekong Schistosoma were studied by scanning and transmission electronmicroscopy. The observation of the eggs by the scanning and light microscopy revealed fine shell fenestration and a prominent knoblike spine. There are marked differences between the surface structures of male and female as studied by scanning and transmission electronmicroscopy. The surface of the male schistosome is moderately rough while that of the female is relatively smooth. SEM reveals certain basic features such as spines in the oral sucker, minute spines and folds in the gynecophoral canal of the male, and general features of male and female tegumental surfaces. The observations of the cross sections of adult schistosomes by transmission technique revealed certain features such as spines or ridges, and mucin droplets on the surface, the smooth muscles lining the integument, the mucin-producing cells and numerous lipid droplets in the body of the Schistosoma.