The motility of many parasites is critical for the infection process of their host, as exemplified by the transmission cycle of the blood fluke Schistosoma mansoni [1]. In their human infectious stage, immature, submillimetre-scale forms of the parasite known as cercariae swim in freshwater and infect human hosts by penetrating through the skin [1, 2]. This infection causes Schistosomiasis, a p...

In many infection experiments attention has been focused mainly on the rate of the larval development of F. hepatica and the number of rediae and mature cercariae produced by infected L. truncatula (Kendall, 1949; Roberts, 1950; Boray, 1969). Very little consideration has been given to the actual numbers of cercariae which emerge from infected snails. Knowledge of the output of cercariae from i...

The morphology of cercariae of freshwater snails from Erawan Waterfall, Erawan National Park, Kanchanaburi Province was studied between December 2002 and August 2003. The snail samples were collected by handpicking using a counts per unit of time sampling method. The cercariae, larva stage of a trematode, were investigated using the shedding method where they were categorized into three groups ...

It has previously been postulated that L-arginine emitted by penetrating Schistosoma mansoni cercariae serves as an intraspecific signal guiding other cercariae to the penetration site. It was suggested that penetrating in groups offers a selective advantage. If this hypothesis is correct and group penetration at one site on the host offers an advantage, it would follow that at such a site, suc...

The invasive larvae (cercariae) of schistosomes penetrate the skin of their definitive hosts. During the invasion, they undergo dramatic ultrastructural and physiological transitions. These changes result in the development of the subsequent stage, schistosomulum, which migrates through host tissues in close contact with host's immune system. One of the striking changes in the transforming cerc...

background: human echinostomiasis is an intestinal disease caused by the members of family echinostomatidae parasites. the aim of present research was to identify echinos­tomatidae cercariae emitted by lymnaea palustris snails from mazandaran province in the north of iran based on the morphological and morphometrical charac­teristics of the different stages of experimental parasite life cycle. ...

background: cercariae (larva of helminth parasites) are covered by a thick glycocalyx coat, which serves as an osmotic pro­tection during their free existence, and contain carbohydrates conjugated as glycoproteins, glycolipids and mu­co­polysaccharides. although, limited studies have been made on life cycle of cercariae from fresh water snails, however, car­bo­hydrate studies on cercariae have ...

Certain long-chain polyunsaturated fatty acids (FA) found on mammalian skin trigger cercariae to penetrate and transform into schistosomules; however, the mechanism by which FAs stimulate cercariae is unknown. In order to determine whether argentophilic papillae concentrated at the apical region of the cercariae are the chemoreceptors that may mediate cercarial response to FAs, an assay assesse...

The infection rate and cercarial production from B. glabrata, in comparison with B. alexandrina snails, post their exposure to S. mansoni miracidia of an Egyptian strain after two cycles in albino-mice was studies.The results indicated that infection rate of B. glabrata with the Egyptian strain of S. mansoni was less than that of B. alexandrina snails On the other hand infected B. glabrata exhi...

Schistosoma mansoni cercariae were removed from clear and turbid water by flocculation with Sudanese bentonite clays, with Moringa oleifera seeds as well as with pure bentonite. The flocculation technique employed corresponds to that used to clarify Nile water in Sudanese villages. Moringa seeds, pure bentonite and one type of bentonite clay were able to reduce the number of cercariae by more t...