Twenty mice were exposed to cercariae from mollusks treated with hydrocortisone and another 20 mice received cercariae from non-treated mollusks. The behavior of the parasites from the two groups of mollusks was compared based on the ability of cercariae to penetrate mice, on the total number of worms recovered after eight weeks of infection, on the relationship between the number of penetratin...

The pathogenicity of Diplostomum cercariae shed from two different snail species (Lymnaea. stagnalis and Radix auricularia) to rainbow trout fry (5-6 cm body length) was investigated. Thus, 1000 cercariae per fish elicited 100 % mortality within 24 h. Cercariae shed from L. stagnalis (Diplostomum pseudospathaceum) elicited higher mortality in rainbow trout compared to cercariae (Diplostomum par...

background: trematodes are a diverse group of endoparasites which require molluscan and vertebrate animals as intermediate and definitive hosts in their life cycle. the present study was carried out to determine the diversity and geographic distribution of infection with trematodes’cercariae in the snail lymnaea gedrosiana from north-west iran. methods: a total number of 6759 lymnaeidae snails ...

The transmission dynamics of the cercariae of Diplostomum spathaceum were investigated under laboratory conditions using cercariae collected from naturally infected Lymnaea stagnalis. Cercariae were kept in a constant temperature of 20 degrees C and the survival and infectivity to naïve young rainbow trout recorded at 3-h intervals until few cercariae were alive. Mortality initially remained co...

The cercarial density in natural water and number of infected Bulinus globosus were monitored over a one-year period to identify the transmission foci in an endemic area of schistosomiasis haematobia in Kenya. Overall prevalence and intensity of infection of the study community were 59.2% and 10.9 eggs/10 ml of urine. Cercariometry was carried out on 456 occasions at 20 study sites while snail ...

Trematode cercariae are commonly found in many freshwater gastropods. These cercariae can serve to identify the occurrence of such trematodes as Centrocestus formosanus, Haplorchis taichui, Haplorchoides sp, and Stellantchasmus falcatus, which are important parasites in Chiang Mai Province, Thailand. As the species of these cercariae cannot be identified accurately based on morphology, this stu...

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...