Cercariae


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cercaria

 [ser-kar´e-ah] (pl. cerca´riae) (L.)
the final, free-swimming larval stage of a trematode parasite.

cercaria

(ser-ka're-a) plural.cercariae [Gr. kerkos, tail]
A free-swimming stage in the development of a fluke or trematode. Cercariae develop within sporocysts or rediae that parasitize snails or bivalve mollusks. They emerge from the mollusk and either enter their final host directly or encyst in an intermediate host that is ingested by the final host. In the latter case, the encysted tailless form is known as a metacercaria.
See: fluke; trematode

Cercariae

The free-living form of the schistosome worm that has a tail, swims, and has suckers on its head for penetration into a host.
Mentioned in: Schistosomiasis
References in periodicals archive ?
In the laboratory, the snails were kept individually in vials with 20 mL of tap water, and were observed for the emergence of cercariae.
Each snail was carefully observed under a dissecting microscope every day after the exposure of sunlight; when the shedding was complete, the cercariae were separated.
magna infection (Swales 1936, Pybus 2001), some cercariae may encyst as free-floating metacercariae in surface water (Morley 2015).
However, even with a small infestation of the population, it may be sufficient to maintain opisthorchiasis foci, as opisthorchis larvae's parthenogenetic reproduction occurs in the shellfish body for a long time, resulting in the multiple increase in the numerosity and displacement forms of cercariae.
2) After 4-6 weeks of infecting the snail, the cercariae leave the snail and gyrates around for about 72 h looking out for the skin of a prospective host.
mansoni cercariae, infected animals were divided into the remaining four groups, the second group is infected (-MLE) group.
This includes temperature ranging from 23-26oC for development of eggs (Rowcliffe and Ollerenshaw 1960; Thomas 1883 ab) and maximal growth of snails (Kendall 1953) and humidity level upto 90 % caused by plenty of water available facilitates embryonation (Andrew 1999) emergence of miracidium from eggs due to increased activity of cilia (Thomas 1883 ab) and liberation of cercariae from snails (Alicata 1938; Dixon1966).
We did not observe emission of cercariae during consumption of parasitized snails of the Mc and Gc classes.
From the derivatives studied, 15 naphthoquinones blocked penetration by cercariae when applied to the tails of mice 24 h prior to infection through the tail.
As soon as temperature increases to 20oC, the development of larvae commences and at an optimum temperature range (25oC to 247oC), maximum shedding of cercariae (a larval stage) take place.