n. (pl. rediae) the third-stage larva of a parasitic *fluke. Rediae develop within the body of a freshwater snail and undergo a process of asexual reproduction, giving rise to many fourth-stage larvae called *cercariae. See also miracidium; sporocyst.
n. any of the parasitic flatworms belonging to the group Trematoda. Adult flukes, which have suckers for attachment to their host, are parasites of humans, occurring in the liver (liver flukes; see Fasciola), lungs (see Paragonimus), gut (see Heterophyes), and blood vessels (blood flukes; see Schistosoma) and often cause serious disease. Eggs, passed out with the host’s stools, hatch into larvae called *miracidia, which penetrate an intermediate snail host. Miracidia give rise asexually to *redia larvae and finally *cercariae in the snail’s tissues. The released cercariae may enter a second intermediate host (such as a fish or crustacean); form a cyst (*metacercaria) on vegetation; or directly penetrate the human skin.... fluke
n. the second-stage larva of a parasitic *fluke, found within the tissues of a freshwater snail. A sporocyst develops from a first stage larva (see miracidium) and gives rise either to the next larval stage (see redia) or daughter sporocysts. The latter develop directly into the final larval stage (see cercaria) without the intermediate redia stage.... sporocyst
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