In biology, the fourth larval stage of a fluke usually free-swimming; penetrates the body of a second alternate host of definitive host.
The final larval stage of any parasitic trematode. The cercariae, which have tails but otherwise resemble the adults, are released into water from the snail host in which the parasite undergoes part of its development. Several thousand cercariae may emerge from a single snail in a day.
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.
Within the realm of parasitic organisms, there exists a fascinating creature known as the schistosome worm. This peculiar being assumes a free-living existence, boasting a distinguishing attribute—a notable tail that enables it to navigate aquatic environments with graceful ease. Moreover, perched upon its head, one can discern the presence of remarkable suckers, aptly designed to facilitate its penetration into the body of a host.