The free-swimming trematode larva that emerges from its host snail; it may penetrate the skin of a final host (as in Schistosoma of humans), encyst on vegetation (as in Fasciola), in or on fish (as in Clonorchis), or penetrate and encyst in various arthropod hosts. Body and tail are greatly varied in form, and specialized function is adapted to the particular life cycle demands of each species. SEE ALSO: sporocyst (1), redia. [G. kerkos, tail]
* * *
cer·car·ia (.)sər-'kar-ē-ə, -'ker- n, pl -i·ae -ē-.ē a usu. tadpole-shaped larval trematode worm that develops in a molluscan host from a redia
cer·car·i·al -ē-əl adj
* * *
n. (pl. cercariae)
the final larval stage of any parasitic trematode (see fluke). 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.
* * *
cer·ca·ria (sər-karґe-ə) pl. cercaґriae [Gr. kerkos tail] the final free-swimming larval stage of a trematode parasite, consisting of a body and tail. Some cercariae encyst on aquatic vegetation and penetrate the skin of a fish or the tissues of an aquatic arthropod to form encysted metacercariae. Cercariae of schistosomes penetrate directly into the skin of the definitive host without forming metacercariae.Medical dictionary. 2011.