cercaria
/sərˈkɛriə/
noun
- A free-swimming larval stage of a parasitic flatworm (trematode) that emerges from a snail host and can infect a final host, such as a fish or human.
- Each cercaria has a tail that helps it move through the water.
- The cercaria swims in water until it finds a suitable host to infect.
- Swimmers in some lakes risk exposure to cercariae that cause swimmer's itch.