cercaria

zoology

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Last updated

June 24, 2026

Quick Summary

A cercaria is a larval stage of a trematode, a type of parasitic flatworm. These tadpole-shaped larvae develop within a mollusk, such as a snail, which acts as an intermediate host. After developing from earlier larval stages (sporocysts and rediae), the cercariae exit the snail and swim in the water. Their primary goal is to find and infect a vertebrate host to continue their life cycle, sometimes requiring a second intermediate host like a fish or amphibian before reaching their final definitive host.12

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schistosomiasis
Types and process of infection
Fork-tailed larvae, the cercariae, subsequently emerge from the snail into the water and, upon contact with the skin of a mammal, drop their tails and penetrate the tissues, getting into the blood circulation, where they feed.
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Fork-tailed larvae, the cercariae, subsequently emerge from the snail into the water and, upon contact with the skin of a mammal, drop their tails and penetrate the tissues, getting into the blood circulation, where they feed.
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flatworm
Development
…known as sporocysts, rediae, and cercariae. Through a complex process of asexual replication, each miracidium larva gives rise to dozens, or even hundreds, of cercariae. The cercariae exit the snail and swim for a number of hours in the surrounding water. The cercariae must locate a vertebrate host to complete…
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…known as sporocysts, rediae, and cercariae. Through a complex process of asexual replication, each miracidium larva gives rise to dozens, or even hundreds, of cercariae. The cercariae exit the snail and swim for a number of hours in the surrounding water. The cercariae must locate a vertebrate host to complete…
Read More

mimicry
Parasitic worms
…large larvae form, called a cercaria. The size of this cercaria and its hopping mode of locomotion cause it to resemble a small, swimming crustacean or mosquito larva, with the result that fish mistake it for food and swallow it. Research on parasites of this kind is much easier when…
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…large larvae form, called a cercaria. The size of this cercaria and its hopping mode of locomotion cause it to resemble a small, swimming crustacean or mosquito larva, with the result that fish mistake it for food and swallow it. Research on parasites of this kind is much easier when…
Read More