From them arise tadpole-like cercariae, which leave snails to seek the next host. Clonorchis sinensis , the Chinese liver fluke . Adult lives in bile ducts of liver. Eggs out the intestine and out with feces. Cercarial stage finds a fish, penetrates its skin, and encysts.
Fluke colonizes human with eating of poorly cooked fish.
Schistosoma species, the blood fluke . Live in bloodstream, with male and female continously copulating. Eggs with spines to help passage in either feces or urine. Miracidia hatches and sporocyst stage matures in snail before next larval stage or cercariae, which penetrate human skin and mature in bloodstream. The tapeworms are well known intestinal parasites of vertebrates.