Parasite
Fasciola hepatica
Sheep liver fluke from watercress
fah-SEE-oh-luh heh-PAT-ih-kuh
High-yield clue
Metacercariae on watercress (not fish) migrate to the bile ducts - the key distinction from Clonorchis.
Overview
The sheep liver fluke, a large trematode acquired by eating aquatic plants such as watercress bearing metacercariae, used to contrast plant-borne with fish-borne liver flukes.
Classification
- Trematode (fluke)
- Large leaf-shaped adult
- Snail intermediate host, aquatic-plant metacercariae
- Adults in bile ducts / liver
Lab & identification clues
- Large operculated eggs on stool examination
- Eggs hard to distinguish from Fasciolopsis vocabulary
- Serology in early (migratory) phase concept
Associations
- Ingestion of watercress/aquatic plants with metacercariae
- Liver and biliary phase vocabulary
- Sheep and cattle reservoir (zoonosis)
- Sheep-raising region epidemiology
Commonly confused with
- Clonorchis sinensis
- Paragonimus westermani
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.