Fasciola hepatica, commonly known as the sheep liver fluke, is a parasitic flatworm that infects the livers of sheep and other ruminants. It resides in the bile ducts of infected animals and passes eggs through their feces that hatch in water and infect freshwater snails, developing through several stages before releasing larvae that encyst on aquatic plants. Humans become infected by ingesting these encysted larvae on plants like watercress, after which the fluke migrates through the body and lives/reproduces in the bile ducts, potentially causing liver damage and symptoms like jaundice. Diagnosis involves finding eggs in stool or bile samples, and treatment uses antihelmintic

1. TREMATODA Fasciola hepatica

6. A stained adult Fasciola hepatica ; approximate length = 20 mm. The internal organs are highly branched, thus making it very difficult to differentiate the various internal organs All of their major systems are branched, including the intestine, testes, and ovary.

8. The ova Length 130-145 µm Width 70-90 µm Regular ellipse Thin shell Operculum at one pole Granular yellowish-brown contents filling whole egg

9. egg capsule with emerging miracidium of Fasciola hepatica . 400x unembryonated egg capsule of F. hepatica . earlier stage of development. 400x embryonated egg capsule of Fasciola hepatica. So-named because the miracidium is fully formed and ready to emerge. The operculum can be seen to the left. 400x

10. Redia and cercaria of Fasciola hepatica Miracidium of Fasciola hepatica . This ciliated, non-feeding larval stage, has about 24 hours to find its specific snail host, such as Fossaria modicella or Stagnicola bulimoides. 400x

11. The Life Cycle

23. Next : Fasciolopsis buski