Fasciola hepatica

Liver flukes are found world-wide, especially in the U.S., Europe, Asia, and S. Africa. Basically they inhabit any region where mammals and snails are found.

The habitat of the liver fluke changes in relation to its current life stage.

Liver flukes reproduce both sexually and asexually. Adults are hermaphroditic, capable of both cross- and self-fertilization. The larvae stage known as sporocyst reproduces asexually with its offspring developing into rediae, which also multiply asexually. Adults live in the bile ducts of their mammalian host. Their eggs enter the host gut and are passed on with feces. They hatch to form free-living egg larvae or miracidia, which can live only a few hours in water. If a suitable snail host is entered, the miracidium develop into a sporocyst, which produce, either more rediae or another type of larvae called cercaria. The cercaria exit the snail via the pulmonary cavity, free-swim until attaching to grass or some other object, and develop into cyst-encased metacercaria. The metacercaria remain secure in their cysts until eaten by a mammal. If eaten, a metacercarium bores through to the mammal's liver and remains until it matures into an egg producing adult, at which time it settles in the bile ducts.

Liver flukes have no distinguishing behavior traits or social systems. They can live solitarily or together in a host.

Adult liver flukes feed on liver tissue while in the mammal host. The larvae stage known as redia feed on the digestive gland or liver while in the snail host. The free-living miracidium and metacercarium stages are non-feeding.

None.

Liver flukes cause tremendous loss to farmers of cattle and sheep. They are responsible for such diseases as liver rot and black disease, which are detrimental to livestock. They are very hard to control in grazing animals. Though drugs will kill adults, they have no effect when the fluke is in a migratory stage. Vaccines given to livestock do not reduce infection. Grazing management reduces but does not eliminate infestation, probably because wild animals such as rabbits serve as reservoirs.