Microscopy

Eggs of Fasciola hepatica are broadly ellipsoidal, operculated and measure 130-150 µm long by 60-90 µm wide.  The eggs are unembryonated when passed in feces.  The eggs of F. hepatica can be difficult to distinguish from Fasciolopsis spp., although the abopercular end of the former often has a roughened or irregular area.

A	B

A, B:  Eggs of F. hepatica in an unstained wet mount, taken at 400x magnification.

Adults

Adults of Fasciola hepatica are large and broadly-flattened, measuring up to 30 mm long and 15 mm wide.  The anterior end is cone-shaped, unlike the rounded anterior end of Fasciolopsis buski.  Adults reside in the bile ducts of the liver in the definitive host.

C	D

C: Unstained adult of F. hepatica fixed in formalin.
D: Adult of F. hepatica stained with carmine.