Egg
Adult E. soleae lays tetrahedral eggs that have a tanned protein shell. A detachable operculum constitutes one of the tetrahedron corners of the egg. The cap-like operculum is bonded to the rest of the egg-shell by a thin cement layer. The opercular bond is strong in which operculum detachment only occurs through the actions of oncomiracidium and the secretion of hatching fluid by glands from the head region. The oncomiracidium of E. soleae escapes through an aperture of the operculum during hatching.
The egg-shell of E. soleae has a similar structural appearance to Fasciola hepatica but without a membrane on the egg-shell lining. Egg-shell is produced by integration of shell material droplets from vitelline cells. Hatching of the egg occurs via chemical removal of the opercular cement and physical rupture of the rest of the egg-shell and opercular bond.
Read more about this topic: Entobdella Soleae
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