Egg envelopes
are elaborated by follicle cells and laid down in a well defined sequence (Gaino and Mazzinmi, 1990). The ultrastructural
analysis of newly spawned eggs of O. massavensis revealed
that they were covered by the characteristic chorion
with three different regions; the marginal, central and frontal
regions. This may be due to different distributions of underlined
yolky materials (El-Sherief, 1990)