Figure 1. Egg development from oviposition to first hatching and release of a morula-like structure.

A. Egg of A. ervi in the first hours after oviposition. B. Cellularisation occurs after limited syncytial cleavages, cell membranes are visible through the chorion (arrows in B). C. Folding processes of serosa cells beneath the egg chorion. D. Chorion rupture and embryo emergence from the chorion in the host hemocoel within the 24 h after oviposition (first hatching). E. Morula-like structure, about 24 h after hatching in the blastocoels. It is formed by the primordium (pr) surrounded by a monolayer of large cells, serosa cells (sc) forming the serosa membrane (Scale bars 25 µm for all panels). Abbreviations: pr, primordium; sc, serosa cells.