Aquatic eggs question?

The aquatic egg of Nymphula has no trabecular layer and no aeropyles. Four tubular micropyles only traverse the anterior part of the chorion. Presumably, the egg contains a sufficient quantity of air to allow the development of the caterpillar when the egg is immersed in paraffin oil. Under the chorion, the vitelline membrane possesses crypts and furrows which seem filled by air. This air can enter through the permeable regions of the vitelline membrane. The mucus, between the chorion and the under surface of the leaf, may constitute an external air reserve dependent on photosynthesis.