[1] During embryonic development the perivitelline fluid is ingested macropinocytotically by the embryos and the resulting phagosomes fuse with β-granules containing hydrolytic enzymes, which digest the perivitelline fluid components.
Fertilized oocytes enter the albumen gland and, on their way out, are coated with the perivitelline fluid.
[8] In this regard, it has been shown in Pomacea apple snails that during the reproductive season, when the nutrient precursors decrease in the albumen gland due to successive ovipositions, females tend to reduce the number of eggs per clutch but not the amount allocated to each egg.
Specifically, the eggs of most gastropod accumulate the polysaccharide galactogen,[8][10][11][12][13] which would provide the main energy source for the developing embryo.
[26][27] Recent proteomic analyses, however, showed that the perivitelline fluid from Pomacea snails has between 34-38 different proteins with a wide variety of functions.