[2] The egg jelly is located immediately surrounding the vitelline envelope and consists primarily of a network of short peptides and sulfated fucan glycoproteins.
[1] An example of such a peptide is resact, which has been studied as the primary means of attracting and orientating sperm to the eggs in sea urchins.
[3] The sulfated fucan glycoproteins play an important role in binding to sperm receptors and triggering the acrosomal reaction.
[3] For echinoderms the jelly coat can increase the diameter of the egg by more than 100%, making it efficient in enhancing fertilization.
In female P. shqipericus, the Albanian water frog, the jelly coat cause sperm to become motile and move faster.