..., respectively, we documented the effect of decreased pH on the egg jelly coat, an extracellular matrix that increases target size for sperm and contains sperm-attracting molecules. In near-future conditions (pH 7.8, 7.6), the jelly coat of H. tuberculata decreased by 11% and 21%, reducing egg target size by 9...

... an alternative hypothesis that accessory structures play an important physical role in fertilization by increasing the size and buoyancy of the egg, making it a better target for sperm. In the sand dollar Dendraster excentricus , the jelly coat increases egg target size sixfold. At nonsaturating sperm...