Multiple events occur at the interface between the sperm and egg membrane during fertilization, including sperm‐egg binding, species‐specific discrimination, membrane fusion, and egg activation. Each of these events is believed to rely upon discrete cell surface molecules. To date, only a handful of egg membrane proteins have been identified in any species. The process of fertilization as a whole is not well understood on a molecular level, from the initial sperm and egg binding, to the activation of early development. An excellent model organism to address these problems is the Pacific bat star, Patiria miniata, because they produce a large quantity of synchronized oocytes that are large, nearly transparent, and rigid enough to hold their shape despite removal of extracellular layers. Furthermore, we are learning that their genome is similar to humans with less complexity. Recent work suggests that proteases are necessary for successful fertilization, raising the possibility that fragments of egg membrane proteins could be released from the surface during fertilization. This could provide a mechanism for the identification of fertilization‐relevant membrane proteins. Using biotinylation and western blotting, we show that peptides ranging from 50kD to 250kD are being cleaved from the egg surface and released into the sea water within three minutes of introducing sperm. These peptides have been collected by affinity interaction against streptavidin conjugated mag‐sepharose beads and their identities are being determined by tandem mass spectrometry. Since a proteome has not yet been created for P. miniata, a recently developed transcriptome of the mature unfertilized egg (NCBI accession number: PRJNA398668) will be used to identify the peptides revealed by tandem mass spectrometry. Furthermore, this transcriptome is also being examined computationally with the purpose of identifying and grouping transcripts that may be integral to fertilization, as a whole, and with a specific focus on the egg cell surface. Understanding how fertilization takes place at the molecular level in starfish could eventually lead to understanding infertility issues, as well as offer new possible non‐hormonal prophylactics for use in humans.Support or Funding InformationNIH R15This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.