clupeine

noun
clu·​pe·​ine | \ ˈklü-pē-ən How to pronounce clupeine (audio) , -ˌēn How to pronounce clupeine (audio) \
variants: also clupein \ -​ən How to pronounce clupein (audio) \

Medical Definition of clupeine

: a protamine contained in the spermatozoa of the herring