Clawed lobsters copulate shortly after the female sheds her old exoskeleton. The male then attaches an additional gelatinous material to the outside of the female's receptacle. Once this transfer is accomplished, mating is complete and the female tail flips out from under the male as he releases her. The gelatinous material hardens within the first day, effectively plugging the female so the spermatophore won't be lost. The sperm plug falls off several days later, leaving behind the hardened spermatophore.
Females can also mate in the hard-shelled condition.
This may be important for very large females who molt infrequently. Material provided in this document is not to be cited or used without permission . Copyright by The Lobster Conservancy, 1998.