Females Lobsters mate during the soft-shell phase after molting. The courtship process is a little odd.
Before molting, the female approaches a male’s den and stands outside, releasing her scent in a stream of urine. When he emerges from his den, the two spar briefly, then the female places her claws on his head to let him know she is ready to molt and mate.
They enter his bachelor pad, and she languidly strips off her shell. He tenderly turns her limp, yielding body over onto her back with his legs and his mouth.
The male, still hard-shelled and passionate, passes his sperm into her body with a pair of rigid and grooved swimmerets, small appendages normally used for swimming.
Afterward, she sinks into the soft warmth of the ocean bed and stays in the safety of his den for about a week. When her new shell is hard again, she calls a cab and goes home.
The sperm she received from the male goes into a special repository, where it stays viable for two years. When she decides that conditions are right to settle down and have a family, she fertilizes her eggs, numbering from 3,000 to 100,000.
She carries them first in her body, then for another nine to twelve months under the swimmerets attached to her tail until they hatch. Her larvae float for a month after hatching, then settle to the bottom of the ocean to turn into lobsters proper.
Still, their odds are not good, for every 100,000 eggs hatched, 4 to 6 typically survive long enough to get up to a one-pound weight.
We were eating lobster that my friend caught and we wondered about how they mate. We came across your explanation and we laughed til we cried. Very clever.