Reproductive Habits
     May and June are the most common months in which mating occurs, though it can occur at other times of the year. Mating occurs between hard-shelled male crabs and newly-molted, soft-shelled female crabs. The female stores the sperm in a seminal receptacle until the fall when the eggs are fertilized. She cannot molt in the fall when the male does because she loses the sperm receptacle at that time. When the fertilized eggs are extruded, the resulting mass, often called the sponge, is attached to the female. A large female may carry in excess of 2 1/2 million eggs. Females carrying eggs usually bury themselves in sandy razor clam beaches during the fall.

Hatching and Development
     The embryos develop during the winter and the eggs darken to a dirty brown. Between January and March, the larval crabs hatch and swim freely in the sea. They do not resemble adult crabs at this time, and must molt repeatedly and grow much larger before they are recognizable as crabs. When they reach a quarter of an inch in size, approximately one year after the mating that produced them, the juveniles finally resemble the adults they will become. At that time, they take up bottom residence, though it will be another 2-3 years before they reach the minimum sizes for legal catches. Since the male reaches sexual maturity a year before he reaches legal harvesting size and females are completely protected from legal harvest, the Dungeness Crab is unlikely to be decimated by over-harvesting.