Additionally, they have been found in San Francisco Bay and are considered to be a potential threat to the natural crab population. Growth Because of the chitinous exoskeleton growth is accomplished by molting or shedding with the new shell forming under the old shell. Carbohydrate, proteins and calcium of the old shell are dissolved and stored in the body for use in the new shell. Muscle attachments are loosened and the stomach lining is lost during a molt and reattached and reformed to the new shell. The new shell is soft and elastic and a large amount of water needs to be absorbed.
Females have the ability to store sperm for multiple spawnings.
Zoea are advected offshore where they continue to develop and transform into megalopae upon which time they reenter the Bay. Bay grass beds and oyster reefs provide habitat for the crabs to metamorphose into a juvenile.