Reproduction
The males have testes which produce sperm. It is located above the hepatopancreas on both sides of their stomach. Females have sponges that are connected to swimmerets which hold/produce their eggs. It is located under their apron.
They are usually sexually mature after 12-18 months or after 18-20 post-larval molts. Males do a dance to get the female's attention. They then produce a chemical in attempt to allure the female. If the female shows interest she will respond by waving her claws. "The gonopod, not the penis, is the intromittent organ used to deliver spermatophores to the female gonopore (the penis fits into a groove on the gonopod to which it delivers sperm). The second pleopod is much shorter and functions as a piston to push spermatophores through the hollow core of the gonopod." The sperm given to the female usually works successfully her whole life which is good because she will only mate once in her life. The female can produce many fertilized eggs after. Males and females have a chromosome number of 127.
[1] http://web.vims.edu/adv/ed/crab/guts3.html
[2] http://chesapeakebay.noaa.gov/fish-facts/blue-crab
[3] http://www.bluecrab.info/lifecycle.html
[4] http://www.bluecrab.info/mating.html
They are usually sexually mature after 12-18 months or after 18-20 post-larval molts. Males do a dance to get the female's attention. They then produce a chemical in attempt to allure the female. If the female shows interest she will respond by waving her claws. "The gonopod, not the penis, is the intromittent organ used to deliver spermatophores to the female gonopore (the penis fits into a groove on the gonopod to which it delivers sperm). The second pleopod is much shorter and functions as a piston to push spermatophores through the hollow core of the gonopod." The sperm given to the female usually works successfully her whole life which is good because she will only mate once in her life. The female can produce many fertilized eggs after. Males and females have a chromosome number of 127.
[1] http://web.vims.edu/adv/ed/crab/guts3.html
[2] http://chesapeakebay.noaa.gov/fish-facts/blue-crab
[3] http://www.bluecrab.info/lifecycle.html
[4] http://www.bluecrab.info/mating.html
Development
Females carry eggs for 2-9 months, become mature between 12-18 months and live for 2-3 years. The first stage of development is "zoeze". It lasts 31-49 days. This is when they become "[f]ilter feeders, and live a planktonic existence in the high-salinity surface waters near the spawning grounds." They molt 4-7 times and then start their second stage of development, "megalops". It lasts -20 days. "The megalops larva is more crablike in appearance than the zoeae, its carapace is broader in relation to its length, and has biting claws and pointed joints at the ends of the legs." They typically have 500,000 eggs but many die. They also do not take care of their young, they only care for their eggs.
[1] http://www.avivadirectory.com/trivia/213-20-fast-facts-about-blue-crabs/
[2] http://www.dnr.state.md.us/education/mydnr/KIDS/bbc_adult.asp
[3]http://www.bluecrab.info/lifecycle.html
[4] http://www.ceoe.udel.edu/kiosk/bluecrab.html
[1] http://www.avivadirectory.com/trivia/213-20-fast-facts-about-blue-crabs/
[2] http://www.dnr.state.md.us/education/mydnr/KIDS/bbc_adult.asp
[3]http://www.bluecrab.info/lifecycle.html
[4] http://www.ceoe.udel.edu/kiosk/bluecrab.html