Crabs usually mate during the breeding season, which varies by species and location. The male crab will approach a female and attempt to grasp her with his claws. He may also perform a courtship ritual, which can involve displaying his claws or performing a dance.
If the female is receptive, she will allow the male to mate with her. The male transfers his sperm to the female through a pair of specialized appendages called gonopods, which are located near the base of his hind legs. The female stores the sperm until she is ready to fertilize her eggs.
After mating, the female will lay her eggs in a safe location, such as buried in sand or attached to her abdomen. The eggs will hatch into larval crabs, which will continue to develop and grow over several months until they are fully formed adults.