Blue Crabs- Mating
Female blue crabs can mate only once in their lifetime, so it is important for them to have a foolproof way of finding mates. Female blue crabs release a pheromone in their urine to attract male blue crabs. When the two blue crabs find each other, the male blue crab will carry and protect the female blue crab until the female crab's shell gets soft during molting.The pair will mate following the molting stage.The female will capture and store the male's sperm in sac-like receptacles so it can fertilize its eggs at a later time. When the female's shell hardens, the male will release her and she will move to waters with higher salinity to spawn.
Spawning
Most crabs spawn two to nine months after they mate.The fertilized eggs are extruded into a cohesive mass of eggs or "sponge." The sponge remains attached to the crab's abdomen until the larvae emerge.