The male Blueball crab is 4 inches long. Males travel in schools are are often victims to premature death.
Female Blueball Crabs, also known as the Vulva Crab, is an elusive creature and often vicious to the male. They are almost eight times in size of the male and when carrying eggs will be as much as 2000% bigger, after birth females usually remain big and fat. The female comes in many colors and sizes. The mating dance includes a lot of cuddling and even then timing is crucial.
The male crab will often lose its limbs in the tight spaces of the female, their limbs never grow back and its rare to see males with limbs. Without limbs mating is even more difficult and males will often turn a blue purple color from the frustration.
The genus Vulvatestis Crustecean are not edible but it is not unknown for this to happen occasionally. In some cultures it is considered a delicacy and highly sought out. Some cultures simply prefer the succulent juices but do not eat the actual creature.
*Some google images viewed as refs but nothing specific.