The males shed their shells later in July or August. The shell shedding of the Dungeness crab is best described by saying that it appears to be physically impossible, but they still do it. When these animals shed their shell, they leave behind remnants of all the hard parts. This includes the external coverings of the legs, gills, eyestalks, body, and body lamella. In other word, they leave everything behind but come out completely intact with no ruptures in the newly formed shell.
Growth occurs during and shortly after shedding.
It is fairly easy to determine the difference between a shed shell and a dead crab. Figure 1, shows what a new shed shell looks like just after shedding. The crab, sometimes prior to shedding, reabsorbs much of the calcium from the old shell. As a result the old shell is quite delicate and soon breaks up into numerous parts. Figure 3 shows what the back or carapace would look like if the animal had died.