Some crustaceans use exo-skeletal change to remove heavy metals they contain in your body. For example, in an investigation conducted at the Rutgers University in the United States, it has been shown that the violinist crabs (Minuca pugnas) are able to expel three-quarters of their lead in the body during the summer.
In fact, just before the mute occurs, they accumulate lead in the exoskeleton, eliminating this harmful metal for the organism along with the loss of the exoskeleton.