Complex sentence: They begin to rebuild their shells after that, and when eaten, have a thin shell developing, they are then referred to as "papershells" and are more crunchy when eaten--making them less desirable to many people.
Split into simpler sentences: They begin to rebuild their shells after that, and when eaten, have a thin shell developing. They are then referred to as "papershells" and are more crunchy when eaten, making them less desirable to many people.