Is the Golden Den Den Mushi mechanical, or a living specimen? The Golden Den Den Mushi is used for ordering the Buster Call and seems to be made of rigid gold. It's strange and unusual for the rest of the species.

Is it an actual living being, or (unlike regular Den Den Mushis) some kind of mechanically improved, or purely mechanical device?
In Chapter 386 Spandam is holding the Golden Den Den Mushi and mentions that it is a precious species, indicating that it is in fact, a living snail.