Den Den Mush are a species of anthropomorphic snails, frequently employed by Marines, pirates, or civilians alike as a medium for telecommunications. These "Phone Snails" possess the unique ability to broadcast and recieve radio waves, allowing the relaying of information over long distances. There are numerous species of Den Den Mushi, though the majority of differences are trivial. Some of the more pronounced species include:
Photographic Den Den Mushi: A species of Den Den Mushi that is able to convey image signals in addition to sounds. The recieved image is then printed out by the snail on a piece of paper, which emerges from the snail's mouth.
Baby Den Den Mushi: Though not a seperate species of Den Den Mushi, baby snails are small and portable, but they lack the ability to recieve or transmit information over long distances.
Black Den Den Mushi: An uncommon species that is able to intercept transmissions of other snails; the strength of their reception is largely dependent on distance, though they are commonly employed by the Marines as a form of "wire tapping".
Golden Den Den Mushi: One of the rarest snails in the One Piece series, the Golden Den Den Mushi is used exclusively by the three admirals and Cipher Pol #9 chief as a means to call the elite "Buster Call" naval fleet.
Silver Den Den Mushi: Apparently related to the Golden Den Den Mushi, this species of snail is confined to the Marine Headquarters, and is used exclusively as a reciever for the Buster Call authorization transmission.