Yarukiman Mangrove (Hustle Muscle Mangrove in the FUNimation subs and dub) are giant striped trees that have large roots. The roots reach all the way to the bottom of the sea. Seventy nine of these trees make up the entire Sabaody Archipelago; so far, this is the only place they are known to grow.
Each Yarukiman Mangrove tree is capable of producing a special resin, which can be made into a variety of special bubble based devices and is blown into bubbles when the trees "breathe out" through cellular respiration and photosynthesis. These bubbles can only exist in and around the Archipelago's atmosphere or underwater, which makes them unique. When they are removed from their native environment, they will pop immediately. Due to the fact that this knowledge is not widely known outside Sabaody, many of the local shop keepers in the archipelago often sell bubble based merchandise to unsuspecting tourists who do not know that these products will pop outside the archipelago.
The resin is also used for coating ships, allowing them to submerse to incredible depths. This process is necessary for ships attempting to go to Fishman Island. The World Nobles also use such bubbles as helmets during their visit in the Archipelago, in order to protect themselves from "breathing the same air as commoners".