Indonesian white gum. Indonesian white gum, commonly known as Bai Yin, is the swim bladder of yellow croaker; The swim bladder, also known as the belly of fish, is an organ that plays the role of ups and downs in fish. Nibea albiflora (scientific name: Nibea albiflora) is a kind of fish belonging to the genus Nibea. The body is elongated, the side is flat, and the back is slightly raised.