Ipoh's Gua Tambun - Dugong Neolithic Wall Painting
is a 5000-year old wall painting of a dugong, apparently drawn by neolithic peoples, found in Tambun Cave of Ipoh city in the state of Perak, Malaysia. This was discovered by Lt.R.L Rawlings in 1959 while on a routine patrol in the area. This dugong image together with some thirty other images were painted using haematite, a type of red colouring easily available in the area to ancestors of the Orang Asli living in and around Tambun. When seen from above, the top half of a dugong or manatee can appear like that of a human woman. Coupled with the tail fin, this produced an image of what mariners often mistook for an aquatic human--possibly the origin of the mermaid myth.
During the Renaissance and the Baroque eras, dugongs were often exhibited in wunderkammers. They were also presented as Fiji mermaids in sideshows.
In the Bible
The dugong is referred to in the Bible by the phrase "sea cow" in several places in Exodus (for example, 25:5 & 26:14) and in Numbers. Dugong hides may have been used in the construction of the Tabernacle, if dugong is an accurate translation of the biblical animal tachash.
Dugong in captivity
Worldwide, only six dugongs are held in captivity. Two are the featured attraction of Toba Aquarium in Japan; the third, named Gracie, is at Underwater World, Sentosa Island, Singapore; one is in Sea World Indonesia  which was saved after being caught by a local fisherman; and the last two (Pig, a 10-year-old male, and Wuru, a four-year-old female) used to live in Sea World on the Gold Coast, Queensland, Australia, but they have been relocated to Sydney Aquarium