Dugongs, along with manatees, make up the mammalian Order, Sirenia. Dugongs are more streamlined and spindle-shaped than manatees and have a split tail fluke. Adult dugongs average about 2.7 meters (8.9 feet) in length and weigh between 250 and 300 kilograms (551 - 661 pounds). Males and females are similar in size. Adult males can usually be distinguished by short tusks which erupt at 12 - 15 years of age, although tusks are occasionally found in old females as well. The dugong's paddle-like flippers do not have nails.

Calves are about one meter (3.3 feet) long and weigh 20 - 35 kilograms (44 - 77 pounds) at birth. Dugongs are a pale cream color at birth, darkening to gray-brown as they age. Their skin is smooth, with hairs scattered over its surface. Dugongs are difficult to observe in the wild because the valve-like nostrils are located at the tip of the nose. This means that only a small portion of the head is visible above the surface of the water when they breathe. The muzzle is turned downward, an adaptation to bottom feeding, and the upper lip is covered with bristles which are used to locate and manipulate seagrasses, the mainstay of their diet.

Dugong facts. Dugongs are widely distributed in the waters of 43 countries along the western Pacific and Indian Oceans. They formerly inhabited most of the coastal areas of the tropical and subtropical Indo-West Pacific, where shallow seagrass meadows were found. Dugongs are the only sirenian found in the Indo-Pacific region. They are the most marine of the sirenians in their habitat preference, and almost never enter fresh water. Dugongs are most often found in shallow water, less than five meters deep.

Generally elusive and shy, dugong endangered species have been observed feeding in groups of 100 animals or more. They swim slowly (less than 5.4 knots) using the tail fluke for propulsion and their flippers for braking, turning or sculling to keep their nostrils above the waves in rough water. Speeds of up to 13.5 knots can be maintained for short distances, another of the interesting dugong facts.

Dugongs breed in all seasons, with seasonal peaks varying in different areas of their range. Sexual maturity is reached at nine to ten years of age, although some females do not reproduce until they are 15 - 17 years old. Because calves are nursed for more than a year and may stay with their mothers for two years or more, females give birth to a single calf only every three to five years. Dugongs may live up to 70 years.

Dugongs, like manatees, have been reported to feed almost exclusively on a variety of seagrasses. However, there is growing evidence that dugongs in subtropical areas also feed on sessile benthic invertebrates (ascidians and polychaetes), perhaps as a result of nutritional stress caused by seasonal fluctuations in the abundance of seagrasses in the southern edge of their range.

Dugong facts about population: the dugong population is estimated to number approximately 100,000 animals. The largest population of the dugong is found in Australia.