The body of the dugong is fusiform, about 3 meters long, and weighs 300-500 kilograms. There are sparse short fine body hairs all over the body. There is no obvious neck, the head is small, the upper lip resembles a horseshoe, the end of the muzzle protrudes with bristles, two nearly round breathing holes juxtaposed in the front of the head; no external auricle, the ear holes are located behind the eyes. No dorsal fin, fin limb oval. Caudal fin broad, flattened and symmetrical on right and left sides, posterior margin forked, without notches. A pair of breasts is present on the underside of the fin limbs. The dorsum is predominantly dark gray, the abdomen slightly lighter.
The dugong is a marine herbivore. Its distribution is closely related to water temperature, sea currents and the distribution of seaweed as the main food. More than 20 meters from the coast in the seaweed bushes, sometimes with the tide into the estuary, and after feeding with the ebb tide back to the sea, rarely swim to the sea. They are found in family groups of 2-3, living at the bottom of seagrass areas with good hiding conditions and surfacing regularly to breathe. Often recognized as "mermaids" surfacing, leaving people with a lot of beautiful legends.