Dugong: Chinese alias: manatee, Haima, mermaid, mermaid, the South China Sea Cow
Shape features: are herbivorous mammals only in the ocean, the biggest difference with other animal such as the purpose of the manatee is the manatee manatee tail is round, and dugong tail shape and dolphin tail similar. These large heads, head and body proportion is the biggest animal in the sea. Large and vertical mouth, tongue, so that it is more conducive to eating sea plants and the sand exclusion. The hole in the head at the top of the dugong, an average of 15 minutes for a gas. The head and back of the skin is hard and thick.
The dugong body size spindlelike, body length of about 2.4 to 2.7 meters, 3 meters above the individual quite rare, generally females will be bigger than the male. The skin is smooth, the appearance is brown to dark gray, abdominal color is more shallow than the back, the surface of the hair is sparse. Neck is short, but still can have a limit to the rotation of the head or nod. The forelegs are short, slightly rounded at the end of a fin, and the lack of pectoral fin is young dugong toenail; main drive source, later it was changed to the main tail. 1 pairs of breast, nipple located at the base of the fore. No dugongs only see small ears, ears, eyes are also very small. Nose is located in the snout tip, around the film when diving in water to cover the nostrils. Wide and flat mouth is located at the end of the heavy kiss, and the short mouth is an important tool for eating.
There are 2 pairs of dugong incisors, upper and lower jaw each have 3 premolars and 3 molars on the teeth, but all does not exist at the same time, with the increase of age, they will lose first of all incisors, premolars and molars of first, two of the remaining lifetime will grow. The second of the male will penetrate the upper incisor exposed at 12-15 years old, but when the mouth closed will be thick lip covered invisible; female rarely exposed incisors, but a few will be retained to about 30 years old.
Dugong lung, extends from the chest to the kidney near, by dividing the level of the diaphragm and other organs. Most of the area of bronchial lung deeply, fine branches less and half made of cartilage, it is still not clear whether the lung and dugong diving whales generally have a collapse of the situation. Compared with other marine mammals, the fat layer thickness is thin, while the body does not seem to exist around the counter current heat exchange system (a heat countercurrent exchange system vascular structure, arteries and veins of the extremities close to the body to maintain the heat dissipation), which may be related to their habitat in warm waters. Gastric structure is simple, large (two times the size of the stomach), it is speculated that the main digestive sites of cellulose, length of more than 25 meters, equivalent to two times the length of the small intestine.
Distribution: dugong marine (and occasionally into freshwater basin) mammals, mainly distributed in the Western Pacific and India ocean, especially rich in seagrass growth areas. Although they are thought to inhabit shallow seas, they sometimes move to deeper waters, about 23 meters deep. Their distribution is not continuous, which may be related to habitat suitability and human activity. Dugong in India Ocean from the east coast of Africa, the Red Sea and the Persian Gulf, South Africa, Madagascar, Arabia and Sri Lanka east to the sea, where the number of most areas are few. In the Pacific region including Indonesia, Malaysia and Papua New Guinea to the East Indies, to the north of Taiwan and south of the Japanese island of Okinawa, including adjacent waters outside of South australia. Some areas called them "manatee" (sea cow), "the pig" (sea pig), or "sea camel" (sea camel).
In our country is mainly distributed in the northern Gulf of Guangxi coast. Guangdong and the southern coast of Hainan Island and the western coast of Taiwan, such as the eight Hong Kong also has a trail.
BBC's expedition to Mozambique in Bazaruto Archipelago, 9 miles off the coast of the location, found a lot of dugong.
Living habits: slow, gentle temperament, poor eyesight, hearing, the daily show lethargy. In addition to water ventilation after feeding from time to time, love to sneak into the 30 40m deep seabed, down to the rocks at the wait, never far away from the coast to the deep ocean. The sea surface temperature has certain requirements, do not go to the cold sea. Sensitivity to cold, the water temperature is below 15 DEG C, susceptible to pneumonia and died; poor quality also likely to suffer from skin ulcer, parasites etc..
Only the bottom feeding diet: dugong plants, a depth of about 1 to 5 meters, with a variety of marine plant roots, stems, leaves, and some algae for food, often eat the whole plant. They are not used to cut teeth of seaweed, but with its large and prehensile kiss feeding. Sometimes they will leave a gnawing traces, when exposed at low tide the kelp forests can be seen. Dugong general day or night will eat, but in areas of frequent human activities are mostly at night to feed. Every day to consume more than 45 kilograms of aquatic plants, a large part of the time spent on food. Foraging seaweed move like cow, chewing side, side kept swinging head, so there is a "manatee".
HI group activities, with 2 to 3 head of family activities, although often separate action, but it will also form a small group of 6 or so, sometimes up to hundreds of. Life at the bottom of a well covered seaweed area, regularly surfaced to breathe. Naturally shy, as long as a little frightened, it will immediately escape. Never far from the coast. Action speed is not fast, usually about 2 nautical miles per hour, but also in the 5 sea miles to escape. General every 1 to 2 minutes to float to the surface of the water, but sometimes it will be more than 8 minutes of diving. Only when the snout tip will float out of the water, dive like dolphins generally the whole body vertical rotation 1 laps. In general about 25 kilometers per day of swimming distance.
Calls for continued chug or more sharp sound, similar to manatees. Sharks, Orcas and crocodile known I would kill dugong.