The dugong (Dugong dugon), sometime called "Seacow", is a large marine mammal which, together with the manatees, is one of four living species of the order Sirenia.

The dugong is the only strictly-marine herbivorous mammal, as all species of manatee utilize fresh water to some degree.

Early explorers and sailors believed that they were mermaids because of their streamlined bodies and the large teats at the base of their flippers.

Like all other mammals, dugongs must surface to breathe. However, unlike other marine mammals such as some whales and dolphins, dugongs cannot hold their breath under water for very long. It is generally for only a few minutes, especially if they are swimming fast.

 

An adult dugong skull with tusks

Skeleton of the dugong

Dugong grazing sea-grass

 

The dugong reproduction

Their mating behavior involves groups of male dugongs splashing, tail-thrashing, and lunging as they compete for a single female. Calves are born after a 12- to 14-month gestation period, and spend several years with their mother, even after weaning at 18 months. Newborn calves are about 100-120 cm long and weigh 20-35 kg. Both males and females reach sexual maturity at around 9 or 10 years.

Defence

Dugongs are slow-moving and have little protection against predators. Being large animals, however, only large sharks, Saltwater Crocodiles and Killer Whales are a danger to them. Young Dugongs hide behind their mothers when in danger.

 

 

Conservation

Hunting has drastically reduced dugong populations in some areas. Although dugong are protected by law in most countries (under the Endangered Species Act in the United States), aboriginal subsistence hunting is permitted in Northern Australia and Papua New Guinea.

Dugong habitat is also under pressure from coastal development, pollution, and other degradation.

Worldwide, only five dugongs are held in captivity. Two are the featured attraction of Toba, Mie Toba Aquarium in Japan; the third, named Gracie, is at Underwater World, Sentosa Island, Singapore; and the last two are found in Sea World on the Gold Coast, Queensland, Australia.