Dugongs come from the dugongidae family. They are a very large marine mammal that are one of the four living species in the order Sirenia including manatees, dugongs and the Steller's Cow (which became extinct in the 18th century) the order evolved during the Eocene period, more than 50 million years ago. Dugongs are an endangered species and are currently stated as Vulnerable.
Dugongs were once mistaken for mermaids because of their fish shaped flippers and tails, unlike sharks they have no dorsal fin. Dugongs can't hold their breath for very long underwater, as a result their nostrils are near the head so that they can breathe with most of their bodies in the water. They also have a very large upperlip covered in bristles used to find and grasp sea grass. They can grow up to 3 metres in length and can reach a weigh of up to 400kg. They have very thick, smooth, skin with eyes and ears on the side of their head. Dugongs look similar to rotund grey-brown dolphins, and move slowly and gracefully through the waters.
Dugongs are herbivores. They mainly eat sea grass and sometimes add invertebrae animals to finalise their meals. Dugongs that live along the Great Barrier Reef (a World Heritage Listed site and the largest coral reef in the world), eat small delicate sea grass that are low in fibre, high in nitrogen and are easy to digest.
Dugongs range from Shark Bay in Western Australia to around the North Moreton Bay in Queensland. Dugongs are commonly found in sheltered bays and lagoons less than 5 metres deep, but have been found in waters as deep as 90 metres. Dugongs tend to avoid inshore areas but occasionally move into river mouths or creeks. Dugongs can also sometimes be found in the shallow areas of the Indian and Pacific Oceans.
A female dugong first breeds when she is 6-17 years old. This happens when the female is oestrous (on heat). Male dugongs will follow the female around and will only have a single mate for the breeding season. The mating process can be violent and gives the female several scars on her back. The pregnancy last 14 months and the calves (baby dugongs) are usually born between September and October. The calf will remain with the mother for 1-2 years and the average dugong will live for 70 years. The female dugong will produce a calf once every 3-7years.
Aboriginal and Torres Strait Islanders have hunted Dugongs for 1,000's of years and are still hunting dugongs in controlled areas. Other threats are loss of habitat from polllution and shark nets that entangle dugongs, causing them to drown.
There are approximately 80 Dugongs in Australian water, with approximately 14,000 in the Great Barrier Reef. Please help us as we try to increase these population numbers. You can help by raising further awareness, donating money and not polluting their enviroment.
Ground Breaking Study to Test the Metabolism of Dugongs
Every year at Morten Bay in Queensland, biologists and veterinarians assess the clinical health, body condition and reproductive status of the dugong. This year in a world first, the metabolic rates of three wild dugongs will be measured. The purpose behind this is to find out how much food dugongs need to survive.
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