Management of reproduction is a critical component in the husbandry of wildlife in captivity. A Decrease font size. They were also presented as Fiji mermaids in sideshows. When eating they ingest the whole plant, including the roots, although when this is impossible they will feed on just the leaves. (AP Photo/Linda Lombardi) This Sept. 5, 2012 photo shows Serena, a dugong at the Toba Aquarium in Toba, Japan.  Dugongs have two teats, one located behind each flipper. , Despite being legally protected in many countries, the main causes of population decline remain anthropogenic and include hunting, habitat degradation, and fishing-related fatalities.  The Mediterranean is the region where the Dugongidae originated in the mid-late Eocene, along with Caribbean Sea. The eastern side of the Red Sea is home to large populations numbering in the hundreds, and similar populations are thought to exist on the western side.  They are usually located at a depth of around 10 m (33 ft), although in areas where the continental shelf remains shallow dugongs have been known to travel more than 10 kilometres (6 mi) from the shore, descending to as far as 37 metres (121 ft), where deepwater seagrasses such as Halophila spinulosa are found. Australia is a signatory to both these conventions.  The Gulf of Thailand was historically home to large number of the animals, but none have been sighted in the west of the gulf in recent years, and the remaining population in the east is thought to be very small and possibly declining.  Con Dao is now the only site in Vietnam where dugong are regularly seen, protected within the Côn Đảo National Park. Different sounds have been observed with different amplitudes and frequencies, implying different purposes. Australia is the stronghold for the species: a significant chunk of the world’s population – an estimated 70,000 – cruise about in the shallows of at least 10 different locations along the 25,000km of our northern coastline, stretching from Shark Bay, Western Australia, to Moreton Bay.  The way that females know how a male has reached sexual maturity is by the eruption of tusks in the male since tusks erupt in males when testosterone levels reach a high enough level. Its snout is sharply downturned, an adaptation for feeding in benthic seagrass communities.  Although almost completely herbivorous, they will occasionally eat invertebrates such as jellyfish, sea squirts, and shellfish. , The Persian Gulf has the second-largest dugong population in the world, inhabiting most of the southern coast, and the current population is believed to range from 5,800 to 7,300.  It was later assigned as the type species of Dugong by Lacépède and further classified within its own family by Gray and subfamily by Simpson.  Dugongs are listed under the Nature Conservation Act in the Australian state of Queensland as vulnerable.  The dugong has two incisors (tusks) which emerge in males during puberty. , Australia is home to the largest population, stretching from Shark Bay in Western Australia to Moreton Bay in Queensland.  The age when a female first gives birth is disputed, with some studies placing the age between ten and seventeen years, while others place it as early as six years. Boat strikes on dugongs occur in heavy boat traffic areas and are usually associated with coastal development. , If dugongs do not get enough to eat they may calve later and produce fewer young. In some areas it remains an animal of great significance, and a growing ecotourism industry around dugongs has had an economic benefit in some countries.. In many countries, the legislation does not exist to protect dugongs, and if it does it is not enforced. Seven different species of sea (or marine) turtles grace our ocean waters, from the shallow seagrass beds of the Indian Ocean, to the colorful reefs of the Coral Triangle, and even the sandy beaches of the Eastern Pacific. Dugong numbers have decreased in recent times. "Dugongs don't do well in captivity," she added. These flukes are raised up and down in long strokes to move the animal forward, and can be twisted to turn.  New sightings of a cow-calf pair have been reported in 2017, indicating a possible breeding had occurred in these waters. In areas where there is a large tidal range, dugongs travel with the tide in order to access shallower feeding areas. Dugongs, the elusive sirenian that served as the model for mermaids, are only raised in two aquariums around the world. The United Arab Emirates has banned all hunting of dugongs within its waters, as has Bahrain. It is one of four living species of the order Sirenia, which also includes three species of manatees. Go behind-the-scenes to see how our trainers care for and interact with these amazing animals, and get up close with some finned, flippered, or feathered friends. The Steller's sea cow became extinct in the 18th century. Due to their poor eyesight, dugongs often use smell to locate edible plants. … , The IUCN Red List lists the dugong as vulnerable, and the Convention on International Trade in Endangered Species of Wild Fauna and Flora regulates and in some areas has banned international trade. In other southern areas of both western and eastern Australia, there is evidence that dugongs actively seek out large invertebrates. Convention on International Trade in Endangered Species, the establishment of a seagrass sanctuary for dugong and other endangered marine fauna, Convention on International Trade in Endangered Species of Wild Fauna and Flora, Dugong: status reports and action plans for countries and territories, "Tactile Hairs on the Postcranial Body in Florida Manatees: A Mammalian Lateral Line? Dugongs are notoriously difficult to keep in captivity because of their specialised diet – which is substituted with lettuce instead of … Dugong ribs were used to make carvings in Japan. In Okinawa the small dugong population is threatened by United States military activity. , Most dugongs do not feed on lush areas, but where the seagrass is more sparse. The forelimbs are paddle-like flippers which aid in turning and slowing. Litters of plastic waste (single-use sachets, plastic bottles, Jollibee to-go containers etc.) Australian Geographic acknowledges the First Nations people of Australia as traditional custodians, and pay our respects to Elders past and present, and their stories and journeys that have lead us to where we are today. This study reports on the first multi-year reproductive hormone monitoring program for captive dugongs of both sexes using feces. And unlike manatees, which use freshwater areas, the dugong is strictly a marine mammal. In the 1980s, it was estimated there could be as many as 4,000 dugongs in the Red Sea. An individual this long is expected to weigh around 420 kilograms (926 lb). Plans exist to build a military base close to the Henoko reef, and military activity also adds the threats of noise pollution, chemical pollution, soil erosion, and exposure to depleted uranium.  In some populations, males will establish a territory which females in estrus will visit. Hunting, catching, and harassment are banned by the People's Republic of China. , All the islands of the Philippines once provided habitats for sizeable herds of dugongs. , A small population exists today along the southern coast of China, where efforts are being made to protect it, including the establishment of a seagrass sanctuary for dugong and other endangered marine fauna ranging in Guangxi.  Birth occurs in very shallow water, with occasions known where the mothers were almost on the shore. PLUS receive a gift. , Dugong numbers have decreased in recent times. A female from the Philippines lives at Toba Aquarium in Toba, Mie, Japan. , The dugong's body is large with a cylindrical shape that tapers at both ends. No fossils exist of other members of the Dugongidae. Dugong populations in Madagascar are poorly studied, but due to widespread exploitation it is thought they may have severely declined, with few surviving individuals.  Today populations of dugongs are found in the waters of 37 countries and territories. Dugong feeding may favor the subsequent growth low-fibre, high-nitrogen seagrasses such as Halophilia and Halodule.  Unlike in manatees, the dugong's teeth do not continually grow back via horizontal tooth replacement.  Gatherings of hundreds of dugongs sometimes happen, but they last only for a short time. During the Renaissance and the Baroque eras, dugongs were often exhibited in wunderkammers. , A dugong's brain weighs a maximum of 300 g (11 oz), about 0.1% of the animal's body weight. , Populations also exist around the Solomon Islands archipelago and New Caledonia, stretching to an easternmost population in Vanuatu. In areas such as northern Australia, hunting remains the greatest impact on the dugong population. There is evidence that dugongs actively alter seagrass species compositions at local levels. Most currently live in established marine parks, where boats must travel at a restricted speed and mesh net fishing is restricted. Sewage, detergents, heavy metal, hypersaline water, herbicides, and other waste products all negatively affect seagrass meadows.  When need to be nursed, calves would suck their flippers in a 'thumb sucking' fashion as observed in calves under human care.  In the Seychelles, dugongs had been regarded as extinct in 18th century until a small number was discovered around the Aldabra Atoll. Most measures for protection involve restricting activities such as trawling in areas containing seagrass meadows, with little to no action on pollutants originating from land. , Dugong dugon is the only extant species of the family Dugongidae, and one of only four extant species of the Sirenia order, the others forming the manatee family. The dugong has been hunted for thousands of years for its meat and oil. , Dugongs are semi-nomadic, often traveling long distances in search of food, but staying within a certain range their entire life. There are only six captive dugongs in the world and Australia has two of them.  Once distributed throughout the coastal belt in Sri Lanka, the dugong numbers have declined in last two decades. Feeding trails have been observed as deep as 33 metres (108 ft), and dugongs have been seen feeding as deep as 37 metres (121 ft). Overpopulation and lack of education of all coastal fisherfolk in the Philippines regarding marine trash are clearly harming the coastal environment not only in Palawan but also across the islands of the Philippines. Introduction. The molar teeth are simple and peg-like unlike the more elaborate molar dentition of manatees. The dugong is largely dependent on seagrass communities for subsistence and is thus restricted to the coastal habitats which support seagrass meadows, with the largest dugong concentrations typically occurring in wide, shallow, protected areas such as bays, mangrove channels, the waters of large inshore islands and inter-reefal waters. Today, possibly the smallest and northernmost population of dugongs exists around the Ryukyu islands, and a population formerly existed off Taiwan.  It was later revealed that the government of Japan was hiding evidence of the negative effects of ship lanes and human activities on dugongs observed during surveys carried out off Henoko reef. Get great photography, travel tips and exclusive deals delivered to your inbox. Even in the best conditions, a population is unlikely to increase more than 5% a year, leaving dugongs vulnerable to over-exploitation. Because Halodule leaves are fragile and much leaf material is lost to drift, dugongs … Mothers and calves are in almost constant physical contact, and calves have been known to reach out and touch their mothers with their flippers for reassurance. Commonly known as "sea cows," dugongs graze peacefully on sea grasses in shallow coastal waters of the Indian and western Pacific Oceans.  A vagrant strayed into port near Ushibuka, Kumamoto, and died due to poor health. Australia has two distinct maternal lineages, one of which also contains the dugongs from Africa and Arabia. The two extant families of sirenians are thought to have diverged in the mid-Eocene, after which the dugongs and their closest relative, the Steller's sea cow, split off from a common ancestor in the Miocene. The estimated percentage of females humans can kill without depleting the population is 1–2%.  The population of Shark Bay is thought to be stable with over 10,000 dugongs.  The Great Barrier Reef provides important feeding areas for the species; this reef area houses a stable population of around 10,000, although the population concentration has shifted over time. Body parts are used as food, medicine, and decorations. , In Thailand, the present distribution of dugongs is restricted to six provinces along the Andaman Sea, and very few dugongs are present in the Gulf of Thailand. The phylogenetic analysis of bacterial 16S rRNA genes was conducted for fecal samples, which were taken at 3 …  Females tend to be larger than males. Determining the reproductive status of long-term captive animals is essential because the onset of sexual maturity and reproductive activity may necessitate changes in husbandry requirements. A Increase font size.  However, recent studies revealed severe declines both in population size and distributions among the region.  The use of shark nets has historically caused large numbers of deaths, and they have been eliminated in most areas and replaced with baited hooks. As well as their tendency to stick to murky, or turbid, water, it’s one of the main reasons they’re so elusive – and why few Australians have ever seen one.  These hairs are most developed around the mouth, which has a large horseshoe-shaped upper lip forming a highly mobile muzzle. Deep waters may provide a thermal refuge from cooler waters closer to the shore during winter. , The word "dugong" derives from the Visayan (probably Cebuano) dugung. This is the most significant negative factor affecting seagrass. Some aborigines regard dugongs as part of their Aboriginality.  Dugong populations in these areas were reduced by historical hunts as payments to the Ryukyu Kingdom, before being wiped out because of large-scale illegal hunting and fishing using destructive methods such as dynamite fishing after the Second World War. , In the late 1960s, herds of up to 500 dugongs were observed off the coast of East Africa and nearby islands.  Capturing animals for research has caused only one or two deaths; dugongs are expensive to keep in captivity due to the long time mothers and calves spend together, and the inability to grow the seagrass that dugongs eat in an aquarium. Human activity such as mining, trawling, dredging, land reclamation, and boat propeller scarring also cause an increase in sedimentation which smothers seagrass and prevents light from reaching it. WWFs work on sea turtles focuses on five of those species: green, hawksbill, loggerhead, leatherback and olive ridley. , Although they are social animals, they are usually solitary or found in pairs due to the inability of seagrass beds to support large populations. This number is reduced in areas where calvingis minimal due to food shortages. , Dugongs are found in warm coastal waters from the western Pacific Ocean to the eastern coast of Africa, along an estimated 140,000 kilometres (86,992 mi) of coastline between 26° and 27° degrees to the north and south of the equator.  As soon as the young is born the mother pushes it to the surface to take a breath. The aquarium gift shop sells stuffed dugongs and dugong cookies.  Some of the last reported sightings were made in Kenting National Park in the 1950s and 60s. , Molecular studies have been made on dugong populations using mitochondrial DNA. Only certain seagrass meadows are suitable for dugong consumption, due to the dugong's highly specialized diet. Animals that live under human care are in captivity.Captivity can be used as a generalizing term to describe the keeping of either domesticated animals (livestock and pets) or wild animals.This may include for example farms, private homes and zoos.Keeping animals in human captivity and under human care can thus be distinguished between three primary categories according …  If the dugong is wounded, its blood will clot rapidly. The effects are unknown.  The last one, a male, is kept at Sydney Aquarium, where he has resided since he was a juvenile. , Dugongs, along with other sirenians, are referred to as "sea cows" because their diet consists mainly of sea-grass. The dugong became the first marine animal protected by Philippine law, with harsh penalties for harming them. In Southern China dugongs were traditionally regarded as a "miraculous fish", and it was bad luck to catch them. This Sept. 5, 2012 photo shows Serena, a dugong at the Toba Aquarium in Toba, Japan. Dugongs, a sea mammal related to the manatee, are rare in captivity. Indonesia lists dugongs as a protected species, however protection is not always enforced and souvenir products made from dugong parts can be openly found in markets in Bali. Wells S., Dwivedi N.S., Singh S., Ivan R. Marsh, Helene; O'Shea, Thomas J. and Reynolds, John E. (2012), Adulyanukosol K., Poovachiranon S. (2006), CS1 maint: BOT: original-url status unknown (, Berta, Annalisa; Sumich, James L.; Kovacs, Kit M. (2005). The dugong sampled in this case was in captivity during sampling and had been fed a diet of the eelgrass, Zostera marina .  Despite these efforts, numbers continue to decrease, and in 2007 it was reported that no more dugong could be found on the west coast of the island of Hainan. The results have suggested that the population of Southeast Asia is distinct from the others. Small populations live along the coast of at least 37 countries in the Indo-Pacific region. The colour of a dugong can change due to the growth of algae on the skin. Detected pathogens include helminths, cryptosporidium, different types of bacterial infections, and other unidentified parasites. They have been known to collect a pile of plants in one area before eating them. Seahorses, dugongs, freshwater turtles and tortoises, slow lorises and sun bears are vanishing, but the world pays scant attention.  One of the lineages stretches all the way from Moreton Bay to Western Australia, while the other only stretches from Moreton Bay to the Northern Territory. Unfortunately (or fortunately, depending on how you look at it) dugongs are rarely found in captivity, but you can “adopt” your own dugong via the World Wildlife Fund here. Internationally, dugong are listed on Appendix I of the Convention on International Trade in Endangered Species of Wilde Fauna and Flora (CITES), and on Appendix II of the Convention on Migratory Species (the CMS). , Dugongs are long-lived, and the oldest recorded specimen reached age 73. The Asahi Shimbun Company (18 August 2014).  The dugong is the only strictly marine herbivorous mammal, as all species of manatee utilise fresh water to some degree.  The number of growth layer groups in a tusk indicates the age of a dugong, and the cheekteeth move forward with age.  Dugongs may also prefer to feed on younger, less fibrous strands of seagrasses, and cycles of cultivation feeding at different seagrass meadows may provide them with a greater number of younger plants. The dugong has a curved body with forelimbs that act as flippers. Dugong, (Dugong dugon), a marine mammal inhabiting the warm coastal waters of the Indian and Pacific oceans that feeds on seagrasses and is similar to the American manatee.  The lungs in a dugong are very long, extending almost as far as the kidneys, which are also highly elongated in order to cope with the saltwater environment. , Worldwide, only three dugongs are held in captivity. Rising temperatures, shrinking glaciers, wildfires and droughts are now the biggest danger to Earth’s natural heritage sites including the Great Barrier Reef. Large bays facing north on the Queensland coast provide significant habitats for dugong, with the southernmost of these being Hervey Bay and Moreton Bay. They're in Australia, Singapore, Indonesia and Japan, which is Serena, the one shown in the video above. The dugong is a large sea mammal who are sometimes referred to as "sea cows" due to the large amount of seagrass they consume. , Dugongs are generally found in warm waters around the coast with large numbers concentrated in wide and shallow protected bays. Dugong oil is important as a preservative and conditioner for wooden boats to people around the Gulf of Kutch in India, who also believe the meat to be an aphrodisiac. In areas of Thailand, it is believed that the dugong's tears form a powerful love potion, while in parts of Indonesia they are considered reincarnations of women. , A dugong reaches sexual maturity between the ages of eight and eighteen, older than in most other mammals. , Marine mammal, sole living member of the family Dugongidae, This article is about the animal.  Reasons for this drastic population loss include illegal poaching, oil spills and net entanglement. , Oil spills are a danger to dugongs in some areas, as is land reclamation.  Their historic range is believed to correspond to that of seagrasses from the Potamogetonaceae and Hydrocharitaceae families. Home Topics Wildlife Video: Meet Australia’s only captive dugongs.  In Mozambique, most of the remaining local populations are very small and the largest (about 120 individuals) occurs at Bazaruto Island, but they have become rare in historical habitats such as in Maputo Bay and on Inhaca Island. In Moreton Bay, dugongs often travel between foraging grounds inside the bay and warmer oceanic waters.  As dugongs cannot stay underwater for a very long period, they are highly prone to deaths due to entanglement. A population of over 25,000 exists in the Torres Strait such as off Thursday Island, although there is significant migration between the strait and the waters of New Guinea. The UAE has additionally banned drift net fishing.  In Vietnam, an illegal network targeting dugongs had been detected and was shut down in 2012.  This number is reduced in areas where calving is minimal due to food shortages. Recoveries of seagrass beds along former ranges of dugongs, such as the Chilika Lake have been confirmed in recent years, raising hopes for re-colorizations of the species. , Gracie, a captive dugong at Underwater World, Singapore, was reported to have died in 2014 at the age of 19, from complications arising from an acute digestive disorder. A population exists in the Gulf of Mannar Marine National Park and the Palk Strait between India and Sri Lanka, but it is seriously depleted. Further disappearances are likely.  In the course of a study being carried out in 1986 and 1999 on the Persian Gulf, the largest reported group sighting was made of more than 600 individuals to the west of Qatar. Our dugong, nicknamed Serena, was discovered and protected in the Philippines in its infancy. At higher latitudes dugongs make seasonal travels to reach warmer water during the winter.  With very small eyes, dugongs have limited vision, but acute hearing within narrow sound thresholds. The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature:  The dugong is a national animal of Papua New Guinea, which bans all except traditional hunting. 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Asbjørn Jøn has noted, they are often considered as the inspiration for mermaids, and people around the world developed cultures around dugong hunting. The full size of the former range is unknown, although it is believed that the current populations represent the historical limits of the range, which is highly fractured.  Other common local names include "sea cow", "sea pig" and "sea camel". Dugong meat and oil have traditionally been some of the most valuable foods of Australian aborigines and Torres Strait Islanders.  The calf nurses for 14–18 months, although it begins to eat seagrasses soon after birth.
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