20+ Interesting Facts About Dugongs

1. Dugongs are large marine herbivorous mammals with thick and smooth skin. They are the only living members of their family (Dugongidae) and one of the four species of the mammalian order Sirenia, alongside three species of manatees.
2. Paleontologists discovered a skull of a marine mammal from Panama in 2019. This skull, which belongs to a species of dugongs, is 20 million years old, making it the oldest known marine mammal in Central America. Scientists have so far recovered nearly 30 extinct species of dugongs. The last of these species, Steller’s Sea Cow, became extinct in the 18^th Century. (Source)
3. Dugongs are also called sea cows because their primary food is sea grasses and other aquatic plants. However, these herbivorous mammals may sometimes eat algae and small invertebrates. Their preferred habitats are shallow bays and other coastal regions with plenty of seagrasses.
4. Dugongs eat nitrogen-rich plants low in fiber. Their eating behavior regenerates sea grass and prevents algae growth. It assists the local and global atmosphere because seagrasses clean coastal waters and absorb carbon 35% faster than tropical rainforests. (Source)
5. Dugongs can achieve a length of 7 to 11 feet and weigh up to 550 kg. These marine mammals are without hind limbs, while their forelimbs are nail-less rounded flippers. Their tiny eyes have poor eyesight but compensate for this with strong hearing and other senses. They locate sea grasses and other edible plants using smell and sensory hairs on their snouts.
6. Dugongs are present in warm coastal waters of the Indo-Pacific region, from East Africa to Australia. Their largest population is around the waters of Australia, numbering around 80,000 individuals. The Gulf region (Saudi Arabia, UAE, Qatar, and Bahrain) contains the second-largest population of these mammals. Dugongs are the most widely distributed among sirenians.
7. According to estimates, the global population of dugongs has reduced by over 20% in the last 90 years, while the decline has been severe since the 1960s. These mammals have disappeared from parts of several countries, including Japan, China, Maldives, Mauritius, etc.
8. Female dugongs give birth to a single baby after a gestation period of 12 to 14 months. The nursing period is 18 months, while the young one remains with its mother for several years as she may reproduce again after 3 to 7 years. The calf starts eating seagrass during the nursing period. 

   

   The strongest bond in dugongs is between mother and its calf
   
   

9. Dugongs usually stay single or as a pair (particularly mother and calf). However, they are sometimes seen in herds of 100 to 200 individuals in places with plenty of seagrass. The largest herd ever recorded contained around 450 dugongs.
10. Dugongs are similar in appearance to manatees, their closest relatives. However, there are several visible differences between these two marine mammals. Dugongs have fluked tails, like that of whales, compared to paddle-shaped tails in manatees. Dugongs also have a broader trunk that faces downward. Dugongs (adult males and older females) have two incisors in the form of tusks, while these teeth are absent in manatees. Molar teeth continuously grow in manatees, but dugongs cannot replace their lost molars and premolars.
11. Apart from manatees, the closest relatives of dugongs are land mammals. They are more related to elephants and hyraxes than other marine mammals, such as dolphins and whales.
12. A pair of tusks is present in male dugongs after puberty and sometimes in females older than 40. These enlarged teeth provide information about the age of dugongs due to cheek-tooth development and dentinal GLGs (growth layer groups).
13. Dugongs and other marine mammals initially appeared on Earth over 34 million years ago, ranging from the Pacific Ocean to the Mediterranean Sea. However, their range has reduced considerably, and their latest extinction is from the waters of China in 2022. This incident makes it the first large vertebrate to become functionally extinct in Chinese coastal waters. However, there are still around 100,000 dugongs in the waters of nearly 40 countries. (Source)
14. Dugongs and manatees are the only herbivorous marine mammals, but manatees sometimes enter freshwater. Therefore, dugongs are the only herbivorous mammals that live exclusively in saltwater habitats.
15. After breathing, dugongs generally stay underwater for up to six minutes. They sometimes use their tails to stand on the seabed and surface their head out of water for breathing.
16. The maximum duration of a dugong’s dive is nearly 10 minutes, while their maximum depth is up to 30 m (around 98 feet). Unlike manatees, dugongs fulfill their water requirement through food due to their strictly marine habitat. (Source)
17. IUCN (International Union for Conservation of Nature) declared dugongs vulnerable in 1982 due to their slow reproduction and hunting for meat, oil, and hides. However, they still face local extinction in some areas due to several factors, such as loss of seagrass (due to climate change and pollution), collision with boats, and accidentally caught in fishing nets.
18. Only large animals can kill dugongs due to their size. Their predators include killer whales, large sharks, and saltwater crocodiles.
19. Dugongs generally live for 60 to 70 years, while the oldest known lived for 73 years. They reach sexual maturity at around ten years and physical maturity at nearly 20.
20. Dugongs produce various sounds to communicate with each other. These include echoing chirps, barks, and whistlelike songs.
21. Like manatees, dugongs are also considered to inspire the tales of mermaids and sirens. It is due to their docile nature, smiling face, medium body size, and other features. The translation of the word “dugong” in the Malay language is “lady of the sea.”
22. There is a history of using dugong tusks as sword handles in the Persian Gulf region. Additionally, people in the same region have also used the bones of these marine mammals for ceremonial purposes in the past. (Source)
23. Keeping dugongs in captivity is very difficult due to their specific diet of seagrass. Therefore, only a limited number of these mammals remain in captivity, where their food includes seagrass substitutes, such as lettuce. Breeding is even more complicated, and there is no instance of dugong reproduction in captivity.