Species D. dugong
The dugong is a marine mammal that spends its life in shallow coastal waters, munching on seagrass. It is the sole member of the Dugongidae family that has survived. It is a close cousin to manatees. Dugongs, sometimes known as “sea cows,” are the only marine mammals that feed almost exclusively vegetation.
The body of a dugong is long and cylindrical, with no dorsal fins. They feature a fluked dolphin-like tail for swimming and little flippers as forelimbs for turning and slowing down. Their skin is thick and silky, with just a few tiny hairs covering it. When they’re young, they have a delicate cream hue, which darkens to a brownish or grey tint as they become older, depending on the kind of algae on their skin.
Their ears are on the side of their heads, and their noses are on top. They have a large horseshoe-shaped upper lip that forms part of the muzzle on the bottom of their heads. Foraging is aided by this large, strong lip. They can stay underwater for up to 6 minutes without taking a breath of air while eating.
When males attain sexual maturity, which occurs between the ages of 8 and 18, they have two incisor tusks. Females have tusks as well, although they do not normally emerge from their mouths until later in life. Dugongs live for a long time, with the oldest known specimen living to be 73 years old.
A Shrinking Range
Dugongs may be found in approximately 40 nations and on 57,000 km of shoreline in the West Pacific. The biggest populations may be found in estuaries, bays, and mangroves, which are vast, shallow, and sheltered coastal environments. Northern Australia has one of the world’s most powerful populations.
Dugong numbers are reported to be dwindling as a result of poaching, habitat loss, and fishing-related deaths. The IUCN has classified them as vulnerable, and they have already vanished from Hong Kong, Mauritius, Taiwan, and other regions of Asia.
Fun Facts about Dugongs!
For thousands of years, humans and dugongs have interacted, partly because they are easy prey for hunters. A 5,000-year-old artwork of a dugong by neolithic peoples has been discovered in a cave in Malaysia. Dugongs may be the source of siren and mermaid legends!
Dugong vs. Manatee
The dolphin-like tail of dugongs distinguishes them from manatee species, while manatees have hind fins that resemble those of seals or walruses. They also have unusual adaptations such as a down-turned snout and peg-like molar teeth that enable them to graze exclusively on seagrass.
Slow-moving and slow-growing
Dugongs grow slowly, much like humans. After a year of pregnancy, females give birth to just one calf. For up to 18 months, her young will stay close to her. Despite legislative protection, dugong populations are threatened due to their lengthy life span (70 years) and limited reproductive rates. For thousands of years, humans have hunted dugongs for their flesh and oil.
In addition, their seagrass environment is fragmented and endangered, putting the dugong populations that feed on it in jeopardy. Only 1-2 percent of populations may be lost to human-caused risks in order for populations to be maintained. Many individual populations are thought to be on the verge of extinction.
Using Hair to See
Dugongs have poor vision but excellent hearing. They’re also coated in short hair from head to tail. These hairs are clustered around the mouth and are supposed to facilitate navigation through the seagrass beds, similar to how dogs and cats use their whiskers.
The insides of dugong bones are nearly devoid of bone marrow and are very solid. The bones of dugongs are among the densest in the animal world. These might function as a kind of ballast, enabling the animal to float smoothly just below the water’s surface while resting. When sleeping or resting with just part of their heads above the surface to breathe, they may sometimes lay their tail on the bottom to hold themselves in place.
Because of their size, adult dugongs have few predators, but they are vulnerable to illnesses such as helminths, cryptosporidium, and other bacterial and parasite infections. In Queensland, Australia, illness is responsible for up to 30% of dugong mortality. Even still, habitat loss and mortality at the hands of humans remain the most serious threats to dugongs.