Imagine being a sailor aboard a merchant ship in the late 1700s. One day while traveling through the West Indies, you look into the water and see a sleek animal gliding under your boat. You blink and rub your eyes, not trusting your vision. You look again and catch a glimpse of the tail in the water before you lose sight of the mysterious creature. Given this scenario, it’s easy to see why the early explorers and explorers thought they saw mermaids on long expeditions. Today we know that the creatures these people saw were most likely manatees or dugongs. These large aquatic marine mammals, also known as sea cows, spend most of their days swimming in brackish water in search of marine plants. They both belong to the Lilac squad and are similar to each other. However, several distinctive features can help you distinguish a dugong from a manatee.
In this article, we will compare the size, habitat, appearance and behavior of a dugong and a manatee. At the end of the article, we will also answer a few frequently asked questions regarding dugongs and manatees to help resolve ongoing confusion. Here are 9 major differences between dugongs and manatees.
Comparison of dugongs and manatees
| Dugong | Manatee | |
| The size | Up to 13.32 feet 551 to 2240 lbs |
Up to 15.1 feet 800 to 3913 lbs |
| Habitat | Indo-West Pacific Shallow coastal waters including coves, harbors and mangrove canals. Salt water only |
Caribbean, Gulf of Mexico, Amazon and West Africa Swampy coastal areas and rivers Sea and fresh water |
| Muzzle | Wide short barrel pointing down Thin mouth |
Shorter muzzle Split upper lip |
| Teeth | Tusks | No canines, but lifelong replacements for molars “Marching molars” |
| Tail | Blurry, dolphin-like tail | Scapular, beaver-shaped tail |
| Leather | Smooth; smooth | Rude |
| Nails | No nails | West Indian and African manatees have nails |
| Diet and feeding | Algae and some invertebrates Pluck plants with lips and teeth |
Marine and freshwater plants and algae Walk with your fins along the bottom and scoop the food to your mouth. |
| Mating and reproduction | Monogamous Females give birth for about 10 years. |
Polygamous Females give birth for about 3 years. |
9 major differences between dugongs and manatees
Dugongs and manatees: size
One of the most noticeable differences between dugongs and manatees is their size. On average, manatees grow longer and heavier than dugongs, although individual dugongs can grow larger than most manatees. The average length of the dugong is about 9.8 feet, although wild specimens can reach 13.32 feet. Although they usually weigh between 551 and 1984 pounds, they can reach 2240 pounds. Meanwhile, manatees usually reach 11 feet in length but can reach 15.1 feet in length. Typically weighing between 880 and 1210, especially massive manatees can reach 3913 pounds. In both manatees and dugongs, females tend to weigh more than males.
Dugongs and manatees: habitat
Dugongs and manatees may belong to the Lilac squad, but they live on opposite ends of the planet. Dugongs are the only remaining members of the Dugongidae family, and their current range is much more limited than in the past. Today they inhabit the Indo-Western Pacific Ocean, from the coast of East Africa to the waters of Northern Australia. Throughout their range, they live in shallow, saltwater areas off the coast, including bays, harbors, and mangrove canals.
On the other hand, manatees belong to the Trichechidae family and are divided into three different species. These include the Amazonian manatee found in the Amazon, the West Indian manatee found in the Caribbean and the Gulf of Mexico, and the West African manatee. Unlike dugongs, manatees spend their time in both salt and freshwater rivers and swampy coastal areas. For example, West Indian manatees cannot live in waters below 60 degrees Fahrenheit, so they migrate to warmer freshwater habitats in winter.
Dugongs and Manatees: Muzzle
The shape and size of the muzzle are also among the most notable differences between dugongs and manatees. Dugongs have a broad muzzle that resembles an elephant’s trunk. The torso is directed downward and ends with a thin mouth. This device helps dugongs to graze on algae growing on the seabed. Meanwhile, the muzzles of the manatees seem to be noticeably shorter than those of the dugongs. In addition, manatees have a split, grippy upper lip that helps them gather food and communicate with their fellow manatees.
Dugongs and manatees: teeth
Although dugongs and manatees are herbivores, they have developed completely different sets of teeth. Dugongs develop two incisors, or canines, that appear when males reach puberty. Females also develop canines, but their tusks usually appear much later. Scientists can estimate the age of a particular dugong from the tusk growth layers. Unlike dugongs, manatees do not grow tusks. Instead, these are only rough cheek teeth and there is no clear distinction between molars and premolars. Over the course of its life, the manatee will constantly replace its teeth, with new teeth growing in the back of the mouth and old teeth being pushed forward. This phenomenon is called “marching molars” and is similar to how the teeth of an elephant grow.
Dugongs and manatees: tail
Another obvious feature that distinguishes dugongs from manatees is the shape of their tails. The dugongs have developed a curved, dolphin-like tail, with deep grooves and a trailing edge. They move forward, swinging their tail up and down, and can also twist it to change direction. Evidence suggests that dugongs sometimes stood on their tails, piercing their heads above the surface of the water to breathe. On the other hand, the tails of the manatee are scapular and look more like the tail of a beaver. Like a dugong, a manatee moves by flapping its tail up and down.
Dugongs and manatees: leather
There are a few small differences between dugong and manatee skins. Dugongs have thick, smooth skin that is usually light gray or creamy at birth. As they grow older, their color may become darker and appear brown or dark gray. This may be because their backs and tails slowly build up a layer of algae over time. While manatees also tend to grow algae and change color, the texture of the manatee is different from that of the dugong. The manatee’s skin is coarser and wrinkled than that of the dugong, but just as thick. Like the dugong, the manatee’s skin is covered with coarse, short hair that helps it navigate its environment.
Dugongs and manatees: nails
Both dugongs and manatees have flippers that they use to help them swim and navigate the water. However, there is a slight difference in their fins that will help you distinguish between dugong and manatee. Unlike manatees, dugong flippers lack claws. West Indian and African manatees grow three or four tiny nails at the tips of their fins that look like elephant toenails. Scientists believe that their toes are remnants of the days when manatees walked on land. Nails can now help manatees hold onto the seabed and uproot plants.
Dugongs and manatees: diet and feeding
While both are herbivores, the diet and feeding behavior of the dugong and manatee differ in several key parameters. Dugongs primarily feed on algae, but can sometimes feed on invertebrates, including squid and octopus. When feeding, they eat the entire plant, including the roots, although they seem to prefer to eat only the leaves. In addition, they tend to feed in areas where there is less algae than in more heavily overgrown areas. This can be done to maximize the intake of nutrient-dense sea grasses, rather than eating a lot of nutrient-poor plants.
Although manatees also eat sea grasses, they also eat a wide variety of freshwater grasses. In addition, evidence suggests that manatees sometimes eat small fish, which they tend to catch from their nets. When feeding, manatees “walk” on flippers, which they also use to dig up plants and roots. They will then use their flippers to push food up to their mouth and grip it with their lips.
Dugongs and manatees: mating and reproduction
Another difference between dugongs and manatees has to do with their mating and breeding habits. Dugongs are generally monogamous and spouses for life, although they may take another partner if their current partner has passed away. Female dugongs usually reach sexual maturity between 6 and 17 years of age, with an average age of about 10 years. Meanwhile, manatees usually lead a polygamous lifestyle, with some men having multiple sexual partners at once. In addition, female manatees reach sexual maturity at a younger age and can give birth to their first cub at about 3 years old.
Frequently asked questions about dugongs and manatees
How many years do dugongs and manatees live?
Both dugongs and manatees are relatively long-lived. When they reach puberty at a young age, they can live to be 65 or 70 years old.
How long can dugongs and manatees hold their breath?
Although they can hold their breath for up to 20 minutes, dugongs and manatees usually float up every few minutes to breathe.
Do dugongs and manatees sleep underwater?
Dugongs and manatees sleep near the surface. They roll over onto their backs and swim near the surface of the water to sleep and breathe at the same time.