10 Manatee Facts You Didn't Know

light gray manatee swims in dark blue waters with large flippers placed below body

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The manatee is the gentle giant of the ocean. It spends most of its time grazing on sea grass and swimming slowly through warm, shallow waters. But there's more to this sea creature than eating and lounging. Humans have cared about its protection for over a century, and it has a surprising connection to mermaid legends. Not to mention, it is related to a massive land animal and has lungs the length of most of its body. Keep reading to learn more about these marine mammals.

1. There Are Only 3 Manatee Species

Belonging to the genus Trichechus, the manatee does not have many variations. Across the world, there are only three living manatee species. One is the Amazonian manatee (Trichechus inunguis), which is the smallest of the group and is found in South America. The West Indian Manatee, also known as the North American manatee, is the largest. Much less is known about the African manatee, but it is the only species to be found in the Old World.

2. Manatees Can Weigh Thousands of Pounds

portrait-style photo of manatee face close up showing wrinkles in face and body

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They may be swimmers, but manatees are not light. On average, these sea creatures weigh about 1,000 pounds, though manatees weighing up to 3,500 pounds have been recorded. This weight does not come from blubber — which is common for marine mammals — because manatees don't have any. Instead of that layer of fat, their weight (and indeed, large size) is made up mostly of its stomach and intestines.

Their size and weight are part of the reason they are slow movers, swimming at an average of three to five miles per hour.

3. They're Also Known as Sea Cows

manatee swimming in dark waters, eating greenish sea grass along bottom of the ocean

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You may commonly hear manatees called by their other name: sea cows. They've acquired this name for a few reasons, starting with their diet. Manatees are herbivores, so their diet consists entirely of plants, especially sea grasses. Much like cows, they graze lollingly on their grassy meals.

Manatees are also slow-moving creatures, which is reminiscent of cows as well.

4. Manatees' Closest Relative Is the Elephant

Despite their other name, manatees are not related to cows. Instead, their closest living relative is another land animal: the elephant. Manatees and elephants evolved from the same ancestor over 50 million years ago.

When you look at the details, the relationship between the two creatures isn't so surprising. They both have a sphere-shaped heart, for example, which is unusual in the animal kingdom. They also have similar eating techniques, with the manatee's flexible lips working similarly to an elephant's trunk.

5. They Need Warm Water — and Migrate To Get It

manatees congregate in shallow clear water near bank with leafy trees

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Without blubber to insulate them and a low metabolic rate, manatees are sensitive to cold water. In fact, they need to remain in water that is warmer than 60 degrees — some Florida winters saw hundreds of manatees dying due to cold stress.

This is where manatees' migratory nature comes into play. When temperatures begin to drop, they gather in groups to seek out warm-water sources. These refuges can include warm-water discharges from power plants and natural springs and basins that temporarily trap warm water.

6. Manatee Moms Are Very Committed

mom and calf manatee swimming, seen from above clear water

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When it comes to reproduction, female manatees are committed mothers. Their gestation period is about one year long, but it's when the calf is born that the real work starts. Calves nurse for two years before being able to venture out on their own. In the meantime, mother manatees teach their babies about feeding, warm-water refuges, and travel routes. Male manatees do not take on any parenting role for a calf.

This long period of work is why manatee calves are typically born every two to five years — a mother needs enough time to give appropriate attention to one calf before giving birth to another.

7. Their Lungs Are Big and Strong

Like whales and dolphins, manatees breathe air. They go to the surface for a gulp of air every three to five minutes. However, they can hold their breath underwater for up to 20 minutes. This may have to do with the size of their lungs, as they run much of the length of the manatee's body.

With each breath, manatees replace about 90 percent of the air in their lungs. In comparison, humans only replace about 10 percent.

8. They Are Close to Nature

two manatees swimming in murky water, one with back covered in layer of green algae

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If you look at a manatee's back, you may notice some green spots. That's not the manatee's skin — it's algae. Thanks to its combination of slow movement and need to be close to the surface, manatees provide an ideal breeding ground for algae that love water and sunlight. The partnership may be mutually beneficial because the algae may help to protect the manatee from the sun's harmful rays.

Manatees' skin flakes off periodically, and the algae goes along with it. The prevents a buildup of too much algae on a manatee's back.

9. Manatees May Have Inspired Mermaid Legends

Throughout history, a number of sailors believed they caught glimpses of mermaids. This is true even for Christopher Columbus, who, when sailing near the Dominican Republic, was disappointed in the "mermaids" he saw, calling them "not half as beautiful as they are painted."

In actuality, these sailors were likely looking at manatees. Even though the similarities between mermaids and manatees are debatable, the confused sightings certainly helped the myth of the mermaid persist.

10. Conservation Efforts Have Lasted Over a Century

manatee zone slow speed sign coming out of water with sunrise in background

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Manatees have been under attack by humans for a long time, threatened by fishing nets, boat collisions, and coastal development that negatively impacts their habitat. As a result, conservation efforts have been in place since the 19th century. 1893 saw the first piece of manatee-protection legislation, making it illegal to hunt manatees in Florida and imposing a fine and/or jail time for assaulting or killing a manatee.

Manatees are also protected in the United States under the Marine Mammal Protection Act and internationally through CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Still, as of 2020, all three manatee species are considered vulnerable by the IUCN Red List.

Save the Manatee

  • Do not throw items into the water, and pick up any litter you can reach.
  • Report when you see an injured or stranded manatee. You can find instructions here.
  • Look out for manatees while boating to prevent collisions.
  • Support conservation efforts, such as the Save the Manatee Club.