Each year on the last Wednesday of March, the world comes together to appreciate manatees, the beloved underwater couch potato. Commonly known as the “sea cow,” this slow-moving mammal has been found in the warm waters of the Caribbean, the Amazon, and the west coast of Africa.

The most significant challenge manatees face today is loss of habitat. As a migratory species, they are also often fatally injured in collisions with boats.

Read More: 9 Surprising Facts About Whales, the Ocean’s Largest Mammal

The good news — this blubbery creature has officially been removed from the endangered species list.

In honor of Manatee Appreciation Day, here are seven fun facts about these mighty mammals.

Manatees are extremely docile creatures, and have no natural enemies.

They are herbivores that eat sea grass, mangrove leaves, and algae found in warm, shallow waters.  

Over 50 million years ago, manatees evolved from the same land animals as elephants. Evidence of this relationship can be spotted by both animals’ three to four fingernails.

At least two species — the West indian and West African manatees —  are able to internally regulate salt concentrations, and spend their lives alternating between both salty and fresh water.

Unlike most mammals with seven neck vertebrae, manatees have just six. Only manatees and tree sloths have this irregular number of vertebrae.

“Slow and steady” is the manatee’s motto. In rare instances, however, the mammal can swim up to 20 mph.

Manatees are believed to be the basis for the legend of mermaids. Christopher Colombus’ “mermaid sighting” happened to be the actual first written record of manatees in North America.