What mammal is known as the 'sea cow'?

The mammal known as the “sea cow” is the manatee. Manatees are large, fully aquatic herbivores that live in warm coastal waters, rivers, estuaries, and wetlands.

The nickname refers to their peaceful, slow-moving nature and plant-based diet. A manatee may eat more than 60 kinds of freshwater and saltwater plants, including seagrasses and water lettuce, and can consume up to about 10–15% of its body weight in vegetation each day.

Manatees belong to the order Sirenia, which also includes the dugong. That is the most common quiz mix-up: “sea cows” can refer broadly to sirenians, but manatee is the standard singular answer in general-audience trivia. The extinct Steller’s sea cow was another sirenian and was hunted to extinction by 1768.

Despite their fishlike lifestyle, manatees are more closely related to elephants and hyraxes than to seals or whales. Their closest living relative outside the manatee family is the dugong, which lives mainly in the Indo-West Pacific.