Manatees

They live alone, in small groups, or herds of up to 200 individuals.

An excerpt from the article 16 facts about manatees

They are gentle, slow, and social animals. They establish bonds with each other through touch, verbal communication, and smell. Manatees are strictly aquatic, they are hopeless and vulnerable on land. In captivity, they live up to 10-12,5 years. Their life expectancy in the wild is unknown.