Manatee

Manatees (family Trichechidae, genus Trichechus) are large, fully-aquatic marine mammals sometimes known as sea cows. The name comes from the Spanish manatí, which itself comes from a Carib word meaning "breast." They comprise three of the four living species in the order Sirenia, the other being the dugong, which is native to the Eastern Hemisphere.The manatee is sometimes credited as an explanation for mermaid sightings.