Sirenians are a group of marine mammals that includes manatees, dugongs, and sea cows. They are often referred to as "sea cows" due to their gentle and herbivorous nature, but they are also called "mermaids" because of their mermaid-like appearance and behavior. Some other synonyms for sirenians include sirenes, which is the plural form of sirenian in French, and lamantins, which is the French word for manatees. In Spanish, they are referred to as manatíes or dugones, while in Portuguese they are called peixes-boi. Regardless of what you call them, these slow-moving and docile creatures are important and beloved inhabitants of our oceans and coastlines.