Centuries ago, manatee sightings by sailors at sea gave rise to the myth of mermaids. But the vision was a mirage-like hallucination brought on by sleep deprivation, dehydration, malnutrition, and maybe a little wishful thinking on the sailor's part! The scientific name for manatees is Sirenia, derived from the Greek Sirens, the dangerous sea nymphs who lured sailors with song, drawing them and their vessels into the rocky shores. It's also another term for mermaids,