A mermaid is a legendary aquatic creature with the upper body of a woman and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including the Near East, Europe, China, and India. The first stories appeared in ancient Assyria, in which the goddess Atargatis transforms herself into a mermaid out of shame for accidentally killing her human lover. Mermaids are sometimes depicted as perilous creatures associated with floods, storms, shipwrecks, and drowning. In other folk traditions (or sometimes within the same tradition) they can be benevolent, bestowing boons or falling in love with humans. Mermaids are associated with the Sirens of Greek mythology and with the Sirenia, a biological order which comprises dugongs and manatees. Historical sightings by sailors may have been the result of misunderstood encounters with these aquatic mammals.