All jellyfish are Cnidaria, an animal phylum that contains jellies, sea anemones, and corals, among others. There are more than 10,000 species of Cnidaria, and less than 4,000 of these are Medusazoa—those animals we think of as jellyfish. Those 4,000 jellyfish can be divided into four different groups.
Based on an ancient papyrus document, Egyptian women urinated on wheat and barley seeds to determine if they were pregnant or not, according to the Office of History in the National Institutes of Health. If wheat grew, it predicted a female baby. If barley grew, it predicted a male baby. The woman was not pregnant if nothing grew. Experimenting with this seed theory in 1963 proved it was accurate 70 percent of the time.