The first in-depth look at the genome of a jellyfish -- the moon jelly Aurelia aurita -- shows that early jellyfish recycled existing genes to gain the ability to morph from polyp to medusa. Jellyfish ...

Jellyfish undergo an amazing metamorphosis, from tiny polyps growing on the seafloor to swimming medusae with stinging tentacles. This shape-shifting has served them well, shepherding jellyfish ...