Add Yahoo as a preferred source to see more of our stories on Google. An upside-down jellyfish drifts in a shallow lagoon, rhythmically contracting its translucent bell. By night that beat drops from ...

Last month, Cassiopea andromeda, more commonly known as the upside-down jellyfish, were found to have similar sleep patterns to humans—but they do not have brains. Like humans, Cassiopea andromeda ...

An upside-down jellyfish drifts in a shallow lagoon, rhythmically contracting its translucent bell. By night that beat drops from roughly 36 pulses a minute to nearer 30, and the animal slips into a ...