Alien-like comb jellies have a nervous system like nothing ever seen before

Comb jellies, like this warty comb jelly (Mnemiopsis leidyi), appear to have fused nervous systems, raising questions about their evolution.  (Image credit: Andrey Nekrasov/Getty Images)

Ctenophores, or comb jellies, are strange jelly-like animals that ghost through the sea propelled by tiny hairs called cilia. They're an enigmatic bunch, with origins that stretch back approximately 540 million years, and no one is sure exactly when they diverged from the rest of the tree of life. 

Now, researchers have discovered that these alien-like creatures are even weirder than we thought: Their nervous system is like nothing ever seen before. Instead of relying on gaps between nerve cells called synapses for communication, at least part of the ctenophore nervous system is fused.