Comb jellies have a bizarre nervous system unlike any other animal

A 3-D map reveals fused neurons that lack the space, or synapses, most neurons use to communicate

An image of several sea walnuts floating in dark water.

Sea walnuts (Mnemiopsis leidyi) like these pictured are ctenophores, jellyfish-like animals that move by beating iridescent combs. Their nerve cells are fused together, unlike those of all other known animals.

Alexandre Jan

Shimmering, gelatinous comb jellies wouldn’t appear to have much to hide. But their mostly see-through bodies cloak a nervous system unlike that of any other known animal, researchers report in the April 21 Science.