Jellies may seem like some of the strangest and most alien-looking animals on the planet. Here are just three ways in which species in these two groups—cnidarians and ctenophores—set themselves apart.
First, they move in fascinating, but distinct, ways. True jellyfish (cnidarians) propel themselves by “pulsing”—pulling and pushing water in and out of their bodies. Comb jellies (ctenophores) paddle through the water with tiny oar-like cilia.
Jellies of both types are also extremely resilient. Some species can regenerate, or regrow, lost body parts. A rare few are even able to cheat death by “aging backwards.” These jellies can transform back into tiny polyps (the first stage of the jelly life cycle), and then grow into identical copies of the original adult.
Finally, jellies can glow! Many species, especially in the deep sea, are bioluminescent, producing their own light through a chemical reaction in their bodies. Other jellies are biofluorescent, meaning they absorb one light of color and emit it as another. This is how comb jellies generate glistening rainbow colors when they swim.
To learn more about jellies—and experience life in their underwater world—visit The Jelly Dome through June 30 in the Milstein Hall of Ocean Life.