They may look sweet and innocent, but these jellies have a terrifying secret:

Unlike humans, which are just now mastering the art of cloning, Sanderia have been quietly cloning themselves for  millions of years, right under our noses [1].  Human cloning unitizes a female ovum, or egg.  The genetic material is removed and new genetic material (the cloning goodness) is adding.  The new egg grows up and voilà! A clone.  But that’s all messy and complicated and Sanderia is much too pragmatic for that.  In fact, pretty much any way you cut it, Sanderia can clone it, literally.

My first unenthusiastic introduction to Sanderia happened by accident.  I’d gathered up some rare, wonderful purple striped jelly polyps. Purple stripped jelly polyps are an incredible commodity to a young jelly biologist.  But the more I watched them, the more I felt like something was off. For lack of a better word, they were looking, well, weedy.  There were all these weird bumps and strands of tissue and little ciliated balls of cells floating around everywhere.  What is going on with these polyps?

It turns out these were no purple stripped jelly polyps, they were Sanderia polyps, and they were spreading– blebbing off globs of tissue, on the tips of their tentacles, sides of their bodies, even from their gut. Each little ball of cells can grow into a whole new polyps, capable of producing jellies of its own. It’s as if I were to cut off a finger, and not only did I grow a new one, but the old one grew a tiny person attached to it, that, with enough food, would become as big as me. A pretty incredible strategy, and it makes me wonder why Sanderia hasn’t taken over the world yet.

Perhaps it’s an indication of just how hard the life of a jelly polyp may be. Sanderia spreads like crazy in safe, stable environments lake aquariums, but in the wild, where the food supply is unreliable, and the predators fierce, perhaps this methods helps ensure at least some animals will live long enough to produce jellies, starting a new generation. Of course, things are pretty cushy by comparison under my care. That’s why they’re happy as ever in their own corner with their own food, cloning away like the tiny little sea monsters they are.

[1] New insights into reproductive traits of scyphozoans: special methods of propagation in Sanderia malayensis GOETTE, 1886 (Pelagiidae, Semaeostomeae) enable establishing a new classification of asexual reproduction in the class Scyphozoa

http://link.springer.com/article/10.1007/s00227-009-1181-6