Belongs to Turritopsis nutricul The Curious Case of the Immortal Jellyfish | Discoblog | Discover Magazine Jellyfish that can age backwards are invading the world's oceans | Worldhealth.net This tiny, 5mm-wide hydrozoan is the only known animal capable of rolling back the clock, willfully reverting to its immature stage, thus living indefinitely. More fascinating still, this particularly species, native to the Carribean, has slowly been conquering the world, and now can be found in most of the world's oceans. What a wonderful world! The good news? We're getting much closer to clinical regeneration: The downside? The genes that prevent us from regenerating limbs like other species, also prevent us from rapidly developing cancers. Catch-22?