Off the coast of Japan, a jellyfish smaller than a fingernail called Turritopsis dohrnii responds to injury or starvation by collapsing back into a blob on the seafloor and regrowing into a juvenile polyp, effectively resetting its life cycle with no known upper limit on how many times it can do it

Off the coast of Japan, a jellyfish smaller than a fingernail called Turritopsis dohrnii responds to injury or starvation by collapsing back into a blob on the seafloor and regrowing into a juvenile polyp, effectively resetting its life cycle with no known upper limit on how many times it can do it

In the coastal shallows off Japan, a jellyfish no bigger than a fingernail responds to being sliced, starved, or otherwise pushed toward death by doing something no other animal on Earth is known to do: it collapses into a featureless blob on the seafloor, reorganises its cells over 24 to 48 hours, and buds off a fresh polyp carrying its own identical genome. The adult is gone. A juvenile stands in its place. And no upper limit has yet been foun…