Why do some jellyfish never seem to grow old?
Forever Jellyfish
Why do some jellyfish never seem to grow old?
There's a tiny jellyfish, no bigger than your pinky nail, floating in the Mediterranean Sea right now. It might be a hundred years old. Or a thousand. Or ten thousand. Nobody knows, because Turritopsis dohrnii — the "immortal jellyfish" — has discovered a trick that breaks all the rules: when it gets old or hurt, it just starts over.
Most animals have a one-way ticket through life. You start as a baby, grow up, get old, and eventually your body wears out like a car with too many miles. Cells break down, mistakes pile up, things stop working. That's aging, and it happens to almost everything — except this jellyfish figured out reverse gear.
