A Fish Older Than the Telescope

Its heart is packed with parasites — worms that, over a human lifetime, would have killed most hosts three times over. Yet this shark keeps swimming, slow and almost motionless, and it's been doing just fine for four centuries.

The Greenland shark is the longest-living vertebrate on the planet. Radiocarbon dating of the lenses in its eyes puts the biggest individuals at three hundred fifty, even four hundred years old. One female, according to calculations by Julius Nielsen's research team, may have been born around sixteen twenty — before Galileo ever pointed a telescope at the sky.

Picture it: cold darkness nine hundred meters down. Near-freezing water, near-total silence. That's its world — the North Atlantic, the Arctic, icy water where every movement has to be worth the energy it costs. It weighs about a ton and swims at a crawl, just a few kilometers an hour — slower than a person walking.

It doesn't reach sexual maturity until around age one hundred fifty. By the time a female gives birth to her first pups, six or seven human generations have come and gone. Slow and steady wins this race by centuries.

In its genome, scientists found a reinforced system for repairing DNA damage — its cells seem able to fix themselves with remarkable precision. But exactly how it lives five hundred years is still an open question, and one of the hot topics in aging research right now.

A few years back, a photo of one went viral online captioned "older than Isaac Newton" — and that's not an exaggeration. It's simply true.

Somewhere in that icy deep, right now, a fish is swimming that was already alive when modern history as we know it began. And we may lose it before we ever fully understand how it works.

The world is enormous and one question is enough to start. moygid dot online.