Have you ever heard of the Greenland Shark? The diminutive, dull-looking fish that you'll probably never come within 700 miles of in your lifetime?

Rest assured they are some of the strangest animals you're ever apt to learn about:

Greenland sharks have the longest lifespan of any known vertebrate, estimated to be between 250 and 500 years. They are among the largest extant species of shark, usually growing to between 7.9 and 23.0 ft long and weighing between 880 and 3,090 lb. They reach sexual maturity at about 150 years of age, and their pups are born alive after an estimated gestation period of 8 to 18 years.

That is quite a list of accomplishments.

Now, it turns out that we may have some practical knowledge about how this beast stays alive for half a millennium:

The elusive Greenland shark — long marveled for its baffling extreme longevity — does not suffer a significant drop in its muscle's metabolic rate as it ages, according to fresh research presented this week at the Society for Experimental Biology Annual Conference in Prague. ...

"Most species show variation in their metabolism when they age," said lead researcher Ewan Camplisson, a PhD student at the University of Manchester, England, to the Telegraph.

Scientists have long thought that the shark is so long-lived because of the "deep, bone-chilling waters of the north Atlantic Ocean that make for sluggish energy-conserving movements."

So basically they thought it was freezing itself into longevity.

But the metabolic piece of the puzzle could ultimately be the secret to their success — and it could help the rest of us live a little longer, too:

... researchers have now discovered new metabolic muscle clue involving the shark — the world's longest-living vertebrate species — and say it could end up helping to treat human heart disease.

'We want to understand what adaptations they have that allow them to live so long,' Camplisson said.

'By studying the Greenland shark and its heart, we may be able to better understand our own cardiovascular health. These are issues that become progressively more common and severe with increasing age.'

Just nobody tell the sharks we're thinking of this or I think they'll probably excuse themselves from the chat!

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