How a Greenland shark’s heart can beat for centuries
Jeanna Bryner
Everything about a Greenland shark’s life is slow: their heart beats about once every 12 seconds; they swim at an average speed of just a foot per second; they grow at a sluggish rate of just one centimeter (0.4 inch) a year; and they don’t reach sexual maturity until their 150th birthday. The sluggish living makes sense for steely behemoths that live comfortably into their 200s and possible to 400 or more.
Recently, scientists found that the sharks keep their eyesight well into senescence, not.