Polar sharks defy aging: Secrets of their 500‑year lifespan revealed
7:52 PM EDT, July 17, 2024
Polar sharks are fascinating creatures known for their longevity. Specimens that are several hundred years old are not surprising to the scientific world. What is their secret? New research may be crucial for the future of this species.
What makes polar sharks live so long? Their lifespan can "embarrass" even the oldest representatives of giant tortoises, considered a symbol of longevity. A polar shark found in 2017 in the Atlantic Ocean by a group of scientists could have been as old as 512 years. So what is their secret?
For polar sharks, 100 years is nothing
Scientists link the longevity of polar sharks to the temperature of the water they inhabit and their slow, almost sluggish swimming pace—the average speed for this species is 0.75 mph. However, new research was presented at the SEB Conference Prague 2024.
The research indicates that polar sharks' longevity may be related to their metabolism, which remains unchanged. Ewan Camplisson, the study's lead author and a PhD student at the University of Manchester, emphasizes in a message sent to Live Science, "This is important for us as it shows the sharks don't show traditional signs of aging."
For the study, scientists collected and analyzed tissue samples from the muscles of 23 polar sharks caught off the southern coast of Disko Island in central Greenland. They then checked the activity of five enzymes to determine the metabolic rate and response to different temperatures.
Next, the age of the polar sharks was estimated—here, it was necessary to use a unique model that allowed their age to be determined (approximately) based on body length. The specimens studied were between 60 and 200 years old. The most surprising finding was that the activity of the sampled enzymes was the same for each shark, regardless of their age.
Will the polar shark survive in warmer waters?
Polar sharks' constant metabolism may be the key to their longevity. The research also showed that all enzymes, according to trend, have higher activity at higher temperatures.
"We wanted to investigate if the Greenland shark's enzymes were specifically adapted to work more effectively in cold conditions, but we did not see this trend," emphasizes Ewan Camplisson, adding that "the higher activity in warmer conditions would suggest that if these sharks were forced into a warmer environment, then their metabolism would increase significantly which would likely alter their lifestyle."
