Under the cold waters of the Arctic and the North Atlantic, the Greenland shark possesses an astonishing trait: its longevity.
While this predator can live for more than 500 years, scientists have recently unveiled the mystery behind its exceptional longevity. Contrary to previous hypotheses, the key lies in a metabolism that remains constant over time.
Greenland sharks (
Somniosus microcephalus), which can reach depths of 8,700 feet (2,647 meters), have an average lifespan of 250 years, with some exceeding 500 years. Scientists initially believed this longevity was due to their extremely cold environment and low activity levels. However, new research presented at the
Society of Experimental Biology Conference in Prague reveals a surprising factor: their unvarying metabolism.
A team of researchers collected muscle tissue samples from 23 Greenland sharks, captured off the coast of Disko Island, central Greenland. They measured the activity of five different enzymes to evaluate the sharks' metabolic rates and their response to environmental temperatures. By estimating the sharks' ages based on their body length, they found individuals aged between 60 and 200 years.
The results showed that the enzymatic activity of the sharks did not vary with age, unlike most animals where enzyme efficiency diminishes over time. This metabolic stability appears to prevent cellular degradation, thus explaining the exceptional longevity of Greenland sharks.
Tissue sampling of a Greenland shark captured off the southern coast of Disko Island, central Greenland.
Credit: Ewan Camplisson Tests also showed that enzymatic activity increased significantly at higher temperatures. This suggests that if Greenland sharks were exposed to warmer conditions, their metabolism could increase markedly, potentially altering their lifestyle. These tests are particularly relevant given the projected rise in ocean temperatures due to climate change.
These discoveries pave the way for further research into shark aging markers and metabolism, aiming to better understand how to protect them in a rapidly changing environment.