(photo: Hemming1952)
The Greenland Shark has the longest lifespan of any vertebrate (up to 500 years), and doesn’t even reach sexual maturity until they are 150 years old
One theory to explain this long lifespan is that the Greenland shark has a very slow metabolism, an adaptation to the deep, cold waters it inhabits. A NOAA remotely operated vehicle doing a dive off New England encountered a Greenland shark at a depth of 783 meters, but these sharks are known to dive as deep as 2,200 meters. They’re also the only shark that can withstand the cold waters of the Arctic Ocean year-round.
The slow metabolism could explain the shark’s slow growth, slow aging, and sluggish movement — its top speed is under 2.9 kilometers per hour. Because the sharks grow so slowly, they aren’t thought to reach sexual maturity until they’re over a century old. That means removing mature Greenland sharks from the ocean affects the species and the ecosystem for many decades. Though the Greenland shark used to be hunted for its liver oil, the majority of Greenland sharks that end up in fishing nets and lines now are caught by accident. Reducing bycatch is critical in conserving this unique species.