Saturday, January 29, 2022

"Greenland sharks: Toxic, half-blind giants of the ocean"

From LiveScience:

Greenland sharks live longer than any other vertebrate.

Greenland sharks (Somniosus microcephalus) are the longest-living animals with a backbone, and survive for up to hundreds of years in the deep, cold waters of the Arctic and North Atlantic oceans. Greenland sharks belong to a family called sleeper sharks, which move slowly and stealthily through the water. 

These sharks sneak up on live prey and scavenge a variety of dead animals, including other sharks, seals, drowned horses and polar bears. Greenland sharks rarely encounter humans and scientists still have much to learn about their lifestyles. 

Greenland sharks grow up to 24 feet (7.3 meters) long and weigh up to 2,645 pounds (1,200 kilograms), according to the St. Lawrence Shark Observatory (ORS). That's longer than great white sharks (Carcharodon carcharias), which are estimated to grow up to 20 feet (6 m) long. (Although unconfirmed reports suggest they can reach 23 feet (7 m) in length, according to the Florida Museum of Natural History.) ....

....Greenland sharks' exact life span is unknown. A 2016 study published in the journal Science estimated that Greenland sharks have a maximum life span of at least 272 years, based on analysis of the sharks' eye tissue. Researchers estimated that the oldest Greenland shark in that study was about 392 years old, but the estimate had a margin of error of 120 years, which led to speculation that Greenland sharks could live to 512 years old. The estimated range hasn't been verified....