Resumen de Sharks that may get to the ripe old age of 500
A Greenland shark has lived at least 272 years, making the species the world's longest-lived vertebrate, smashing the previous record held by a 211-year-old bowhead whale. But the shark may have been as old as 500 years. Greenland sharks are apex predators living in the deep frigid waters of the Arctic. It was once thought to be impossible to age sharks. Their skeletons, made of cartilage, lack the calcified growth rings of hard-boned vertebrates. Other fish are aged by measuring calcareous bodies that grow in their ears, but this doesn't work for sharks. Instead Nielsen and his colleagues focused on traces of radiation in the sharks' eyes, left over from nuclear bomb tests in the 1950s and 60s.
