Shark That Lives Up to 400 Years Identified

Zoologists say they have identified a shark that can live up to 400 years. Researchers believe that this shark, which lives off the coast of Greenland, has one of the longest lifespans among animals, if not the longest. A report published in the prestigious journal Science states that these massive sharks do not reach maturity until they are 150 years old, and only after that do they gain the ability to mate. This report is the result of the work of an international team of scientists led by Julius Nielsen from the University of Copenhagen in Denmark, in the waters of Greenland, Norway, and America. The researchers used carbon-14 age determination methods on 28 female sharks that were accidentally caught in the nets of Greenlandic fishermen. They examined the layers of the sharks' eyes to find the amount of carbon-14. Carbon-14 is a specific isotope of carbon that entered the environment during the 1950s alongside nuclear bomb testing. The shark's eye forms while still in the mother's womb. If a shark was pregnant in the 1960s, the amount of carbon-14 in the layers of the offspring's eyes would be higher. The researchers found that most of these sharks are over 50 years old. Since Greenland sharks grow one centimeter per year, their age can be estimated based on their size. By combining the results obtained from carbon-14 tests and the size of these sharks, researchers estimated the age of the oldest known shark in these waters to be 392 years. The next largest shark was 335 years old. They say the average lifespan of these sharks is 272 years.