Greenland Shark Likely to Have Lived to at Least 272 Years Old
(p. A11) The mysterious Greenland shark lives at extreme depths in dark, icy waters, which have long protected it from scientists' prying eyes.
But now, an international group of researchers has estimated the dark brown cartilaginous fish may live as long as 500 years--which would make it the longest-living vertebrate on the planet.
The work, published Thursday [Aug. 11, 2016] in the journal Science, "offers the first hard evidence of how long-lived this poorly understood shark species can be," said Steve Campana, a shark expert at the University of Iceland in Reykjavik, who wasn't involved in the study.
. . .
. . . the 11-person team of researchers turned to math models and radiocarbon dating, a technique typically used to date fossils. They focused their work on the eye lens nucleus of each shark, a structure that stops developing at birth and therefore serves as a rough proxy of birth date. They measured the levels of carbon-14 in the tissue, which animals stop accumulating when they die.
The oldest shark in the study, which measured more than 16 feet, lived an estimated 392 years, according to the scientists. Because the study had a margin of error of 120 years for that fish, the researchers concluded the sharks could live up to about 500 years.
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(Note: ellipses, and bracketed date, added.)
(Note: the online version of the story has the date Aug. 11, 2016, and has the title "Mysterious Greenland Shark May Live Hundreds of Years, Scientists Say." The online version included several additional sentences, interspersed through the article, that were not included in the print version. The sentences quoted above, appeared in both versions, but the formatting of the quotes above, most closely follow the print version.)
The research article reporting findings discussed above, is:
Nielsen, Julius, Rasmus B. Hedeholm, Jan Heinemeier, Peter G. Bushnell, Jørgen S. Christiansen, Jesper Olsen, Christopher Bronk Ramsey, Richard W. Brill, Malene Simon, Kirstine F. Steffensen, and John F. Steffensen. "Eye Lens Radiocarbon Reveals Centuries of Longevity in the Greenland Shark (Somniosus microcephalus)." Science 353, no. 6300 (Aug. 12, 2016): 702-04.