![]() Researchers from the University of Copenhagen have discovered that the Greenland Shark can live to be over 400 years old! These sharks are now known as the longest-living vertebrate known to mankind. Professor John Steffenson and former student Julius Nielsen led the study on the Greenland Sharks. They wanted to research the sharks because little was known about these reclusive fish, including their life expectancy. To find out the average age of these sharks, they looked into their eye lenses. In some shark species, like the Greenland shark, inactive transparent tissue in the eye lenses becomes replaced by new layers. The researchers peeled back the layers to find the one from the shark’s infancy and used it to analyze its age. They used radiocarbon dating (a process in which they burn the shark’s innermost layer of eye lens to see how much carbon it contains). They studied 28 sharks, most of which had been accidentally caught in trawling nets meant to catch other fish. The oldest shark in the group was 392 years, the youngest was 272 years old. However, given that radiocarbon dating doesn’t always provide accurate results, the scientists estimate the sharks could live up from 272 - 512 years. "Even the lowest part of the age range - at least 272 years- still makes Greenland sharks the longest-living vertebrate known to science." -Julius Nielsen, co-leader of the study. The reason these sharks can live so long is due to the fact that they live in such cold water. Research shows that the colder temperatures help slow down the growth and biochemical activity of these sharks, expanding their lifetimes. I think it’s very interesting that these sharks can live to be so old. It’s incredible to think that some of these sharks were alive before America became a country. It’s also amazing that there’s a way to determine an animal's age by looking at its eye lenses. Source: http://www.dogonews.com/2016/8/24/its-official-the-greenland-shark-is-the-longest-living-vertebrate-known-to-science
9 Comments
Eli
8/29/2016 11:21:32 am
I loved the topic it was very interesting and well written. Do you know how long the sharks are?
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Justine
8/29/2016 11:47:32 am
Yes; the sharks can get up to 20 feet long. They grow about one centimeter a year.
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Michelle
8/30/2016 12:58:04 pm
Nice topic! It was nicely written and very interesting. Good Job!
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Sarah Park
8/30/2016 12:58:39 pm
I really enjoyed reading this! Great article, and interesting topic.
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Ansa Schmulbach
8/30/2016 01:01:05 pm
This was interesting and well written. Nice work! It was great to be able to read something very different from the other articles.
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Nicole
8/31/2016 09:51:43 am
This is something so unheard of, and it's something positive! I love it! Good job Justine.
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TA Rach
8/31/2016 09:53:18 am
This is great! I just learned about this in Marine Bio. Keep up the good work.
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Wanqi
9/1/2016 10:53:30 am
I hope I could live that long. Very interesting thing to learn, I wish I have known that earlier.
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Ada Fathers
9/1/2016 01:56:18 pm
This is really cool and interesting. Do you think that if people lived in really cold temperatures, they could be able to have a longer life time.
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