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Sharks Can Live a Long Time
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Feb 10, 2019 09:37:33   #
jerryc41 (a regular here)
 
I had no idea that some species of shark can live for hundreds of years.

https://www.livescience.com/61210-shark-not-512-years-old.html

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Feb 11, 2019 06:35:44   #
sb (a regular here)
 
Well - I guess they wouldn't make good pets then.......

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Feb 11, 2019 07:08:18   #
Largobob (a regular here)
 
Ya....and they seem to lose their teeth all over Florida beaches and phosphate pits.

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Feb 11, 2019 11:44:16   #
Bykewrydr
 
Yeh And you can't flush them down the toilet when they do die.

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Feb 11, 2019 13:51:15   #
rpavich (a regular here)
 
jerryc41 wrote:
I had no idea that some species of shark can live for hundreds of years.

https://www.livescience.com/61210-shark-not-512-years-old.html


Well....maybe...maybe not.

The article is filled with caveats.


The article starts off by saying:

///The creature in question — a Greenland shark — does, in fact, live to be several centuries old, according to a study that was published in August 2016 in the journal Science, and which was referenced in the news coverage.///

As if that's actually a fact.

But then went on to qualify just about everything that they said.

///Eye tissue analysis presented a probability range suggesting that the sharks were at least 272 years old, and could potentially be as much as 512 years old, Live Science previously reported. [Extreme Life on Earth: 8 Bizarre Creatures]

it went on to say:

///For some shark species, scientists use bony structures such as calcified vertebrae to track their age, reading rings that form in the hardened tissue as the shark ages. But Greenland sharks are "soft sharks" whose vertebrae don't harden enough to form telltale age markers, so scientists needed a new method to determine how old the sharks were, Julius Nielsen, author of the 2016 study about the sharks, told Live Science that year.

The scientists used radiocarbon dating to measure carbon isotopes absorbed by Greenland sharks' eye tissue, working with sharks that were captured as bycatch, the study authors reported.

The tissue gave them a range for the sharks' ages — they were at least 272 years old, and as much as 512 years old. The two biggest sharks — and probably the oldest — were estimated to be 335 and 392 years old, respectively. And the midpoint of the range — "the most likely single-year age in the 272- to 512-year range" — was 390 years, Nielsen told Live Science. [Photos: The World's Oldest Living Things]


"It's important to keep in mind there's some uncertainty with this estimate," Nielsen said. "But even the lowest part of the age range — at least 272 years — still makes Greenland sharks the longest-living vertebrate known to science."

As long-lived as they may be, Greenland sharks don't even come close to the longevity of hydra — freshwater polyps. These unassuming-looking invertebrates continuously regenerate their own cells, and are thought to be able to live forever under the right conditions.

Creatures that swim the ocean depths are notoriously difficult to observe in their natural habitat, and there is still much to be learned about many species that have been known to science for decades — and Greenland sharks are no exception, Nielsen told Live Science in 2016.

"Almost all of their biology is a mystery," he said.///


Talk about an article that starts out with what "seems" to be a fact and then qualifies it down to a guess that might be right.

Add to that the difficulties with radiocarbon dating assumptions and there you go...what passes for modern scientific "fact".

https://www.varchive.org/ce/c14.htm

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Feb 11, 2019 17:16:44   #
Dan Copeland
 
jerryc41 wrote:
I had no idea that some species of shark can live for hundreds of years.

https://www.livescience.com/61210-shark-not-512-years-old.html


That is because they ate all the whales in the Great Lakes

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Feb 13, 2019 21:46:52   #
RainierView
 
Dan Copeland wrote:
That is because they ate all the whales in the Great Lakes



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