• 3 days ago
This shark may have be roaming the ocean for about 500 years...

Meet the Greenland shark, the oldest vertebrate known to man.

Category

🐳
Animals
Transcript
00:00Even if you go with the most conservative estimate, which is at least 272 years,
00:08then the Greenland shark is still the oldest vertebrate animal that we know.
00:16It is amazing to have been able to do this work with such a big deep-sea shark
00:22that no one knows very much about it.
00:31Seeing a Greenland shark is super rare because they live in the Arctic and they live in the deep sea.
00:37They have a very rough skin. They do look old, even when they are a small one.
00:51That was a huge surprise. We came up with an estimate of the oldest shark in our study.
00:57The estimate of the oldest shark in our study was somewhere between 272 and 512 years old.
01:04Now we have a number. We have something solid to say, even though we can't say the exact age very accurately.
01:10We can say with very high certainty that it is a very old animal.
01:27There is especially one which is often presented as a 400-year-old Greenland shark.
01:54But the thing is, that particular shark, where there is this very cool image of it,
02:00and it looks very old and very big, that was actually a shark that we released with satellite tags.
02:05Therefore, we have never investigated how old it was.
02:09So it's not correct that that specific animal is very old,
02:13but it's correct that the species Greenland shark can be very old.
02:19People always ask, how is it to see an animal that is 50 years old or 100 years old?
02:25That's impressive. But one thing that is always in my mind more is how long time it can actually live after me.
02:33When you catch a shark of two or three meters, then you're thinking,
02:36oh, wow, this animal can actually live for another 100 years or 200 years.
02:41And I think that is kind of impressive.
02:44That is important in terms of conservation considerations and things like that.
02:48Greenland sharks are a species that are caught as bycatch in some fisheries,
02:53where we expect the females to be actually over 100 years when they are reaching sexual maturation.
03:00And that number should kind of start all warning signs in terms of whether the species is endangered.
03:08But the next question that then comes into play is how many pups do they get per pregnancy?
03:13We know where lions give birth or where crocodiles give birth and how they do it
03:16and how many eggs they get or turtles or things like that.
03:19But when it comes to the ocean and especially when it comes to the deep sea,
03:22all these fundamental questions become relevant.
03:25Here in Greenland, they are most common from 200 meters to 700 meters.
03:30And the deepest record there is of a Greenland shark is almost three kilometers down.
03:35At this moment, I wouldn't consider it endangered,
03:38but it's a species that should be kept under high observation
03:41and especially the reporting methods should be improved.

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