Scientists Say Greenland Sharks May Live 400 Years

NOAA, Flickr // CC BY-2.0
NOAA, Flickr // CC BY-2.0

Get ready to feel like a baby: There may be sharks alive today that are older than the United States. Like, much older. Researchers found a Greenland shark that’s around 392 years old—and 27 others with an average age of 272 years old. They published their findings today, August 11, in the journal Science. 

Young or old, Greenland sharks (Somniosus microcephalus, literally “tiny-headed sleeper”) are extraordinary creatures. They’re the second-largest carnivorous sharks in the world, reaching 2500 pounds. Their teeth are shaped and angled to remove plugs of flesh from their prey, and their own flesh is poisonous. 

Even so, Greenland sharks, like most sharks, present no risk to humans. They’re incredibly slow swimmers and live deep, deep down in the icy waters of the Arctic Ocean. These qualities make them both fascinating to scientists and tricky to track and study. And without data, it’s hard to argue that the sharks need protection.

Julius Nielsen

Previous studies had already found these sharks to have astonishingly long lives. The last estimate, based on a shark caught in 1952, concluded that they could live to be at least 200 years old. 

Science has come a long way since the 1950s, and researchers decided it was time to check again. Fortunately, they had access to a good number of Greenland sharks; unfortunately, that’s because those sharks had been accidentally caught in fishing nets and scientists’ long lines between 2010 and 2013. All 28 female sharks used in the study had been fatally injured by the time they landed onboard—some by other sharks, and some by fishing equipment—and so all were euthanized. After the sharks’ deaths, researchers measured each shark and took tissue samples from the lenses of its eyes. 

The scientists used radiocarbon dating on the samples to see if they could age the sharks. Once again, they had good data thanks to a bad situation—in this case, nuclear warfare. Scientists have known since the 1950s that nuclear bomb tests leave permanent molecular marks on sea creatures. Consequently, the appearance of bomb-related changes in an animal’s tissue can be seen as a sort of time stamp. But because these changes persist, even animals born after any given bomb can be marked by it if the animals they eat were alive during the test. 

By combining this information with the sharks’ body measurements, the scientists were able to estimate each animal’s approximate age. The youngest sharks sampled were less than 10 feet long and under 100 years old. These were mere pups for Greenland sharks; the data suggested that these animals don’t even reach sexual maturity until they’re around 150 years old. 

The oldest two sharks were 16 feet long apiece, and the scientists estimated their age at 335 (plus or minus 75 years) and 392 (plus or minus 120 years). Considering these averages, the researchers say, a conservative estimate of the shark’s longevity would put them at about 272 years old—still making them the oldest vertebrates on the planet. 

Given these astonishing findings and the threats posed to Greenland sharks by commercial fishing, the authors write, it’s time we start thinking about how to protect them.

Know of something you think we should cover? Email us at tips@mentalfloss.com.

 

100 Dachshunds Competed in Cincinnati’s Annual ‘Running of the Wieners’

NORRIE3699/iStock via Getty Images
NORRIE3699/iStock via Getty Images

Every year, to kick off Cincinnati’s Oktoberfest Zinzinnati, 100 dachshunds compete in heats to decide who the fastest dachshund in the Midwest is. This year marks the 43rd annual Oktoberfest—one of the biggest Oktoberfest celebrations outside of Germany (more than 500,000 people attend the three-day event).

On the afternoon of Thursday, September 19, 100 wiener dogs (and their owners and handlers) gathered in downtown Cincinnati for the 2019 "Running of the Wieners." The dogs, dressed in hot dog costumes, ran 10 heats, which lasted 75 feet or five seconds each. The winner of each heat advanced to the final round, where the top three finishers were decided.

Maple, a long-haired, one-year-old dachshund, ran his way into first place—and into our hearts.

Maple’s owner, Jake Sander, told WCPO that Maple is one of five dachshunds in the family, and that he learned to run fast by chasing his brother around. Leo and Bucky, two other doxies, placed second and third, respectively.

Besides the Running of the Wieners, Zinzinnati also hosts the World’s Largest Chicken Dance. However, the wiener dogs are more fun to watch.

Photographer Captures Polka-Dotted Zebra Foal in Kenya

Frank Liu
Frank Liu

Zebras are known for their eye-catching patterns, but this polka-dotted foal recently photographed in Kenya's Masai Mara National Reserve really stands out from the herd. As National Geographic reports, the zebra baby likely has pseudomelanism, a rare pigment condition that's been observed in the wild just a handful of times.

Nature photographer Frank Liu saw the zebra foal while looking for rhinos in the savannah wilderness preserve. After initially confusing the specimen for a different type of animal, he realized upon closer inspection that it was actually a plains zebra born with spots instead of stripes. The newborn foal was named Tira after the Maasai guide Antony Tira who first pointed him out.

Zebra foal with spots walking with mother.
Frank Liu

Zebra foal with spots.
Frank Liu

A typical zebra pattern is the result of pigment cells called melanocytes, which are responsible for the black base coat, and melanin, which gives the animal its white stripes. (So if you've ever wondered if zebras are white with black stripes or black with white stripes, the answer is the latter). In Tira and other zebras with pseudomelanism, the melanocytes are fully expressed, but a genetic mutation causes the melanin to appear as dots rather than unbroken stripes.


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Though rare, this isn't the only time a zebra with pseudomelanism has been documented in nature. Pseudomelanistic zebras have also been spotted in Botswana’s Okavango Delta, but Liu believes this could be the first time one was found in the Masai Mara preserve.

Zebra stripes aren't just for decoration. The distinct pattern may act as camouflage, bug repellant, and a built-in temperature regulation system. Without these evolutionary benefits, Tira has a lower chance of making it to adulthood: Pseudomelanistic zebra adults are rarely observed for this reason. But as Liu's photographs show, the foal has the protection and acceptance of his herd on his side.

[h/t National Geographic]

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