What Is the World's Longest-Living Vertebrate?

live a little over two hundred years. A greenland shark alive today could have been swimming in the deep during the sixteen hundreds, and despite having been around for well what seems like forever, the greenland shark was only recently recognized as the longest living vertebrate because scientists have been

stumped for centuries about how to determine their age. Other sharks and most other vertebrates have hardened spines that form growth ring similar to what occurs inside a tree, and those can be counted to determine how long any given sharp toothed beast has been roaming the seas, but the greenland shark lacks hard tissue making age measurement nearly impossible, that is until the recent intersection of Danish scientists, human cadavers,

and a dash of murder mystery. The story starts with one Jon Heinemeyer, an expert in radiocarbon dating at our House University in Denmark. He didn't specifically have the Greenland shark on his radar, but he proved that you really can tell a lot about a person by their eyes.

His team was studying the crystallians, which are a type of protein that remains stable over time, and the carbon fourteen levels in the eyes of human cadavers, and since the carbon level fluctuates from year to year, every period in time has its own carbon fourteen signature, allowing researchers to use radiocarbon dating to determine a body's age using the lenses of the eyes. But before the technique helped

to age sharks, it found its way to forensics. His team got a request from police in Germany to help them solve a bizarre murder mystery. The victims had been frozen for years, so the scientists were able to use this technique on their eye lens is to precisely determine

their ages and thus the year of the crime. Then, when marine biologist John Flann Stephenson reached out to Hannemeyer to see if they could use radiocarbon dating on shark vertebra, he learned about the murder case and a new approach. Isolated tissue that formed when a shark was very young could be radiocarbon dated to give scientists the sharks new approximate age. So how does the greenland shark manage to

live so long? One theory is an extreme cold produces anti aging qualities, and lucky for these sharks, they hang out in water that hovers around twenty nine degrees fahrenheit that's negative one point six celsius. A low metabolism is also thought to be a play, but scientists don't have the full answer yet. That is, the studies are currently underway to examine the sharks genes, heart, and immune system to help solve this age old age puzzle, and there

may be a bonus. They're hoping to be able to use what they find to create immune boosting therapies for us humans. Given the greenland sharks need to conserve energy, they creep along at an average pace of just point three meters per second or point eight miles per hour, giving them the nickname sleeper sharks, but don't discount their ability to attack. When truly necessary, they can increase their

speed in short bursts. The greenland shark can grow to be up to twenty four ft or over seven meters long and weigh ended up to hundred pounds or about twelve kilos, but they don't exactly have a teenage growth spurt. Instead, they make an extremely slow, steady climb to their final size, only growing by about half an inch or one centimeter per year. With that slow growth comes slow sexual maturity.

They only become able to reproduce once they're around a hundred and fifty years of age, and to add to their quirkiness, these slow giants might not even be able to see well. Oh. We spoke by email with Dr Stephen E. Campana, Professor of Life and Environmental Sciences at the University of Iceland. He said greenland sharks in the Arctic often have copapod or small crustacean ectoparasites attached on

or over their eyes. There's no known advantage to these parasites, and indeed it seems likely that these parasites obscure or even block the vision of the shark. Even though they have a coveted spot at the top of the food chain, the greenland shark doesn't always hunt for live prey. When they do, they mostly catch seals and fish. But more than anything, they seem to enjoy living more of a scavenger lifestyle, eating animal carcasses such as polar bear or

reindeer that may have fallen through the ice. Since the greenland shark usually hangs out such deep waters, it's rare to see one at times, even for scientists. Campana said, there's almost no direct fishing towards greenland sharks. Rather, they are usually caught accidentally, as bycatch of fisheries for other deep water or cold water marine species. A small number of people do in fact hunt the greenland shark for

their meat, but eating it is a risky endeavor. The meat must be dried and specially processed over time to remove the t m O A, which is a substance that causes heavy intoxication in humans. Anyone who eats the unprocessed meat will end up shark drunk with a really nasty hangover for a few days, and there haven't been any documented attacks on humans, but that may have to

do with the depth of their living quarters. While their true conservation status is unknown, Professor Campana said the fact that greenland shark densities remain high in some areas suggests the continued catches over the past century have not been enough to push the population into a critical decline, although they are almost certainly at low abundance overall. Today's episode was written by Katie Carmen and produced by Tyler Clang. For more on this and lots of other sharp topics,

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