Speaker 1: Welcome to brain Stuff, a production of I Heart Radio,
Speaker 1: Hey brain Stuff, Lauren Boga Bam here. They may not
Speaker 1: have their own cult classic movie like the infamous great
Speaker 1: white shark, but the equally massive greenland shark taxonomic names
Speaker 1: Omniosis microcephalis, holds a pretty impressive record. They're the longest
Speaker 1: living vertebrate known to science. It's estimated that they can
Speaker 1: live up to about four hundred years, beating out the
Speaker 1: former record holder, a species of bohead whale that can
Speaker 1: live a little over two hundred years. A greenland shark
Speaker 1: alive today could have been swimming in the deep during
Speaker 1: the sixteen hundreds, and despite having been around for well
Speaker 1: what seems like forever, the greenland shark was only recently
Speaker 1: recognized as the longest living vertebrate because scientists have been
Speaker 1: stumped for centuries about how to determine their age. Other
Speaker 1: sharks and most other vertebrates have hardened spines that form
Speaker 1: growth ring similar to what occurs inside a tree, and
Speaker 1: those can be counted to determine how long any given
Speaker 1: sharp toothed beast has been roaming the seas, but the
Speaker 1: greenland shark lacks hard tissue making age measurement nearly impossible,
Speaker 1: that is until the recent intersection of Danish scientists, human cadavers,
Speaker 1: and a dash of murder mystery. The story starts with
Speaker 1: one Jon Heinemeyer, an expert in radiocarbon dating at our
Speaker 1: House University in Denmark. He didn't specifically have the Greenland
Speaker 1: shark on his radar, but he proved that you really
Speaker 1: can tell a lot about a person by their eyes.
Speaker 1: His team was studying the crystallians, which are a type
Speaker 1: of protein that remains stable over time, and the carbon
Speaker 1: fourteen levels in the eyes of human cadavers, and since
Speaker 1: the carbon level fluctuates from year to year, every period
Speaker 1: in time has its own carbon fourteen signature, allowing researchers
Speaker 1: to use radiocarbon dating to determine a body's age using
Speaker 1: the lenses of the eyes. But before the technique helped
Speaker 1: to age sharks, it found its way to forensics. His
Speaker 1: team got a request from police in Germany to help
Speaker 1: them solve a bizarre murder mystery. The victims had been
Speaker 1: frozen for years, so the scientists were able to use
Speaker 1: this technique on their eye lens is to precisely determine
Speaker 1: their ages and thus the year of the crime. Then,
Speaker 1: when marine biologist John Flann Stephenson reached out to Hannemeyer
Speaker 1: to see if they could use radiocarbon dating on shark vertebra,
Speaker 1: he learned about the murder case and a new approach.
Speaker 1: Isolated tissue that formed when a shark was very young
Speaker 1: could be radiocarbon dated to give scientists the sharks new
Speaker 1: approximate age. So how does the greenland shark manage to
Speaker 1: live so long? One theory is an extreme cold produces
Speaker 1: anti aging qualities, and lucky for these sharks, they hang
Speaker 1: out in water that hovers around twenty nine degrees fahrenheit
Speaker 1: that's negative one point six celsius. A low metabolism is
Speaker 1: also thought to be a play, but scientists don't have
Speaker 1: the full answer yet. That is, the studies are currently
Speaker 1: underway to examine the sharks genes, heart, and immune system
Speaker 1: to help solve this age old age puzzle, and there
Speaker 1: may be a bonus. They're hoping to be able to
Speaker 1: use what they find to create immune boosting therapies for
Speaker 1: us humans. Given the greenland sharks need to conserve energy,
Speaker 1: they creep along at an average pace of just point
Speaker 1: three meters per second or point eight miles per hour,
Speaker 1: giving them the nickname sleeper sharks, but don't discount their
Speaker 1: ability to attack. When truly necessary, they can increase their
Speaker 1: speed in short bursts. The greenland shark can grow to
Speaker 1: be up to twenty four ft or over seven meters
Speaker 1: long and weigh ended up to hundred pounds or about
Speaker 1: twelve kilos, but they don't exactly have a teenage growth spurt. Instead,
Speaker 1: they make an extremely slow, steady climb to their final size,
Speaker 1: only growing by about half an inch or one centimeter
Speaker 1: per year. With that slow growth comes slow sexual maturity.
Speaker 1: They only become able to reproduce once they're around a
Speaker 1: hundred and fifty years of age, and to add to
Speaker 1: their quirkiness, these slow giants might not even be able
Speaker 1: to see well. Oh. We spoke by email with Dr
Speaker 1: Stephen E. Campana, Professor of Life and Environmental Sciences at
Speaker 1: the University of Iceland. He said greenland sharks in the
Speaker 1: Arctic often have copapod or small crustacean ectoparasites attached on
Speaker 1: or over their eyes. There's no known advantage to these parasites,
Speaker 1: and indeed it seems likely that these parasites obscure or
Speaker 1: even block the vision of the shark. Even though they
Speaker 1: have a coveted spot at the top of the food chain,
Speaker 1: the greenland shark doesn't always hunt for live prey. When
Speaker 1: they do, they mostly catch seals and fish. But more
Speaker 1: than anything, they seem to enjoy living more of a
Speaker 1: scavenger lifestyle, eating animal carcasses such as polar bear or
Speaker 1: reindeer that may have fallen through the ice. Since the
Speaker 1: greenland shark usually hangs out such deep waters, it's rare
Speaker 1: to see one at times, even for scientists. Campana said,
Speaker 1: there's almost no direct fishing towards greenland sharks. Rather, they
Speaker 1: are usually caught accidentally, as bycatch of fisheries for other
Speaker 1: deep water or cold water marine species. A small number
Speaker 1: of people do in fact hunt the greenland shark for
Speaker 1: their meat, but eating it is a risky endeavor. The
Speaker 1: meat must be dried and specially processed over time to
Speaker 1: remove the t m O A, which is a substance
Speaker 1: that causes heavy intoxication in humans. Anyone who eats the
Speaker 1: unprocessed meat will end up shark drunk with a really
Speaker 1: nasty hangover for a few days, and there haven't been
Speaker 1: any documented attacks on humans, but that may have to
Speaker 1: do with the depth of their living quarters. While their
Speaker 1: true conservation status is unknown, Professor Campana said the fact
Speaker 1: that greenland shark densities remain high in some areas suggests
Speaker 1: the continued catches over the past century have not been
Speaker 1: enough to push the population into a critical decline, although
Speaker 1: they are almost certainly at low abundance overall. Today's episode
Speaker 1: was written by Katie Carmen and produced by Tyler Clang.
Speaker 1: For more on this and lots of other sharp topics,
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