WEBVTT - What Is the World's Longest-Living Vertebrate? 0:00:03.160 --> 0:00:05.680 Welcome to brain Stuff, a production of I Heart Radio, 0:00:08.240 --> 0:00:11.720 Hey brain Stuff, Lauren Boga Bam here. They may not 0:00:11.880 --> 0:00:15.000 have their own cult classic movie like the infamous great 0:00:15.040 --> 0:00:19.520 white shark, but the equally massive greenland shark taxonomic names 0:00:19.520 --> 0:00:24.440 Omniosis microcephalis, holds a pretty impressive record. They're the longest 0:00:24.520 --> 0:00:27.960 living vertebrate known to science. It's estimated that they can 0:00:28.000 --> 0:00:30.960 live up to about four hundred years, beating out the 0:00:31.000 --> 0:00:34.040 former record holder, a species of bohead whale that can 0:00:34.120 --> 0:00:37.280 live a little over two hundred years. A greenland shark 0:00:37.320 --> 0:00:39.920 alive today could have been swimming in the deep during 0:00:39.920 --> 0:00:43.880 the sixteen hundreds, and despite having been around for well 0:00:43.920 --> 0:00:47.360 what seems like forever, the greenland shark was only recently 0:00:47.400 --> 0:00:50.760 recognized as the longest living vertebrate because scientists have been 0:00:50.760 --> 0:00:54.840 stumped for centuries about how to determine their age. Other 0:00:54.920 --> 0:00:59.080 sharks and most other vertebrates have hardened spines that form 0:00:59.240 --> 0:01:02.880 growth ring similar to what occurs inside a tree, and 0:01:02.880 --> 0:01:05.520 those can be counted to determine how long any given 0:01:05.560 --> 0:01:09.080 sharp toothed beast has been roaming the seas, but the 0:01:09.080 --> 0:01:13.800 greenland shark lacks hard tissue making age measurement nearly impossible, 0:01:14.600 --> 0:01:19.319 that is until the recent intersection of Danish scientists, human cadavers, 0:01:19.520 --> 0:01:23.160 and a dash of murder mystery. The story starts with 0:01:23.240 --> 0:01:27.200 one Jon Heinemeyer, an expert in radiocarbon dating at our 0:01:27.280 --> 0:01:31.679 House University in Denmark. He didn't specifically have the Greenland 0:01:31.720 --> 0:01:34.600 shark on his radar, but he proved that you really 0:01:34.680 --> 0:01:37.119 can tell a lot about a person by their eyes. 0:01:38.120 --> 0:01:40.680 His team was studying the crystallians, which are a type 0:01:40.680 --> 0:01:43.679 of protein that remains stable over time, and the carbon 0:01:43.760 --> 0:01:47.680 fourteen levels in the eyes of human cadavers, and since 0:01:47.720 --> 0:01:51.400 the carbon level fluctuates from year to year, every period 0:01:51.440 --> 0:01:55.840 in time has its own carbon fourteen signature, allowing researchers 0:01:55.880 --> 0:01:59.200 to use radiocarbon dating to determine a body's age using 0:01:59.200 --> 0:02:03.240 the lenses of the eyes. But before the technique helped 0:02:03.280 --> 0:02:07.000 to age sharks, it found its way to forensics. His 0:02:07.120 --> 0:02:09.680 team got a request from police in Germany to help 0:02:09.720 --> 0:02:13.240 them solve a bizarre murder mystery. The victims had been 0:02:13.280 --> 0:02:16.240 frozen for years, so the scientists were able to use 0:02:16.280 --> 0:02:19.079 this technique on their eye lens is to precisely determine 0:02:19.080 --> 0:02:23.240 their ages and thus the year of the crime. Then, 0:02:23.320 --> 0:02:27.600 when marine biologist John Flann Stephenson reached out to Hannemeyer 0:02:27.720 --> 0:02:30.600 to see if they could use radiocarbon dating on shark vertebra, 0:02:31.080 --> 0:02:33.840 he learned about the murder case and a new approach. 0:02:34.360 --> 0:02:37.040 Isolated tissue that formed when a shark was very young 0:02:37.240 --> 0:02:40.519 could be radiocarbon dated to give scientists the sharks new 0:02:40.600 --> 0:02:45.360 approximate age. So how does the greenland shark manage to 0:02:45.400 --> 0:02:49.280 live so long? One theory is an extreme cold produces 0:02:49.320 --> 0:02:52.959 anti aging qualities, and lucky for these sharks, they hang 0:02:52.960 --> 0:02:55.800 out in water that hovers around twenty nine degrees fahrenheit 0:02:55.960 --> 0:02:59.959 that's negative one point six celsius. A low metabolism is 0:03:00.040 --> 0:03:03.400 also thought to be a play, but scientists don't have 0:03:03.520 --> 0:03:07.440 the full answer yet. That is, the studies are currently 0:03:07.520 --> 0:03:10.920 underway to examine the sharks genes, heart, and immune system 0:03:11.040 --> 0:03:14.720 to help solve this age old age puzzle, and there 0:03:14.760 --> 0:03:17.040 may be a bonus. They're hoping to be able to 0:03:17.120 --> 0:03:19.840 use what they find to create immune boosting therapies for 0:03:19.919 --> 0:03:23.519 us humans. Given the greenland sharks need to conserve energy, 0:03:23.560 --> 0:03:26.080 they creep along at an average pace of just point 0:03:26.160 --> 0:03:29.200 three meters per second or point eight miles per hour, 0:03:29.600 --> 0:03:34.040 giving them the nickname sleeper sharks, but don't discount their 0:03:34.040 --> 0:03:37.280 ability to attack. When truly necessary, they can increase their 0:03:37.320 --> 0:03:40.960 speed in short bursts. The greenland shark can grow to 0:03:41.000 --> 0:03:43.240 be up to twenty four ft or over seven meters 0:03:43.320 --> 0:03:46.560 long and weigh ended up to hundred pounds or about 0:03:46.600 --> 0:03:52.600 twelve kilos, but they don't exactly have a teenage growth spurt. Instead, 0:03:52.720 --> 0:03:56.200 they make an extremely slow, steady climb to their final size, 0:03:56.560 --> 0:03:59.200 only growing by about half an inch or one centimeter 0:03:59.360 --> 0:04:03.520 per year. With that slow growth comes slow sexual maturity. 0:04:03.600 --> 0:04:06.040 They only become able to reproduce once they're around a 0:04:06.120 --> 0:04:10.400 hundred and fifty years of age, and to add to 0:04:10.440 --> 0:04:14.080 their quirkiness, these slow giants might not even be able 0:04:14.120 --> 0:04:16.880 to see well. Oh. We spoke by email with Dr 0:04:16.960 --> 0:04:20.480 Stephen E. Campana, Professor of Life and Environmental Sciences at 0:04:20.480 --> 0:04:24.240 the University of Iceland. He said greenland sharks in the 0:04:24.320 --> 0:04:29.159 Arctic often have copapod or small crustacean ectoparasites attached on 0:04:29.360 --> 0:04:33.080 or over their eyes. There's no known advantage to these parasites, 0:04:33.240 --> 0:04:36.359 and indeed it seems likely that these parasites obscure or 0:04:36.400 --> 0:04:39.320 even block the vision of the shark. Even though they 0:04:39.320 --> 0:04:41.400 have a coveted spot at the top of the food chain, 0:04:41.560 --> 0:04:45.279 the greenland shark doesn't always hunt for live prey. When 0:04:45.279 --> 0:04:48.560 they do, they mostly catch seals and fish. But more 0:04:48.600 --> 0:04:51.200 than anything, they seem to enjoy living more of a 0:04:51.200 --> 0:04:55.080 scavenger lifestyle, eating animal carcasses such as polar bear or 0:04:55.120 --> 0:04:58.320 reindeer that may have fallen through the ice. Since the 0:04:58.320 --> 0:05:01.880 greenland shark usually hangs out such deep waters, it's rare 0:05:01.920 --> 0:05:05.720 to see one at times, even for scientists. Campana said, 0:05:06.040 --> 0:05:09.760 there's almost no direct fishing towards greenland sharks. Rather, they 0:05:09.760 --> 0:05:13.120 are usually caught accidentally, as bycatch of fisheries for other 0:05:13.200 --> 0:05:17.400 deep water or cold water marine species. A small number 0:05:17.440 --> 0:05:19.720 of people do in fact hunt the greenland shark for 0:05:19.760 --> 0:05:23.000 their meat, but eating it is a risky endeavor. The 0:05:23.040 --> 0:05:25.960 meat must be dried and specially processed over time to 0:05:26.040 --> 0:05:28.760 remove the t m O A, which is a substance 0:05:28.760 --> 0:05:32.520 that causes heavy intoxication in humans. Anyone who eats the 0:05:32.560 --> 0:05:35.400 unprocessed meat will end up shark drunk with a really 0:05:35.480 --> 0:05:38.960 nasty hangover for a few days, and there haven't been 0:05:39.000 --> 0:05:42.039 any documented attacks on humans, but that may have to 0:05:42.040 --> 0:05:44.839 do with the depth of their living quarters. While their 0:05:44.839 --> 0:05:48.799 true conservation status is unknown, Professor Campana said the fact 0:05:48.839 --> 0:05:52.440 that greenland shark densities remain high in some areas suggests 0:05:52.440 --> 0:05:55.160 the continued catches over the past century have not been 0:05:55.279 --> 0:05:58.520 enough to push the population into a critical decline, although 0:05:58.560 --> 0:06:07.839 they are almost certainly at low abundance overall. Today's episode 0:06:07.839 --> 0:06:10.200 was written by Katie Carmen and produced by Tyler Clang. 0:06:10.440 --> 0:06:12.479 For more on this and lots of other sharp topics, 0:06:12.560 --> 0:06:14.880 visit how Stuff works dot com. Brain Stuff is a 0:06:14.880 --> 0:06:17.160 production of I Heart Radio. Or more podcasts in my 0:06:17.200 --> 0:06:20.080 heart Radio, visit the iHeart Radio app, Apple Podcasts, or 0:06:20.080 --> 0:06:21.840 wherever you listen to your favorite shows.