WEBVTT - Are Lobsters Functionally Immortal? 0:00:01.840 --> 0:00:07.880 Welcome to Brainstuff, a production of iHeartRadio. Hey, Brainstuff, Lauren 0:00:07.920 --> 0:00:14.720 Bogelbaum here. Lobsters are odd creatures. Their appearance has earned 0:00:14.760 --> 0:00:17.759 them the nickname cockroaches of the sea, and yet they're 0:00:17.760 --> 0:00:21.320 considered a delicacy by people around North America and Europe, 0:00:21.920 --> 0:00:25.520 which is where the cold water lobster Genus Homerus resides, 0:00:25.760 --> 0:00:29.240 which is the one we're talking about today. As we've 0:00:29.240 --> 0:00:32.680 discussed on the show before, they haven't always been so prized. 0:00:33.080 --> 0:00:36.159 Lobsters were so abundant around New England during the seventeen 0:00:36.159 --> 0:00:38.879 and eighteen hundreds that their meat was fed to pigs 0:00:39.280 --> 0:00:42.720 and some indentured servants in Massachusetts we're so sick of 0:00:42.760 --> 0:00:45.080 eating it that they went to court to prevent their 0:00:45.120 --> 0:00:48.080 bosses from feeding them lobster more than three times a week, 0:00:48.720 --> 0:00:53.520 and they won. But whatever you think of them, lobsters 0:00:53.600 --> 0:00:58.480 aren't quite sophisticated critters. Today, let's talk about how they 0:00:58.560 --> 0:01:02.720 interact with the watery rolled around them, including why they 0:01:02.760 --> 0:01:11.000 don't age, making them biologically immortal, though not functionally. But okay, 0:01:11.400 --> 0:01:15.920 let's start a little bit more granular. Lobsters don't see 0:01:15.959 --> 0:01:18.680 particularly well, but they make up for it in their 0:01:18.720 --> 0:01:23.600 senses of taste, smell, and touch. A lobster has four 0:01:23.760 --> 0:01:27.640 spindly antennay and sensing hairs that allow it to smell 0:01:27.720 --> 0:01:31.240 amino acids in the waterlike those given off by prey. 0:01:32.640 --> 0:01:35.399 Lobsters are carnivores that will hunt and eat pretty much 0:01:35.400 --> 0:01:38.280 anything they can get their claws on. They're even known 0:01:38.319 --> 0:01:41.960 to munch on their vulnerable lobster brethren, though that's more 0:01:41.959 --> 0:01:45.560 common in captivity, and it's also why captive lobsters will 0:01:45.600 --> 0:01:49.760 have rubber bands put on their claws. Lobsters will sometimes 0:01:49.800 --> 0:01:53.520 bury their catch and eat it over several days. They 0:01:53.600 --> 0:01:57.040 grind up their food using titeness teeth like things called 0:01:57.080 --> 0:01:59.960 a gastric mill that's located in the first of their 0:02:00.160 --> 0:02:05.960 two stomachs. But that aforementioned excellent sense of smell isn't 0:02:06.000 --> 0:02:09.760 restricted to finding prey. They also use it to identify 0:02:09.840 --> 0:02:15.440 other lobsters, mostly via urine, which they excrete from openings 0:02:15.520 --> 0:02:20.800 on their face. Yep, lobsters pee out of their faces 0:02:20.919 --> 0:02:25.960 for behavioral purposes. A lobster excretes waste from a few 0:02:26.000 --> 0:02:28.800 spots on its body, but it urinates out of openings 0:02:28.800 --> 0:02:33.080 on its face called nephrifhores, and it's not just about 0:02:33.120 --> 0:02:37.160 getting rid of toxins. Lobsters urinate in each other's faces 0:02:37.240 --> 0:02:42.799 during fights to express themselves literally, and female lobster's urine 0:02:42.840 --> 0:02:47.280 contains pheromones to get male lobsters relaxed and in the mood. 0:02:48.440 --> 0:02:51.520 A part of the lobster mating process involves a female 0:02:51.520 --> 0:02:55.160 lobster repeatedly urinating into the shelter belonging to the male 0:02:55.200 --> 0:02:58.480 lobster that she hopes to mate with. By the way, 0:02:58.760 --> 0:03:02.160 I know what Phoebe says on friends, but lobsters don't 0:03:02.240 --> 0:03:07.880 mate for life. Their relationships last about two weeks anyway. 0:03:08.520 --> 0:03:14.400 Speaking of the reproduction process, female lobsters practice reproductive planning. 0:03:15.480 --> 0:03:18.400 A female lobster chooses her mate and makes the first moves, 0:03:18.639 --> 0:03:21.720 and then can carry around a male's live sperm with 0:03:21.800 --> 0:03:24.560 her for up to two years before using it to 0:03:24.680 --> 0:03:29.280 fertilize her eggs. She'll have some tens of thousands of eggs, 0:03:29.400 --> 0:03:32.440 so she might collect sperm from multiple males before going 0:03:32.440 --> 0:03:37.040 ahead with fertilization. The survival of her spawn depends on 0:03:37.120 --> 0:03:40.200 the environment she chooses for them, so it's good that 0:03:40.240 --> 0:03:44.360 she's picky out of every fifty thousand eggs she lays. 0:03:44.600 --> 0:03:47.720 Only two will live long enough to become an adult 0:03:47.760 --> 0:03:54.480 lobster of catchable size, not two thousand, just two. A 0:03:54.520 --> 0:03:58.800 lobster's early life is fraught with danger because they start small, 0:03:59.120 --> 0:04:01.720 and we're not the only ones that find them tasty. 0:04:02.960 --> 0:04:05.560 When they hatch. They are tiny, about the size of 0:04:05.560 --> 0:04:09.400 a mosquito, and they don't resemble adult lobsters as much 0:04:09.440 --> 0:04:14.400 as miniature dark crystal era hensing creations. Their gills are 0:04:14.400 --> 0:04:16.760 on the outside of their bodies and they don't have 0:04:16.800 --> 0:04:19.840 a shell yet, and they pretty much float around near 0:04:19.839 --> 0:04:23.800 the surface of the ocean eating plankton. They'll go through 0:04:23.839 --> 0:04:26.440 a few metamorphoses over the course of a month or 0:04:26.480 --> 0:04:29.159 so before they migrate to the ocean floor and start 0:04:29.200 --> 0:04:33.560 to look and behave like lobsters, you know, an armored 0:04:33.600 --> 0:04:36.120 skeleton on the outside of their body instead of on 0:04:36.160 --> 0:04:40.440 the inside, with a large, powerful tail, and ten legs total, 0:04:40.720 --> 0:04:44.280 with claws on the first four, including a large asymmetrical 0:04:44.320 --> 0:04:49.320 pair up front. That's right. Most lobsters have a dominant 0:04:49.320 --> 0:04:52.440 front claw, meaning they're either right clawed or left clawed. 0:04:53.440 --> 0:04:56.360 The dominant one is referred to as the crusher and 0:04:56.600 --> 0:04:59.560 it's bigger and strong enough to crack open the shells 0:04:59.560 --> 0:05:03.760 of prey. The smaller claw, called the cutter or caesar, 0:05:04.120 --> 0:05:08.719 grabs food and shreds it for consumption. But some lobsters 0:05:08.760 --> 0:05:14.360 may have two crushers or two cutters and use them interchangeably. However, 0:05:14.800 --> 0:05:18.719 lobsters are not all that attached to their limbs. Literally. 0:05:19.680 --> 0:05:23.440 They can detach a leg, claw, or antenna in an emergency. 0:05:23.839 --> 0:05:27.640 This is called a reflex amputation. It's not a big 0:05:27.680 --> 0:05:30.400 deal because they can grow it back during their molting cycle. 0:05:31.560 --> 0:05:34.880 A lobsters must molt in order to grow, splitting and 0:05:35.000 --> 0:05:38.560 shedding each hard piece of their carapas. If they've lost 0:05:38.600 --> 0:05:41.160 a limbs since their last molt, they'll grow it back 0:05:41.200 --> 0:05:45.520 as they grow a new, larger shell. They'll start by 0:05:45.520 --> 0:05:48.640 eating their molted shells as they're full of the calcium 0:05:48.720 --> 0:05:52.800 they need to grow the new one. But this brings 0:05:52.880 --> 0:05:57.320 us to perhaps the weirdest thing about lobsters. Given everything 0:05:57.400 --> 0:06:01.119 we know about life as we know it, lobsters show 0:06:01.240 --> 0:06:06.359 no apparent signs of aging. They don't slow down or 0:06:06.400 --> 0:06:10.640 become weaker or more susceptible to disease. They don't become infertile. 0:06:11.000 --> 0:06:15.320 Older lobsters are actually more fertile than younger ones. For 0:06:15.360 --> 0:06:18.320 as long as they can keep growing and molting and 0:06:18.400 --> 0:06:22.600 building a new shell, they'll just keep on going. They 0:06:22.640 --> 0:06:26.160 are such hardy creatures that scientists aren't even sure how 0:06:26.200 --> 0:06:30.719 old lobsters can get, and determining a lobster's age is 0:06:30.760 --> 0:06:35.000 difficult because they continue functioning as normal. Size isn't the 0:06:35.040 --> 0:06:38.000 best indicator either, because they can grow at different rates 0:06:38.040 --> 0:06:41.919 depending on their environment. If you dissect a lobster, you 0:06:41.960 --> 0:06:45.279 can look for calcified growth rings on their eyestalks and 0:06:45.360 --> 0:06:49.240 in their gastric mills, parts that never shed and do 0:06:49.440 --> 0:06:53.960 grow every year, similar to the growth rings in a tree. 0:06:54.040 --> 0:06:56.680 You can count these calcified rings to figure out a 0:06:56.680 --> 0:07:03.400 lobster's age, but obviously that's a little invasive, and generally speaking, 0:07:03.560 --> 0:07:06.320 you can figure that a cold water lobster will take 0:07:06.360 --> 0:07:09.520 about five to seven years and twenty to thirty molts 0:07:09.600 --> 0:07:12.240 to reach a pound in weight, which is about four 0:07:12.360 --> 0:07:15.400 hundred and fifty grams, which is about the minimum weight 0:07:15.440 --> 0:07:18.520 a lobster can be to be harvested in most fisheries. 0:07:19.840 --> 0:07:23.480 The largest lobster on record weighed about forty four pounds 0:07:23.680 --> 0:07:27.000 or twenty kilos. It was caught in nineteen eighty eight 0:07:27.080 --> 0:07:29.320 off the coast of Nova Scotia and was three and 0:07:29.360 --> 0:07:31.760 a half feet long that's a little over a meter. 0:07:33.120 --> 0:07:36.400 Scientists think it was at least one hundred years old. 0:07:37.120 --> 0:07:40.080 The studies have found that the average lobster is closer 0:07:40.120 --> 0:07:43.560 to half to a third of that though, which is 0:07:43.640 --> 0:07:48.280 really impressive, but it means that no. Lobsters are not immortal. 0:07:48.960 --> 0:07:52.440 Diseases do affect them. They might be caught and eaten 0:07:52.560 --> 0:07:57.440 by another animal, including a human. Also, molting takes a 0:07:57.520 --> 0:08:00.840 lot of energy, and it takes more energy the larger 0:08:00.960 --> 0:08:05.520 lobster gets, so sheer exhaustion can do a big lobster 0:08:05.640 --> 0:08:08.040 in when it outgrows its shell, even if it was 0:08:08.080 --> 0:08:13.080 bopping along like a whipper snapper up until then. For humans, 0:08:13.280 --> 0:08:16.800 decline is an accepted part of old age, even for 0:08:16.920 --> 0:08:20.720 those still searching for a fountain of youth. We expect 0:08:20.760 --> 0:08:23.280 the same in our pets and in the flies that 0:08:23.320 --> 0:08:27.480 buzz around us, albeit at different rates, but some animals 0:08:27.520 --> 0:08:30.560 are different. We've talked about this a bit before on 0:08:30.640 --> 0:08:34.120 the show. It has to do with senescence or planned 0:08:34.280 --> 0:08:38.960 cell death in humans and most other animals. Most of 0:08:39.000 --> 0:08:41.760 our cells have a limited life span, at the end 0:08:41.760 --> 0:08:44.559 of which the selling question will divide itself into two 0:08:44.840 --> 0:08:48.960 daughter cells, each containing a copy of the original cells DNA. 0:08:50.240 --> 0:08:53.760 Now DNA, you know, the code that tells our bodies 0:08:53.760 --> 0:08:57.840 how to function, is coiled up into structures called chromosomes, 0:08:58.520 --> 0:09:02.280 and chromosomes are on the ends with protective bits of 0:09:02.520 --> 0:09:07.840 otherwise useless DNA called telomeres. Every time a cell divides, 0:09:08.000 --> 0:09:12.440 those telomeres break off a little bit. They're protective because 0:09:12.520 --> 0:09:15.440 for as long as the telomeres are there, they prevent 0:09:15.480 --> 0:09:20.160 your working DNA from breaking off. When that happens, the 0:09:20.200 --> 0:09:24.160 cell will stop dividing and either destroy itself or become inactive. 0:09:25.520 --> 0:09:29.040 Telomeres protect your DNA like the little plastic caps on 0:09:29.080 --> 0:09:32.559 the end of a shoelace. The reason that we age 0:09:32.800 --> 0:09:36.480 is that eventually those telomere caps do break all the 0:09:36.480 --> 0:09:40.800 way off, and on a cellular level, our organs stop 0:09:40.840 --> 0:09:43.839 working as well, and we're less able to fight off 0:09:43.880 --> 0:09:47.719 illness and repair damage to our tissue. You know, we 0:09:47.840 --> 0:09:52.040 might get arthritis or cataracts or Parkinson's, and if we 0:09:52.120 --> 0:09:54.840 break a bone, it's much harder for us to recover. 0:09:56.160 --> 0:09:59.880 This doesn't happen in lobsters because they have an abundance 0:10:00.120 --> 0:10:06.199 an enzyme called telomerase. Telomerase works to add length to telomeres, 0:10:06.600 --> 0:10:12.400 thus extending cells lifespans. We humans do have telomerase in 0:10:12.440 --> 0:10:17.240 some specialized cells, like stem cells, which do specialized growth 0:10:17.280 --> 0:10:20.880 and repair work, but lobsters have them in most of 0:10:20.920 --> 0:10:24.040 their cells, which is why they can keep growing and 0:10:24.120 --> 0:10:28.439 repairing their whole bodies up to replacing missing limbs and 0:10:28.520 --> 0:10:33.640 not experiencing twilight years. They're not the only animals with 0:10:33.760 --> 0:10:38.440 quirky telomeres. Many types of turtles don't show compromised immunity 0:10:38.600 --> 0:10:42.000 or physical breakdown because of age. They also tend to 0:10:42.040 --> 0:10:44.960 become more fertile as they get older, and usually die 0:10:44.960 --> 0:10:49.720 because of predation or illness unrelated to age. There's a 0:10:49.760 --> 0:10:53.160 bird known as Leech's storm petrel that can sit in 0:10:53.200 --> 0:10:57.240 a human hand yet lives more than thirty years. Their 0:10:57.280 --> 0:11:02.920 telomeres grow longer with age. Unfortunately, we can't just turn 0:11:03.040 --> 0:11:07.319 on telmraase enzymes in humans to make us biologically immortal. 0:11:08.480 --> 0:11:11.120 That's because one of the times that we do see 0:11:11.240 --> 0:11:16.760 active telomerase throughout adult humans is in cancer. That's why 0:11:16.880 --> 0:11:20.240 cancerous cells don't die when they're supposed to and just 0:11:20.400 --> 0:11:25.720 keep replicating. There's a theory that in large, long lived 0:11:25.760 --> 0:11:31.120 species like humans, it's been evolutionarily advantageous to stop telomerase 0:11:31.200 --> 0:11:36.440 activity during adulthood in order to help prevent cancer. We 0:11:36.600 --> 0:11:39.200 still have a lot to learn about all of this. 0:11:40.280 --> 0:11:43.760 For example, we can take the interesting case of naked 0:11:43.800 --> 0:11:48.080 mole rats. These small rodents can live to about thirty 0:11:48.080 --> 0:11:51.760 five years old, whereas close relatives like guinea pigs, only 0:11:51.800 --> 0:11:55.520 live to about seven. Research has shown that naked mole 0:11:55.600 --> 0:11:58.560 rats do age, but they don't tend to die because 0:11:58.559 --> 0:12:01.480 of old age, and they seem to have evolved a 0:12:01.720 --> 0:12:06.280 non teleomere related way to fend off cancer. A lots 0:12:06.320 --> 0:12:10.800 more research is being conducted on many fronts. If one 0:12:10.840 --> 0:12:14.319 day we discover an important new treatment for cancer, it 0:12:14.400 --> 0:12:17.600 may be due to one of these creatures, or to 0:12:17.760 --> 0:12:21.160 a four hundred pound lobster eating its way around the 0:12:21.160 --> 0:12:29.080 North Atlantic. Today's episode is based on the articles ten 0:12:29.160 --> 0:12:32.559 Weird Facts about Lobsters by Shanna Friedman and is there 0:12:32.640 --> 0:12:35.800 a four hundred pound Lobster out There? By Jacob Silverman, 0:12:36.120 --> 0:12:39.400 both on How Stuffworks dot Com. Brain Stuff is production 0:12:39.440 --> 0:12:42.280 of iHeartRadio in partnership with hou stuffworks dot Com and 0:12:42.360 --> 0:12:45.400 is produced by Tyler Klang. Four more podcasts from my 0:12:45.440 --> 0:12:49.400 heart Radio. Visit the iHeartRadio app, Apple Podcasts, or wherever 0:12:49.440 --> 0:12:51.000 you listen to your favorite shows.