WEBVTT - Give ‘Em Shell: The Glorious Hermit Crab, Part 1 0:00:03.040 --> 0:00:06.040 Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. 0:00:13.039 --> 0:00:15.000 Hey you welcome to Stuff to Blow your Mind. My 0:00:15.080 --> 0:00:15.840 name is Robert. 0:00:15.720 --> 0:00:18.800 Lamb and my name is Joe McCormick. And we're back 0:00:18.840 --> 0:00:21.480 after the holidays. All right, I guess you've already been back, 0:00:21.560 --> 0:00:23.160 rob I'm back for the first time now. 0:00:24.520 --> 0:00:28.120 Yeah, that's right. I left a little early and then 0:00:28.480 --> 0:00:30.880 and then I came back to you know, scramble together 0:00:30.920 --> 0:00:34.800 a few episodes. But now it's time to return proper 0:00:35.520 --> 0:00:38.160 with a true core episode of Stuff to Blow Your Mind. 0:00:38.400 --> 0:00:41.320 But we're ringing in the new year once more with crabs, 0:00:41.360 --> 0:00:44.320 because of course, crab content is suitable for any holiday, 0:00:44.800 --> 0:00:47.080 and there is an abundance. 0:00:46.520 --> 0:00:48.199 Of it, you know. I don't know if it's just 0:00:48.240 --> 0:00:51.960 the name of Christmas Island that that created this correlation, 0:00:52.080 --> 0:00:54.560 but I think we tend to do crab content in 0:00:54.600 --> 0:00:57.320 the winter. Have you noticed that that's not on purpose, 0:00:57.400 --> 0:00:59.120 at least not on my part. 0:00:59.120 --> 0:01:02.280 No, this is this. I think the Christmas Island crab 0:01:02.320 --> 0:01:05.880 thing kicked it off a bit a while back. That's 0:01:05.959 --> 0:01:10.080 part of it. For sure. There's something maybe holiday centric 0:01:10.120 --> 0:01:14.240 about crabs. It also helps that sometimes my family and 0:01:14.280 --> 0:01:17.520 I travel during the winter break and go somewhere where 0:01:17.600 --> 0:01:21.720 crabs are abundant. And yeah, I'm excited to talk about 0:01:21.760 --> 0:01:23.920 crabs once more because over the holidays, my family and 0:01:23.920 --> 0:01:27.319 I were fortunate enough to once more visit Glover's Reef, 0:01:27.680 --> 0:01:31.919 a partially submerged atoll located off the southern coast of Belize. 0:01:32.840 --> 0:01:35.160 Tremendous fun. We stayed on a small island all week. 0:01:35.240 --> 0:01:38.479 There were other humans, certainly, but we spend as much 0:01:38.480 --> 0:01:41.080 time as possible getting into the water to snorkel to 0:01:41.160 --> 0:01:43.679 check out the fish and the coral. But the predominant 0:01:43.720 --> 0:01:48.000 land organism was, without a doubt, the terrestrial hermit crab. 0:01:48.600 --> 0:01:50.640 So this is a holiday with crabs underfoot. 0:01:51.080 --> 0:01:53.640 Yes, I mean, I don't think anyone ever stepped on one, 0:01:53.720 --> 0:01:58.400 but they were everywhere. Most hermit crab species are aquatic, 0:01:58.440 --> 0:02:02.320 as we'll probably touch on several times during this episode, 0:02:03.240 --> 0:02:06.080 but I'm going to be talking mostly about the terrestrial 0:02:06.160 --> 0:02:09.160 variants like those that I encountered on this island, that 0:02:09.320 --> 0:02:12.040 still depend on the ocean for reproduction, but which live 0:02:12.120 --> 0:02:15.240 most of their lives on land, and that comes with 0:02:15.400 --> 0:02:21.200 various complications and innovations. And also they're very visible, you know, 0:02:21.480 --> 0:02:23.680 you don't need a snorkel, you don't need a dive 0:02:23.760 --> 0:02:27.880 suit to engage with the world of the hermit crab, 0:02:27.960 --> 0:02:30.400 because on places like this they are everywhere and they 0:02:30.400 --> 0:02:32.640 are widespread. You don't also don't have to go to 0:02:32.800 --> 0:02:36.799 Belize to encounter hermit crabs, terrustrial hermit crabs, even they 0:02:36.800 --> 0:02:37.440 are out there. 0:02:37.639 --> 0:02:40.520 So roughly, how big were or how big was the 0:02:40.639 --> 0:02:42.480 range of the ones you were seeing? Is are we 0:02:42.520 --> 0:02:47.080 talking like silver dollar size or hand size? Like what 0:02:47.120 --> 0:02:48.000 are we dealing with here? 0:02:48.440 --> 0:02:50.640 Yeah? The size differential is one of the things that 0:02:50.800 --> 0:02:53.840 makes hermit crab watching in the wild so fun because 0:02:54.000 --> 0:02:55.880 you never know exactly what size you're going to encounter. 0:02:56.000 --> 0:02:58.000 Like some of the very small ones, you know, oh 0:02:58.040 --> 0:03:01.520 so cute, it's the size of a or something. You know, 0:03:01.520 --> 0:03:04.639 it's very small. But other times it'll be like, I'm 0:03:04.639 --> 0:03:07.200 probably exaggerating to save the size of a catcher's met 0:03:08.200 --> 0:03:10.519 but at least the size of a very large fist, 0:03:10.600 --> 0:03:13.560 you know, just a big chonker of a hermit crab. 0:03:14.520 --> 0:03:16.360 And as you're going as we were going about on 0:03:16.400 --> 0:03:20.280 the little pathways on the island, you know, they would 0:03:20.320 --> 0:03:23.240 be moving around pretty much all the time. That they're 0:03:23.360 --> 0:03:27.960 very busy. They're constantly trooping about, they're scavenging, they're competing 0:03:27.960 --> 0:03:30.840 for shells. Though I don't think we ever directly observe this, 0:03:31.000 --> 0:03:34.360 but clearly it is happening. And if you come across 0:03:34.400 --> 0:03:38.760 one while it's say, crossing the sandy path, they'll suddenly stop, 0:03:38.960 --> 0:03:40.800 and then if you get a little bit closer, they'll 0:03:40.840 --> 0:03:42.880 retreat into their shells, and as they do that, that'll 0:03:42.920 --> 0:03:45.040 cause them to roll over onto their back, and then 0:03:45.080 --> 0:03:48.000 of course they cap the shell opening with their larger 0:03:48.120 --> 0:03:50.320 claw and then give them enough time and then get 0:03:50.320 --> 0:03:54.000 back up and they continue on with their business. So, yeah, 0:03:54.000 --> 0:03:57.200 there's just something magical about hermit crabs, at least to 0:03:57.240 --> 0:03:59.040 someone like me who doesn't get to observe them all 0:03:59.120 --> 0:04:01.600 the time. But but even the team on the island here, 0:04:01.600 --> 0:04:03.640 they seem to find a certain amount of joy in 0:04:03.680 --> 0:04:06.560 the creatures, despite how accustomed they were to their presence. 0:04:07.080 --> 0:04:10.640 I heard that one of the cooks brought some shells 0:04:11.000 --> 0:04:14.960 for the crabs with her from the mainland, with the 0:04:15.080 --> 0:04:17.760 names of each of her children written on them, and 0:04:17.800 --> 0:04:21.360 then and then would enjoy like running into various crabs 0:04:21.360 --> 0:04:24.120 who would claim these shells and make them their homes. 0:04:24.440 --> 0:04:27.280 Oh, that's funny. It's like when people write funny things 0:04:27.320 --> 0:04:29.800 on a dollar, you know, it's like, are you expecting 0:04:29.839 --> 0:04:30.919 to encounter this again? 0:04:31.720 --> 0:04:35.000 Yeah? Yeah, And yeah. There's just something they're like little 0:04:35.800 --> 0:04:40.120 like biomachines, you know. There's just something about how industrious 0:04:40.120 --> 0:04:44.040 and relentless they are as they scavenge the terrain. For instance, 0:04:44.080 --> 0:04:46.800 at this place that we were staying, this a place 0:04:46.839 --> 0:04:49.800 called Off the Wall. The communal dining area at the 0:04:49.800 --> 0:04:53.720 place has a sand floor, and Jim and Kindred, who 0:04:53.760 --> 0:04:55.719 run the place, told us that first thing in the morning, 0:04:55.720 --> 0:04:58.719 when you go in there, the sand is completely devoid 0:04:58.760 --> 0:05:02.640 of human footprints because during the night the crabs have come, 0:05:02.839 --> 0:05:05.279 the hermit crabs have come, and so in the morning 0:05:05.279 --> 0:05:08.920 they are only crab tracks, and not even the slightest 0:05:08.960 --> 0:05:11.960 crom left behind because they have come and claimed everything. 0:05:12.440 --> 0:05:13.240 Crab wipe. 0:05:13.640 --> 0:05:17.760 Yeah, so I love it. After experiencing all that, I 0:05:17.800 --> 0:05:19.360 was like, well, we've got to find some more things 0:05:19.360 --> 0:05:21.800 to talk about with hermit crabs. We've talked about them before, 0:05:22.320 --> 0:05:23.960 but now we're going to go in a little more depth. 0:05:24.200 --> 0:05:27.320 Well, it turns out I think hermit crabs are very 0:05:27.320 --> 0:05:30.200 interesting and there is a lot we can talk about, 0:05:30.279 --> 0:05:33.240 so I guess we will start with the basics. What 0:05:33.400 --> 0:05:37.400 are hermit crabs are hermit crabs crabs? The answer is 0:05:37.880 --> 0:05:42.919 sort of. Hermit crabs are decapod crustaceans that means decapod. 0:05:42.960 --> 0:05:47.960 They're ten legged invertebrates with a hard exoskeleton that grow 0:05:48.080 --> 0:05:51.800 by molting, so they shed their old exoskeleton and emerge soft, 0:05:51.839 --> 0:05:54.279 and then a new exoskeleton hardens when they need to 0:05:54.279 --> 0:05:57.560 get bigger when they grow bigger, but they are considered 0:05:57.600 --> 0:06:01.440 distinct from what are called true crab. True crabs belong 0:06:01.520 --> 0:06:06.240 to the infraorder Brachyuria. Hermit crabs belong to the related 0:06:06.279 --> 0:06:09.719 info order animura a n O m U r A. 0:06:10.160 --> 0:06:14.480 They're close cousins to true crabs, but different. Other animurans 0:06:14.720 --> 0:06:19.200 or false crabs include the Lithodoidea or the king crabs, 0:06:19.320 --> 0:06:23.839 and the Porcelainidae, which are the porcelain crabs. And one 0:06:23.839 --> 0:06:27.840 thing animurins generally have in common is that okay, so 0:06:28.320 --> 0:06:31.920 these decapods all have five pairs of legs ten legs total, 0:06:32.400 --> 0:06:35.800 and in the animurans, the last pair of legs farthest 0:06:35.800 --> 0:06:39.800 away from the head is fund sized, so these animals 0:06:39.839 --> 0:06:43.000 are still decapods, but a lot of them look like 0:06:43.080 --> 0:06:46.000 they have only eight legs instead of ten, or maybe 0:06:46.040 --> 0:06:49.520 six legs and two claws. Those front front legs, the 0:06:49.839 --> 0:06:52.880 chelli or the claws are legs, but in crabs they're 0:06:52.880 --> 0:06:55.960 often claw shaped, but they look like they have only 0:06:56.000 --> 0:07:00.240 eight legs instead of ten because the hindmost pair is 0:07:00.320 --> 0:07:03.720 tiny and often hidden or tucked away under another body part. 0:07:04.080 --> 0:07:07.680 Yeah, and we'll get back to this particular detail later 0:07:07.760 --> 0:07:10.120 on in our discussion. If not this episode, then perhaps 0:07:10.200 --> 0:07:11.360 a second episode. 0:07:11.560 --> 0:07:14.320 So animurans have tin legs a lot of times it 0:07:14.360 --> 0:07:17.880 looks like they only have eight. Hermit Crabs belong in 0:07:17.960 --> 0:07:23.520 the taxonomic superfamily Pagurroidea, and with a few exceptions, they 0:07:23.560 --> 0:07:27.000 are mostly notable for exactly what you're thinking of their 0:07:27.080 --> 0:07:33.720 dependence on externally scavenged material for armor and shelter. Usually 0:07:33.800 --> 0:07:38.280 this armor is a shell that once belonged to a gastropod, 0:07:38.440 --> 0:07:42.440 such as a snail, a periwinkle, or a whelk. Though 0:07:42.480 --> 0:07:45.400 there are some animals in the family that don't need 0:07:45.440 --> 0:07:47.760 scaven shelter at all. We can talk about those in 0:07:47.840 --> 0:07:50.080 a minute, and there are a few that rely on 0:07:50.160 --> 0:07:53.920 things other than mollusk shells. One example cited in a 0:07:53.920 --> 0:07:56.200 paper that I'll get to in a minute is the 0:07:56.840 --> 0:08:01.000 discorso Pagurus schmitty, which takes a shelter not in a 0:08:01.040 --> 0:08:06.160 gastropod shell, but in empty polyheat worm tubes. The hermit 0:08:06.200 --> 0:08:11.240 crabs that do rely on external mollusk shells have bodies 0:08:11.280 --> 0:08:14.800 that are actually shaped by this need. So while true 0:08:14.840 --> 0:08:19.920 crabs have hard exoskeletons covering their entire bodies, hermit crabs 0:08:20.000 --> 0:08:24.920 have what you might call non calcified abdomens. So the 0:08:24.960 --> 0:08:27.880 front facing part of a hermit crab's body the head, 0:08:28.280 --> 0:08:30.960 the thorax, and the front pairs of legs and claws. 0:08:31.440 --> 0:08:35.160 These all have hard exoskeletal coating like any other crab. 0:08:35.520 --> 0:08:38.520 But the back part of the hermit crab, the abdomen, 0:08:38.600 --> 0:08:41.040 and what you might call the tail or the telson, 0:08:42.040 --> 0:08:45.720 this doesn't really resemble a crab body at all in 0:08:45.800 --> 0:08:47.520 a lot of species. It looks kind of like a 0:08:47.640 --> 0:08:52.120 curly fat worm, and it does not have a hard exoskeleton. 0:08:52.480 --> 0:08:57.040 The abdomen is flexible, soft and vulnerable. It is covered 0:08:57.080 --> 0:09:01.080 in an external coating, but it's just very thin and soft. 0:09:01.120 --> 0:09:04.800 It's very uncrab. This is the part of a hermit 0:09:04.840 --> 0:09:08.920 crab that curls up inside the externally sourced shell. 0:09:09.559 --> 0:09:12.319 Yeah, so if you're just encountering hermit crabs out in 0:09:12.360 --> 0:09:16.000 the wild, or even seeing them in an enclosure somewhere, 0:09:16.600 --> 0:09:19.200 you're probably not going to see this part of the 0:09:19.360 --> 0:09:24.480 organism with its abdomen inside the shell. As we've been discussing, 0:09:24.520 --> 0:09:26.880 it actually walks on its second or in third pairs 0:09:26.880 --> 0:09:30.240 of legs. The first pairs are modified to form pinchers, 0:09:30.760 --> 0:09:33.160 and its fourth and fifth pairs of legs are small 0:09:33.200 --> 0:09:36.960 and specialized to grip the inside of the shell. It 0:09:37.000 --> 0:09:39.800 also has appendages called europods at the end of its 0:09:39.840 --> 0:09:42.800 abdomen to aid and securing that shell. So, you know, 0:09:42.960 --> 0:09:45.559 all these things aiding to sort of grip and hold 0:09:45.600 --> 0:09:48.760 on to that shell that it has taken on as 0:09:48.800 --> 0:09:53.920 its shelter. The larger left europod hooks the central post 0:09:54.080 --> 0:09:56.640 of a shell, and they can also use this europod 0:09:56.679 --> 0:09:58.920 to hold on to other things when they are out 0:09:58.920 --> 0:10:02.160 of the shell. I've read about how they can attach to, 0:10:02.160 --> 0:10:04.360 say like a tree or something, and it can also 0:10:04.520 --> 0:10:05.840 use it to maintain balance. 0:10:06.679 --> 0:10:09.319 Yeah, so I think it's interesting that the hermit crab 0:10:09.440 --> 0:10:12.960 is an animal. Its body is shaped in a for 0:10:13.040 --> 0:10:16.880 double purpose. So the front end of it is shaped 0:10:16.920 --> 0:10:20.040 for facing the external world. It has the chelli, it 0:10:20.040 --> 0:10:23.120 has the claws like many other crabs you would think of, 0:10:23.800 --> 0:10:26.160 but the back end of it is shaped entirely for 0:10:26.440 --> 0:10:30.560 holding on to this piece of mobile shelter. And the 0:10:30.640 --> 0:10:35.360 concept of mobile shelter, while not completely unique, is pretty 0:10:35.440 --> 0:10:38.720 unique and what makes the hermit crab interesting to read 0:10:38.720 --> 0:10:42.280 a quote from a highly cited paper on hermit crabs 0:10:42.280 --> 0:10:45.920 that I was looking at by a biologist named Brian Hazlet. 0:10:46.080 --> 0:10:48.880 The paper is called the Behavioral Ecology of Hermit Crabs. 0:10:49.320 --> 0:10:54.480 Hazlet writes, quote, many animals utilize exogenous shelters, but almost 0:10:54.559 --> 0:10:59.479 all eight hundred species of hermit crabs are mobile while sheltered. 0:11:00.040 --> 0:11:04.359 The combination of mobility and protection afforded by this lifestyle 0:11:04.760 --> 0:11:08.040 must contribute to the large numbers of these crustaceans found 0:11:08.120 --> 0:11:12.280 in virtually all marine environments as well as in tropical 0:11:12.360 --> 0:11:17.720 terrestrial shores. So Hazlt is sort of saying the hermit 0:11:17.840 --> 0:11:22.400 crab plan is a successful plan, clearly shown by the 0:11:22.400 --> 0:11:25.800 diversity of these species found all around the world. That 0:11:26.000 --> 0:11:29.960 This is a plan that works because sourcing shelter from 0:11:30.000 --> 0:11:33.120 outside the body that you can take with you when 0:11:33.200 --> 0:11:38.440 you move works really well. But it also comes with costs, 0:11:38.480 --> 0:11:41.840 and we'll talk about those costs as we go on. 0:11:41.840 --> 0:11:44.720 One thing I think to understand is that in general, 0:11:45.320 --> 0:11:49.760 while a hermit crab can leave its externally acquired shell 0:11:49.800 --> 0:11:52.800 and it can survive for some time outside of its 0:11:53.200 --> 0:11:57.199 external shell, the acquisition of a shell for external armor 0:11:57.360 --> 0:12:01.240 is not optional for a hermit crab a nice to have. 0:12:02.000 --> 0:12:05.400 It is essential for survival in the wild, and the 0:12:05.400 --> 0:12:09.040 hermit crab's evolution has been shaped by the need for 0:12:09.120 --> 0:12:11.079 these externally sourced shells. 0:12:11.840 --> 0:12:14.400 Yeah. Yeah, this is not just somewhere it goes to 0:12:14.440 --> 0:12:16.520 sleep at night like. It has to have this with it. 0:12:16.559 --> 0:12:18.720 And if it does not have the shell, then it 0:12:18.800 --> 0:12:23.440 is highly vulnerable to predation exposure. It very well likely 0:12:23.480 --> 0:12:24.719 will not survive without it. 0:12:25.040 --> 0:12:28.240 Right, So I want to turn to a paper I 0:12:28.280 --> 0:12:31.480 was reading for a general overview of hermit crabs and 0:12:31.520 --> 0:12:35.000 related species. This was an overview published in the journal 0:12:35.040 --> 0:12:39.920 Current Biology called hermit Crabs by Mark Briefa and Sophie L. 0:12:40.120 --> 0:12:43.120 Moles in two thousand and eight, and they're going to 0:12:43.160 --> 0:12:45.079 paint the picture here of the kind of hermit crab 0:12:45.240 --> 0:12:49.560 family tree. So there are currently more than eight hundred 0:12:49.720 --> 0:12:53.760 known species of hermit crabs. Most of these species live 0:12:53.760 --> 0:12:57.319 in the ocean their marine, with a few exceptions. One 0:12:57.600 --> 0:13:02.200 is a species called Clibinari fontic cola, and this is 0:13:02.280 --> 0:13:07.760 the only known freshwater hermit crab which lives in Vanuatu, 0:13:07.880 --> 0:13:12.079 that's a volcanic archipelago in the Pacific. And there are 0:13:12.200 --> 0:13:15.600 other freshwater and a murans, but they are not hermit crabs. 0:13:16.120 --> 0:13:19.360 So this is the one freshwater hermit crab out there. 0:13:19.720 --> 0:13:22.000 I should throw in that the hermit crabs that we 0:13:22.000 --> 0:13:24.480 were observing in the wild, I believe are the Caribbean 0:13:24.520 --> 0:13:29.360 hermit crab. And this is a variety that's common to 0:13:29.760 --> 0:13:33.560 the West Atlantic, Belize, Southern Florida, Venezuela, and the West Indies. 0:13:33.800 --> 0:13:35.600 Yes, and the ones you were observing, you were saying 0:13:35.800 --> 0:13:38.800 were terrestrial or semi terrestrial, right, they spend a lot 0:13:38.840 --> 0:13:39.600 of time on land. 0:13:39.920 --> 0:13:42.840 Yeah, these were land boys. We did see one variety 0:13:42.880 --> 0:13:46.079 and I didn't identify this one one variety of aquatic 0:13:46.080 --> 0:13:49.520 hermit crab out law snorkling. But yes, the ones that 0:13:49.559 --> 0:13:53.319 I'm mostly talking about here are the hermit crabs, the 0:13:53.360 --> 0:13:54.440 terrestrial hermit crabs. 0:13:54.840 --> 0:13:58.320 So there are about a dozen species of land dwelling 0:13:58.400 --> 0:14:01.920 or semi land dwelling hermit crab descendants in a family 0:14:02.000 --> 0:14:07.400 called Sinobotids. This family includes one famous species that has 0:14:07.480 --> 0:14:11.160 shed its need for an externally acquired shell altogether, and 0:14:11.200 --> 0:14:14.920 that is the coconut crab or robber crab. We've talked 0:14:14.960 --> 0:14:17.800 extensively about these before, but the coconut crab is the 0:14:17.960 --> 0:14:22.000 largest land dwelling invertebrate in the world. It can have 0:14:22.040 --> 0:14:24.240 a leg span of up to one meter and can 0:14:24.280 --> 0:14:27.720 weigh almost five kilograms or about ten pounds. They live 0:14:27.800 --> 0:14:31.280 mostly in coastal areas throughout the Indian and Pacific Oceans. 0:14:32.120 --> 0:14:34.800 I think we talked a good bit about coconut crabs 0:14:34.800 --> 0:14:37.160 in our series on the Christmas Island Crabs that we 0:14:37.200 --> 0:14:40.720 did several years back. This was the animal where we 0:14:40.720 --> 0:14:42.960 were talking about the field notes of Darwin from the 0:14:43.040 --> 0:14:45.200 Voyage of the Beagle, where he's like, you know, they 0:14:45.240 --> 0:14:48.560 make really good eat, and you boil the fat under 0:14:48.600 --> 0:14:51.680 their tail and it makes a quart bottle of limpid oil. 0:14:52.200 --> 0:14:54.160 And then he also tells a story about how they 0:14:54.560 --> 0:14:58.440 locked one inside of a biscuit tin with wire and 0:14:58.600 --> 0:15:01.560 using its claws it was able to essentially like rip 0:15:01.640 --> 0:15:03.480 the tin out and escape the box. 0:15:04.120 --> 0:15:07.400 Oh man, there's a whole horror movie for you right there. Yeah, 0:15:07.520 --> 0:15:10.800 it would be Charles Darwin and crew on the Beagle 0:15:10.840 --> 0:15:13.040 having to fight off the killer coconut crab. 0:15:13.440 --> 0:15:15.640 They come and they just find the empty box. They're like, 0:15:15.680 --> 0:15:18.880 it's loose, No one knows where it is. 0:15:20.680 --> 0:15:23.360 You know, As long as we're throwing around Charles Darwin quotes, 0:15:23.560 --> 0:15:27.320 there's another place in the Voyage of the Beagle where 0:15:27.320 --> 0:15:32.160 he mentions hermit crabs. This is not a particularly insightful quote. 0:15:32.200 --> 0:15:34.680 It's just a mention, but I still had to drag 0:15:34.720 --> 0:15:37.680 it out. Quote. In every part one meets hermit crabs 0:15:37.880 --> 0:15:40.840 of more than one species, carrying on their backs the 0:15:40.880 --> 0:15:43.600 shells which they have stolen from the neighboring beach. 0:15:43.920 --> 0:15:44.400 Stolen. 0:15:45.080 --> 0:15:48.120 And yes, there is a fair amount of shell theft, 0:15:48.160 --> 0:15:51.480 as we'll get into. As long as you're thrown around 0:15:51.560 --> 0:15:54.440 quotes unrelated, I want to throw in this quote from 0:15:54.440 --> 0:15:56.520 Aristotle from the History of Animals. 0:15:56.680 --> 0:15:58.200 Is he gonna tell us where they come from? 0:15:58.600 --> 0:16:03.280 Yes? Yes he will reveal at the time non controversial 0:16:03.920 --> 0:16:08.560 hypothesis on crab origins. Quote, the hermit crab grows spontaneously 0:16:08.640 --> 0:16:11.840 out of soil and slime and finds its way into 0:16:12.320 --> 0:16:16.240 untenanted shells. As it grows, it shifts to a larger shell, 0:16:16.440 --> 0:16:20.040 as for instance, into the shell of the nearites or 0:16:20.280 --> 0:16:23.680 of the strombus or the like, and very often into 0:16:23.720 --> 0:16:27.440 the shell of the small cirrix. After entering a new shell, 0:16:27.560 --> 0:16:30.080 it carries it about and begins again to feed, and 0:16:30.240 --> 0:16:33.120 by and by, as it grows it shifts again into 0:16:33.160 --> 0:16:34.320 another larger one. 0:16:35.040 --> 0:16:39.640 Okay, I give Aristotle half credit on this. I think 0:16:39.640 --> 0:16:42.440 he's a bit wrong on the spontaneous generation out of 0:16:42.480 --> 0:16:46.880 slime and soil, but he correctly observes the shell shifting 0:16:47.120 --> 0:16:51.160 behavior of hermit crabs, which is a major feature of 0:16:51.200 --> 0:16:53.840 hermit crabs society that we'll have to talk about later 0:16:53.840 --> 0:16:54.640 in the episode. 0:16:55.120 --> 0:16:59.360 Yeah, he's absolutely wrong on spontaneous generation. We don't everally 0:16:59.400 --> 0:17:02.560 have to drive that home, but in a weird way, like, 0:17:02.640 --> 0:17:06.240 in a very general way, the idea of like matter 0:17:06.320 --> 0:17:10.720 becomes crabs, nature becomes crabs. Maybe not that far off, 0:17:10.760 --> 0:17:11.879 as we'll discuss later on. 0:17:12.600 --> 0:17:16.000 But apart from the coconut crab. There are various other 0:17:16.040 --> 0:17:19.719 species of hermit crab that live basically would live their 0:17:19.760 --> 0:17:22.840 adult lives on land, though they still usually live out 0:17:22.880 --> 0:17:25.800 part of their life cycle in the water, with females 0:17:25.840 --> 0:17:30.240 releasing larvae into the sea, and apart from these exceptions, 0:17:30.280 --> 0:17:32.359 hermit crabs are marine species. 0:17:32.640 --> 0:17:34.800 Absolutely. We'll come back to some of the ramifications of 0:17:34.840 --> 0:17:45.920 this in a bit now. 0:17:45.920 --> 0:17:49.240 According to Brifa and Moles, there are five families of 0:17:49.240 --> 0:17:52.640 hermit crabs, and it breaks down like this. You've got Pagurity, 0:17:52.800 --> 0:17:57.040 which are the right handed hermit crabs, and you've got diogeneity, 0:17:57.200 --> 0:18:01.480 which are the left handed hermit crabs right handed, left handed. 0:18:01.520 --> 0:18:04.000 What does that mean? We'll come back to that. Then 0:18:04.040 --> 0:18:07.760 you've got senobitity, which are the land hermit crabs, You've 0:18:07.800 --> 0:18:11.760 got parapagurity, which are the deep sea hermit crabs, and 0:18:11.800 --> 0:18:16.399 you've got Pilo chelady, which are symmetrical hermit crabs. Though 0:18:16.480 --> 0:18:19.600 the more than eight hundred species of hermit crabs display 0:18:19.640 --> 0:18:24.359 different local adaptations and behaviors, for the most part, it 0:18:24.400 --> 0:18:28.880 seems like hermit crabs are take what you can get foragers, 0:18:28.960 --> 0:18:32.159 which is true of many true crabs as well, but 0:18:32.600 --> 0:18:35.560 hermit crabs. For the most part, they will eat bits 0:18:35.600 --> 0:18:38.880 of dead organic matter, both animal and vegetable. They will 0:18:38.920 --> 0:18:42.320 eat live prey when they can catch it. Like true crabs, 0:18:42.320 --> 0:18:45.959 most hermit crabs are not very picky about food. Whatever 0:18:46.000 --> 0:18:48.000 they can get in their mouth, they're probably gonna eat. 0:18:49.040 --> 0:18:51.800 Yeah. Yeah. Both times that I was in believes there 0:18:51.840 --> 0:18:53.280 was a lot of fun to be had, especially with 0:18:53.359 --> 0:18:56.760 the kids, of leaving something out for them with permission 0:18:56.760 --> 0:18:59.439 of course, like I'm talking about the like like a 0:18:59.480 --> 0:19:03.760 cracked coke cannot and then seeing the hermit crabs eventually 0:19:03.800 --> 0:19:05.160 swarm over the material. 0:19:06.640 --> 0:19:10.080 So while foraging for food is of course essential for survival, 0:19:10.160 --> 0:19:14.480 so is foraging for shelter. We will have more to 0:19:14.480 --> 0:19:16.320 say about this as we go on, but obviously a 0:19:16.440 --> 0:19:21.119 huge part of the hermit crab's survival revolves around acquiring 0:19:21.200 --> 0:19:24.119 a good shell to live in, and the majority of 0:19:24.160 --> 0:19:27.800 these shells come from as we've said, mollusks like snails, 0:19:28.160 --> 0:19:32.080 but hermit crabs don't have to fight the snail for 0:19:32.240 --> 0:19:35.560 its shell. They generally move into the shell that is 0:19:35.640 --> 0:19:40.600 left behind after a snail dies. Also, finding a shell 0:19:40.800 --> 0:19:44.480 is not a one time pursuit. Hermit crabs grow larger 0:19:44.560 --> 0:19:47.440 throughout their lives, which means they need to trade up 0:19:47.480 --> 0:19:51.600 for bigger shells, which can lead to very interesting mass behaviors. 0:19:51.640 --> 0:19:54.679 More on that later. One thing the authors of this 0:19:54.720 --> 0:19:58.520 overview point out is that the gastropod shell filled by 0:19:58.560 --> 0:20:01.879 a hermit crab is not only a hard surface to 0:20:02.040 --> 0:20:04.880 protect the soft part of the body, the soft abdomen, 0:20:05.400 --> 0:20:08.919 it also forms a kind of shelter against the external environment. 0:20:09.320 --> 0:20:11.960 Now what kind of shelter against the environment would a 0:20:12.000 --> 0:20:15.960 hermit crab need. One example I recall from some documentary 0:20:16.000 --> 0:20:18.919 footage I saw years ago, was the idea that, you know, 0:20:18.960 --> 0:20:21.920 a hermit crab that's on land is under the hot sun, 0:20:22.520 --> 0:20:25.680 and if it's got soft body parts exposed outside of 0:20:25.720 --> 0:20:27.960 the shell, it could quickly sort of bake and dry 0:20:28.000 --> 0:20:31.119 out without the shelter and moisture provided by a shell. 0:20:31.880 --> 0:20:34.439 Yeah. Absolutely, Yeah. There again, they have to keep in 0:20:34.480 --> 0:20:37.720 mind that even though they are terrestrial, they are linked 0:20:37.760 --> 0:20:41.400 inherently to the ocean, and especially I when you're dealing 0:20:41.440 --> 0:20:44.720 with tropical heat environments. Yeah, they've they have to use 0:20:44.760 --> 0:20:47.640 that shell also to protect themselves and carry around some moisture. 0:20:47.960 --> 0:20:50.000 So I think it makes sense to look at a 0:20:50.000 --> 0:20:54.000 hermit crab's external shell in two different ways that both 0:20:54.080 --> 0:20:57.400 have some truth to them. On one hand, you could 0:20:57.400 --> 0:21:01.560 look at the external shell as an out sourced exoskeleton. 0:21:01.760 --> 0:21:04.119 It is, you know, it's like doing the role that 0:21:04.160 --> 0:21:08.520 would normally be done by the hard kiteness outer skeleton 0:21:08.680 --> 0:21:11.960 of a true crab. But another way to think of 0:21:12.000 --> 0:21:14.640 it is that it's like a portable burrow. And this 0:21:14.720 --> 0:21:17.800 is the point that Brian Haslitt was making in that quote. 0:21:17.840 --> 0:21:21.119 I read earlier about the idea of mobile shelter. Lots 0:21:21.119 --> 0:21:24.280 of animals find holes to hide in and rocks or 0:21:24.320 --> 0:21:28.000 other objects with recesses to provide a protective home. Hermit 0:21:28.080 --> 0:21:32.600 crabs find protective recesses that can actually come along anywhere 0:21:32.640 --> 0:21:35.080 with them. Now, I wanted to come back to the 0:21:35.200 --> 0:21:39.280 concept of asymmetry, which we already mentioned. Rob. You brought 0:21:39.280 --> 0:21:42.080 it up earlier, and it came up in the idea 0:21:42.119 --> 0:21:45.560 that there are these different families of hermit crabs, the 0:21:45.680 --> 0:21:49.680 right handed hermit crabs the pagurady, and the left handed 0:21:49.720 --> 0:21:51.400 hermit crabs the diogeneity. 0:21:51.880 --> 0:21:55.080 Yeah, this is all very important because we think about 0:21:55.080 --> 0:21:58.879 the asymmetry of the crab in this case, and the 0:21:59.640 --> 0:22:02.439 lines up with the asymmetry of the shells that they 0:22:02.480 --> 0:22:03.760 are probably going to be inhabiting. 0:22:04.160 --> 0:22:07.240 Right, So, one thing is that hermit crabs have a 0:22:07.280 --> 0:22:10.600 directional curve in the abdomen. The abdomen can kind of 0:22:11.600 --> 0:22:15.160 curl in a spiraling direction one way or the other. 0:22:15.520 --> 0:22:17.919 But there's also an important difference in the size of 0:22:17.960 --> 0:22:20.800 the claws. And from what I could tell, it was 0:22:20.840 --> 0:22:23.880 the claw asymmetry that was primarily used to sort these 0:22:23.920 --> 0:22:28.200 animals into the different families. One claw is often bigger 0:22:28.240 --> 0:22:31.240 than the other in hermit crabs. Now why would the 0:22:31.280 --> 0:22:35.600 animals be asymmetrical in this way. Well, so, the gastropod 0:22:35.640 --> 0:22:39.920 shells are most often inhabited by hermit crabs also have 0:22:40.119 --> 0:22:43.000 right handed or left handed spirals as you're saying, rob 0:22:43.480 --> 0:22:46.560 and the abdomens are curled so that they fit into 0:22:46.800 --> 0:22:50.119 the chiral shell. Meanwhile, one claw is often bigger than 0:22:50.160 --> 0:22:52.400 the other, so it can function as what the authors 0:22:52.520 --> 0:22:57.479 call an operculum, which in general means a structure that 0:22:57.680 --> 0:23:01.800 closes an opening or an aperture, but in the context 0:23:01.800 --> 0:23:05.919 of gastropods like snails, it has a specific meaning. A 0:23:05.920 --> 0:23:09.960 lot of snails are able not only to retract the 0:23:10.000 --> 0:23:13.920 soft parts of their bodies into their shells when threatened. 0:23:14.400 --> 0:23:18.680 They actually have a movable hard plate that they can 0:23:18.800 --> 0:23:22.560 use to close the door, essentially to block the opening 0:23:22.600 --> 0:23:25.239 of their shell behind them after they retract, like a 0:23:25.320 --> 0:23:29.680 solid trap door. And this is the snail's operculum. And 0:23:29.720 --> 0:23:33.600 the interesting thing is it seems that hermit crabs evolved 0:23:33.760 --> 0:23:37.240 claw a symmetry at least in part to fulfill the 0:23:37.280 --> 0:23:42.200 same function as the operculum of the snails that formed 0:23:42.280 --> 0:23:45.280 the shells that the hermit crabs take over after the 0:23:45.320 --> 0:23:48.879 snails die. So Abrifa and Moles write that a hermit 0:23:48.920 --> 0:23:52.240 crab can use its larger claw to close off the 0:23:52.280 --> 0:23:55.639 aperture of its shell after it retreats when threatened. And 0:23:55.680 --> 0:23:58.160 this connects to what you were talking about seeing, rob 0:23:58.200 --> 0:24:01.159 where the hermit crabs, you know, they might flip over 0:24:01.320 --> 0:24:03.439 on their back and then cover up the opening of 0:24:03.480 --> 0:24:05.960 the shell with one claw, maybe the bigger claw. 0:24:06.560 --> 0:24:08.960 Yeah, exactly, Yeah, I got to see this happen so 0:24:09.000 --> 0:24:12.240 many times. It's like, imagine some sort of futuristic crab 0:24:12.800 --> 0:24:17.600 that has evolved to use abandoned human portagoons or you know, 0:24:17.640 --> 0:24:21.160 portable toilets like you see at concert venues as its home, 0:24:21.480 --> 0:24:26.480 and then it has evolved its larger pincher to be 0:24:26.720 --> 0:24:30.040 the exact shape needed to serve as the door of 0:24:30.040 --> 0:24:30.800 that portagon. 0:24:31.960 --> 0:24:33.800 I thought you were going to say it has evolved 0:24:34.160 --> 0:24:36.640 a claw that can say either vacant or in use. 0:24:36.680 --> 0:24:38.359 I guess it would never want it to say vacant, 0:24:38.480 --> 0:24:40.399 so it says in use on its claw. 0:24:40.960 --> 0:24:43.159 Yeah, I mean, and maybe it wants people to go. 0:24:43.240 --> 0:24:45.320 That's how you get mimics. That that's exactly how you 0:24:45.320 --> 0:24:45.879 get mimics. 0:24:46.359 --> 0:24:49.119 So anyway, you end up with these asymmetries. You have 0:24:49.240 --> 0:24:52.359 right handed and left handed hermit crabs, the pagurids and 0:24:52.400 --> 0:24:56.400 the diogenids, respectively. There are also what are known as 0:24:56.440 --> 0:25:02.040 symmetrical hermit crabs called the pilocelids, which do unlike the others, 0:25:02.080 --> 0:25:05.479 they have hardened exoskeletons on their abdomens, though they do 0:25:05.520 --> 0:25:09.199 still hide in burrows like in you know, recesses in 0:25:09.240 --> 0:25:12.280 wood or rock that are thought to leave these burrows 0:25:12.280 --> 0:25:15.359 to feed. So they're related animals, but they live somewhat 0:25:15.359 --> 0:25:19.560 different lifestyles. Now we need to talk more about the 0:25:19.720 --> 0:25:25.120 selection of shells among asymmetrical hermit crabs and how that 0:25:25.359 --> 0:25:30.080 important biological need shapes hermit crab behavior and even what 0:25:30.119 --> 0:25:33.040 you might call hermit crabs society. One thing you might 0:25:33.119 --> 0:25:36.360 naturally wonder about with hermit crabs and the selection of shells, 0:25:36.480 --> 0:25:39.240 is is one shell as good as the next? You know, 0:25:39.440 --> 0:25:41.679 is any shell just as good as another? And the 0:25:41.720 --> 0:25:45.320 answer is no, not at all, in multiple ways. One 0:25:45.400 --> 0:25:49.639 big factor is, of course size. A shell that is 0:25:49.840 --> 0:25:53.919 too small or too large will greatly reduce a hermit 0:25:53.960 --> 0:25:57.719 crab's fitness, and studies show that when a hermit crab's 0:25:57.720 --> 0:26:01.560 shell is too small, for one thing, just increases mortality. 0:26:01.640 --> 0:26:03.439 Too small a shell means the hermit crab is more 0:26:03.520 --> 0:26:07.080 likely to die, but it also has less room to grow, 0:26:07.440 --> 0:26:11.879 and females with smaller shells produce fewer offspring, So it 0:26:12.000 --> 0:26:14.080 is not good for a hermit crab to have too 0:26:14.119 --> 0:26:17.000 small of a shell. However, it doesn't just want the 0:26:17.040 --> 0:26:20.639 biggest shell possible, because if the shell is too big, 0:26:20.960 --> 0:26:25.000 that increases the energy cost of carrying it, So you are, 0:26:25.080 --> 0:26:28.359 you know, massively wasting a lot of energy lugging around 0:26:28.440 --> 0:26:30.960 a shell that is heavy and too big for you. 0:26:31.280 --> 0:26:33.560 It's kind of like, I don't know, being encumbered in 0:26:33.640 --> 0:26:36.359 d and d or something. You know, you've got too 0:26:36.480 --> 0:26:38.639 much of a load. This is harming your ability to 0:26:38.680 --> 0:26:39.639 do everything else. 0:26:40.400 --> 0:26:43.240 Yeah, absolutely, So finding. 0:26:42.880 --> 0:26:46.480 A shell of just the right size is crucial, and 0:26:47.000 --> 0:26:50.639 that right size will change throughout the hermit crab's life 0:26:50.720 --> 0:26:51.439 as it grows. 0:26:52.160 --> 0:26:55.159 Yeah, so let's get into this a bit more like 0:26:55.640 --> 0:26:58.399 it's such an important aspect of the hermit crab, and 0:26:58.400 --> 0:26:59.720 it's you know, it's the first thing we think about 0:27:00.160 --> 0:27:05.520 really defines almost everything about their social interaction. And it's 0:27:05.600 --> 0:27:09.000 interesting to think about hermit crab society, or at least, 0:27:09.240 --> 0:27:12.399 you know, think of them as social organisms because we 0:27:12.440 --> 0:27:15.040 call them hermit crabs, which is a bit misleading because 0:27:15.040 --> 0:27:17.879 in human history and into sort of common usage, what 0:27:18.000 --> 0:27:20.000 is a hermit. A hermit is someone who withdraws from 0:27:20.040 --> 0:27:22.960 society and or civilization. So it might lead you to 0:27:22.960 --> 0:27:26.960 believe that hermit crabs are also loners in a certain sense. 0:27:27.000 --> 0:27:31.200 They are, but you know, that doesn't mean that they 0:27:31.400 --> 0:27:33.960 don't have interactions with others of their kind. In fact, 0:27:33.960 --> 0:27:36.640 they have a lot of interactions and they're very complex. 0:27:37.240 --> 0:27:39.720 So don't be too literal in thinking that a hermit 0:27:39.760 --> 0:27:42.639 crab is an actual hermit. In the same way that you 0:27:42.640 --> 0:27:45.560 wouldn't think that a king crab actually rules over decapods 0:27:45.640 --> 0:27:49.920 or something, right, and thissue is decrees. Yeah yeah. As 0:27:50.080 --> 0:27:53.560 Mark E Lydra pointed out in an article for Natural 0:27:53.640 --> 0:27:57.440 History Magazine back in I Believe twenty nineteen, hermit crabs 0:27:57.480 --> 0:28:02.280 live actually highly social lives, absolutely full of drama, just 0:28:02.440 --> 0:28:05.399 way more drama than you you'd expect your local human 0:28:05.440 --> 0:28:07.200 hermit to have, I'd wager. 0:28:07.240 --> 0:28:10.400 Yeah, I mean, I guess unless hermits were like constantly 0:28:10.440 --> 0:28:12.920 fighting one another to try to trade clothes. 0:28:13.480 --> 0:28:15.280 Yeah, or a pillar. You know, if you have your 0:28:15.359 --> 0:28:17.240 your pillar developers, it'd be like, no, I want the 0:28:17.280 --> 0:28:18.280 I want the taller pillar. 0:28:18.520 --> 0:28:21.440 Yeah, I'm gonna do exactly. I'm gonna bang my pillar 0:28:21.480 --> 0:28:23.560 on your pillar until you give me your pillar, unless 0:28:23.600 --> 0:28:25.240 I decide I want my old pillar back. 0:28:27.359 --> 0:28:33.480 So the various dramas that they encounter and instigate includes, 0:28:33.520 --> 0:28:37.639 but is not limited to, according to Elidra, commotion of 0:28:37.800 --> 0:28:44.120 social aggregations, UH, intergenerational inheritance of homes, life or death, 0:28:44.240 --> 0:28:48.560 competitive struggles. So the author points out that, in contrast 0:28:48.600 --> 0:28:50.880 to a lot of other social organisms you might think about, 0:28:51.320 --> 0:28:56.040 terrestrial hermit crabs socialize with non relatives and this is 0:28:56.080 --> 0:28:59.120 crazy to think about. The reason he points he points 0:28:59.120 --> 0:29:02.080 out is that while they spend most of their lives 0:29:02.120 --> 0:29:04.920 on land, we're talking about terrestrial hermit crabs again, not 0:29:04.960 --> 0:29:07.360 the aquatic ones. They spend most of their lives on land, 0:29:07.360 --> 0:29:10.200 but they are born in the sea. That's where the 0:29:10.280 --> 0:29:14.320 larva larvae are released. They become mixed in the ocean, 0:29:14.880 --> 0:29:19.360 and then they land on far flung shores via the tides. 0:29:20.200 --> 0:29:22.560 So I want to read this quote from Eldra. He says, quote, 0:29:22.560 --> 0:29:25.400 By the time an immature crab first arrives on land, 0:29:25.960 --> 0:29:28.560 it is therefore far away from any of its relatives, 0:29:28.640 --> 0:29:33.280 encountering instead only an assortment of non kin. Moreover, because 0:29:33.320 --> 0:29:36.760 the abundance of terrestrial hermit crabs on short stretches of 0:29:36.800 --> 0:29:39.720 beach often measures in the hundreds of thousands or even 0:29:39.760 --> 0:29:43.480 the millions, each crab is but a stranger within a 0:29:43.560 --> 0:29:44.280 vast crowd. 0:29:44.640 --> 0:29:47.000 However, you know, if you think of a human analogy, 0:29:47.120 --> 0:29:51.720 imagine a bunch of very selfish humans are thrown into 0:29:51.720 --> 0:29:54.880 a mix of you know, they're all living together beside 0:29:54.880 --> 0:29:57.560 one another, and not amongst their kin, just amongst strangers. 0:29:57.600 --> 0:30:01.040 And you know, maybe imagine they're not. Uh, they're not 0:30:01.160 --> 0:30:03.680 very nice people, they're not very inclined to be helpful 0:30:03.720 --> 0:30:06.520 to others. They still might find reasons to hang out 0:30:06.560 --> 0:30:09.560 around one another, even if they're mostly selfish. And one 0:30:09.560 --> 0:30:12.160 of those reasons might be the need for trade or 0:30:12.200 --> 0:30:14.640 an economy of sorts exactly. 0:30:14.680 --> 0:30:16.800 And what are they gonna have an economy of sorts about? 0:30:16.800 --> 0:30:17.680 What's gonna be the shell? 0:30:17.760 --> 0:30:18.160 Of course? 0:30:19.560 --> 0:30:21.840 I also like how this idea, it kind of matches 0:30:21.960 --> 0:30:24.800 up with the you know, the the huge stereotype that 0:30:24.840 --> 0:30:27.880 one encounters of big city life, particularly in movies from 0:30:27.880 --> 0:30:30.680 like the seventies and I guess into the eighties as well, 0:30:30.720 --> 0:30:33.479 Like nobody's related to each other in the city. You 0:30:33.520 --> 0:30:36.200 go to the city, it's just everybody's for themselves. You're 0:30:36.240 --> 0:30:38.400 gonna you're gonna lose your shell in that big city. 0:30:39.960 --> 0:30:41.960 And I guess it's kind of kind of that way 0:30:42.000 --> 0:30:44.600 with the crabs here. But anyway, the shells that they use, 0:30:44.680 --> 0:30:47.440 like you're saying, yeah, these are scavenged from dead mollusks, 0:30:48.600 --> 0:30:52.520 but this is also key, Uh, they have been remodeled. 0:30:52.560 --> 0:30:56.720 These are remodeled homes. Elidra points out, Uh, the crabs 0:30:56.880 --> 0:30:58.640 you when they have when they have a fresh shell 0:30:58.760 --> 0:31:00.920 that is gonna like this is okay, something has died. 0:31:01.160 --> 0:31:02.840 The snail has dyed, and now I'm going to make 0:31:02.880 --> 0:31:05.080 this shell into a home. You can't just put it 0:31:05.120 --> 0:31:07.640 on and wear it out. No, No, you need to 0:31:07.760 --> 0:31:12.200 use chemical secretions to weaken the shells calcium carbonate, as 0:31:12.240 --> 0:31:16.600 well as additional physical sculpting via your appendages. You're going 0:31:16.640 --> 0:31:20.760 to change the shell into something that absolutely suits you 0:31:20.840 --> 0:31:22.640 and absolutely suits your purposes. 0:31:23.120 --> 0:31:25.760 Right, So, this is another way in which one shell 0:31:25.840 --> 0:31:28.640 is not necessarily as good as any other. Size matters 0:31:28.680 --> 0:31:30.680 a lot, which is a sort of inherent feature of 0:31:30.720 --> 0:31:35.240 the shell, but also the remodeling condition of the shell 0:31:35.360 --> 0:31:40.080 matters a lot. There are shells that have been recently 0:31:40.120 --> 0:31:43.240 renovated and that's much more desirable than a shell that 0:31:43.320 --> 0:31:44.520 is a real fixer. 0:31:44.240 --> 0:31:49.520 Upper right, right, And this is unique to terrestrial hermit crabs, 0:31:49.520 --> 0:31:51.440 and we'll get it more into why in a second. 0:31:51.520 --> 0:31:54.560 But yeah, as Lighter points out, it's absolutely necessary for 0:31:54.720 --> 0:31:58.760 terrestrial hermes because they can't depend on water buoyancy to 0:31:58.840 --> 0:32:02.560 help them carry that shell around. It's just the basic 0:32:03.120 --> 0:32:06.120 reality of living out of the water. And some of 0:32:06.160 --> 0:32:09.960 these shells can be quite hefty for the crab, and 0:32:10.120 --> 0:32:13.200 so by reducing the shell mass, they're lowering the energy 0:32:13.240 --> 0:32:15.200 cost of just traveling across land, and they do a 0:32:15.240 --> 0:32:19.640 lot of traveling. Additionally, shell remodeling increases the internal space 0:32:19.680 --> 0:32:22.240 in the shell, allowing not only more room for the crab, 0:32:22.280 --> 0:32:25.120 but more room for increased water reserves to keep the 0:32:25.240 --> 0:32:27.880 organism from drying out. Like we mentioned earlier, the importance 0:32:27.920 --> 0:32:31.840 of this being a way to help them sustain themselves 0:32:31.920 --> 0:32:35.680 when they are living times in very hot environments. He 0:32:35.760 --> 0:32:39.080 also points out that while aquatic hermit crabs would conceivably 0:32:39.160 --> 0:32:42.760 benefit from shell remodeling as well, because even though you 0:32:42.760 --> 0:32:45.400 have buoyant sea, lighter shells could still be a benefit. Right, 0:32:45.680 --> 0:32:50.240 more internal space could still be a benefit. However, aquatic 0:32:50.720 --> 0:32:54.640 hermit crabs have to contend with shell expert predators in 0:32:54.680 --> 0:33:01.840 the ocean, organisms that are highly evolved to bypass shell protection. Therefore, 0:33:02.280 --> 0:33:04.680 it would be a mistake to sacrifice any of your 0:33:04.680 --> 0:33:08.120 shell's protection in order to get any of these benefits. Meanwhile, 0:33:08.400 --> 0:33:13.120 on land, the terrestrial hermit crabs have far fewer shells 0:33:13.200 --> 0:33:16.840 specialists to contend with, and Lidra points to various research 0:33:16.920 --> 0:33:19.920 that's shown that like your average predator that would be 0:33:20.000 --> 0:33:22.360 messing with a hermit crab is just not going to 0:33:22.400 --> 0:33:25.680 have like the byte power or the not going to 0:33:25.720 --> 0:33:31.320 have the tools necessary to crack open even a partially degraded, 0:33:31.360 --> 0:33:35.240 a partially remodeled hermit crab chosen shell. Now, Joe I 0:33:35.280 --> 0:33:39.280 included a photographer. This is from Lydra's paper and an 0:33:39.320 --> 0:33:43.560 example of an unmodified versus a modified shell. The central 0:33:43.600 --> 0:33:47.120 axis is often removed, but the shell again retains protection 0:33:47.200 --> 0:33:49.680 against the bite strength of terrestrial predators. 0:33:50.160 --> 0:33:51.880 Yeah, and one thing you can see in this picture 0:33:51.920 --> 0:33:54.760 is that a lot of the effort in the remodeling 0:33:54.800 --> 0:33:57.320 seems to be focused on the interior of the shell, 0:33:57.480 --> 0:34:00.880 sort of like expanding the interior cab and making more 0:34:00.960 --> 0:34:02.560 room there and smoothing it out. 0:34:03.240 --> 0:34:07.000 Yeah, and certainly removing some of the additional protection of 0:34:07.040 --> 0:34:09.880 the shell. But again it's apparently not going to matter 0:34:10.200 --> 0:34:22.920 for terrestrial variants. Now, like we said, one of the 0:34:23.080 --> 0:34:26.399 huge factors in hermit crab societies is of course the 0:34:26.440 --> 0:34:28.880 need for these shells, and the fact that as the 0:34:29.520 --> 0:34:33.160 crab grows and molts, they'll need to abandon smaller shells 0:34:33.200 --> 0:34:35.799 in favor of larger shells and as Liger points out, 0:34:35.840 --> 0:34:39.560 there's something really interesting about all of this quote. Over time, 0:34:39.960 --> 0:34:43.160 remodeled shells have come to dominate the housing market of 0:34:43.280 --> 0:34:48.480 terrestrial hermit crabs. Exhaustively sampling these housing markets, I have 0:34:48.560 --> 0:34:52.880 found few unremodeled shells, and also few shells that are 0:34:52.920 --> 0:34:56.520 still in the process of being remodeled. Most shells have 0:34:56.640 --> 0:35:01.920 already been completely remodeled. Remodeled shells present a superior home, and, 0:35:01.960 --> 0:35:05.400 as with any superior resource, it is understandable that terrestrial 0:35:05.400 --> 0:35:09.800 hermit crabs should prefer remodeled shells over unremodeled shells. However, 0:35:10.120 --> 0:35:14.400 over evolutionary time, a mere preference has transformed into an 0:35:14.440 --> 0:35:19.440 absolute dependence. As remodeled shells accumulated, terrestrial hermit crabs came 0:35:19.480 --> 0:35:22.279 to specialize in living in them, to the point that 0:35:22.360 --> 0:35:27.600 life in unremodeled shells became nearly impossible. My field experiments 0:35:27.680 --> 0:35:31.120 revealed that after an early life stage, most terrestrial hermit 0:35:31.160 --> 0:35:35.839 crabs cannot survive in unremodeled shells for even a single day. 0:35:36.400 --> 0:35:38.319 Wow, Okay, I did not realize that. 0:35:39.239 --> 0:35:41.439 Yeah, yeah, because you know what's the current hermit crab 0:35:41.440 --> 0:35:43.400 to do? If you need a shell, well, you could 0:35:43.440 --> 0:35:47.399 remodel your own shell technically, but most crabs simply can't 0:35:47.440 --> 0:35:49.880 do this anymore, in large part because they end up 0:35:49.880 --> 0:35:52.360 too big to access the inner parts of a fresh shell. 0:35:52.840 --> 0:35:57.040 So only the smallest immature hermit crabs actually can get 0:35:57.040 --> 0:35:59.719 in there and do this, which paradoxically often means that 0:35:59.760 --> 0:36:04.400 they're left with oversized shells. But as such, all terrestrial 0:36:04.440 --> 0:36:08.759 hermit crab individuals highly prefer a remodeled shell over a 0:36:08.800 --> 0:36:11.719 fresh one. Even even if they can fit inside that 0:36:11.800 --> 0:36:14.719 fresh shell and conceivably remodel it and make it their own, 0:36:15.280 --> 0:36:19.760 remodeling the shell is still a last resort. Ledra stresses 0:36:19.800 --> 0:36:22.560 that this is this is the only factor that ensures 0:36:22.560 --> 0:36:26.640 the continued creation of remodeled shells. That some crabs, hermit 0:36:26.680 --> 0:36:28.600 crabs are going to be put in a position where 0:36:28.640 --> 0:36:31.719 they have no choice wow, because I mean, they can 0:36:31.800 --> 0:36:33.920 do other things too. It should not like if a 0:36:34.520 --> 0:36:37.439 hermit crab is left without anything and there, and we'll 0:36:37.520 --> 0:36:39.920 touch on how this occurs in a moment, they may 0:36:40.000 --> 0:36:42.680 use something like a bottle cap and that might buy 0:36:42.680 --> 0:36:46.160 them a little time, but they need a shell. The 0:36:46.200 --> 0:36:49.680 thing is, you don't just find many emptied remodeled shells. 0:36:50.880 --> 0:36:54.000 He points out that on a given beach, the only 0:36:54.080 --> 0:36:57.160 empty remodeled shells you're likely to find are the ones 0:36:57.200 --> 0:36:59.720 that have been physically compromised in one way or another, 0:36:59.800 --> 0:37:03.360 so like they're broken, they don't actually protect the hermit 0:37:03.360 --> 0:37:06.400 crab anymore, or they're clogged with a rock something like that, 0:37:06.400 --> 0:37:10.880 they're no longer functional. The competition for remodeled shells is intense, 0:37:11.239 --> 0:37:13.440 and they're just you're just not going to As a 0:37:13.440 --> 0:37:15.279 hermit crab, you are not going to find them out 0:37:15.320 --> 0:37:19.759 there unless you're extremely lucky. As such, hermit crabs have 0:37:19.800 --> 0:37:22.920 to remain vigilant at all times, always looking out for 0:37:22.960 --> 0:37:26.040 a bigger shell, because either you need one or you're 0:37:26.080 --> 0:37:28.360 about to need one, so you need to always be looking. 0:37:28.800 --> 0:37:32.000 And also you have to be peeking over your shoulder 0:37:32.040 --> 0:37:35.879 because there's probably someone eyeing your shell that is looking 0:37:35.960 --> 0:37:38.680 for a slightly bigger shell, and they're trying to decide 0:37:38.800 --> 0:37:40.440 if it's worth trying to take it from you. 0:37:40.920 --> 0:37:43.640 Right, So this leads to the fact that hermit crabs 0:37:43.840 --> 0:37:47.960 very often get into well, I guess there's some debate 0:37:48.040 --> 0:37:51.600 over how exactly to characterize these encounters, whether they are 0:37:52.200 --> 0:37:56.920 purely agonistic fights, or whether you might consider them in 0:37:56.920 --> 0:38:00.400 some way a kind of trade or negotiation. Maybe we 0:38:00.400 --> 0:38:02.600 can talk about that some more in the next episode. 0:38:02.640 --> 0:38:07.360 But they get into these encounters that lead to shell swapping. 0:38:07.880 --> 0:38:13.120 Yeah, they're the very least aggressive negotiations. Yeah, but you 0:38:13.200 --> 0:38:16.640 know so, I'll continue to categorize them as battles. But yeah, 0:38:16.680 --> 0:38:21.000 give with that caveat in mind. Basically, what seems to 0:38:21.000 --> 0:38:23.600 be happening is one crab will attempt to flip the 0:38:23.640 --> 0:38:26.480 other on its back and force its opponent out of 0:38:26.520 --> 0:38:29.880 their shell. But as Lijra points out, this kind of 0:38:29.880 --> 0:38:32.960 thing can last hours, and it might just end in 0:38:33.000 --> 0:38:36.000 a stalemate. It might just end in everyone just going 0:38:36.040 --> 0:38:39.399 home or carrying on with the shell they had two 0:38:39.440 --> 0:38:42.400 hours ago. And that alone, I think that's pretty fascinating. 0:38:42.400 --> 0:38:46.600 Most animal competitions and struggles are fascinating. But it's the 0:38:46.760 --> 0:38:51.400 onlookers that make this even more interesting. Elijra writes. Quote. 0:38:51.520 --> 0:38:54.680 As bystanders gather at the site, and as the moment 0:38:54.680 --> 0:38:58.480 of evictioneers order emerges out of the chaos of commotion 0:38:58.880 --> 0:39:04.120 in the aggregation, the crabs array themselves literally into a line, 0:39:04.320 --> 0:39:06.520 each holding the shell of the crab ahead of it. 0:39:06.960 --> 0:39:11.440 This social formation emanates from the pair of antagonists, with 0:39:11.560 --> 0:39:15.319 the line of crabs there after being size ordered from 0:39:15.360 --> 0:39:19.880 biggest to smallest. Because if a crab is forced to 0:39:19.920 --> 0:39:22.920 give up its shell, the winner will leave its shell, 0:39:23.320 --> 0:39:26.040 and this will set off what's called a vacancy chain. 0:39:26.440 --> 0:39:29.520 All of the onlookers will have a shot at leveling 0:39:29.600 --> 0:39:33.799 up their current shell situation to a new one that 0:39:33.880 --> 0:39:34.760 is slightly bigger. 0:39:35.080 --> 0:39:37.320 You can find video of this online. By the way, 0:39:37.239 --> 0:39:41.279 there are multiple documentaries that have captured versions of this, 0:39:42.040 --> 0:39:45.120 and it's amazing to see they literally do just organize 0:39:45.160 --> 0:39:49.319 themselves in a size ordered line where they're each grasping 0:39:49.400 --> 0:39:52.560 the shell of the slightly bigger one, like feeling around 0:39:52.600 --> 0:39:54.680 on it, trying to make sure that it's what they want. 0:39:55.440 --> 0:39:59.000 Because the whole process, by the way in which hermit 0:39:59.080 --> 0:40:02.640 crabs sess a shell where the qualities they want is 0:40:02.719 --> 0:40:06.000 interesting on its own. There seem to be some visual 0:40:06.200 --> 0:40:08.480 processes going on. They you know, look at a shell 0:40:08.560 --> 0:40:11.359 to assess from a distance whether it's something they would want, 0:40:11.360 --> 0:40:14.120 but that's never enough. They have to inspect it physically. 0:40:14.160 --> 0:40:17.120 They like feel all over it with their antennae and 0:40:17.160 --> 0:40:19.920 their and their chelly, you know, the claws and the legs, 0:40:20.200 --> 0:40:23.040 and then usually they will want to sort of like 0:40:23.239 --> 0:40:26.320 dip into it with their legs and maybe their abdomen 0:40:26.400 --> 0:40:29.719 to see if they fit right, and they may end 0:40:29.800 --> 0:40:31.719 up changing their mind and wanting to go back to 0:40:31.760 --> 0:40:35.560 the previous shell, though obviously that could be a tricky thing. 0:40:35.640 --> 0:40:38.919 If a bunch of hermit crabs are lined up all 0:40:39.120 --> 0:40:41.360 trying to level up at the same time, it is 0:40:41.400 --> 0:40:42.560 an amazing thing to see. 0:40:43.239 --> 0:40:45.680 Yeah, to your point about like sizing up the shell, 0:40:45.719 --> 0:40:48.480 trying it on, Like sometimes you have a situation where 0:40:48.600 --> 0:40:53.839 you remember the asymmetry of shells and and hermit crabs here, 0:40:54.080 --> 0:40:58.120 and sometimes you have a you have a like a 0:40:58.400 --> 0:41:00.000 like what a left handed crab trying to get into 0:41:00.080 --> 0:41:03.920 or right handed shell or vice versa, and that's going 0:41:03.960 --> 0:41:05.960 to be a situation where the crab is going to 0:41:06.200 --> 0:41:08.560 quickly realize this does not fit, this is not the 0:41:08.560 --> 0:41:11.359 shell I want to live. We may come back with 0:41:11.400 --> 0:41:16.319 more details on that regarding the left right handedness in 0:41:16.640 --> 0:41:20.279 hermit crabs and shells. Now Ldra again points out that 0:41:20.320 --> 0:41:23.560 all this competition is based again not on kinship, but 0:41:23.680 --> 0:41:28.560 on selfishness and competition, and he has this wonderful part 0:41:28.600 --> 0:41:30.279 in the paper where he says that it's what's kind 0:41:30.280 --> 0:41:33.479 of the antithesis of something like a US social ant, 0:41:33.880 --> 0:41:36.120 you know, where all the ants in a colony are kin, 0:41:36.239 --> 0:41:39.280 and they work together to ensure the success of the colony, 0:41:39.360 --> 0:41:42.800 the success of their genetic line. But that is not 0:41:42.920 --> 0:41:46.440 the case with the hermit crab, and Lidra writes the 0:41:46.480 --> 0:41:50.680 following quote. If in an alternative world, interactions in terrestrial 0:41:50.760 --> 0:41:54.839 hermit crabs were among close kin rather than strangers, then 0:41:54.880 --> 0:41:58.600 the crab's social lives might be different, with individuals potentially 0:41:58.680 --> 0:42:01.960 being more interested in the queathing their finest shell to 0:42:02.040 --> 0:42:05.480 a close relative than in stealing the coveted shell of 0:42:05.520 --> 0:42:12.040 a stranger. Now, there have been plenty of other researchers 0:42:12.520 --> 0:42:15.200 and also science journalists and writers and so forth that 0:42:15.239 --> 0:42:19.000 have commented on all of this. Elizabeth Preston wrote all 0:42:19.440 --> 0:42:21.480 about this topic for The New York Times in twenty 0:42:21.560 --> 0:42:25.560 nineteen in an article titled even hermit crabs have wealth inequality. 0:42:25.920 --> 0:42:29.000 This was based on a twenty twenty study. This is 0:42:29.040 --> 0:42:31.840 because the New York Times paper came out a month 0:42:31.880 --> 0:42:35.560 before the twenty twenty study. This was in a December publication, 0:42:35.680 --> 0:42:38.759 So that's why the dates would seem to be in 0:42:38.800 --> 0:42:41.719 the wrong order here. But that particular paper was a 0:42:41.760 --> 0:42:45.000 comparison of wealth inequality in humans and non humans by 0:42:45.080 --> 0:42:47.919 Chase at all. This was a study that, as I recall, 0:42:48.000 --> 0:42:51.200 received a fair amount of mainstream attention at the time, because, 0:42:51.239 --> 0:42:55.240 of course, wealth inequality is always a topic of interest 0:42:55.239 --> 0:43:00.520 among human beings, and crabs are inherently interesting. You can 0:43:00.520 --> 0:43:03.920 throw hermit crabs into any study and it's going to 0:43:03.920 --> 0:43:06.520 be fascinating, even if there's not really connective tissue there. 0:43:06.640 --> 0:43:08.279 Well, is there connective tissue here? 0:43:08.760 --> 0:43:10.799 To a certain extent, it seems to okay, I mean, 0:43:11.160 --> 0:43:13.360 so in the study, Chase and his co authors gathered 0:43:13.400 --> 0:43:16.359 around three hundred hermit crabs on Long Island Beach and 0:43:16.520 --> 0:43:20.279 took away all their shells, which, okay, for science, I 0:43:20.320 --> 0:43:22.399 will allow this, but you know, obviously I can't help 0:43:22.400 --> 0:43:26.280 it sympathize because this is literally all these crabs care about. 0:43:27.320 --> 0:43:30.160 The researchers weighed and measured the various shells, and then 0:43:30.160 --> 0:43:34.799 they considered how they were distributed across the sample population 0:43:35.239 --> 0:43:39.200 of hermit crabs. And this is a quote here from 0:43:39.200 --> 0:43:43.120 that article by Preston. Quote the distribution curve they found 0:43:43.120 --> 0:43:46.200 peaked around medium sized shells, then dropped as the shells 0:43:46.200 --> 0:43:50.040 got larger, before tapering off very gradually through the largest shells. 0:43:50.040 --> 0:43:53.560 Of all, this matches the shape of wealth distribution curves 0:43:53.600 --> 0:43:57.200 in many human societies, so it's interesting. But at the 0:43:57.200 --> 0:44:01.440 same time, the New York Times article, of citing anthropologists 0:44:01.480 --> 0:44:04.960 Monique Molder, points out that we shouldn't get too carried 0:44:05.000 --> 0:44:08.040 away comparing hermit crabs to humans in this scenario, because, 0:44:08.520 --> 0:44:10.760 first of all, there are plenty of other factors involved 0:44:10.880 --> 0:44:13.799 in human inequality. You know, it's one of those it's 0:44:13.800 --> 0:44:16.560 often described as a wicked problem. You know, it's complex 0:44:16.640 --> 0:44:18.880 enough that you can't just point to necessarily. There are 0:44:18.880 --> 0:44:23.560 certainly large factors, but there are multiple factors. And Molder 0:44:23.640 --> 0:44:27.200 here who again as an anthropologist, speculated that vacancy chains 0:44:27.200 --> 0:44:29.640 are probably also not the only factor in terrestrial hermit 0:44:29.640 --> 0:44:32.319 crabs as well. I mean, you know, there are other 0:44:32.400 --> 0:44:35.279 factors as well into how they are dealing with each other, 0:44:35.320 --> 0:44:38.319 even on the basis of their shells. Still, you know, 0:44:38.360 --> 0:44:40.839 we can't help but compare ourselves to the hermit crabs. Again, 0:44:40.920 --> 0:44:43.239 part of it is just that hermit crabs are that interesting, 0:44:43.600 --> 0:44:46.239 and we as human beings are that self absorbed. Why 0:44:46.320 --> 0:44:48.920 we can't help but see ourselves in the crabs. We 0:44:48.920 --> 0:44:52.320 can't help but anthropomorphize the crabs, and you know, especially 0:44:52.320 --> 0:44:55.760 when we see them, you know, in a very complex fashion, 0:44:56.040 --> 0:45:00.439 struggle over limited resources like this. That again, I think 0:45:00.440 --> 0:45:02.600 if you're just casually aware of hermit crabs, you might 0:45:02.640 --> 0:45:06.240 not realize that just any shell, it's not a situation 0:45:06.280 --> 0:45:09.080 where any shell will do, and it is a situation 0:45:09.120 --> 0:45:14.160 where the shells have been augmented, and therefore it's competition 0:45:14.280 --> 0:45:19.240 not just for random garbage left over by dead snails, 0:45:19.520 --> 0:45:25.360 it's competition for mostly previously augmented shells, like the products 0:45:25.400 --> 0:45:28.720 of a hermit crab civilization, if you will, Well. 0:45:28.640 --> 0:45:31.080 That's funny if you think of it as like more 0:45:31.160 --> 0:45:35.720 fighting over fighting over a limited pool of finished goods 0:45:35.840 --> 0:45:38.279 rather than creating new goods. It's almost like a human 0:45:38.320 --> 0:45:39.800 post apocalyptic scenario. 0:45:40.520 --> 0:45:41.000 Exactly. 0:45:41.080 --> 0:45:43.879 Yeah, it's kind of Mad Max. 0:45:44.239 --> 0:45:46.279 It's kind of Fallout, right. It reminds me that in 0:45:46.480 --> 0:45:48.760 at least some of the Fallout games, you do encounter 0:45:48.800 --> 0:45:51.799 a giant hermit crab that is using what some sort 0:45:51.800 --> 0:45:53.720 of like a bus or something like a school bus 0:45:53.719 --> 0:45:57.160 for its it's abdomen. I can't remember offhand, but I 0:45:57.200 --> 0:45:59.719 remember when I would when I would play those Reasons 0:45:59.719 --> 0:46:04.160 fall game, I would occasionally encounter that that creature and yeah, yeah, 0:46:04.239 --> 0:46:07.719 I mean it's it's it's interesting. Where are they getting 0:46:07.719 --> 0:46:10.359 all these school buses? So what are they changing about? 0:46:10.400 --> 0:46:12.280 I guess they're taking all the seats out? Yeah? 0:46:12.440 --> 0:46:14.880 Is it a right handed bus or a left handed bus? 0:46:15.200 --> 0:46:17.480 I don't know. Yeah, And are they sizing up from 0:46:17.520 --> 0:46:21.160 different buses? Like they start with a like a shorter bus, 0:46:21.160 --> 0:46:22.960 then they go to a full sized school bus and 0:46:23.000 --> 0:46:25.280 they're going to like a megabus, then it's a double 0:46:25.320 --> 0:46:29.000 decker bus. Those are only that's only on Fallout London propertly, 0:46:29.160 --> 0:46:33.000 but you know you could go wild with the scenario. 0:46:33.280 --> 0:46:36.000 Well, hey, we've got more hermit crab stuff to talk about, 0:46:36.080 --> 0:46:37.760 so join us again next time. 0:46:38.239 --> 0:46:40.520 That's right, we have some more content lined up regarding 0:46:40.520 --> 0:46:42.000 the hermit crabs. We're going to fish around for a 0:46:42.080 --> 0:46:46.120 bit more. Because I'm hermit crabs. There's a lot of 0:46:46.120 --> 0:46:49.239 research out there. That's one of the reasons I felt 0:46:49.239 --> 0:46:51.440 pretty secure and going in and discussing them again, even 0:46:51.480 --> 0:46:54.120 though we've discussed them in the past, because there's constantly 0:46:54.160 --> 0:46:57.080 new hermit crab research coming out and there are some 0:46:57.160 --> 0:47:02.520 remaining mysteries and controversies about hermit crabs, so we'll get 0:47:02.560 --> 0:47:05.800 into all of that in the next episode. In the meantime, 0:47:05.880 --> 0:47:07.680 we'll remind you that Stuff to Blow Your Mind is 0:47:07.719 --> 0:47:12.080 a science podcast with core episodes on Tuesdays and Thursdays. 0:47:12.120 --> 0:47:14.800 That's the main event. You can also tune in for 0:47:14.840 --> 0:47:18.880 a short episode on Wednesday, a listener mail episode on Mondays, 0:47:19.000 --> 0:47:21.080 and on Fridays. We set aside most serious concerned to 0:47:21.120 --> 0:47:23.560 just talk about a weird movie on Weird House Cinema. 0:47:24.120 --> 0:47:28.400 If you listen to us on Apple or an Apple device, 0:47:28.840 --> 0:47:31.400 what have you going in And just make sure that 0:47:31.440 --> 0:47:33.600 you're still subscribed to the show, that nothing's changed there, 0:47:33.600 --> 0:47:37.080 make sure you're still getting downloads worth a check. That 0:47:37.160 --> 0:47:39.919 helps us out. And hey, as far as just rating 0:47:39.960 --> 0:47:42.080 and reviewing, we haven't beat the drum about this in 0:47:42.080 --> 0:47:45.280 a while, but hey, if you haven't rated and reviewed 0:47:45.320 --> 0:47:47.920 the show before, why didn't you do that? Throw us 0:47:47.920 --> 0:47:51.160 a good five stars somewhere. That also helps us out 0:47:51.160 --> 0:47:51.799 in the long run. 0:47:52.400 --> 0:47:56.440 Huge thanks as always to our excellent audio producer jj Posway. 0:47:56.560 --> 0:47:58.160 If you would like to get in touch with us 0:47:58.160 --> 0:48:00.319 with feedback on this episode or any other there, to 0:48:00.400 --> 0:48:02.839 suggest a topic for the future, or just to say hello, 0:48:03.040 --> 0:48:05.760 you can email us at contact at stuff to Blow 0:48:05.800 --> 0:48:14.399 your Mind dot com. 0:48:14.440 --> 0:48:17.400 Stuff to Blow Your Mind is production of iHeartRadio. For 0:48:17.480 --> 0:48:21.320 more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, 0:48:21.400 --> 0:48:37.720 or wherever you listen to your favorite shows.