1 00:00:03,040 --> 00:00:06,840 Speaker 1: Welcome to Stuff to Blow Your Mind, the production of iHeartRadio. 2 00:00:12,920 --> 00:00:14,520 Speaker 2: Hey you welcome to Stuff to Blow your Mind. 3 00:00:14,520 --> 00:00:17,319 Speaker 3: My name is Robert lamp and I'm Joe McCormick, and 4 00:00:17,360 --> 00:00:20,079 Speaker 3: we are back with part two in our series on 5 00:00:20,440 --> 00:00:24,480 Speaker 3: hermit crabs. Now a rob on a recent vacation, you 6 00:00:24,600 --> 00:00:27,640 Speaker 3: got to oversee the fields of hermit crabs as they 7 00:00:27,680 --> 00:00:32,159 Speaker 3: crawl about doing their busy, busy business, and so you 8 00:00:32,280 --> 00:00:34,680 Speaker 3: got very into the idea of talking about these animals. 9 00:00:34,720 --> 00:00:38,360 Speaker 3: And it turns out there is way more interesting stuff 10 00:00:38,400 --> 00:00:40,720 Speaker 3: to say about hermit crabs than you might think. There's 11 00:00:40,760 --> 00:00:43,040 Speaker 3: a lot of interesting research on them. They kind of 12 00:00:43,080 --> 00:00:46,879 Speaker 3: has implications beyond the hermit crab just as an animal 13 00:00:46,920 --> 00:00:50,520 Speaker 3: in itself, and can even inform us maybe about human 14 00:00:50,600 --> 00:00:54,800 Speaker 3: economics and sociology and strange corners of knowledge like that. 15 00:00:55,120 --> 00:00:57,240 Speaker 2: Yeah, so definitely go back and listen to the previous 16 00:00:57,280 --> 00:01:01,160 Speaker 2: episode if you did not all read, because we'll touch 17 00:01:01,160 --> 00:01:03,360 Speaker 2: on the basics of what hermit crabs are and what 18 00:01:03,400 --> 00:01:07,679 Speaker 2: they are not. For example, they are not considered true crabs, 19 00:01:08,480 --> 00:01:10,600 Speaker 2: but I mean in our hearts they're true crabs, but 20 00:01:11,360 --> 00:01:12,920 Speaker 2: technically speaking, not true crabs. 21 00:01:12,959 --> 00:01:17,200 Speaker 3: There's no moral implication there, it's just a different taxonomic divisions. 22 00:01:17,240 --> 00:01:22,120 Speaker 3: So the so called true crabs are decapod crustaceans ten 23 00:01:22,200 --> 00:01:28,080 Speaker 3: footed crusty animals in the info order Brachyura. These hermit 24 00:01:28,080 --> 00:01:32,560 Speaker 3: crabs belong to a cousin infraorder called Anomura a n 25 00:01:32,600 --> 00:01:36,639 Speaker 3: o m. A Animura, which are not technically true crabs, 26 00:01:36,680 --> 00:01:40,080 Speaker 3: but they are also decapod crustaceans. They also have ten 27 00:01:40,160 --> 00:01:43,920 Speaker 3: legs five pairs of legs, generally five an tennie though 28 00:01:44,000 --> 00:01:48,120 Speaker 3: in the animurans often even though they have five pairs 29 00:01:48,120 --> 00:01:52,080 Speaker 3: of legs, often like the last pair of legs will 30 00:01:52,160 --> 00:01:54,680 Speaker 3: will be diminished or hidden in some ways, so they 31 00:01:54,680 --> 00:01:57,240 Speaker 3: can often look like they have eight legs even though 32 00:01:57,240 --> 00:01:59,720 Speaker 3: they do really have ten. Maybe the last pair is 33 00:01:59,760 --> 00:02:03,240 Speaker 3: kind of tucked in somewhere, and that's certainly the case 34 00:02:03,280 --> 00:02:06,760 Speaker 3: in hermit crabs. Because, of course, the really characteristic thing 35 00:02:07,280 --> 00:02:10,360 Speaker 3: about most of the eight hundred plus species of hermit 36 00:02:10,400 --> 00:02:16,640 Speaker 3: crabs is that they are specially evolved anatomically and behaviorally 37 00:02:17,120 --> 00:02:22,000 Speaker 3: to depend on shelter, most often a type of mobile shelter, 38 00:02:22,600 --> 00:02:26,120 Speaker 3: such as the abandoned shell of another animal, most often 39 00:02:26,680 --> 00:02:29,880 Speaker 3: a gasterpod of some kind, and in the last episode, 40 00:02:29,919 --> 00:02:33,000 Speaker 3: we talked a lot about hermit crabs dependence on in 41 00:02:33,120 --> 00:02:36,800 Speaker 3: fierce competition for these shells that they use as their 42 00:02:36,880 --> 00:02:37,760 Speaker 3: mobile shelters. 43 00:02:38,880 --> 00:02:42,960 Speaker 2: That's right, they have this unique relationship with their environment, 44 00:02:44,639 --> 00:02:49,080 Speaker 2: not only scavenging. Certainly generally with hermit crabs, you have 45 00:02:49,200 --> 00:02:53,560 Speaker 2: the scavenging of old shells, particularly snail molls, skells, that 46 00:02:53,639 --> 00:02:56,120 Speaker 2: sort of thing. And then as we discussed with terrestrial 47 00:02:56,120 --> 00:02:59,960 Speaker 2: hermit crabs, which is a minority of hermit crab species, 48 00:03:00,840 --> 00:03:05,400 Speaker 2: you will see not only the acquisition of these discarded shells, 49 00:03:05,440 --> 00:03:10,240 Speaker 2: but then the alteration of these shells to make something 50 00:03:10,360 --> 00:03:12,760 Speaker 2: that is more in line and more with what the 51 00:03:12,800 --> 00:03:17,240 Speaker 2: crab want wants, and also makes it more economic, like 52 00:03:17,280 --> 00:03:21,080 Speaker 2: from an energy standpoint for the crab. So there are 53 00:03:21,120 --> 00:03:24,200 Speaker 2: all these fabulous ins and outs without even getting to 54 00:03:24,240 --> 00:03:27,919 Speaker 2: the point of like comparing the competition for hermit crab 55 00:03:27,960 --> 00:03:30,120 Speaker 2: shells to say, the human housing market. 56 00:03:31,480 --> 00:03:33,280 Speaker 3: Now, I thought it would be a good place to 57 00:03:33,320 --> 00:03:37,320 Speaker 3: start today to talk about some alternatives to snail shells 58 00:03:37,400 --> 00:03:41,040 Speaker 3: in the hermit crab shelter world. So, as we talked 59 00:03:41,080 --> 00:03:44,840 Speaker 3: about last time, hermit crabs do most often look for 60 00:03:45,120 --> 00:03:49,720 Speaker 3: gastropod shells as their mobile shelters. These shells originally belonged 61 00:03:49,760 --> 00:03:54,800 Speaker 3: to snails, periwinkles, whelks, animals of that sort, and these 62 00:03:54,880 --> 00:03:59,280 Speaker 3: original animals died and left the shells behind for crabs 63 00:03:59,320 --> 00:04:02,720 Speaker 3: to take up and in some cases remodel to their specifications. 64 00:04:03,040 --> 00:04:05,280 Speaker 3: There is, though I don't know if I've ever heard 65 00:04:05,360 --> 00:04:07,960 Speaker 3: this before. I was reading online that there is apparently 66 00:04:08,160 --> 00:04:11,600 Speaker 3: sort of a myth or an urban legend that hermit 67 00:04:11,640 --> 00:04:14,680 Speaker 3: crabs have to kill the snails to take their shells 68 00:04:14,720 --> 00:04:16,880 Speaker 3: from them, and that does not appear to be true. 69 00:04:16,920 --> 00:04:22,559 Speaker 3: Hermit crabs appear to scavin shells from snails that died 70 00:04:22,720 --> 00:04:26,960 Speaker 3: for other reasons. That died either were killed by in 71 00:04:27,000 --> 00:04:30,520 Speaker 3: some cases other snails, predatory other snails, or just died 72 00:04:30,600 --> 00:04:34,080 Speaker 3: for whatever reason. A shell is empty now, and in 73 00:04:34,120 --> 00:04:36,480 Speaker 3: some cases a hermit crab can take it up and 74 00:04:36,640 --> 00:04:39,520 Speaker 3: added into the hermit crab shell economy. 75 00:04:40,040 --> 00:04:43,560 Speaker 2: Yeah, the type competition is not for shells currently occupied 76 00:04:43,560 --> 00:04:48,400 Speaker 2: by snails. The competition among terrestrial hermit crabs is for 77 00:04:48,480 --> 00:04:50,760 Speaker 2: the shells occupied by other hermit crabs. 78 00:04:51,120 --> 00:04:54,360 Speaker 3: So, while across this whole family of animals, snail shells 79 00:04:54,520 --> 00:04:58,719 Speaker 3: are the most popular for a mobile shelter, there are 80 00:04:58,920 --> 00:05:01,840 Speaker 3: some examples of hermit crabs that use other types of 81 00:05:01,920 --> 00:05:06,120 Speaker 3: objects and in some cases even living organisms for shelter. 82 00:05:06,880 --> 00:05:10,640 Speaker 3: So on the less exciting end, some species make their 83 00:05:10,640 --> 00:05:14,279 Speaker 3: homes in plant structures, maybe hollow pieces of bamboo or 84 00:05:14,320 --> 00:05:18,320 Speaker 3: coconut shells, other plant matter like that. But there are 85 00:05:18,360 --> 00:05:22,800 Speaker 3: also these interesting relationships between hermit crabs and for example, 86 00:05:23,080 --> 00:05:25,560 Speaker 3: c anemones. Rob I know you have something in that 87 00:05:25,760 --> 00:05:27,240 Speaker 3: on that you're going to get into in a bit, 88 00:05:27,880 --> 00:05:32,120 Speaker 3: but first I wanted to talk about coral and sponges. 89 00:05:32,720 --> 00:05:36,200 Speaker 3: So there is a paper that was published in Plus 90 00:05:36,200 --> 00:05:41,400 Speaker 3: one in twenty seventeen by Momoko Igawa and Makoto Kato 91 00:05:42,040 --> 00:05:46,000 Speaker 3: called a new species of hermit crab, Diogenes heterops sama 92 00:05:46,000 --> 00:05:53,200 Speaker 3: coola replaces a mutualistic sepunculin in a walking coral symbiosis. Again, 93 00:05:53,279 --> 00:05:56,159 Speaker 3: this was the year twenty seventeen, and shout out I 94 00:05:56,200 --> 00:05:59,080 Speaker 3: came across this finding because of an article in the 95 00:05:59,120 --> 00:06:02,360 Speaker 3: Conversation I found by Sarah Minott, which is a summary 96 00:06:02,440 --> 00:06:06,960 Speaker 3: of this finding. So rob I included some images of 97 00:06:07,000 --> 00:06:12,080 Speaker 3: this hermit crab with its natural with its coral companion. 98 00:06:12,120 --> 00:06:17,440 Speaker 3: Here this is Diogenes heteropsamacola. And I would say it's 99 00:06:17,480 --> 00:06:20,480 Speaker 3: one of the weirder looking ones we've found. It does 100 00:06:20,520 --> 00:06:22,760 Speaker 3: look like a hermit crab in the front, but with 101 00:06:22,839 --> 00:06:26,200 Speaker 3: a huge kind of foot shaped mass of pink bar 102 00:06:26,360 --> 00:06:30,080 Speaker 3: soap hanging off its back. So the hermit crab itself 103 00:06:30,120 --> 00:06:34,000 Speaker 3: is is bright red and white, sort of candy cane 104 00:06:34,080 --> 00:06:37,719 Speaker 3: color scheme, with very tall eye stalks and these long 105 00:06:38,120 --> 00:06:41,680 Speaker 3: featherlike antennas. So this is a marine species of hermit crab. 106 00:06:43,000 --> 00:06:45,880 Speaker 3: And then I've got another picture for you to see here, Rob. 107 00:06:46,040 --> 00:06:49,159 Speaker 3: This is with the crab's abdomen exposed, So this is 108 00:06:49,240 --> 00:06:52,760 Speaker 3: outside of its shelter. The abdomen, while the front is 109 00:06:52,880 --> 00:06:55,719 Speaker 3: very red and white and has a crabby appearance, the 110 00:06:55,760 --> 00:06:59,520 Speaker 3: abdomen looks kind of like a like a grub. It's 111 00:06:59,560 --> 00:07:04,560 Speaker 3: like a train loocent whiteworm. So this paper and plus 112 00:07:04,600 --> 00:07:08,560 Speaker 3: one documents the discovery of a hermit crab species that 113 00:07:08,680 --> 00:07:12,400 Speaker 3: takes up mobile shelter in what are known as solitary 114 00:07:12,640 --> 00:07:17,520 Speaker 3: corals or sometimes walking corals. The species of hermit crab 115 00:07:17,640 --> 00:07:22,920 Speaker 3: was found in southern Japan by scientists affiliated with Kyoto University. Again. 116 00:07:23,000 --> 00:07:28,320 Speaker 3: The new species name is Diogenes heteropsama cola. And it's 117 00:07:28,360 --> 00:07:31,640 Speaker 3: a very tiny crab. It's just a few millimeters in length. 118 00:07:32,320 --> 00:07:36,000 Speaker 3: So you might wonder why select a chunk of living 119 00:07:36,200 --> 00:07:40,560 Speaker 3: coral as shelter instead of the shells favored by the 120 00:07:40,640 --> 00:07:45,880 Speaker 3: vast majority of hermit crabs. Well, apparently, one major advantage 121 00:07:45,880 --> 00:07:48,960 Speaker 3: for the crab is the very fact that the coral 122 00:07:49,120 --> 00:07:54,040 Speaker 3: is living and thus structurally dynamic. So most hermit crabs 123 00:07:54,080 --> 00:07:58,560 Speaker 3: have to engage in this obsessive, ongoing survey of the 124 00:07:58,600 --> 00:08:01,559 Speaker 3: housing market, trading up for bigger shells as they grow, 125 00:08:01,960 --> 00:08:06,120 Speaker 3: which as we know, can involve aggressive competition. This is 126 00:08:06,160 --> 00:08:10,160 Speaker 3: because the size of each gastropod shell is basically fixed. 127 00:08:10,160 --> 00:08:12,280 Speaker 3: I mean, in some cases in some species they might 128 00:08:12,360 --> 00:08:15,480 Speaker 3: do some interior remodeling, but the overall dimensions of the 129 00:08:15,480 --> 00:08:18,400 Speaker 3: shell are not going to change much. This species, when 130 00:08:18,440 --> 00:08:22,680 Speaker 3: it lives inside a wad of living coral, does not 131 00:08:22,840 --> 00:08:26,360 Speaker 3: have this problem. It has found a forever home because 132 00:08:26,840 --> 00:08:30,840 Speaker 3: the cavity occupied in the living coral can actually grow 133 00:08:31,000 --> 00:08:35,040 Speaker 3: along with the crab. Another thing mentioned in this article 134 00:08:35,160 --> 00:08:39,359 Speaker 3: is that coral provides active defenses. Whereas a dead gastropod 135 00:08:39,400 --> 00:08:42,880 Speaker 3: shell is a type of armor, it provides a solid 136 00:08:42,920 --> 00:08:46,600 Speaker 3: barrier against predators. The corals can actually sting. 137 00:08:47,000 --> 00:08:49,400 Speaker 2: That's right. So you have this added level of like 138 00:08:49,480 --> 00:08:54,560 Speaker 2: chemical weapon and like living self repair armor. It's just 139 00:08:54,760 --> 00:08:59,000 Speaker 2: a fabulous upgrade exactly. And apparently it is not only 140 00:08:59,040 --> 00:09:02,800 Speaker 2: the hermit crab that benefits from the symbiotic relationship. The 141 00:09:02,880 --> 00:09:05,480 Speaker 2: coral benefits as well, and that would make this an 142 00:09:05,559 --> 00:09:09,160 Speaker 2: example of the symbiosis we call mutualism. If only the 143 00:09:09,200 --> 00:09:12,240 Speaker 2: crab benefited and the coral was not affected either way, 144 00:09:12,280 --> 00:09:14,679 Speaker 2: it would be what is called commensalism. But this is 145 00:09:14,760 --> 00:09:19,000 Speaker 2: mutualism because they both get a benefit. So what is 146 00:09:19,040 --> 00:09:20,120 Speaker 2: the benefit. 147 00:09:19,840 --> 00:09:23,079 Speaker 3: For the coral. It appears to be that the hermit 148 00:09:23,160 --> 00:09:27,280 Speaker 3: crab gives the coral the benefit of mobility. So the 149 00:09:27,360 --> 00:09:32,720 Speaker 3: coral in question is of the genus Heteropsamia, and this 150 00:09:32,840 --> 00:09:35,880 Speaker 3: is not the kind of coral that forms into large 151 00:09:36,000 --> 00:09:39,440 Speaker 3: structured reefs. So this is a solitary coral, or again 152 00:09:39,520 --> 00:09:43,920 Speaker 3: sometimes called a walking coral. Rabi attached some pictures of 153 00:09:43,960 --> 00:09:47,400 Speaker 3: this coral for you to look at in its normal form, 154 00:09:47,559 --> 00:09:50,160 Speaker 3: just sitting there on the ocean floor. It looks kind 155 00:09:50,200 --> 00:09:52,959 Speaker 3: of like a blob with some you can see the 156 00:09:53,240 --> 00:09:56,800 Speaker 3: polyp cups and the tentacles on top. These corals can 157 00:09:56,840 --> 00:09:59,719 Speaker 3: be found in small masses, usually about two to three 158 00:09:59,720 --> 00:10:04,600 Speaker 3: cent meters in diameter, sitting on flat sandy seafloors, and 159 00:10:04,760 --> 00:10:08,679 Speaker 3: their polyp cups and feeding tentacles are positioned facing up 160 00:10:08,720 --> 00:10:12,679 Speaker 3: into the water. One danger for an organism like this 161 00:10:13,000 --> 00:10:15,680 Speaker 3: is that it has to be positioned correctly in order 162 00:10:15,760 --> 00:10:19,720 Speaker 3: to survive. But the coral mass is not ambulatory. It 163 00:10:19,720 --> 00:10:23,000 Speaker 3: can't walk around, so imagine being sort of a small 164 00:10:23,200 --> 00:10:26,120 Speaker 3: rock with a mouth and I guess kind of finger teeth. 165 00:10:26,840 --> 00:10:29,760 Speaker 3: Alone on the seafloor, it is at risk of either 166 00:10:29,880 --> 00:10:33,800 Speaker 3: being buried by sediment or being knocked over and left 167 00:10:33,880 --> 00:10:36,760 Speaker 3: upside down, both of which could be a death sentence 168 00:10:36,800 --> 00:10:41,160 Speaker 3: for the coral. So Heteropsamia has evolved a relationship with 169 00:10:41,240 --> 00:10:45,200 Speaker 3: another organism, not the hermit crab. This is an organism 170 00:10:45,280 --> 00:10:49,480 Speaker 3: known as a cupunculated worm. This is a small worm 171 00:10:49,920 --> 00:10:53,280 Speaker 3: that lives in a cavity on the underside of the coral, 172 00:10:53,640 --> 00:10:56,400 Speaker 3: and it carries the coral around with it when it 173 00:10:56,480 --> 00:11:00,800 Speaker 3: crawls along the bottom. It seems that in some cases, 174 00:11:00,840 --> 00:11:04,680 Speaker 3: specifically in areas around the Amami Islands, which are islands 175 00:11:04,720 --> 00:11:08,160 Speaker 3: that they're part of Japan but way south of the 176 00:11:08,200 --> 00:11:11,320 Speaker 3: main Japanese islands. In these cases, the hermit crabs have 177 00:11:11,520 --> 00:11:14,199 Speaker 3: taken over the role that was once played by the 178 00:11:14,240 --> 00:11:19,000 Speaker 3: worms in this relationship. So how would this swap occur 179 00:11:19,160 --> 00:11:22,400 Speaker 3: between you know, going from the coral partnering with the 180 00:11:22,400 --> 00:11:26,120 Speaker 3: worm to the coral partnering with the hermit crab, Because 181 00:11:26,120 --> 00:11:28,760 Speaker 3: as you know, a lot of times these tight symbiotic 182 00:11:28,800 --> 00:11:32,040 Speaker 3: relationships are very sort of finely tuned by evolution. Like 183 00:11:32,120 --> 00:11:36,120 Speaker 3: they it would not usually be easy to just swap 184 00:11:36,200 --> 00:11:39,719 Speaker 3: one animal in for another. Well, the author of this 185 00:11:40,360 --> 00:11:43,000 Speaker 3: feature I was reading interviewed the lead author of the paper, 186 00:11:43,120 --> 00:11:48,200 Speaker 3: Momoko Igawa, and she explained that the normal process of 187 00:11:48,760 --> 00:11:53,800 Speaker 3: establishing a relationship between a coral and a supunculate worm 188 00:11:54,520 --> 00:11:56,880 Speaker 3: goes like this. So when the coral is young, it 189 00:11:56,960 --> 00:12:01,680 Speaker 3: begins by attaching itself to a tiny shell and begins 190 00:12:01,720 --> 00:12:05,760 Speaker 3: to grow around the shell as it matures and builds 191 00:12:05,800 --> 00:12:09,920 Speaker 3: its solid base. So the coral lands on a small 192 00:12:09,920 --> 00:12:14,240 Speaker 3: shell that is already inhabited by a worm. So there's 193 00:12:14,280 --> 00:12:18,440 Speaker 3: already a relationship between the worm and the inanimate shell. 194 00:12:18,920 --> 00:12:22,239 Speaker 3: The worm is using the shell for shelter, and then somehow, 195 00:12:22,720 --> 00:12:24,880 Speaker 3: you know from the worm's point of view, the shell 196 00:12:25,120 --> 00:12:29,120 Speaker 3: just suddenly it keeps getting bigger and like it grows 197 00:12:29,120 --> 00:12:31,120 Speaker 3: all around it. And this is the coral taking up 198 00:12:31,160 --> 00:12:34,000 Speaker 3: residence on the shell and growing around it, forming a 199 00:12:34,040 --> 00:12:37,079 Speaker 3: sort of perfect little cavity for the worm to hide in. 200 00:12:37,720 --> 00:12:41,360 Speaker 3: And according to Igawa, it seems likely that a similar 201 00:12:41,400 --> 00:12:46,320 Speaker 3: process led to hermit crabs inhabiting the corals, and in 202 00:12:46,360 --> 00:12:49,120 Speaker 3: the end the benefits that they would trade off are similar. 203 00:12:49,280 --> 00:12:52,760 Speaker 3: So the mobility of the crab protects the coral from 204 00:12:52,800 --> 00:12:56,080 Speaker 3: being buried in sand or stuck upside down, and the 205 00:12:56,120 --> 00:12:58,560 Speaker 3: coral helps protect the crab from predators. 206 00:12:59,280 --> 00:13:02,600 Speaker 2: Yeah, this is fair fascinating. Again, it just kind of 207 00:13:02,600 --> 00:13:04,840 Speaker 2: takes the basic concept of the hermit crab that I 208 00:13:04,840 --> 00:13:07,840 Speaker 2: think most people are familiar with to some degree and 209 00:13:07,960 --> 00:13:12,760 Speaker 2: just takes it into like weird areas. And indeed, I 210 00:13:12,800 --> 00:13:15,960 Speaker 2: have another example here to discuss, and this is where 211 00:13:16,000 --> 00:13:19,680 Speaker 2: we get into into deep sea hermit crabs. And I 212 00:13:19,720 --> 00:13:22,120 Speaker 2: think you know, if you've ever heard us talk about 213 00:13:22,520 --> 00:13:26,480 Speaker 2: deep sea biology before, you know that the things can 214 00:13:26,480 --> 00:13:30,800 Speaker 2: get weird down there. And so I want to talk 215 00:13:30,840 --> 00:13:36,360 Speaker 2: about some of these hermit crabs from the family parapap Gurity. 216 00:13:36,600 --> 00:13:39,600 Speaker 2: By the way, as long as we're talking about names here, 217 00:13:39,880 --> 00:13:43,240 Speaker 2: you know, did we stop me if we already talked 218 00:13:43,240 --> 00:13:46,680 Speaker 2: about this, but did we talk about the family of 219 00:13:46,720 --> 00:13:52,199 Speaker 2: hermit crabs, Diogenidae being named after Diogenies the. 220 00:13:52,440 --> 00:13:54,200 Speaker 3: Oh yeah, Diogenes the cynic. 221 00:13:54,720 --> 00:13:57,400 Speaker 2: Yeah, who of course lived in a tub according to 222 00:13:57,440 --> 00:13:58,199 Speaker 2: the story. 223 00:13:58,080 --> 00:14:00,760 Speaker 3: So right, So yeah, Diogeny the synec. He was an 224 00:14:00,760 --> 00:14:05,520 Speaker 3: ancient Greek philosopher who supposedly would live in i think 225 00:14:05,559 --> 00:14:08,640 Speaker 3: the marketplace of Athens, just in a big ceramic jar. 226 00:14:10,720 --> 00:14:14,079 Speaker 3: And as a cynic philosopher, his big thing was, you know, 227 00:14:14,120 --> 00:14:17,600 Speaker 3: that one should not act against their nature according to 228 00:14:17,640 --> 00:14:20,600 Speaker 3: the expectations of others. So he was he was very 229 00:14:21,000 --> 00:14:23,640 Speaker 3: you know, against society's rules and stuff. 230 00:14:25,160 --> 00:14:27,160 Speaker 2: Yeah, is that, in a way kind of a perfect 231 00:14:28,400 --> 00:14:31,720 Speaker 2: model for us to look to in naming the hermit crabs. 232 00:14:32,000 --> 00:14:35,960 Speaker 2: So anyway, we're talking about deep sea hermit crabs here, 233 00:14:36,280 --> 00:14:39,480 Speaker 2: and in particular one that wears not a deceased mollusk, 234 00:14:39,720 --> 00:14:42,000 Speaker 2: but the living body of a cea. An enemy is 235 00:14:42,000 --> 00:14:45,600 Speaker 2: Mary kay Wixton described for you know aa back in 236 00:14:45,720 --> 00:14:49,800 Speaker 2: twenty fifteen. Young crabs of this of these, this particular 237 00:14:49,840 --> 00:14:53,720 Speaker 2: type start out inhabiting a Pilford shell, you know, typical 238 00:14:54,160 --> 00:14:56,800 Speaker 2: you know, snail shell or what have you. But then 239 00:14:57,440 --> 00:15:02,800 Speaker 2: the cea, anemony of the family hor Methadaae, settles on 240 00:15:02,840 --> 00:15:08,200 Speaker 2: the shell, over grows it, and then ultimately dissolves that 241 00:15:08,320 --> 00:15:12,560 Speaker 2: shell to become the living housing of the crab. And 242 00:15:13,360 --> 00:15:15,440 Speaker 2: as much with the example we were talking about earlier 243 00:15:15,480 --> 00:15:18,720 Speaker 2: with the coral, grows and expands with the hermit crabs. 244 00:15:18,760 --> 00:15:21,120 Speaker 2: So now this is indeed another example of the forever 245 00:15:21,200 --> 00:15:26,720 Speaker 2: home of a bio armor that will grow with the crab. Brilliant. 246 00:15:26,880 --> 00:15:29,600 Speaker 2: Now the enemity gains mobility this way, you know, the 247 00:15:29,600 --> 00:15:31,720 Speaker 2: hermit crab is like, hey, you stick with me, baby, 248 00:15:31,760 --> 00:15:35,400 Speaker 2: I'll show you the world. And so the crab also, 249 00:15:35,640 --> 00:15:39,040 Speaker 2: as with the coral example, gains chemical production from predators, 250 00:15:39,280 --> 00:15:45,280 Speaker 2: specifically protection against octopods and this species. The species in 251 00:15:45,280 --> 00:15:48,080 Speaker 2: this particular rite up is not specified or was perhaps 252 00:15:48,200 --> 00:15:49,920 Speaker 2: not known at the time. I get to think one 253 00:15:49,960 --> 00:15:53,560 Speaker 2: of the exciting things about hermit crabs, particularly marine hermit crabs, 254 00:15:53,840 --> 00:15:57,440 Speaker 2: is we keep discovering new species and we keep making 255 00:15:57,480 --> 00:16:00,400 Speaker 2: new discoveries about how they lift their strange life in 256 00:16:00,440 --> 00:16:03,920 Speaker 2: the ocean, especially the deep ocean. Now, according to a 257 00:16:04,040 --> 00:16:08,920 Speaker 2: twenty twenty study by gusmo at All published in Molecular Phylogenetics. 258 00:16:09,160 --> 00:16:11,400 Speaker 2: There are some cases where these deep water hermit crabs 259 00:16:11,400 --> 00:16:15,440 Speaker 2: simply carry around protective sea anemies on their intact shells, 260 00:16:16,040 --> 00:16:19,920 Speaker 2: and in these cases especially, the crab actually selects and 261 00:16:20,040 --> 00:16:23,640 Speaker 2: places the organisms on its own shell, you know, goes 262 00:16:23,640 --> 00:16:27,680 Speaker 2: out shopping besides which ones it wants and places them there. However, 263 00:16:28,040 --> 00:16:32,520 Speaker 2: the author stresses that quote c aneminies can also mount 264 00:16:32,520 --> 00:16:38,720 Speaker 2: shells unaided triggered by mollusk derived substances in periostrasum of 265 00:16:38,800 --> 00:16:42,480 Speaker 2: the shell. So the exact mutualistic relationship differs depending on 266 00:16:42,520 --> 00:16:47,160 Speaker 2: the species of the hermit crab. But it's pretty amazing 267 00:16:47,160 --> 00:16:49,080 Speaker 2: here the idea that like, in some cases the hermit 268 00:16:49,120 --> 00:16:52,640 Speaker 2: crab is shopping, in other cases it is sought out. 269 00:16:53,120 --> 00:16:56,120 Speaker 3: Oh, I want more detail on exactly what the shopping 270 00:16:56,200 --> 00:16:58,760 Speaker 3: is like. Does the crab like crawl along and sort 271 00:16:58,800 --> 00:17:02,680 Speaker 3: of feel around the anemone, like pick it up and 272 00:17:02,800 --> 00:17:05,640 Speaker 3: put it on there? Like what is the selection process? 273 00:17:05,800 --> 00:17:05,879 Speaker 1: Like? 274 00:17:06,400 --> 00:17:08,680 Speaker 2: Yeah, I mean they're very very choosy as we see, 275 00:17:08,720 --> 00:17:11,359 Speaker 2: even just with their selection of snail shells and whatnot. 276 00:17:11,680 --> 00:17:13,440 Speaker 2: I'm to terrestrial hermit crabs. 277 00:17:13,600 --> 00:17:16,520 Speaker 3: Oh that's true. Yeah, the selection of the gasterpodshell involves 278 00:17:16,560 --> 00:17:19,040 Speaker 3: an awful lot of feeling. Usually, you know, it's not 279 00:17:19,119 --> 00:17:21,639 Speaker 3: just like looking at it. They go and they feel 280 00:17:21,680 --> 00:17:24,040 Speaker 3: all over it. They turn it around, they climb inside 281 00:17:24,040 --> 00:17:26,080 Speaker 3: it and try it out, and sometimes decide they don't 282 00:17:26,080 --> 00:17:28,520 Speaker 3: want it. I mean, that's the whole thing. Like, sometimes 283 00:17:28,560 --> 00:17:30,560 Speaker 3: they do try it out and decay and that's not 284 00:17:30,680 --> 00:17:32,200 Speaker 3: right and they go back to the old one. 285 00:17:32,560 --> 00:17:34,960 Speaker 2: And then sometimes is the case with the shells, and 286 00:17:35,080 --> 00:17:38,360 Speaker 2: might be the case with cnemonies as well, is that 287 00:17:39,119 --> 00:17:43,720 Speaker 2: they are also making choices that their survival depends upon. 288 00:17:43,840 --> 00:17:46,000 Speaker 2: So sometimes they will go with a shell that they 289 00:17:46,000 --> 00:17:48,400 Speaker 2: don't like all that much, or they is not their 290 00:17:48,400 --> 00:17:50,840 Speaker 2: first choice or even their second choice, but they need 291 00:17:50,880 --> 00:17:54,320 Speaker 2: to survive until they can get something better. And so yeah, 292 00:17:54,320 --> 00:17:56,840 Speaker 2: perhaps that's the case here as well. But again, researchers 293 00:17:56,880 --> 00:18:02,360 Speaker 2: are still making fantastic discoveries regarding deep water hermes. For example, 294 00:18:02,560 --> 00:18:05,320 Speaker 2: a twenty twenty two team from the University of Tokyo 295 00:18:05,440 --> 00:18:10,880 Speaker 2: discovered a new species of anemone. This is Stylobatis calcifer, 296 00:18:11,440 --> 00:18:15,119 Speaker 2: named after the fire demon Calcifer from the novel and 297 00:18:15,240 --> 00:18:19,520 Speaker 2: studio Ghibli film. How's moving Castle? This is the one 298 00:18:19,520 --> 00:18:22,919 Speaker 2: that's in the Disney dub is voiced by Billy Crystal. 299 00:18:23,680 --> 00:18:27,240 Speaker 3: Okay, yeah wait, this is the it's like for cooking 300 00:18:27,280 --> 00:18:30,159 Speaker 3: the food, right they like yes, they're cooking bacon and 301 00:18:30,160 --> 00:18:32,080 Speaker 3: eggs and stuff in the pan over this boy. 302 00:18:32,760 --> 00:18:36,080 Speaker 2: Yeah yeah yeah. A very fun character. Great movie. Yeah, 303 00:18:36,119 --> 00:18:41,959 Speaker 2: and inspired inspired the name for the anemone, and it 304 00:18:42,000 --> 00:18:45,560 Speaker 2: lives on the shells of a particular hermit crab species. 305 00:18:46,040 --> 00:18:49,000 Speaker 2: And I included an image of this for you here, Joe. Now, 306 00:18:49,040 --> 00:18:51,440 Speaker 2: there may be some lighting in the image I provided, 307 00:18:51,480 --> 00:18:55,639 Speaker 2: but it still looks beautiful. It's it's like this. It 308 00:18:55,640 --> 00:18:58,399 Speaker 2: does look very fiery. It looks like a creature that 309 00:18:58,600 --> 00:19:00,959 Speaker 2: is composed of within flame. 310 00:19:01,400 --> 00:19:04,080 Speaker 3: Oh yeah, it's beautiful. And I can see why you 311 00:19:04,160 --> 00:19:06,760 Speaker 3: might call it that given the animation style of that 312 00:19:07,600 --> 00:19:11,320 Speaker 3: in House Moving Castle. Like the way the flame just 313 00:19:11,400 --> 00:19:14,760 Speaker 3: kind of bobs and undulate. It's almost like the way 314 00:19:14,800 --> 00:19:16,840 Speaker 3: you might see the I don't know, flesh of a 315 00:19:16,920 --> 00:19:21,119 Speaker 3: jellyfish moving underwater or something. And I can imagine that 316 00:19:21,160 --> 00:19:25,480 Speaker 3: if you see this anemony in motion, it probably looks 317 00:19:25,480 --> 00:19:26,280 Speaker 3: something like that. 318 00:19:26,720 --> 00:19:28,760 Speaker 2: Yeah. Yeah, it's pretty great. If you want to find 319 00:19:28,840 --> 00:19:31,440 Speaker 2: some of these images for yourself. There was a twenty 320 00:19:31,480 --> 00:19:36,000 Speaker 2: twenty two Mongbay article by Liz Kimbro that you can 321 00:19:36,040 --> 00:19:38,240 Speaker 2: look up, and that's one of the sources I was 322 00:19:38,280 --> 00:19:50,320 Speaker 2: looking at for the section of the episode. Now, on 323 00:19:50,359 --> 00:19:53,000 Speaker 2: the subject of deep sea hermit crabs, we should also 324 00:19:53,040 --> 00:19:57,240 Speaker 2: talk about hydrothermal vent environments. We've talked about hydrothermal events 325 00:19:57,280 --> 00:19:59,120 Speaker 2: plenty of times in the show before. These are deep 326 00:19:59,160 --> 00:20:04,560 Speaker 2: sea seabed fissures that release geothermically heated water that can 327 00:20:04,600 --> 00:20:09,119 Speaker 2: result in very biologically active oases in the deep ocean 328 00:20:09,119 --> 00:20:13,720 Speaker 2: that provide home to many different unique species of organism. Now, 329 00:20:13,720 --> 00:20:17,000 Speaker 2: one of the more famous vent dwellers is the Kiwa 330 00:20:17,119 --> 00:20:21,240 Speaker 2: tay lari or Hoff crab, which is actually a squat lobster. 331 00:20:21,560 --> 00:20:23,199 Speaker 2: And this is not a hermit crab, but it is 332 00:20:23,320 --> 00:20:26,560 Speaker 2: kin to hermit crabs. It's not a quote unquote true crab. 333 00:20:27,240 --> 00:20:30,399 Speaker 2: But in two thousand and four, researchers discovered the first 334 00:20:30,440 --> 00:20:35,280 Speaker 2: known hermit crab to recide at a hydrothermal vent. This 335 00:20:35,320 --> 00:20:42,320 Speaker 2: one was dubbed Peraggio pageeras Vento Lattis, and it was 336 00:20:42,359 --> 00:20:46,480 Speaker 2: discovered in the waters off Taiwan, and this was I 337 00:20:46,560 --> 00:20:49,879 Speaker 2: was thinking about this in a paper by raphael LEA. Matre, 338 00:20:50,640 --> 00:20:53,680 Speaker 2: then in a twenty eleven paper by kome At All 339 00:20:54,680 --> 00:20:58,560 Speaker 2: these hermit crabs were found elsewhere on the Nico Seamount. 340 00:20:58,680 --> 00:21:01,960 Speaker 2: This is a submarine volcano in like southern Japanese waters. 341 00:21:02,560 --> 00:21:05,000 Speaker 2: Now I was mentioning some of this to my wife 342 00:21:05,280 --> 00:21:06,919 Speaker 2: as I was researching it, and when I brought up 343 00:21:06,960 --> 00:21:10,600 Speaker 2: the idea of hydrothermal event crabs, her question was where 344 00:21:10,600 --> 00:21:12,520 Speaker 2: do they get their shells? Do they have shells? And 345 00:21:12,560 --> 00:21:14,440 Speaker 2: I hadn't really thought about this, but yeah, it does 346 00:21:14,480 --> 00:21:19,680 Speaker 2: seem that while this species prefers gastropod shells, they would 347 00:21:19,720 --> 00:21:23,800 Speaker 2: prefer to have standard like snail shells. They are indeed 348 00:21:24,359 --> 00:21:29,679 Speaker 2: scarce in these habitats, these hydrothermal vents, so they'll end 349 00:21:29,760 --> 00:21:32,120 Speaker 2: up having to use something else. It's not their first choice, 350 00:21:32,280 --> 00:21:37,159 Speaker 2: but they will use the empty tubes of the syboglintid worm. 351 00:21:38,200 --> 00:21:40,800 Speaker 2: This is like a tube worm, and they will use 352 00:21:40,880 --> 00:21:45,320 Speaker 2: these discarded empty tubes for their shell if they cannot 353 00:21:45,359 --> 00:21:47,760 Speaker 2: get an actual gastropod shell. Ah. 354 00:21:47,840 --> 00:21:50,840 Speaker 3: Yeah, so I had read some unspecified references to hermit 355 00:21:50,880 --> 00:21:55,320 Speaker 3: crabs using worm tubes as mobile shelter, and I wonder 356 00:21:55,320 --> 00:21:58,400 Speaker 3: if it might be talking about this or maybe related 357 00:21:58,440 --> 00:22:01,359 Speaker 3: animals that use other worm tubes as well. 358 00:22:01,640 --> 00:22:04,080 Speaker 2: Yeah, yeah, it's pretty fascinating. I do want to point 359 00:22:04,080 --> 00:22:07,640 Speaker 2: out this is not an obligate hydrothermal vent dweller, though. 360 00:22:07,680 --> 00:22:10,480 Speaker 2: You do have various organisms that have to have that 361 00:22:10,560 --> 00:22:13,680 Speaker 2: hydrothermal vent environment, and it is something that very much 362 00:22:13,720 --> 00:22:18,280 Speaker 2: defines them. These creatures apparently can live beyond the hydrothermal vents, 363 00:22:18,280 --> 00:22:23,320 Speaker 2: but have been observed to reside there. So see anemones, 364 00:22:23,920 --> 00:22:32,200 Speaker 2: coral tubeworm, discarded tubworm tubes. So many different things can 365 00:22:32,640 --> 00:22:34,440 Speaker 2: become housing for a hermit. 366 00:22:34,160 --> 00:22:38,879 Speaker 3: Crab thinking outside the snailshell. Yes, and of course all 367 00:22:38,920 --> 00:22:42,080 Speaker 3: these things we're talking about are things that you would expect. 368 00:22:42,320 --> 00:22:45,159 Speaker 3: They're like an adapted relationship in some way, things you 369 00:22:45,200 --> 00:22:48,959 Speaker 3: would expect to see with some regularity in nature. You 370 00:22:48,960 --> 00:22:52,400 Speaker 3: can find weird, isolated examples of hermit crabs using all 371 00:22:52,480 --> 00:22:55,600 Speaker 3: kinds of stuff as a temporary shelter if they are 372 00:22:55,640 --> 00:22:56,280 Speaker 3: in a jam. 373 00:22:57,160 --> 00:22:59,960 Speaker 2: That's right. We mentioned like the intense competition for shell 374 00:23:00,400 --> 00:23:05,600 Speaker 2: and the cascading events that will occur when a conflict 375 00:23:05,640 --> 00:23:09,280 Speaker 2: between hermit crabs over a shell resolves, and then somebody's 376 00:23:09,320 --> 00:23:12,960 Speaker 2: left out. Usually it's the whichever crab lost in the 377 00:23:13,000 --> 00:23:17,680 Speaker 2: combat now has no shell, and in those cases, again, 378 00:23:17,720 --> 00:23:20,080 Speaker 2: its survival is on the line, so it may use 379 00:23:20,080 --> 00:23:23,080 Speaker 2: something like even like a discarded pop top I saw 380 00:23:23,160 --> 00:23:26,040 Speaker 2: referenced in one article. Doesn't mean it's happy about it, 381 00:23:26,080 --> 00:23:29,360 Speaker 2: but it will use it for the time being. Now 382 00:23:29,400 --> 00:23:32,560 Speaker 2: there's another wrinkled to this whole, you know, not true 383 00:23:32,560 --> 00:23:39,240 Speaker 2: crabs story, because there's another cousin to true crabs, known as, 384 00:23:39,240 --> 00:23:40,960 Speaker 2: of course, the king crab. I think a lot of 385 00:23:41,040 --> 00:23:43,520 Speaker 2: you've heard of the king crab. Sometimes it winds up 386 00:23:43,520 --> 00:23:46,560 Speaker 2: on the menu. Right. There are over one hundred species 387 00:23:46,560 --> 00:23:49,280 Speaker 2: of king crabs, and while we don't know for certain, 388 00:23:49,560 --> 00:23:54,119 Speaker 2: it is widely hypothesized that king crabs derived from hermit 389 00:23:54,160 --> 00:23:57,840 Speaker 2: crab ancestors. This brings us once more to the topic 390 00:23:58,000 --> 00:24:03,000 Speaker 2: of carcinization. This is convergent evolution, in which non crab 391 00:24:03,080 --> 00:24:07,000 Speaker 2: crustaceans evolve crab like bodies, and in this case we're 392 00:24:07,040 --> 00:24:10,280 Speaker 2: specifically dealing with what's referred to as the hermit to 393 00:24:10,440 --> 00:24:14,800 Speaker 2: king hypothesis, which we should stress is not universally accepted, 394 00:24:15,359 --> 00:24:18,360 Speaker 2: but it does seem to be the current scientific consensus, 395 00:24:19,000 --> 00:24:23,560 Speaker 2: though again again not everyone agrees though, but thankfully this 396 00:24:23,600 --> 00:24:25,920 Speaker 2: is not one of those scientific consensus issues that has 397 00:24:25,920 --> 00:24:28,400 Speaker 2: been politicized, though I guess it would be. It would 398 00:24:28,440 --> 00:24:33,400 Speaker 2: be maybe amusing if it were. As Noah and Glenner 399 00:24:33,520 --> 00:24:36,520 Speaker 2: point out in the Origin of King Crabs. This is 400 00:24:36,560 --> 00:24:42,280 Speaker 2: twenty seventeen, published in Zoological Journal of the Lenaean Society. 401 00:24:42,640 --> 00:24:46,600 Speaker 2: The hypothesis itself dates back to the nineteenth century and 402 00:24:46,760 --> 00:24:50,320 Speaker 2: has been controversial that long as well. It's not a 403 00:24:50,359 --> 00:24:54,040 Speaker 2: new controversy. They signed an eighteen ninety five paper by 404 00:24:54,160 --> 00:24:59,560 Speaker 2: French entomologist Eugene Louis Bouvier who lived eighteen fifty six 405 00:25:00,000 --> 00:25:04,320 Speaker 2: teen forty four. This guy studied molus and crustaceans early 406 00:25:04,359 --> 00:25:07,280 Speaker 2: in his career, and they summarize that the basic idea 407 00:25:07,480 --> 00:25:12,320 Speaker 2: is that quote, king crabs are secondarily calcified hermit crabs 408 00:25:12,560 --> 00:25:16,879 Speaker 2: that left the protective gastropod housing and transformed to a 409 00:25:16,960 --> 00:25:18,000 Speaker 2: crab like form. 410 00:25:18,480 --> 00:25:22,000 Speaker 3: That is such a strange, wonderful path. If that is 411 00:25:22,480 --> 00:25:24,680 Speaker 3: in fact the case of what happened with king crabs, 412 00:25:25,200 --> 00:25:28,679 Speaker 3: that you would get what was originally some type of 413 00:25:28,840 --> 00:25:34,760 Speaker 3: crustacean ancestor that evolved to have this obligate relationship with 414 00:25:34,840 --> 00:25:40,680 Speaker 3: external shelter, so its backside is this soft, windy, wormy 415 00:25:40,720 --> 00:25:43,840 Speaker 3: little thing that is protected by a shell. And it 416 00:25:44,119 --> 00:25:46,199 Speaker 3: makes this i don't know what would seem to be 417 00:25:46,320 --> 00:25:52,200 Speaker 3: a very dramatic and irreversible kind of evolutionary right turn 418 00:25:52,280 --> 00:25:53,840 Speaker 3: or left turn, whatever you want to call it, that 419 00:25:54,280 --> 00:25:57,360 Speaker 3: it goes down this weird road of depending on these 420 00:25:57,400 --> 00:26:02,639 Speaker 3: external shells, and then part of that family goes it 421 00:26:02,680 --> 00:26:06,800 Speaker 3: back in the other direction, changes course again, abandons the shells, 422 00:26:07,040 --> 00:26:09,520 Speaker 3: and becomes fully hardened on the outside. 423 00:26:10,080 --> 00:26:12,680 Speaker 2: Yeah. I mean, it's one of the crazy things about evolution, 424 00:26:12,840 --> 00:26:17,520 Speaker 2: these various changes that occur over time, like you know, 425 00:26:17,600 --> 00:26:21,480 Speaker 2: the different species evolving different forms of wings, you know, 426 00:26:21,600 --> 00:26:26,080 Speaker 2: different morphological approaches to the same basic concept, and then 427 00:26:26,160 --> 00:26:29,800 Speaker 2: creatures like flightless birds that just yeah, like I don't 428 00:26:29,800 --> 00:26:33,000 Speaker 2: really need to do that anymore, I have, it's not necessary, 429 00:26:33,000 --> 00:26:35,199 Speaker 2: and it really was. It was a huge pain in 430 00:26:35,200 --> 00:26:36,359 Speaker 2: the butt to do it to begin with. 431 00:26:36,760 --> 00:26:38,399 Speaker 3: Oh, actually, you know what I think would be a 432 00:26:38,440 --> 00:26:43,720 Speaker 3: great parallel example is marine mammals. You know, so the 433 00:26:44,280 --> 00:26:47,359 Speaker 3: all terrestrial life comes from what was originally in the sea, 434 00:26:47,840 --> 00:26:50,840 Speaker 3: and these animals came evolved from animals that once lived 435 00:26:50,880 --> 00:26:55,520 Speaker 3: exclusively in the sea. All marine mammals evolve from terrestrial mammals. 436 00:26:55,960 --> 00:26:59,560 Speaker 3: They were once you know, four footed, quadrupedal mammals wandering 437 00:26:59,600 --> 00:27:03,600 Speaker 3: around land, and they evolved to go back to full 438 00:27:03,640 --> 00:27:04,639 Speaker 3: time water life. 439 00:27:05,240 --> 00:27:08,000 Speaker 2: Yeah. So there's like this line from like, oh, thank goodness, 440 00:27:08,119 --> 00:27:10,080 Speaker 2: I'm out of here for just a little bit, out 441 00:27:10,119 --> 00:27:14,159 Speaker 2: of the fierce competition of the water. And then you know, 442 00:27:14,280 --> 00:27:17,560 Speaker 2: millions upon millions of years later, something that will become 443 00:27:17,560 --> 00:27:19,800 Speaker 2: an orca goes back in again and says, you know, 444 00:27:20,240 --> 00:27:21,680 Speaker 2: I think I got it this time. I think I'm ready. 445 00:27:21,720 --> 00:27:23,960 Speaker 2: I'm going back. And then, of course plenty of things 446 00:27:23,960 --> 00:27:27,080 Speaker 2: that don't become orchis that don't they are not success 447 00:27:27,160 --> 00:27:28,400 Speaker 2: stories as well, I suppose. 448 00:27:28,800 --> 00:27:29,840 Speaker 3: Yeah. 449 00:27:29,960 --> 00:27:32,480 Speaker 2: So again, the hermit to king hypothesis goes back to 450 00:27:32,520 --> 00:27:36,879 Speaker 2: the nineteenth century, and initially the evidence was largely morphological 451 00:27:37,359 --> 00:27:42,080 Speaker 2: king crabs lithoughtids. They don't really look like hermit crabs, 452 00:27:42,080 --> 00:27:45,160 Speaker 2: certainly not to the average crab looker. The body shape 453 00:27:45,200 --> 00:27:49,680 Speaker 2: is drastically different, but a few key details would seem 454 00:27:49,720 --> 00:27:50,240 Speaker 2: to remain. 455 00:27:50,600 --> 00:27:53,680 Speaker 3: Okay, so you're looking for body features that king crabs 456 00:27:53,720 --> 00:27:57,000 Speaker 3: have in common with hermit crabs, like like, what would 457 00:27:57,000 --> 00:27:57,199 Speaker 3: they be? 458 00:27:58,080 --> 00:28:02,119 Speaker 2: All right? So first please and claw asymmetry. So the 459 00:28:02,119 --> 00:28:05,200 Speaker 2: plan is the abdomen of the crab. And as we've 460 00:28:05,240 --> 00:28:08,960 Speaker 2: already pointed out, the hermit crab has a highly asymmetrical 461 00:28:09,000 --> 00:28:13,680 Speaker 2: abdomen that evolved to slide into asymmetrical spiral shells. And 462 00:28:13,720 --> 00:28:17,439 Speaker 2: as we mentioned already, their right pincher is usually larger 463 00:28:17,480 --> 00:28:19,440 Speaker 2: so as to cover the opening of the shell when 464 00:28:19,480 --> 00:28:21,680 Speaker 2: they retreat into it, you know, it becomes the door 465 00:28:21,800 --> 00:28:22,399 Speaker 2: for the shell. 466 00:28:22,840 --> 00:28:25,520 Speaker 3: Yeah, though of course there are multiple There are the 467 00:28:25,600 --> 00:28:29,320 Speaker 3: right handed hermit crabs in the left handed hermit crabs, 468 00:28:29,320 --> 00:28:33,200 Speaker 3: so some are reverse. The diogenids actually are the reversed 469 00:28:33,240 --> 00:28:34,480 Speaker 3: ones the left handed ones. 470 00:28:35,080 --> 00:28:39,600 Speaker 2: That's right mouthparts are another one apparently hermitson kings between 471 00:28:39,600 --> 00:28:43,520 Speaker 2: hermitson que kings there are only like minor differences. Also, 472 00:28:43,760 --> 00:28:48,080 Speaker 2: the sieda on the grooming legs one seedyle type, for example, 473 00:28:48,160 --> 00:28:52,719 Speaker 2: is only present in parigrid hermit crabs and king crabs. 474 00:28:52,720 --> 00:28:58,840 Speaker 2: This according to a twenty fifteen study published in Actazoologica. 475 00:28:58,920 --> 00:29:03,680 Speaker 2: Also there's some detail as an internal organ organization. Also, 476 00:29:03,960 --> 00:29:08,480 Speaker 2: there are various correspondences in the vascular system between kings 477 00:29:08,480 --> 00:29:13,440 Speaker 2: and hermits. And then adding to this hypothesis is the observation, 478 00:29:13,600 --> 00:29:16,920 Speaker 2: of course that carsonization may be a thing in general, 479 00:29:16,960 --> 00:29:20,960 Speaker 2: with crab like forms seemingly having evolved multiple times in 480 00:29:21,040 --> 00:29:22,480 Speaker 2: shallow water habitats. 481 00:29:23,000 --> 00:29:25,160 Speaker 3: So it's just a plan that works. And if you 482 00:29:25,200 --> 00:29:29,040 Speaker 3: already have the basic blueprints in place and you can 483 00:29:29,360 --> 00:29:32,560 Speaker 3: evolve in the in the crab shape direction, a lot 484 00:29:32,560 --> 00:29:35,400 Speaker 3: of animals will eventually evolve down that path. 485 00:29:36,000 --> 00:29:41,160 Speaker 2: Yeah, and more recently we have phylogenetic evidence that has 486 00:29:41,160 --> 00:29:44,160 Speaker 2: been presented to back up the hermit to king hypothesis. 487 00:29:44,720 --> 00:29:48,200 Speaker 2: But you know, I think outside of dedicated crab experts, 488 00:29:48,440 --> 00:29:50,760 Speaker 2: we also have to throw in that the mere title 489 00:29:50,800 --> 00:29:53,440 Speaker 2: of the hypothesis is instantly attractive. You know, it's like 490 00:29:53,520 --> 00:29:58,560 Speaker 2: Popper to prints hermit to King. So it's for at least, 491 00:29:58,600 --> 00:30:01,960 Speaker 2: you know, the average consumer of all this information. It's 492 00:30:02,000 --> 00:30:05,640 Speaker 2: hard to shake that that the social implications of this, 493 00:30:05,760 --> 00:30:08,400 Speaker 2: I don't know, it's a you know, it makes it 494 00:30:08,440 --> 00:30:12,000 Speaker 2: a little more fun and engaging too. Again non scientists, 495 00:30:12,320 --> 00:30:13,840 Speaker 2: and maybe to scientists as well. I mean, it's the 496 00:30:13,880 --> 00:30:15,719 Speaker 2: kind of thing you probably can't help their reference, at 497 00:30:15,800 --> 00:30:18,560 Speaker 2: least in the opening matter, for a study or a paper. 498 00:30:19,400 --> 00:30:21,920 Speaker 3: Mm hmm. But it's also just a great thing to 499 00:30:21,920 --> 00:30:23,640 Speaker 3: think about if you're ever going out for a nice 500 00:30:23,680 --> 00:30:24,560 Speaker 3: king crab dinner. 501 00:30:24,720 --> 00:30:25,240 Speaker 2: I mean. 502 00:30:27,000 --> 00:30:29,640 Speaker 3: That this this could well be the descendant of a 503 00:30:30,000 --> 00:30:43,120 Speaker 3: of a hermit crab. So finally, for today's episode, I 504 00:30:43,160 --> 00:30:46,480 Speaker 3: wanted to talk a bit more about the shell economy 505 00:30:46,760 --> 00:30:50,680 Speaker 3: in hermit crabs that do trade in gastropod shells. So, 506 00:30:51,000 --> 00:30:53,560 Speaker 3: of course, last time we talked about the importance of 507 00:30:53,800 --> 00:30:57,280 Speaker 3: exogenous shells for hermit crabs survival and about this this 508 00:30:57,400 --> 00:31:01,840 Speaker 3: weird ordered mass behavior that can urge from hermit crabs 509 00:31:01,880 --> 00:31:06,680 Speaker 3: shell exchanges. So I was reading an interesting article in 510 00:31:07,160 --> 00:31:11,840 Speaker 3: Scientific American by a researcher named Ivan Chase who's a 511 00:31:11,880 --> 00:31:17,160 Speaker 3: professor emeritus at Stonybrook University, called hermit crabs trade up 512 00:31:17,280 --> 00:31:22,400 Speaker 3: by exchanging shells in q so. In this article, Chase 513 00:31:22,480 --> 00:31:27,640 Speaker 3: talks about how hermit crab research has informed thinking about 514 00:31:27,680 --> 00:31:31,600 Speaker 3: the sociology and economics of a concept that we brought 515 00:31:31,680 --> 00:31:35,160 Speaker 3: up specifically when talking about hermit crabs last time, but 516 00:31:35,200 --> 00:31:39,240 Speaker 3: actually is a broader general just dynamic term, and that 517 00:31:39,360 --> 00:31:43,880 Speaker 3: term is a vacancy chain. So Chase's formal definition of 518 00:31:43,880 --> 00:31:48,240 Speaker 3: a vacancy chain goes like this quote an organized method 519 00:31:48,320 --> 00:31:52,880 Speaker 3: of exchanging resources in which every individual benefits by claiming 520 00:31:52,920 --> 00:31:58,200 Speaker 3: a more desirable possession abandoned by another individual. And this 521 00:31:58,240 --> 00:32:02,840 Speaker 3: can be illustrated directly by watching hermit crab behavior. So 522 00:32:03,040 --> 00:32:06,160 Speaker 3: Chase opens the article by telling a story of just 523 00:32:06,160 --> 00:32:10,000 Speaker 3: some observations he personally made in a tide pool on 524 00:32:10,120 --> 00:32:13,600 Speaker 3: Long Island in nineteen eighty six where this was an 525 00:32:13,600 --> 00:32:16,800 Speaker 3: area where there were hermit crabs, and he brought in 526 00:32:16,880 --> 00:32:19,480 Speaker 3: an empty snail shell and just dropped it in the 527 00:32:19,480 --> 00:32:23,000 Speaker 3: tide pool, and he talks about how he waited a 528 00:32:23,040 --> 00:32:26,160 Speaker 3: few minutes, and then finally a little hermit crab comes along. 529 00:32:26,480 --> 00:32:29,160 Speaker 3: It checks out the shell, feels it out with its claws, 530 00:32:29,240 --> 00:32:33,760 Speaker 3: you measures it. It does the full walkthrough, and it decides, yes, 531 00:32:33,840 --> 00:32:36,640 Speaker 3: I want this new shell. So it trades shells, abandons 532 00:32:36,680 --> 00:32:39,680 Speaker 3: its old shell, and walks away with the new one. 533 00:32:39,880 --> 00:32:43,800 Speaker 3: But it doesn't stop there, because another crab eventually comes along, 534 00:32:44,200 --> 00:32:47,040 Speaker 3: checks out the abandoned shell, decides it likes that one 535 00:32:47,080 --> 00:32:50,200 Speaker 3: better than its current shell, walks away with that, and 536 00:32:50,240 --> 00:32:53,240 Speaker 3: then a few minutes later it happens again. Another one 537 00:32:53,280 --> 00:32:55,760 Speaker 3: comes along. This one has a shell that's in really 538 00:32:55,800 --> 00:32:58,720 Speaker 3: bad shape. It's like a shell that is not the 539 00:32:58,760 --> 00:33:01,600 Speaker 3: right size as a whole in it, and it likes 540 00:33:01,640 --> 00:33:05,000 Speaker 3: the abandoned shell better than its very dilapidated current shell 541 00:33:05,440 --> 00:33:09,840 Speaker 3: walks away with the secondary abandoned shell. Now, he never 542 00:33:09,920 --> 00:33:13,120 Speaker 3: mentions if any hermit crab came along to claim the 543 00:33:14,240 --> 00:33:17,239 Speaker 3: shell abandoned by this third animal, But I guess at 544 00:33:17,280 --> 00:33:20,320 Speaker 3: each point it becomes less and less likely because less 545 00:33:20,360 --> 00:33:24,520 Speaker 3: desirable shells are being traded away from And so maybe 546 00:33:24,600 --> 00:33:27,600 Speaker 3: you know, there's not a crab in the general area 547 00:33:27,720 --> 00:33:30,320 Speaker 3: that would prefer a shell that is like very small 548 00:33:30,320 --> 00:33:33,080 Speaker 3: and already has a big hole in it. But multiple 549 00:33:33,120 --> 00:33:36,440 Speaker 3: animals here have gotten a shell that was better than 550 00:33:36,480 --> 00:33:39,640 Speaker 3: the one they started with, and so multiple animals are 551 00:33:39,680 --> 00:33:43,120 Speaker 3: walking away from this series of trades happy. And so 552 00:33:43,240 --> 00:33:47,120 Speaker 3: based on this observation, Chase looked into Chase and other 553 00:33:47,160 --> 00:33:51,240 Speaker 3: colleagues in this area looked into questions like what is 554 00:33:51,280 --> 00:33:54,840 Speaker 3: the average number of trades that occur after a vacancy 555 00:33:54,880 --> 00:33:59,760 Speaker 3: first appears, or what starting conditions lead to more trades 556 00:33:59,840 --> 00:34:03,920 Speaker 3: in the subsequent series, and so forth. So Chase did 557 00:34:03,960 --> 00:34:07,640 Speaker 3: research on a species of hermit crab called Pagurius longic 558 00:34:07,720 --> 00:34:11,840 Speaker 3: carpus aka the long wristed hermit crab, which is native 559 00:34:11,880 --> 00:34:14,440 Speaker 3: to the east coast of North America, and there are 560 00:34:14,480 --> 00:34:19,160 Speaker 3: a few general findings. First of all, crabs usually traded 561 00:34:19,360 --> 00:34:22,799 Speaker 3: up for larger shells, and this should not be surprising 562 00:34:22,960 --> 00:34:25,960 Speaker 3: since part of the reasoning behind shell trading is that 563 00:34:26,040 --> 00:34:29,840 Speaker 3: it allows individual crabs to grow. Crabs grow, of course, 564 00:34:29,880 --> 00:34:32,320 Speaker 3: you know, like other crustaceans, they have to grow through molting, 565 00:34:32,800 --> 00:34:35,080 Speaker 3: but when they get bigger, the shell that they have 566 00:34:35,200 --> 00:34:38,040 Speaker 3: currently doesn't get get any bigger, so they have to 567 00:34:38,120 --> 00:34:41,360 Speaker 3: find a bigger shell to inhabit. And of course there 568 00:34:41,520 --> 00:34:44,200 Speaker 3: could be other reasons for seeking a shell, such as 569 00:34:44,200 --> 00:34:46,960 Speaker 3: maybe getting a shell in a better condition, but one 570 00:34:47,000 --> 00:34:48,719 Speaker 3: of the main ones is you need a bigger one 571 00:34:48,760 --> 00:34:52,719 Speaker 3: as you grow. Next, general observation is that the average 572 00:34:53,239 --> 00:34:56,400 Speaker 3: there was a pretty consistent average number of trades in 573 00:34:56,480 --> 00:35:00,279 Speaker 3: vacancy chains, and it was about two point five if 574 00:35:00,280 --> 00:35:03,400 Speaker 3: it was between two and three, and this could vary 575 00:35:03,400 --> 00:35:07,480 Speaker 3: depending on conditions. For example, vacancy chains that started with 576 00:35:07,600 --> 00:35:11,840 Speaker 3: a larger empty shell were longer than those that started 577 00:35:11,880 --> 00:35:14,879 Speaker 3: with smaller empty shells, so a big empty shell leads 578 00:35:14,920 --> 00:35:18,560 Speaker 3: to more trades overall. And so the really interesting thing 579 00:35:18,760 --> 00:35:22,440 Speaker 3: about a vacancy chain is how even in an environment 580 00:35:22,520 --> 00:35:27,840 Speaker 3: where multiple individuals are competing aggressively for scarce resources, you 581 00:35:27,880 --> 00:35:29,799 Speaker 3: know the number of shells is limited, this is a 582 00:35:29,800 --> 00:35:34,799 Speaker 3: scarce resource. A vacancy chain can mean that everybody in 583 00:35:34,880 --> 00:35:39,279 Speaker 3: the chain wins. It's not a single winner take all competition, 584 00:35:40,200 --> 00:35:44,480 Speaker 3: but one in which many participants all get an upgrade. 585 00:35:45,440 --> 00:35:48,880 Speaker 3: So you could almost view the survival value of the 586 00:35:48,920 --> 00:35:52,239 Speaker 3: empty shell that is placed into the environment at the 587 00:35:52,280 --> 00:35:55,479 Speaker 3: start of the chain, that the value of that shell 588 00:35:55,560 --> 00:36:01,160 Speaker 3: being kind of distributed or averaged across multiple beneficiary because 589 00:36:01,160 --> 00:36:05,000 Speaker 3: it doesn't only help the first taker who directly occupies 590 00:36:05,040 --> 00:36:08,960 Speaker 3: that shell, but indirectly helps all of the subsequent crabs 591 00:36:08,960 --> 00:36:11,160 Speaker 3: in the chain because they all get a better shell 592 00:36:11,239 --> 00:36:15,040 Speaker 3: than they started with. Oh and one thing Chase says 593 00:36:15,040 --> 00:36:18,839 Speaker 3: in this article is that our researchers performed similar experiments 594 00:36:18,880 --> 00:36:21,879 Speaker 3: on Caribbean land hermit crabs, and I think those were 595 00:36:21,920 --> 00:36:23,800 Speaker 3: the that was the species you saw on your trip. 596 00:36:24,280 --> 00:36:26,600 Speaker 2: Yep, yep, that was the one. Again, we did not 597 00:36:26,719 --> 00:36:31,160 Speaker 2: get to directly observe competition for shells or the changing 598 00:36:31,200 --> 00:36:34,239 Speaker 2: out of shells, though obviously this was taking place just 599 00:36:34,840 --> 00:36:37,120 Speaker 2: when we were looking the other way, or you know, 600 00:36:37,120 --> 00:36:38,920 Speaker 2: in parts of the island we aren't went on, or 601 00:36:38,960 --> 00:36:42,600 Speaker 2: you know, underneath the leaves of the various plants and 602 00:36:42,600 --> 00:36:45,720 Speaker 2: so forth. But at one point, my son and another 603 00:36:45,880 --> 00:36:47,640 Speaker 2: child on the island who had a lot of fun 604 00:36:47,760 --> 00:36:51,720 Speaker 2: like watching the crabs and running around, they did find 605 00:36:51,840 --> 00:36:55,839 Speaker 2: a hermit crab that was unhoused. That a naked hermit crab, 606 00:36:55,840 --> 00:36:59,320 Speaker 2: if you will. So I suspect this was the result 607 00:36:59,360 --> 00:37:00,560 Speaker 2: of some sort of competition. 608 00:37:01,080 --> 00:37:04,760 Speaker 3: Mm man, feel bad for that crab. 609 00:37:04,800 --> 00:37:06,120 Speaker 2: They did as well. They were like, we got to 610 00:37:06,120 --> 00:37:07,960 Speaker 2: help this guy get a new shell. So I think 611 00:37:08,000 --> 00:37:10,400 Speaker 2: they were like trying to find some from him. But 612 00:37:11,200 --> 00:37:13,360 Speaker 2: you know, in retrospect, it's like, come on, you guys. 613 00:37:13,480 --> 00:37:15,279 Speaker 2: Maybe they were really into it. So maybe they spent 614 00:37:15,360 --> 00:37:19,000 Speaker 2: an hour looking for shells. But hermit crabs do this 615 00:37:19,200 --> 00:37:22,640 Speaker 2: non stop. They are always looking for shells. So you 616 00:37:22,680 --> 00:37:25,600 Speaker 2: can imagine the frustration where the hermit crab is like, really, 617 00:37:26,360 --> 00:37:29,040 Speaker 2: you guys just started doing this. I've done this my 618 00:37:29,080 --> 00:37:32,399 Speaker 2: whole life, trust me, just let me find it. There's 619 00:37:32,480 --> 00:37:35,359 Speaker 2: very little you can do in this situation. I'm not 620 00:37:35,400 --> 00:37:37,080 Speaker 2: going to live in this half a coconut that you 621 00:37:37,239 --> 00:37:37,760 Speaker 2: just provided. 622 00:37:38,640 --> 00:37:40,720 Speaker 3: Oh, it's nice that they offered. 623 00:37:41,120 --> 00:37:43,359 Speaker 2: It's nice that they tried. I like that they were 624 00:37:43,560 --> 00:37:46,879 Speaker 2: gentle with the crabs and looking out for their well being. 625 00:37:47,440 --> 00:37:50,000 Speaker 3: But to come back to the idea of vacancy chains 626 00:37:50,000 --> 00:37:54,440 Speaker 3: as a concept, another thing Chase mentions that's interesting is 627 00:37:54,440 --> 00:37:59,320 Speaker 3: that researchers have observed two different kinds of vacancy chains 628 00:37:59,360 --> 00:38:04,320 Speaker 3: in hermit crab synchronous and asynchronous, and these are about 629 00:38:04,320 --> 00:38:09,960 Speaker 3: the relationship of the trade series to time. Asynchronous chains 630 00:38:10,040 --> 00:38:12,959 Speaker 3: are the kind that I described a minute ago, where 631 00:38:12,960 --> 00:38:15,840 Speaker 3: like you know, he dropped one empty shell and a tidepool. 632 00:38:16,160 --> 00:38:18,600 Speaker 3: One crab came along and found it, made a trade. 633 00:38:18,960 --> 00:38:21,600 Speaker 3: You know, several minutes later, another one comes along makes 634 00:38:21,600 --> 00:38:25,120 Speaker 3: a trade. That is, that is something that occurs with 635 00:38:25,320 --> 00:38:27,920 Speaker 3: like each step in the process having some kind of 636 00:38:28,000 --> 00:38:31,839 Speaker 3: delay in between. Synchronous trades are, on the other hand, 637 00:38:32,200 --> 00:38:34,480 Speaker 3: are the kind more like we talked about in the 638 00:38:34,520 --> 00:38:40,080 Speaker 3: previous episode, where the animals actually organize themselves in a 639 00:38:40,200 --> 00:38:44,560 Speaker 3: line by size while they're still in their original shells 640 00:38:44,600 --> 00:38:48,000 Speaker 3: and anticipating a trade, and then all suddenly trade at 641 00:38:48,040 --> 00:38:53,120 Speaker 3: the same time. The synchronous trades happen really fast and actually. 642 00:38:53,200 --> 00:38:57,760 Speaker 3: Chase describes particular scenarios that can cause these trades to arise. 643 00:38:57,800 --> 00:39:00,439 Speaker 3: I wanted to read briefly from the article with one 644 00:39:00,480 --> 00:39:04,560 Speaker 3: such scenario he describes, so Chase writes, quote. One of 645 00:39:04,560 --> 00:39:08,919 Speaker 3: the strangest examples involves a predatory snail that attacks other 646 00:39:09,080 --> 00:39:14,000 Speaker 3: kinds of snails, including some whose shells hermit crabs particularly like. 647 00:39:14,719 --> 00:39:19,040 Speaker 3: As the predatory snail grasps the prey, snail drills a 648 00:39:19,120 --> 00:39:22,359 Speaker 3: hole in its shell with a rasp like tongue and 649 00:39:22,480 --> 00:39:28,040 Speaker 3: injects digestive enzymes. Nearby hermit crabs gather round following the 650 00:39:28,080 --> 00:39:31,520 Speaker 3: scent of chemicals released by the injured snail. When the 651 00:39:31,560 --> 00:39:35,400 Speaker 3: predatory snail finally pulls its prey from its protective casing, 652 00:39:35,719 --> 00:39:37,800 Speaker 3: a process that can take as long as an hour, 653 00:39:38,280 --> 00:39:42,480 Speaker 3: the nearest crab dives into the now empty shell. In turn, 654 00:39:42,680 --> 00:39:46,440 Speaker 3: another crab immediately snatches the first crab's old shell, and 655 00:39:46,520 --> 00:39:50,160 Speaker 3: so on. Instead of following the careful inspection rituals that 656 00:39:50,160 --> 00:39:52,840 Speaker 3: we observed on Long Island, crabs at the scene of 657 00:39:52,840 --> 00:39:57,040 Speaker 3: a mollusk murder make split second decisions choosing new homes 658 00:39:57,080 --> 00:40:00,839 Speaker 3: based on vision alone. So I thought this was kind 659 00:40:00,840 --> 00:40:03,600 Speaker 3: of interesting that these different conditions can arise, where in 660 00:40:03,640 --> 00:40:07,400 Speaker 3: some cases animals making trades through the vacancy chain have 661 00:40:07,560 --> 00:40:11,480 Speaker 3: plenty of time to examine what the new shell they're 662 00:40:11,520 --> 00:40:14,000 Speaker 3: looking at and make an informed decision about whether they 663 00:40:14,000 --> 00:40:18,040 Speaker 3: want to make the trade. Other times there's like this immediacy, 664 00:40:18,120 --> 00:40:20,640 Speaker 3: like all these crabs are gathered around, and so crabs 665 00:40:20,680 --> 00:40:24,960 Speaker 3: are making rapid exchanges, and I have to wonder if 666 00:40:25,040 --> 00:40:27,759 Speaker 3: in cases like that, they're more likely to make an 667 00:40:27,880 --> 00:40:30,480 Speaker 3: error and exchange for a shell that is actually not 668 00:40:30,640 --> 00:40:32,440 Speaker 3: as good as they think it is at first, or 669 00:40:32,560 --> 00:40:35,120 Speaker 3: maybe is not even as good as the shell they abandoned. 670 00:40:35,560 --> 00:40:37,680 Speaker 2: Yeah, there's kind of a musical chairs aspect of the 671 00:40:37,719 --> 00:40:38,879 Speaker 2: whole scenario, isn't there. 672 00:40:39,280 --> 00:40:41,560 Speaker 3: So the more hurry there is in the market, the 673 00:40:41,640 --> 00:40:44,879 Speaker 3: less information you can get and the less you're able 674 00:40:44,920 --> 00:40:46,600 Speaker 3: to make sure you're making a good decision. 675 00:40:47,680 --> 00:40:49,839 Speaker 2: Yeah, I mean, I guess you see versions of that 676 00:40:49,880 --> 00:40:53,040 Speaker 2: in the human housing market as well. Right, Yeah, when 677 00:40:53,080 --> 00:40:56,239 Speaker 2: competition is really intense, you have people doing things like 678 00:40:56,280 --> 00:40:59,440 Speaker 2: buying houses sight unseen, you know, just getting in there, 679 00:40:59,560 --> 00:41:03,520 Speaker 2: making big cash offers and so forth. So, Yeah, even 680 00:41:03,560 --> 00:41:07,040 Speaker 2: though as we discussed, there are experts who weigh in 681 00:41:07,120 --> 00:41:09,600 Speaker 2: and say, well, you really can't go one to one 682 00:41:09,640 --> 00:41:12,600 Speaker 2: on this. You know, there's a great deal of nuance 683 00:41:13,400 --> 00:41:16,959 Speaker 2: to human housing market as well as the hermit crab 684 00:41:17,000 --> 00:41:19,840 Speaker 2: competition for shells. But we can't help but compare the 685 00:41:19,880 --> 00:41:21,600 Speaker 2: two and it does seem like there are some interesting 686 00:41:21,600 --> 00:41:22,319 Speaker 2: things that line up. 687 00:41:22,600 --> 00:41:25,439 Speaker 3: Oh yeah, yeah, So you wouldn't want to do what 688 00:41:26,080 --> 00:41:29,239 Speaker 3: people sometimes do and just like observe a behavior in 689 00:41:29,360 --> 00:41:32,799 Speaker 3: animals and then say, ah, well there is just that's 690 00:41:32,800 --> 00:41:35,319 Speaker 3: what humans do as well. I mean, like you would 691 00:41:35,360 --> 00:41:38,160 Speaker 3: need evidence that that is actually what humans do as well. 692 00:41:38,600 --> 00:41:42,719 Speaker 3: But vacancy chains have been studied in animals other than 693 00:41:42,760 --> 00:41:47,280 Speaker 3: hermit crabs, and they have absolutely been studied in human domains, 694 00:41:47,320 --> 00:41:50,800 Speaker 3: such as in human residential real estate. So, for example, 695 00:41:50,880 --> 00:41:53,239 Speaker 3: Chase talks about some research in the United States in 696 00:41:53,239 --> 00:41:57,560 Speaker 3: the nineteen sixties that found that each new housing unit 697 00:41:57,760 --> 00:42:01,799 Speaker 3: constructed triggered a vacant and sy chain that allowed not 698 00:42:02,040 --> 00:42:05,520 Speaker 3: just one family to move into the newly constructed unit, 699 00:42:05,840 --> 00:42:09,600 Speaker 3: but allowed multiple families to move into what they considered 700 00:42:09,640 --> 00:42:14,040 Speaker 3: better housing, better apartments, And Chase refers to one study 701 00:42:14,320 --> 00:42:17,840 Speaker 3: that found average chain lengths of two point four and 702 00:42:17,960 --> 00:42:21,960 Speaker 3: another that found averages of three point five, so a 703 00:42:21,960 --> 00:42:25,120 Speaker 3: lot like with the shells, the construction of a desirable 704 00:42:25,160 --> 00:42:29,160 Speaker 3: new place to live may benefit not only the people 705 00:42:29,239 --> 00:42:32,120 Speaker 3: who directly move in there, but also the people who 706 00:42:32,160 --> 00:42:34,839 Speaker 3: choose to move into the living space vacated by the 707 00:42:34,880 --> 00:42:37,680 Speaker 3: first residents, and so on and so on, for an 708 00:42:37,719 --> 00:42:41,160 Speaker 3: average of maybe you know, somewhere between two and four 709 00:42:42,680 --> 00:42:47,240 Speaker 3: resident moves. In fact, the Harvard sociology professor Harrison White, 710 00:42:47,280 --> 00:42:51,280 Speaker 3: who apparently coined the term vacancy chain, found that vacancy 711 00:42:51,360 --> 00:42:55,080 Speaker 3: chains were also created with certain types of job openings, 712 00:42:55,120 --> 00:42:58,480 Speaker 3: such as the retirement of a pastor at a church 713 00:42:58,960 --> 00:43:01,319 Speaker 3: that opens a spot a new pastor to move in, 714 00:43:01,600 --> 00:43:03,920 Speaker 3: and then somebody and then a pastor moves into that 715 00:43:03,960 --> 00:43:06,439 Speaker 3: position vacated by the person who made the first move, 716 00:43:06,520 --> 00:43:10,200 Speaker 3: and so on. And this was studied across multiple professions 717 00:43:10,239 --> 00:43:14,160 Speaker 3: and fields, including everything from sports coaches to drug dealers, 718 00:43:14,800 --> 00:43:17,920 Speaker 3: and researching the subfield has generally found that when a 719 00:43:18,000 --> 00:43:22,439 Speaker 3: vacancy opens somewhere between two point five and three point five, 720 00:43:22,520 --> 00:43:25,319 Speaker 3: people are able to move into better paying or more 721 00:43:25,360 --> 00:43:29,239 Speaker 3: desirable positions through the operation of a vacancy chain and 722 00:43:29,360 --> 00:43:33,160 Speaker 3: chase speculates that this phenomenon probably applies to certain types 723 00:43:33,160 --> 00:43:36,560 Speaker 3: of consumer goods as well, in addition to housing and 724 00:43:36,680 --> 00:43:40,680 Speaker 3: job openings. One example, though there's not great research on 725 00:43:40,719 --> 00:43:43,160 Speaker 3: this to back this up, but one example might be 726 00:43:43,280 --> 00:43:47,480 Speaker 3: like cars. This would probably only apply to consumer goods 727 00:43:47,480 --> 00:43:51,279 Speaker 3: where there's like a robust market for used options, but 728 00:43:51,440 --> 00:43:53,320 Speaker 3: again this has not been formally studied. 729 00:43:54,239 --> 00:43:57,440 Speaker 2: This does remind me of various headlines though that came 730 00:43:57,520 --> 00:44:00,480 Speaker 2: up during the pandemic. I believe about the value certain 731 00:44:00,600 --> 00:44:04,440 Speaker 2: used cars and how there was intense competition for them. However, 732 00:44:04,680 --> 00:44:07,200 Speaker 2: I don't really retain like car news all that well, 733 00:44:07,640 --> 00:44:10,839 Speaker 2: so maybe listeners out there remember these stories as well, 734 00:44:10,880 --> 00:44:14,919 Speaker 2: something about the value for an intense competition for used 735 00:44:14,920 --> 00:44:18,080 Speaker 2: cars in particular models. They might have something some way 736 00:44:18,120 --> 00:44:20,000 Speaker 2: line up. It might line up with what we're talking 737 00:44:20,000 --> 00:44:20,520 Speaker 2: about here. 738 00:44:21,239 --> 00:44:22,920 Speaker 3: Yeah, well, so maybe we can come back to that 739 00:44:22,960 --> 00:44:25,080 Speaker 3: in a minute. When because I was thinking about like, 740 00:44:25,560 --> 00:44:29,160 Speaker 3: what are the qualities of resources that do lead to 741 00:44:29,160 --> 00:44:32,440 Speaker 3: these vacancy chains versus resources that don't, and Chase actually 742 00:44:32,520 --> 00:44:36,080 Speaker 3: gets into that toward the end of his article. So 743 00:44:36,239 --> 00:44:39,520 Speaker 3: he postes an interesting question like why is it that 744 00:44:39,640 --> 00:44:43,920 Speaker 3: vacancy chains tend to benefit on average about three parties 745 00:44:44,360 --> 00:44:48,160 Speaker 3: in markets as different as hermit crabshells, human apartments, and 746 00:44:48,239 --> 00:44:51,759 Speaker 3: football coaching positions. It's kind of weird that we would 747 00:44:51,800 --> 00:44:54,799 Speaker 3: see this range of roughly two point five to three 748 00:44:54,880 --> 00:45:01,359 Speaker 3: point five beneficiaries across such wildly different domain and Chase 749 00:45:01,400 --> 00:45:04,799 Speaker 3: writes quote My guess is that some as yet undiscovered 750 00:45:04,800 --> 00:45:08,880 Speaker 3: correspondence between the demography of humans and hermit crabs explains 751 00:45:08,920 --> 00:45:11,960 Speaker 3: the effect their birth and death rates, perhaps or the 752 00:45:12,040 --> 00:45:14,960 Speaker 3: rates at which new resource units are produced and used. 753 00:45:15,320 --> 00:45:18,160 Speaker 3: But these are hunches, so we don't really know the answer. 754 00:45:18,719 --> 00:45:22,400 Speaker 3: But one thing we do know is that vacancy chains 755 00:45:22,880 --> 00:45:27,920 Speaker 3: do only seem to occur with certain types of resources, 756 00:45:28,000 --> 00:45:33,440 Speaker 3: resources with particular properties. So there are not vacancy chains 757 00:45:33,480 --> 00:45:38,360 Speaker 3: created by like boxes of breakfast cereal at the grocery store, 758 00:45:38,560 --> 00:45:42,640 Speaker 3: or you know, like cans of artichokes. A vacancy chain 759 00:45:42,760 --> 00:45:46,319 Speaker 3: resource tends to be something that is both scarce and 760 00:45:46,400 --> 00:45:49,600 Speaker 3: highly coveted, so they're very important to the consumer and 761 00:45:49,680 --> 00:45:53,279 Speaker 3: they're hard to get. They tend to be resources that 762 00:45:53,400 --> 00:45:57,240 Speaker 3: can be possessed by only one competitive unit at a time, 763 00:45:57,719 --> 00:46:00,160 Speaker 3: though this unit could be a group such as like 764 00:46:00,239 --> 00:46:03,000 Speaker 3: a family that occupies a house, but the group has 765 00:46:03,040 --> 00:46:06,800 Speaker 3: to function as like a single unit competing for the resource, 766 00:46:07,480 --> 00:46:10,800 Speaker 3: and the resource cannot be claimed unless it is empty 767 00:46:10,960 --> 00:46:14,680 Speaker 3: or vacated by the previous owner. And these principles are 768 00:46:14,719 --> 00:46:18,640 Speaker 3: generally true of the human resources studied, such as housing 769 00:46:18,760 --> 00:46:21,760 Speaker 3: and jobs, but they're also true of hermit crab shells. 770 00:46:22,280 --> 00:46:25,439 Speaker 3: But this makes vacancy chains kind of interesting because they 771 00:46:25,560 --> 00:46:29,640 Speaker 3: are a circumstance that arises in a market that seems 772 00:46:29,680 --> 00:46:32,680 Speaker 3: to be based on the type of resource being competed 773 00:46:32,719 --> 00:46:36,360 Speaker 3: for rather than any characteristics of the competitors. And in 774 00:46:36,400 --> 00:46:39,480 Speaker 3: the end, Chase raises the question of whether experiments in 775 00:46:39,520 --> 00:46:42,759 Speaker 3: hermit crabs could maybe help us create better economic and 776 00:46:42,840 --> 00:46:47,160 Speaker 3: sociological models that would be predictive in certain human economies. 777 00:46:47,600 --> 00:46:50,880 Speaker 3: Interesting question, but then again there's always the danger with that. 778 00:46:50,960 --> 00:46:53,440 Speaker 3: You don't want to think, Aha, I've discovered a principle 779 00:46:53,480 --> 00:46:57,120 Speaker 3: in hermit crabs, Therefore I can just apply it to humans. 780 00:46:57,280 --> 00:46:59,839 Speaker 3: You would need good, independent evidence that it actually does 781 00:47:00,000 --> 00:47:00,920 Speaker 3: apply to humans. 782 00:47:01,200 --> 00:47:03,680 Speaker 2: Yeah, you couldn't just like, all right, I want to 783 00:47:03,719 --> 00:47:06,400 Speaker 2: game my position in the company, so I'm going to 784 00:47:06,440 --> 00:47:08,400 Speaker 2: buy a bunch of hermit crabs. I'm gonna label their 785 00:47:08,480 --> 00:47:11,600 Speaker 2: shells with the names of all of my coworkers, my bosses, 786 00:47:12,040 --> 00:47:14,560 Speaker 2: my competitors, and then I'm just gonna do what the 787 00:47:14,560 --> 00:47:18,560 Speaker 2: hermit crabs do. Not a good idea, right, So, yes. 788 00:47:19,120 --> 00:47:21,200 Speaker 3: You do not want to fall into the trap of 789 00:47:21,320 --> 00:47:24,440 Speaker 3: I have observed hermit crabs, therefore I understand humans. But 790 00:47:24,560 --> 00:47:27,200 Speaker 3: I do think it's very interesting that you have these 791 00:47:27,200 --> 00:47:30,120 Speaker 3: similar principles that appear to be in operation in these 792 00:47:30,160 --> 00:47:32,400 Speaker 3: hermit crab economies and human economies. 793 00:47:33,680 --> 00:47:38,439 Speaker 2: Yeah. Absolutely, you know, this does not bear a lot 794 00:47:38,440 --> 00:47:42,680 Speaker 2: of discussion. But as one final tangent for this episode, 795 00:47:42,800 --> 00:47:45,839 Speaker 2: I want to point out that in twenty fifteen, apparently 796 00:47:46,360 --> 00:47:52,399 Speaker 2: some UFO ologists looked at some NASA Mars Curiosity rover 797 00:47:52,440 --> 00:47:58,640 Speaker 2: footage and in the lower guy, yeah lo fi visual 798 00:47:58,680 --> 00:48:02,040 Speaker 2: information that was collected, they spotted a hermit crab on 799 00:48:02,080 --> 00:48:05,319 Speaker 2: the surface of Mars m Yeah. Also, I think a 800 00:48:05,360 --> 00:48:12,120 Speaker 2: scorpion and maybe a humanoid being. Alf was Alf there possibly, Yeah, 801 00:48:12,160 --> 00:48:15,160 Speaker 2: I think we have to assume it was Alf. Alf 802 00:48:15,280 --> 00:48:19,719 Speaker 2: hermit crab and a scorpion. You know, obviously you can 803 00:48:19,800 --> 00:48:21,920 Speaker 2: go back to our episodes that we did in the 804 00:48:22,120 --> 00:48:25,880 Speaker 2: last several months talking about this very situation. What happens 805 00:48:25,920 --> 00:48:31,560 Speaker 2: when you have low detail, low quality information and you 806 00:48:31,640 --> 00:48:38,279 Speaker 2: really want to see humans or humanoids, aliens and so forth. Well, 807 00:48:38,360 --> 00:48:42,040 Speaker 2: this is exactly what happens. You spot your Martian hermit crabs. 808 00:48:42,080 --> 00:48:45,160 Speaker 3: Hold on, I'm trying to find the image. Oh okay, 809 00:48:45,160 --> 00:48:47,840 Speaker 3: here it is. I've seen something on the Daily Express. 810 00:48:48,040 --> 00:48:50,160 Speaker 3: Ye oh, you know what. I give it to them, 811 00:48:50,200 --> 00:48:52,560 Speaker 3: Like that looks more like I'm not saying it is 812 00:48:52,560 --> 00:48:55,200 Speaker 3: a hermit crab. It's not, but that looks more like 813 00:48:55,239 --> 00:48:57,839 Speaker 3: a hermit crab than most of the things people see 814 00:48:57,840 --> 00:49:00,280 Speaker 3: on Mars actually look like the thing they're saying there. 815 00:49:00,880 --> 00:49:02,080 Speaker 2: So you're saying, there's hope. 816 00:49:02,239 --> 00:49:07,000 Speaker 3: I'm saying it. Really it's got It's a nice, nicely 817 00:49:07,080 --> 00:49:10,960 Speaker 3: selected anomalous image. It has a shadows falling on a 818 00:49:11,040 --> 00:49:12,959 Speaker 3: rock in just a certain way so that it does 819 00:49:13,040 --> 00:49:16,040 Speaker 3: look like legs. Kudos to them for digging up this one. 820 00:49:16,800 --> 00:49:20,080 Speaker 2: I want to believe. All Right, we're gonna go ahead 821 00:49:20,120 --> 00:49:23,160 Speaker 2: close out this episode, but you know we're gonna come 822 00:49:23,160 --> 00:49:26,640 Speaker 2: back with a third hermit crab episode. We've got we've 823 00:49:26,680 --> 00:49:30,520 Speaker 2: got some feelers out there, we've got some ideas. We 824 00:49:30,560 --> 00:49:33,640 Speaker 2: think we have enough to dish out apart three. So 825 00:49:34,040 --> 00:49:36,719 Speaker 2: again because again there's so much hermit crab research out there. 826 00:49:37,239 --> 00:49:40,399 Speaker 2: There's so many different species of hermit crabs and they're 827 00:49:40,440 --> 00:49:44,920 Speaker 2: all amazing. So tune in for more crab action on Thursday. 828 00:49:44,960 --> 00:49:47,600 Speaker 2: Because yes, Stuff to Blow your Mind publishes core episodes 829 00:49:47,600 --> 00:49:51,200 Speaker 2: on Tuesdays and Thursdays. Monday is Listen Mail. Wednesday is 830 00:49:51,200 --> 00:49:53,880 Speaker 2: a short form episode often on Monster fact or an 831 00:49:53,960 --> 00:49:57,520 Speaker 2: artifact might be busting out a new content type in 832 00:49:57,560 --> 00:50:00,480 Speaker 2: the future in that space, and then on front we 833 00:50:00,520 --> 00:50:03,279 Speaker 2: set aside most serious concerns to just talk about a 834 00:50:03,320 --> 00:50:08,200 Speaker 2: weird film on Weird House Cinema. Just a reminder to everyone, Hey, 835 00:50:08,239 --> 00:50:10,120 Speaker 2: if you can rate and review the show wherever you 836 00:50:10,200 --> 00:50:12,520 Speaker 2: rate and review podcasts, help us out. Give us a 837 00:50:12,560 --> 00:50:15,400 Speaker 2: nice review. Another thing you can do is if you 838 00:50:15,440 --> 00:50:18,200 Speaker 2: listen to the show on an Apple device using Apple 839 00:50:18,239 --> 00:50:21,200 Speaker 2: Podcasts or whatever. Go in there. 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