WEBVTT - Give ‘Em Shell: The Glorious Hermit Crab, Part 2 0:00:03.040 --> 0:00:06.840 Welcome to Stuff to Blow Your Mind, the production of iHeartRadio. 0:00:12.920 --> 0:00:14.520 Hey you welcome to Stuff to Blow your Mind. 0:00:14.520 --> 0:00:17.319 My name is Robert lamp and I'm Joe McCormick, and 0:00:17.360 --> 0:00:20.079 we are back with part two in our series on 0:00:20.440 --> 0:00:24.480 hermit crabs. Now a rob on a recent vacation, you 0:00:24.600 --> 0:00:27.640 got to oversee the fields of hermit crabs as they 0:00:27.680 --> 0:00:32.159 crawl about doing their busy, busy business, and so you 0:00:32.280 --> 0:00:34.680 got very into the idea of talking about these animals. 0:00:34.720 --> 0:00:38.360 And it turns out there is way more interesting stuff 0:00:38.400 --> 0:00:40.720 to say about hermit crabs than you might think. There's 0:00:40.760 --> 0:00:43.040 a lot of interesting research on them. They kind of 0:00:43.080 --> 0:00:46.879 has implications beyond the hermit crab just as an animal 0:00:46.920 --> 0:00:50.520 in itself, and can even inform us maybe about human 0:00:50.600 --> 0:00:54.800 economics and sociology and strange corners of knowledge like that. 0:00:55.120 --> 0:00:57.240 Yeah, so definitely go back and listen to the previous 0:00:57.280 --> 0:01:01.160 episode if you did not all read, because we'll touch 0:01:01.160 --> 0:01:03.360 on the basics of what hermit crabs are and what 0:01:03.400 --> 0:01:07.679 they are not. For example, they are not considered true crabs, 0:01:08.480 --> 0:01:10.600 but I mean in our hearts they're true crabs, but 0:01:11.360 --> 0:01:12.920 technically speaking, not true crabs. 0:01:12.959 --> 0:01:17.200 There's no moral implication there, it's just a different taxonomic divisions. 0:01:17.240 --> 0:01:22.120 So the so called true crabs are decapod crustaceans ten 0:01:22.200 --> 0:01:28.080 footed crusty animals in the info order Brachyura. These hermit 0:01:28.080 --> 0:01:32.560 crabs belong to a cousin infraorder called Anomura a n 0:01:32.600 --> 0:01:36.639 o m. A Animura, which are not technically true crabs, 0:01:36.680 --> 0:01:40.080 but they are also decapod crustaceans. They also have ten 0:01:40.160 --> 0:01:43.920 legs five pairs of legs, generally five an tennie though 0:01:44.000 --> 0:01:48.120 in the animurans often even though they have five pairs 0:01:48.120 --> 0:01:52.080 of legs, often like the last pair of legs will 0:01:52.160 --> 0:01:54.680 will be diminished or hidden in some ways, so they 0:01:54.680 --> 0:01:57.240 can often look like they have eight legs even though 0:01:57.240 --> 0:01:59.720 they do really have ten. Maybe the last pair is 0:01:59.760 --> 0:02:03.240 kind of tucked in somewhere, and that's certainly the case 0:02:03.280 --> 0:02:06.760 in hermit crabs. Because, of course, the really characteristic thing 0:02:07.280 --> 0:02:10.360 about most of the eight hundred plus species of hermit 0:02:10.400 --> 0:02:16.640 crabs is that they are specially evolved anatomically and behaviorally 0:02:17.120 --> 0:02:22.000 to depend on shelter, most often a type of mobile shelter, 0:02:22.600 --> 0:02:26.120 such as the abandoned shell of another animal, most often 0:02:26.680 --> 0:02:29.880 a gasterpod of some kind, and in the last episode, 0:02:29.919 --> 0:02:33.000 we talked a lot about hermit crabs dependence on in 0:02:33.120 --> 0:02:36.800 fierce competition for these shells that they use as their 0:02:36.880 --> 0:02:37.760 mobile shelters. 0:02:38.880 --> 0:02:42.960 That's right, they have this unique relationship with their environment, 0:02:44.639 --> 0:02:49.080 not only scavenging. Certainly generally with hermit crabs, you have 0:02:49.200 --> 0:02:53.560 the scavenging of old shells, particularly snail molls, skells, that 0:02:53.639 --> 0:02:56.120 sort of thing. And then as we discussed with terrestrial 0:02:56.120 --> 0:02:59.960 hermit crabs, which is a minority of hermit crab species, 0:03:00.840 --> 0:03:05.400 you will see not only the acquisition of these discarded shells, 0:03:05.440 --> 0:03:10.240 but then the alteration of these shells to make something 0:03:10.360 --> 0:03:12.760 that is more in line and more with what the 0:03:12.800 --> 0:03:17.240 crab want wants, and also makes it more economic, like 0:03:17.280 --> 0:03:21.080 from an energy standpoint for the crab. So there are 0:03:21.120 --> 0:03:24.200 all these fabulous ins and outs without even getting to 0:03:24.240 --> 0:03:27.919 the point of like comparing the competition for hermit crab 0:03:27.960 --> 0:03:30.120 shells to say, the human housing market. 0:03:31.480 --> 0:03:33.280 Now, I thought it would be a good place to 0:03:33.320 --> 0:03:37.320 start today to talk about some alternatives to snail shells 0:03:37.400 --> 0:03:41.040 in the hermit crab shelter world. So, as we talked 0:03:41.080 --> 0:03:44.840 about last time, hermit crabs do most often look for 0:03:45.120 --> 0:03:49.720 gastropod shells as their mobile shelters. These shells originally belonged 0:03:49.760 --> 0:03:54.800 to snails, periwinkles, whelks, animals of that sort, and these 0:03:54.880 --> 0:03:59.280 original animals died and left the shells behind for crabs 0:03:59.320 --> 0:04:02.720 to take up and in some cases remodel to their specifications. 0:04:03.040 --> 0:04:05.280 There is, though I don't know if I've ever heard 0:04:05.360 --> 0:04:07.960 this before. I was reading online that there is apparently 0:04:08.160 --> 0:04:11.600 sort of a myth or an urban legend that hermit 0:04:11.640 --> 0:04:14.680 crabs have to kill the snails to take their shells 0:04:14.720 --> 0:04:16.880 from them, and that does not appear to be true. 0:04:16.920 --> 0:04:22.559 Hermit crabs appear to scavin shells from snails that died 0:04:22.720 --> 0:04:26.960 for other reasons. That died either were killed by in 0:04:27.000 --> 0:04:30.520 some cases other snails, predatory other snails, or just died 0:04:30.600 --> 0:04:34.080 for whatever reason. A shell is empty now, and in 0:04:34.120 --> 0:04:36.480 some cases a hermit crab can take it up and 0:04:36.640 --> 0:04:39.520 added into the hermit crab shell economy. 0:04:40.040 --> 0:04:43.560 Yeah, the type competition is not for shells currently occupied 0:04:43.560 --> 0:04:48.400 by snails. The competition among terrestrial hermit crabs is for 0:04:48.480 --> 0:04:50.760 the shells occupied by other hermit crabs. 0:04:51.120 --> 0:04:54.360 So, while across this whole family of animals, snail shells 0:04:54.520 --> 0:04:58.719 are the most popular for a mobile shelter, there are 0:04:58.920 --> 0:05:01.840 some examples of hermit crabs that use other types of 0:05:01.920 --> 0:05:06.120 objects and in some cases even living organisms for shelter. 0:05:06.880 --> 0:05:10.640 So on the less exciting end, some species make their 0:05:10.640 --> 0:05:14.279 homes in plant structures, maybe hollow pieces of bamboo or 0:05:14.320 --> 0:05:18.320 coconut shells, other plant matter like that. But there are 0:05:18.360 --> 0:05:22.800 also these interesting relationships between hermit crabs and for example, 0:05:23.080 --> 0:05:25.560 c anemones. Rob I know you have something in that 0:05:25.760 --> 0:05:27.240 on that you're going to get into in a bit, 0:05:27.880 --> 0:05:32.120 but first I wanted to talk about coral and sponges. 0:05:32.720 --> 0:05:36.200 So there is a paper that was published in Plus 0:05:36.200 --> 0:05:41.400 one in twenty seventeen by Momoko Igawa and Makoto Kato 0:05:42.040 --> 0:05:46.000 called a new species of hermit crab, Diogenes heterops sama 0:05:46.000 --> 0:05:53.200 coola replaces a mutualistic sepunculin in a walking coral symbiosis. Again, 0:05:53.279 --> 0:05:56.159 this was the year twenty seventeen, and shout out I 0:05:56.200 --> 0:05:59.080 came across this finding because of an article in the 0:05:59.120 --> 0:06:02.360 Conversation I found by Sarah Minott, which is a summary 0:06:02.440 --> 0:06:06.960 of this finding. So rob I included some images of 0:06:07.000 --> 0:06:12.080 this hermit crab with its natural with its coral companion. 0:06:12.120 --> 0:06:17.440 Here this is Diogenes heteropsamacola. And I would say it's 0:06:17.480 --> 0:06:20.480 one of the weirder looking ones we've found. It does 0:06:20.520 --> 0:06:22.760 look like a hermit crab in the front, but with 0:06:22.839 --> 0:06:26.200 a huge kind of foot shaped mass of pink bar 0:06:26.360 --> 0:06:30.080 soap hanging off its back. So the hermit crab itself 0:06:30.120 --> 0:06:34.000 is is bright red and white, sort of candy cane 0:06:34.080 --> 0:06:37.719 color scheme, with very tall eye stalks and these long 0:06:38.120 --> 0:06:41.680 featherlike antennas. So this is a marine species of hermit crab. 0:06:43.000 --> 0:06:45.880 And then I've got another picture for you to see here, Rob. 0:06:46.040 --> 0:06:49.159 This is with the crab's abdomen exposed, So this is 0:06:49.240 --> 0:06:52.760 outside of its shelter. The abdomen, while the front is 0:06:52.880 --> 0:06:55.719 very red and white and has a crabby appearance, the 0:06:55.760 --> 0:06:59.520 abdomen looks kind of like a like a grub. It's 0:06:59.560 --> 0:07:04.560 like a train loocent whiteworm. So this paper and plus 0:07:04.600 --> 0:07:08.560 one documents the discovery of a hermit crab species that 0:07:08.680 --> 0:07:12.400 takes up mobile shelter in what are known as solitary 0:07:12.640 --> 0:07:17.520 corals or sometimes walking corals. The species of hermit crab 0:07:17.640 --> 0:07:22.920 was found in southern Japan by scientists affiliated with Kyoto University. Again. 0:07:23.000 --> 0:07:28.320 The new species name is Diogenes heteropsama cola. And it's 0:07:28.360 --> 0:07:31.640 a very tiny crab. It's just a few millimeters in length. 0:07:32.320 --> 0:07:36.000 So you might wonder why select a chunk of living 0:07:36.200 --> 0:07:40.560 coral as shelter instead of the shells favored by the 0:07:40.640 --> 0:07:45.880 vast majority of hermit crabs. Well, apparently, one major advantage 0:07:45.880 --> 0:07:48.960 for the crab is the very fact that the coral 0:07:49.120 --> 0:07:54.040 is living and thus structurally dynamic. So most hermit crabs 0:07:54.080 --> 0:07:58.560 have to engage in this obsessive, ongoing survey of the 0:07:58.600 --> 0:08:01.559 housing market, trading up for bigger shells as they grow, 0:08:01.960 --> 0:08:06.120 which as we know, can involve aggressive competition. This is 0:08:06.160 --> 0:08:10.160 because the size of each gastropod shell is basically fixed. 0:08:10.160 --> 0:08:12.280 I mean, in some cases in some species they might 0:08:12.360 --> 0:08:15.480 do some interior remodeling, but the overall dimensions of the 0:08:15.480 --> 0:08:18.400 shell are not going to change much. This species, when 0:08:18.440 --> 0:08:22.680 it lives inside a wad of living coral, does not 0:08:22.840 --> 0:08:26.360 have this problem. It has found a forever home because 0:08:26.840 --> 0:08:30.840 the cavity occupied in the living coral can actually grow 0:08:31.000 --> 0:08:35.040 along with the crab. Another thing mentioned in this article 0:08:35.160 --> 0:08:39.359 is that coral provides active defenses. Whereas a dead gastropod 0:08:39.400 --> 0:08:42.880 shell is a type of armor, it provides a solid 0:08:42.920 --> 0:08:46.600 barrier against predators. The corals can actually sting. 0:08:47.000 --> 0:08:49.400 That's right. So you have this added level of like 0:08:49.480 --> 0:08:54.560 chemical weapon and like living self repair armor. It's just 0:08:54.760 --> 0:08:59.000 a fabulous upgrade exactly. And apparently it is not only 0:08:59.040 --> 0:09:02.800 the hermit crab that benefits from the symbiotic relationship. The 0:09:02.880 --> 0:09:05.480 coral benefits as well, and that would make this an 0:09:05.559 --> 0:09:09.160 example of the symbiosis we call mutualism. If only the 0:09:09.200 --> 0:09:12.240 crab benefited and the coral was not affected either way, 0:09:12.280 --> 0:09:14.679 it would be what is called commensalism. But this is 0:09:14.760 --> 0:09:19.000 mutualism because they both get a benefit. So what is 0:09:19.040 --> 0:09:20.120 the benefit. 0:09:19.840 --> 0:09:23.079 For the coral. It appears to be that the hermit 0:09:23.160 --> 0:09:27.280 crab gives the coral the benefit of mobility. So the 0:09:27.360 --> 0:09:32.720 coral in question is of the genus Heteropsamia, and this 0:09:32.840 --> 0:09:35.880 is not the kind of coral that forms into large 0:09:36.000 --> 0:09:39.440 structured reefs. So this is a solitary coral, or again 0:09:39.520 --> 0:09:43.920 sometimes called a walking coral. Rabi attached some pictures of 0:09:43.960 --> 0:09:47.400 this coral for you to look at in its normal form, 0:09:47.559 --> 0:09:50.160 just sitting there on the ocean floor. It looks kind 0:09:50.200 --> 0:09:52.959 of like a blob with some you can see the 0:09:53.240 --> 0:09:56.800 polyp cups and the tentacles on top. These corals can 0:09:56.840 --> 0:09:59.719 be found in small masses, usually about two to three 0:09:59.720 --> 0:10:04.600 cent meters in diameter, sitting on flat sandy seafloors, and 0:10:04.760 --> 0:10:08.679 their polyp cups and feeding tentacles are positioned facing up 0:10:08.720 --> 0:10:12.679 into the water. One danger for an organism like this 0:10:13.000 --> 0:10:15.680 is that it has to be positioned correctly in order 0:10:15.760 --> 0:10:19.720 to survive. But the coral mass is not ambulatory. It 0:10:19.720 --> 0:10:23.000 can't walk around, so imagine being sort of a small 0:10:23.200 --> 0:10:26.120 rock with a mouth and I guess kind of finger teeth. 0:10:26.840 --> 0:10:29.760 Alone on the seafloor, it is at risk of either 0:10:29.880 --> 0:10:33.800 being buried by sediment or being knocked over and left 0:10:33.880 --> 0:10:36.760 upside down, both of which could be a death sentence 0:10:36.800 --> 0:10:41.160 for the coral. So Heteropsamia has evolved a relationship with 0:10:41.240 --> 0:10:45.200 another organism, not the hermit crab. This is an organism 0:10:45.280 --> 0:10:49.480 known as a cupunculated worm. This is a small worm 0:10:49.920 --> 0:10:53.280 that lives in a cavity on the underside of the coral, 0:10:53.640 --> 0:10:56.400 and it carries the coral around with it when it 0:10:56.480 --> 0:11:00.800 crawls along the bottom. It seems that in some cases, 0:11:00.840 --> 0:11:04.680 specifically in areas around the Amami Islands, which are islands 0:11:04.720 --> 0:11:08.160 that they're part of Japan but way south of the 0:11:08.200 --> 0:11:11.320 main Japanese islands. In these cases, the hermit crabs have 0:11:11.520 --> 0:11:14.199 taken over the role that was once played by the 0:11:14.240 --> 0:11:19.000 worms in this relationship. So how would this swap occur 0:11:19.160 --> 0:11:22.400 between you know, going from the coral partnering with the 0:11:22.400 --> 0:11:26.120 worm to the coral partnering with the hermit crab, Because 0:11:26.120 --> 0:11:28.760 as you know, a lot of times these tight symbiotic 0:11:28.800 --> 0:11:32.040 relationships are very sort of finely tuned by evolution. Like 0:11:32.120 --> 0:11:36.120 they it would not usually be easy to just swap 0:11:36.200 --> 0:11:39.719 one animal in for another. Well, the author of this 0:11:40.360 --> 0:11:43.000 feature I was reading interviewed the lead author of the paper, 0:11:43.120 --> 0:11:48.200 Momoko Igawa, and she explained that the normal process of 0:11:48.760 --> 0:11:53.800 establishing a relationship between a coral and a supunculate worm 0:11:54.520 --> 0:11:56.880 goes like this. So when the coral is young, it 0:11:56.960 --> 0:12:01.680 begins by attaching itself to a tiny shell and begins 0:12:01.720 --> 0:12:05.760 to grow around the shell as it matures and builds 0:12:05.800 --> 0:12:09.920 its solid base. So the coral lands on a small 0:12:09.920 --> 0:12:14.240 shell that is already inhabited by a worm. So there's 0:12:14.280 --> 0:12:18.440 already a relationship between the worm and the inanimate shell. 0:12:18.920 --> 0:12:22.239 The worm is using the shell for shelter, and then somehow, 0:12:22.720 --> 0:12:24.880 you know from the worm's point of view, the shell 0:12:25.120 --> 0:12:29.120 just suddenly it keeps getting bigger and like it grows 0:12:29.120 --> 0:12:31.120 all around it. And this is the coral taking up 0:12:31.160 --> 0:12:34.000 residence on the shell and growing around it, forming a 0:12:34.040 --> 0:12:37.079 sort of perfect little cavity for the worm to hide in. 0:12:37.720 --> 0:12:41.360 And according to Igawa, it seems likely that a similar 0:12:41.400 --> 0:12:46.320 process led to hermit crabs inhabiting the corals, and in 0:12:46.360 --> 0:12:49.120 the end the benefits that they would trade off are similar. 0:12:49.280 --> 0:12:52.760 So the mobility of the crab protects the coral from 0:12:52.800 --> 0:12:56.080 being buried in sand or stuck upside down, and the 0:12:56.120 --> 0:12:58.560 coral helps protect the crab from predators. 0:12:59.280 --> 0:13:02.600 Yeah, this is fair fascinating. Again, it just kind of 0:13:02.600 --> 0:13:04.840 takes the basic concept of the hermit crab that I 0:13:04.840 --> 0:13:07.840 think most people are familiar with to some degree and 0:13:07.960 --> 0:13:12.760 just takes it into like weird areas. And indeed, I 0:13:12.800 --> 0:13:15.960 have another example here to discuss, and this is where 0:13:16.000 --> 0:13:19.680 we get into into deep sea hermit crabs. And I 0:13:19.720 --> 0:13:22.120 think you know, if you've ever heard us talk about 0:13:22.520 --> 0:13:26.480 deep sea biology before, you know that the things can 0:13:26.480 --> 0:13:30.800 get weird down there. And so I want to talk 0:13:30.840 --> 0:13:36.360 about some of these hermit crabs from the family parapap Gurity. 0:13:36.600 --> 0:13:39.600 By the way, as long as we're talking about names here, 0:13:39.880 --> 0:13:43.240 you know, did we stop me if we already talked 0:13:43.240 --> 0:13:46.680 about this, but did we talk about the family of 0:13:46.720 --> 0:13:52.199 hermit crabs, Diogenidae being named after Diogenies the. 0:13:52.440 --> 0:13:54.200 Oh yeah, Diogenes the cynic. 0:13:54.720 --> 0:13:57.400 Yeah, who of course lived in a tub according to 0:13:57.440 --> 0:13:58.199 the story. 0:13:58.080 --> 0:14:00.760 So right, So yeah, Diogeny the synec. He was an 0:14:00.760 --> 0:14:05.520 ancient Greek philosopher who supposedly would live in i think 0:14:05.559 --> 0:14:08.640 the marketplace of Athens, just in a big ceramic jar. 0:14:10.720 --> 0:14:14.079 And as a cynic philosopher, his big thing was, you know, 0:14:14.120 --> 0:14:17.600 that one should not act against their nature according to 0:14:17.640 --> 0:14:20.600 the expectations of others. So he was he was very 0:14:21.000 --> 0:14:23.640 you know, against society's rules and stuff. 0:14:25.160 --> 0:14:27.160 Yeah, is that, in a way kind of a perfect 0:14:28.400 --> 0:14:31.720 model for us to look to in naming the hermit crabs. 0:14:32.000 --> 0:14:35.960 So anyway, we're talking about deep sea hermit crabs here, 0:14:36.280 --> 0:14:39.480 and in particular one that wears not a deceased mollusk, 0:14:39.720 --> 0:14:42.000 but the living body of a cea. An enemy is 0:14:42.000 --> 0:14:45.600 Mary kay Wixton described for you know aa back in 0:14:45.720 --> 0:14:49.800 twenty fifteen. Young crabs of this of these, this particular 0:14:49.840 --> 0:14:53.720 type start out inhabiting a Pilford shell, you know, typical 0:14:54.160 --> 0:14:56.800 you know, snail shell or what have you. But then 0:14:57.440 --> 0:15:02.800 the cea, anemony of the family hor Methadaae, settles on 0:15:02.840 --> 0:15:08.200 the shell, over grows it, and then ultimately dissolves that 0:15:08.320 --> 0:15:12.560 shell to become the living housing of the crab. And 0:15:13.360 --> 0:15:15.440 as much with the example we were talking about earlier 0:15:15.480 --> 0:15:18.720 with the coral, grows and expands with the hermit crabs. 0:15:18.760 --> 0:15:21.120 So now this is indeed another example of the forever 0:15:21.200 --> 0:15:26.720 home of a bio armor that will grow with the crab. Brilliant. 0:15:26.880 --> 0:15:29.600 Now the enemity gains mobility this way, you know, the 0:15:29.600 --> 0:15:31.720 hermit crab is like, hey, you stick with me, baby, 0:15:31.760 --> 0:15:35.400 I'll show you the world. And so the crab also, 0:15:35.640 --> 0:15:39.040 as with the coral example, gains chemical production from predators, 0:15:39.280 --> 0:15:45.280 specifically protection against octopods and this species. The species in 0:15:45.280 --> 0:15:48.080 this particular rite up is not specified or was perhaps 0:15:48.200 --> 0:15:49.920 not known at the time. I get to think one 0:15:49.960 --> 0:15:53.560 of the exciting things about hermit crabs, particularly marine hermit crabs, 0:15:53.840 --> 0:15:57.440 is we keep discovering new species and we keep making 0:15:57.480 --> 0:16:00.400 new discoveries about how they lift their strange life in 0:16:00.440 --> 0:16:03.920 the ocean, especially the deep ocean. Now, according to a 0:16:04.040 --> 0:16:08.920 twenty twenty study by gusmo at All published in Molecular Phylogenetics. 0:16:09.160 --> 0:16:11.400 There are some cases where these deep water hermit crabs 0:16:11.400 --> 0:16:15.440 simply carry around protective sea anemies on their intact shells, 0:16:16.040 --> 0:16:19.920 and in these cases especially, the crab actually selects and 0:16:20.040 --> 0:16:23.640 places the organisms on its own shell, you know, goes 0:16:23.640 --> 0:16:27.680 out shopping besides which ones it wants and places them there. However, 0:16:28.040 --> 0:16:32.520 the author stresses that quote c aneminies can also mount 0:16:32.520 --> 0:16:38.720 shells unaided triggered by mollusk derived substances in periostrasum of 0:16:38.800 --> 0:16:42.480 the shell. So the exact mutualistic relationship differs depending on 0:16:42.520 --> 0:16:47.160 the species of the hermit crab. But it's pretty amazing 0:16:47.160 --> 0:16:49.080 here the idea that like, in some cases the hermit 0:16:49.120 --> 0:16:52.640 crab is shopping, in other cases it is sought out. 0:16:53.120 --> 0:16:56.120 Oh, I want more detail on exactly what the shopping 0:16:56.200 --> 0:16:58.760 is like. Does the crab like crawl along and sort 0:16:58.800 --> 0:17:02.680 of feel around the anemone, like pick it up and 0:17:02.800 --> 0:17:05.640 put it on there? Like what is the selection process? 0:17:05.800 --> 0:17:05.879 Like? 0:17:06.400 --> 0:17:08.680 Yeah, I mean they're very very choosy as we see, 0:17:08.720 --> 0:17:11.359 even just with their selection of snail shells and whatnot. 0:17:11.680 --> 0:17:13.440 I'm to terrestrial hermit crabs. 0:17:13.600 --> 0:17:16.520 Oh that's true. Yeah, the selection of the gasterpodshell involves 0:17:16.560 --> 0:17:19.040 an awful lot of feeling. Usually, you know, it's not 0:17:19.119 --> 0:17:21.639 just like looking at it. They go and they feel 0:17:21.680 --> 0:17:24.040 all over it. They turn it around, they climb inside 0:17:24.040 --> 0:17:26.080 it and try it out, and sometimes decide they don't 0:17:26.080 --> 0:17:28.520 want it. I mean, that's the whole thing. Like, sometimes 0:17:28.560 --> 0:17:30.560 they do try it out and decay and that's not 0:17:30.680 --> 0:17:32.200 right and they go back to the old one. 0:17:32.560 --> 0:17:34.960 And then sometimes is the case with the shells, and 0:17:35.080 --> 0:17:38.360 might be the case with cnemonies as well, is that 0:17:39.119 --> 0:17:43.720 they are also making choices that their survival depends upon. 0:17:43.840 --> 0:17:46.000 So sometimes they will go with a shell that they 0:17:46.000 --> 0:17:48.400 don't like all that much, or they is not their 0:17:48.400 --> 0:17:50.840 first choice or even their second choice, but they need 0:17:50.880 --> 0:17:54.320 to survive until they can get something better. And so yeah, 0:17:54.320 --> 0:17:56.840 perhaps that's the case here as well. But again, researchers 0:17:56.880 --> 0:18:02.360 are still making fantastic discoveries regarding deep water hermes. For example, 0:18:02.560 --> 0:18:05.320 a twenty twenty two team from the University of Tokyo 0:18:05.440 --> 0:18:10.880 discovered a new species of anemone. This is Stylobatis calcifer, 0:18:11.440 --> 0:18:15.119 named after the fire demon Calcifer from the novel and 0:18:15.240 --> 0:18:19.520 studio Ghibli film. How's moving Castle? This is the one 0:18:19.520 --> 0:18:22.919 that's in the Disney dub is voiced by Billy Crystal. 0:18:23.680 --> 0:18:27.240 Okay, yeah wait, this is the it's like for cooking 0:18:27.280 --> 0:18:30.159 the food, right they like yes, they're cooking bacon and 0:18:30.160 --> 0:18:32.080 eggs and stuff in the pan over this boy. 0:18:32.760 --> 0:18:36.080 Yeah yeah yeah. A very fun character. Great movie. Yeah, 0:18:36.119 --> 0:18:41.959 and inspired inspired the name for the anemone, and it 0:18:42.000 --> 0:18:45.560 lives on the shells of a particular hermit crab species. 0:18:46.040 --> 0:18:49.000 And I included an image of this for you here, Joe. Now, 0:18:49.040 --> 0:18:51.440 there may be some lighting in the image I provided, 0:18:51.480 --> 0:18:55.639 but it still looks beautiful. It's it's like this. It 0:18:55.640 --> 0:18:58.399 does look very fiery. It looks like a creature that 0:18:58.600 --> 0:19:00.959 is composed of within flame. 0:19:01.400 --> 0:19:04.080 Oh yeah, it's beautiful. And I can see why you 0:19:04.160 --> 0:19:06.760 might call it that given the animation style of that 0:19:07.600 --> 0:19:11.320 in House Moving Castle. Like the way the flame just 0:19:11.400 --> 0:19:14.760 kind of bobs and undulate. It's almost like the way 0:19:14.800 --> 0:19:16.840 you might see the I don't know, flesh of a 0:19:16.920 --> 0:19:21.119 jellyfish moving underwater or something. And I can imagine that 0:19:21.160 --> 0:19:25.480 if you see this anemony in motion, it probably looks 0:19:25.480 --> 0:19:26.280 something like that. 0:19:26.720 --> 0:19:28.760 Yeah. Yeah, it's pretty great. If you want to find 0:19:28.840 --> 0:19:31.440 some of these images for yourself. There was a twenty 0:19:31.480 --> 0:19:36.000 twenty two Mongbay article by Liz Kimbro that you can 0:19:36.040 --> 0:19:38.240 look up, and that's one of the sources I was 0:19:38.280 --> 0:19:50.320 looking at for the section of the episode. Now, on 0:19:50.359 --> 0:19:53.000 the subject of deep sea hermit crabs, we should also 0:19:53.040 --> 0:19:57.240 talk about hydrothermal vent environments. We've talked about hydrothermal events 0:19:57.280 --> 0:19:59.120 plenty of times in the show before. These are deep 0:19:59.160 --> 0:20:04.560 sea seabed fissures that release geothermically heated water that can 0:20:04.600 --> 0:20:09.119 result in very biologically active oases in the deep ocean 0:20:09.119 --> 0:20:13.720 that provide home to many different unique species of organism. Now, 0:20:13.720 --> 0:20:17.000 one of the more famous vent dwellers is the Kiwa 0:20:17.119 --> 0:20:21.240 tay lari or Hoff crab, which is actually a squat lobster. 0:20:21.560 --> 0:20:23.199 And this is not a hermit crab, but it is 0:20:23.320 --> 0:20:26.560 kin to hermit crabs. It's not a quote unquote true crab. 0:20:27.240 --> 0:20:30.399 But in two thousand and four, researchers discovered the first 0:20:30.440 --> 0:20:35.280 known hermit crab to recide at a hydrothermal vent. This 0:20:35.320 --> 0:20:42.320 one was dubbed Peraggio pageeras Vento Lattis, and it was 0:20:42.359 --> 0:20:46.480 discovered in the waters off Taiwan, and this was I 0:20:46.560 --> 0:20:49.879 was thinking about this in a paper by raphael LEA. Matre, 0:20:50.640 --> 0:20:53.680 then in a twenty eleven paper by kome At All 0:20:54.680 --> 0:20:58.560 these hermit crabs were found elsewhere on the Nico Seamount. 0:20:58.680 --> 0:21:01.960 This is a submarine volcano in like southern Japanese waters. 0:21:02.560 --> 0:21:05.000 Now I was mentioning some of this to my wife 0:21:05.280 --> 0:21:06.919 as I was researching it, and when I brought up 0:21:06.960 --> 0:21:10.600 the idea of hydrothermal event crabs, her question was where 0:21:10.600 --> 0:21:12.520 do they get their shells? Do they have shells? And 0:21:12.560 --> 0:21:14.440 I hadn't really thought about this, but yeah, it does 0:21:14.480 --> 0:21:19.680 seem that while this species prefers gastropod shells, they would 0:21:19.720 --> 0:21:23.800 prefer to have standard like snail shells. They are indeed 0:21:24.359 --> 0:21:29.679 scarce in these habitats, these hydrothermal vents, so they'll end 0:21:29.760 --> 0:21:32.120 up having to use something else. It's not their first choice, 0:21:32.280 --> 0:21:37.159 but they will use the empty tubes of the syboglintid worm. 0:21:38.200 --> 0:21:40.800 This is like a tube worm, and they will use 0:21:40.880 --> 0:21:45.320 these discarded empty tubes for their shell if they cannot 0:21:45.359 --> 0:21:47.760 get an actual gastropod shell. Ah. 0:21:47.840 --> 0:21:50.840 Yeah, so I had read some unspecified references to hermit 0:21:50.880 --> 0:21:55.320 crabs using worm tubes as mobile shelter, and I wonder 0:21:55.320 --> 0:21:58.400 if it might be talking about this or maybe related 0:21:58.440 --> 0:22:01.359 animals that use other worm tubes as well. 0:22:01.640 --> 0:22:04.080 Yeah, yeah, it's pretty fascinating. I do want to point 0:22:04.080 --> 0:22:07.640 out this is not an obligate hydrothermal vent dweller, though. 0:22:07.680 --> 0:22:10.480 You do have various organisms that have to have that 0:22:10.560 --> 0:22:13.680 hydrothermal vent environment, and it is something that very much 0:22:13.720 --> 0:22:18.280 defines them. These creatures apparently can live beyond the hydrothermal vents, 0:22:18.280 --> 0:22:23.320 but have been observed to reside there. So see anemones, 0:22:23.920 --> 0:22:32.200 coral tubeworm, discarded tubworm tubes. So many different things can 0:22:32.640 --> 0:22:34.440 become housing for a hermit. 0:22:34.160 --> 0:22:38.879 Crab thinking outside the snailshell. Yes, and of course all 0:22:38.920 --> 0:22:42.080 these things we're talking about are things that you would expect. 0:22:42.320 --> 0:22:45.159 They're like an adapted relationship in some way, things you 0:22:45.200 --> 0:22:48.959 would expect to see with some regularity in nature. You 0:22:48.960 --> 0:22:52.400 can find weird, isolated examples of hermit crabs using all 0:22:52.480 --> 0:22:55.600 kinds of stuff as a temporary shelter if they are 0:22:55.640 --> 0:22:56.280 in a jam. 0:22:57.160 --> 0:22:59.960 That's right. We mentioned like the intense competition for shell 0:23:00.400 --> 0:23:05.600 and the cascading events that will occur when a conflict 0:23:05.640 --> 0:23:09.280 between hermit crabs over a shell resolves, and then somebody's 0:23:09.320 --> 0:23:12.960 left out. Usually it's the whichever crab lost in the 0:23:13.000 --> 0:23:17.680 combat now has no shell, and in those cases, again, 0:23:17.720 --> 0:23:20.080 its survival is on the line, so it may use 0:23:20.080 --> 0:23:23.080 something like even like a discarded pop top I saw 0:23:23.160 --> 0:23:26.040 referenced in one article. Doesn't mean it's happy about it, 0:23:26.080 --> 0:23:29.360 but it will use it for the time being. Now 0:23:29.400 --> 0:23:32.560 there's another wrinkled to this whole, you know, not true 0:23:32.560 --> 0:23:39.240 crabs story, because there's another cousin to true crabs, known as, 0:23:39.240 --> 0:23:40.960 of course, the king crab. I think a lot of 0:23:41.040 --> 0:23:43.520 you've heard of the king crab. Sometimes it winds up 0:23:43.520 --> 0:23:46.560 on the menu. Right. There are over one hundred species 0:23:46.560 --> 0:23:49.280 of king crabs, and while we don't know for certain, 0:23:49.560 --> 0:23:54.119 it is widely hypothesized that king crabs derived from hermit 0:23:54.160 --> 0:23:57.840 crab ancestors. This brings us once more to the topic 0:23:58.000 --> 0:24:03.000 of carcinization. This is convergent evolution, in which non crab 0:24:03.080 --> 0:24:07.000 crustaceans evolve crab like bodies, and in this case we're 0:24:07.040 --> 0:24:10.280 specifically dealing with what's referred to as the hermit to 0:24:10.440 --> 0:24:14.800 king hypothesis, which we should stress is not universally accepted, 0:24:15.359 --> 0:24:18.360 but it does seem to be the current scientific consensus, 0:24:19.000 --> 0:24:23.560 though again again not everyone agrees though, but thankfully this 0:24:23.600 --> 0:24:25.920 is not one of those scientific consensus issues that has 0:24:25.920 --> 0:24:28.400 been politicized, though I guess it would be. It would 0:24:28.440 --> 0:24:33.400 be maybe amusing if it were. As Noah and Glenner 0:24:33.520 --> 0:24:36.520 point out in the Origin of King Crabs. This is 0:24:36.560 --> 0:24:42.280 twenty seventeen, published in Zoological Journal of the Lenaean Society. 0:24:42.640 --> 0:24:46.600