Speaker 1: Hello, and welcome to Stuff to Blow Your Mind. I
Speaker 1: am Joe McCormick. Normally on Tuesdays we would have a
Speaker 1: new core episode of the show for you, but our
Speaker 1: team has some stuff going on early this week, so
Speaker 1: today we are bringing you an episode from the vault.
Speaker 1: This is part three of our series on the Hermit
Speaker 1: Crab and it originally aired on January eleventh, twenty twenty four.
Speaker 1: After today's vault, we're going to be back with all
Speaker 1: new stuff for you the rest of this week. So
Speaker 1: I guess that's everything. Let us seize the empty shell.
Speaker 2: Welcome to Stuff to Blow Your Mind, the production of iHeartRadio.
Speaker 3: Hey, welcome to Stuff to Blow Your Mind.
Speaker 1: My name is Robert Lamb and I am Joe McCormick,
Speaker 1: and we are back with part three in our series
Speaker 1: on Hermit Crabs. Now, if you haven't heard the first
Speaker 1: couple of parts of the series, you might want to
Speaker 1: go back and listen to those first, but also if
Speaker 1: you just want to start here, that's fine. I don't
Speaker 1: know if there's any particular order you need to do
Speaker 1: these in. In the previous two episodes, we talked about
Speaker 1: Rob's recent in person observation of terrestrial Caribbean hermit crabs
Speaker 1: in the wild, which sounds fascinating watching them scuttle about
Speaker 1: and do their business. We talked about the way hermit
Speaker 1: crabs fit into the crustacean family tree, how they differ
Speaker 1: from so called true crabs or the brachyura, how they
Speaker 1: evolved to depend on exogynous mobile shelter in the form
Speaker 1: of things like gastropod shells. We talked about how hermit
Speaker 1: crabs forage and compete for shells within a kind of economy,
Speaker 1: and how this leads to an interesting phenomenon called vacancy chains,
Speaker 1: with parallels in the markets for some certain human resources,
Speaker 1: such as housing and certain kinds of jobs. We discussed
Speaker 1: some surprising evolutionary relationships, such as the widely supported idea
Speaker 1: that free living king crabs, yes, even the kind you eat,
Speaker 1: probably evolved from a hermit crab ancestor so the lineage.
Speaker 1: If this hypothesis is right, the lineage evolved once from
Speaker 1: free living crabs to the hermit crab form, where it
Speaker 1: developed a soft wormy abdomen and evolved to depend entirely
Speaker 1: on these externally sourced shells, and then some branches of
Speaker 1: that family evolved once again to abandon the external shells
Speaker 1: and become fully hardened all over, become these free living
Speaker 1: crab like organisms. Again, king crabs are also anomura. They're
Speaker 1: also not so called true crabs. And also we discussed
Speaker 1: some fascinating alternatives to the common relationship between hermit crabs
Speaker 1: and snail shells. The majority of crabs do hermit crabs
Speaker 1: do prefer to live within the shells of gastropods, snails, welks, periwinkles,
Speaker 1: those kind of things. But there are also hermits that
Speaker 1: take up residents within living sea anemones or solitary corals,
Speaker 1: and so we talked about the reasons those relationships could
Speaker 1: be mutually beneficial.
Speaker 3: That's right, And as we discussed too, I mean, there's
Speaker 3: still so much research going on concerning hermit crabs and
Speaker 3: the discovery of new particularly aquatic hermit crab species, and
Speaker 3: just fully understanding terrestrial hermit crabs as well. So you know,
Speaker 3: we're gonna we're not going to be able to touch
Speaker 3: on everything in this trilogy, but we are going to
Speaker 3: finish the trilogy here. We're going to finish our story
Speaker 3: of hermit crabs, and we're going to get into a
Speaker 3: few remaining and perhaps surprising areas of discussion.
Speaker 1: So the first thing I wanted to talk about today
Speaker 1: was that I was quite interested to find some meditations
Speaker 1: on hermit crabs in the writings of the late Stephen J. Gould,
Speaker 1: the American paleontologist and popular science communicator. So, first of all,
Speaker 1: I did find that Gould wrote a good bit on
Speaker 1: the hermits to King's hypod thesis that we talked about
Speaker 1: in the previous episode, where king crabs are thought to
Speaker 1: have probably evolved from hermit crab ancestors.
Speaker 3: Did he have a particular take or was he just
Speaker 3: generally reporting on the back and forth among evolutionary scientists.
Speaker 1: Well, I saw that he wrote on this subject. I
Speaker 1: did not read everything he did right on this subject,
Speaker 1: so I don't know where he landed in the end.
Speaker 3: I'm just going to assume he probably landed where everyone
Speaker 3: else seems to be in the land, and that is well,
Speaker 3: most people agree that this hypothesis has probably corrected. It
Speaker 3: seems to be the scientific consensus.
Speaker 1: That seems likely to me. But beyond that, I found
Speaker 1: a really interesting anecdote about hermit crabs in an essay
Speaker 1: called Nature's Odd couples from Gould's nineteen eighty collection The
Speaker 1: Panda's Thumb. This essay was great because the core observations
Speaker 1: from Gould are fascinating, but it also sent me off
Speaker 1: on a pretty good tangent that I hope you'll enjoy
Speaker 1: about snail's what look like bloody teeth. So Gould opens
Speaker 1: this essay with a quote. He opens by talking about
Speaker 1: a quote from Alexander Pope's poem An Essay on Man
Speaker 1: and a rhyming couplet. It goes like this, from nature's chain,
Speaker 1: whatever link you strike tenth or ten thousandth breaks the
Speaker 1: chain alike, And he kind of starts by appreciating some
Speaker 1: ways in which this quote is both is and is
Speaker 1: not true. So in the sense in which the spirit
Speaker 1: of the quote is true, organisms throughout an ecosystem are
Speaker 1: all connected by various types of relationships. There are energy relationships,
Speaker 1: you know, some organisms eat one another or affect how
Speaker 1: one another can acquire energy. There are information relationships. Sometimes
Speaker 1: organisms learn about something from another one and so forth,
Speaker 1: and these relationships can be both direct and indirect, So
Speaker 1: things that happen to one organism can ripple through the
Speaker 1: whole ecosystem. In surprising ways. On the other hand, it's
Speaker 1: obviously not the case that the chain of nature to
Speaker 1: use Pope's image here, is completely destroyed anytime one link
Speaker 1: is broken Gould rights quote. Ecosystems are not so precariously
Speaker 1: balanced that the extirpation of one species must act like
Speaker 1: the first domino in that colorful metaphor of the Cold War. Indeed,
Speaker 1: it could not be, for extinction is the common fate
Speaker 1: of all species, and they cannot all take their ecosystems
Speaker 1: with them. Species often have as much dependence on each
Speaker 1: other as longfellows ships that pass in the night. And
Speaker 1: to add to this, I would just say it's a
Speaker 1: very safe estimate that more than ninety nine percent of
Speaker 1: species that have ever existed are already extinct. The American
Speaker 1: Museum of Natural History uses the estimate that it's more
Speaker 1: than ninety nine point nine percent of all species that
Speaker 1: ever existed. So obviously it's just not the case that
Speaker 1: a single link is broken and the entire chain is
Speaker 1: necessarily shattered, or life couldn't exist today. Ecosystems in many
Speaker 1: cases survive and adapt that they have to change. They
Speaker 1: adapt to changes in their makeup, but to come back
Speaker 1: On the other hand, it's absolutely true that the extinction
Speaker 1: of one organism in an ecosystem can be absolutely devastating,
Speaker 1: and it can lead to secondary extinctions. And from a
Speaker 1: human perspective, a major danger here is the lack of
Speaker 1: predictability in these kinds of relationships, Like sometimes we can
Speaker 1: predict what these relationships and domino effects would be, but
Speaker 1: sometimes we can't. We don't always know what would happen
Speaker 1: to a whole environment and ecosystem when one species is
Speaker 1: taken out of the equation.
Speaker 3: That's right, and we've talked about that before in terms
Speaker 3: of situations where there is very much an organism we
Speaker 3: would like to remove from the ecosystem or from parts
Speaker 3: of the ecosystem, such as say mosquito or some other paths,
Speaker 3: something that is interfering with human aims and industries. But
Speaker 3: the question always remains, like, well, what else is that
Speaker 3: organism doing, What eats it, what is kept in check
Speaker 3: by it, and so forth, And so there are all
Speaker 3: these spiraling concerns, and you know, it's kind of like that.
Speaker 3: It reminds me of that old thing I think from
Speaker 3: some movie or another about how if you're going to
Speaker 3: rob a bank or something you know. They're like so
Speaker 3: many ways you can mess up, and if you can
Speaker 3: think of like three of them, you're a genius. It
Speaker 3: seems like a similar situation anytime humans want to mess
Speaker 3: with the ecosystem with the introduction or removal of certain species.
Speaker 3: They are the things that you know can occur or
Speaker 3: likely will occur if you change it. But then there
Speaker 3: are all these additional ripple effects that you cannot necessarily predict.
Speaker 1: Right, So it's not the case that breaking one link
Speaker 1: in the chain necessarily shatters the whole chain, but it
Speaker 1: does change the chain, and you might not like the
Speaker 1: way it changes. Yeah, So we don't always know what's
Speaker 1: going to happen when one species is taken out of
Speaker 1: the equation, and in fact, we can assume the organisms
Speaker 1: in question don't know either. And what's more than that,
Speaker 1: the algorithm of evolution itself, in the metaphorical sense that
Speaker 1: it can know anything, cannot be said to know in
Speaker 1: advance what will result from extinctions, which is why so
Speaker 1: many organisms evolve sort of dangerous precarious relationships. May in
Speaker 1: many cases, organisms evolve unbreakable dependencies on another specific organism.
Speaker 1: For example, a predator that is specialized to eat only
Speaker 1: one type of prey. If that prey organism disappears, the
Speaker 1: predator is doomed. Or a plant that relies on a
Speaker 1: specific animal to help it pollinate and reproduce. One common
Speaker 1: example cited here are yucca plants and yucca moths, which
Speaker 1: both rely on one another in a system known as
Speaker 1: obligate mutualism. You know, yucca plants have to be pollinated
Speaker 1: by yukama and yuka moth larvae grow in the yucca
Speaker 1: plants and grow by eating some, but not all, of
Speaker 1: the yucca seeds. And though with the yucca plant the
Speaker 1: yuca moth the relationship goes both ways, some of these
Speaker 1: relationships don't go both ways. Sometimes they're only one way. Again,
Speaker 1: the predator that can only eat one species for food.
Speaker 1: So while these highly dependent relationships can be helpful specializations
Speaker 1: at a specific time in a specific environment, they're good
Speaker 1: for helping you survive. Now, they're sort of analogous to
Speaker 1: like putting all of your life savings in a single stock.
Speaker 1: You know, like if the company's doing well, that's great
Speaker 1: for you, but if it goes bankrupt, you lose everything.
Speaker 1: And sometimes evolution selects for creatures that do not have
Speaker 1: diverse survival strategies, you know, they're all in on a
Speaker 1: single ecological partner. And this brings us back to Gould's
Speaker 1: essay where he talks about a couple of examples where
Speaker 1: we see what happens to a pair of species that
Speaker 1: either depend on each other or one depends on the
Speaker 1: other in this way the odd couples of the essays
Speaker 1: title what happens to them after a sudden disruption? And
Speaker 1: one of the examples he talks about is a hermit crab.
Speaker 1: So Gould recounts some of his days as a graduate
Speaker 1: student when he was writing his PhD dissertation on the
Speaker 1: land snails of Bermuda. So he was in Bermuda, and
Speaker 1: he says while he was exploring the shores and the
Speaker 1: beaches there, he would quite often come across hermit crabs,
Speaker 1: but not just any hermit crabs, large hermit crabs crammed
Speaker 1: into a shell that was way too small for them.
Speaker 1: He would talk about, like their big claw protruding out
Speaker 1: of the shell. And he says that these tiny shells
Speaker 1: that they were trying to fit into were shells of
Speaker 1: the narrated snail, which he points out includes what he
Speaker 1: calls quote the familiar bleeding tooth.
Speaker 3: That was not.
Speaker 1: Familiar to me. I had no idea what he's talking
Speaker 1: about with the bleed tooth there. I had to look
Speaker 1: that up, and so I'll come back to that in
Speaker 1: a minute.
Speaker 3: I can't wait.
Speaker 1: But on the general subject of the narratid snails, this
Speaker 1: is a fairly lengthy digression, but I had to look
Speaker 1: up this animal because they came up a couple of times.
Speaker 1: We talked about narratids in the first episode of this series,
Speaker 1: and I didn't really know anything about them. So I
Speaker 1: looked them up and I found some interesting backstory. Narratids
Speaker 1: or Nartes are named after a minor sea god from
Speaker 1: Greek mythology who was called Narraties, and it seems that
Speaker 1: the main written source on the narratives myths is the
Speaker 1: second to third century Roman author Alien in his book
Speaker 1: on the Nature of Animals. I think this specific text
Speaker 1: came up in a series we did not too long
Speaker 1: ago on beavers, because Alien is the source of the
Speaker 1: ancient story about how male beavers would bite off their
Speaker 1: own testicles and offer them up to hunters to make
Speaker 1: the hunter stop chasing them. I believe we judge this
Speaker 1: story not true. But Alien has a lot of interesting
Speaker 1: animal facts of that kind. But he also has some
Speaker 1: backstory on the narrated sea snails. So I'm going to
Speaker 1: alternately quote from and summarize Alien's text here. This is
Speaker 1: from the af Skolfield translation of Aliens on the nature
Speaker 1: of animals. He writes, quote, there is in the sea
Speaker 1: a shellfish with a spiral shell, small in size but
Speaker 1: of surpassing beauty. And it is born where the water
Speaker 1: is at it's purest, and upon rocks beneath the sea,
Speaker 1: and on what are called sunken reefs. Its name is Nrites.
Speaker 1: Then this was funny. He goes on to make some
Speaker 1: excuses for why it is okay that he's about to
Speaker 1: tell a couple of stories in the middle of this
Speaker 1: very serious book. He says, it is going to sweeten
Speaker 1: the work.
Speaker 3: So okay, Yeah, like a little bit of a little
Speaker 3: bit of lead sprinkled into your wine, right.
Speaker 1: Exactly, Yeah, the lead sugar. So anyway, there are two
Speaker 1: stories about how this animal came to exist, and in
Speaker 1: both cases the stories trace back to an extremely handsome,
Speaker 1: hyper hunk deity named Nerides, who is the son of
Speaker 1: the sea god Nereus and of the sea goddess Doris,
Speaker 1: the daughter of Okeanos. So in the first story we
Speaker 1: learned that Narides was so overwhelmingly handsome that he became
Speaker 1: the favorite of the goddess Aphrodite, and she fell in
Speaker 1: love with him. And Elien writes quote, and when the
Speaker 1: faded time arrived, at which at the bidding of the
Speaker 1: father of the gods, Aphrodite also had to be enrolled
Speaker 1: among the Olympians. I have heard that she ascended and
Speaker 1: wished to bring her companion and playfellow Benrides. But the
Speaker 1: story goes that he refused, preferring life with his sisters
Speaker 1: and parents to Olympus. And then he was permitted to
Speaker 1: grow wings. This I imagine was a gift from Aphrodite.
Speaker 1: But even this favor he counted as nothing. And so
Speaker 1: the daughter of Zeus was moved to anger and transformed
Speaker 1: his shape into this shell, and if her own accord,
Speaker 1: chose in his place for her attendant and servant, Aros,
Speaker 1: who was also young and beautiful, and to him she
Speaker 1: gave the wings of Narrites.
Speaker 3: Very spiteful, like, very much like, much like her father.
Speaker 1: That that's true. So Narides liked his home in the sea.
Speaker 1: He was not ready to move in with Aphrodite's family
Speaker 1: on the mountain. So, you know, even though she gave
Speaker 1: him wings and everything, he didn't want to budge. So
Speaker 1: she transformed him into a sea snail out of revenge.
Speaker 1: And it's interesting it says specifically that he was transformed
Speaker 1: into the shell. I assume that means the whole animal,
Speaker 1: including the snail. It would be funny if it just
Speaker 1: transformed him into the shell and a snail had to
Speaker 1: live in him.
Speaker 3: But that would very much fit with a lot of
Speaker 3: what we've been talking about with hermikers.
Speaker 1: I guess that's true, And so this story kind of
Speaker 1: matches the general form of these Greco Roman metamorphosis stories.
Speaker 1: You know, somebody offends a god in some way and
Speaker 1: they're transformed into something else. But I was wondering, like
Speaker 1: why a snail in particular. I'm not sure if I'm
Speaker 1: missing something about this story, but I feel like Alien's
Speaker 1: next story has a little bit more of a hint
Speaker 1: about that element, like why he would be transformed into
Speaker 1: a snail. So the next story starts the same Nerides
Speaker 1: was a young, extremely handsome see god, but this time
Speaker 1: instead of becoming the favorite of Aphrodite, he becomes the
Speaker 1: favorite of Poseidon, and he becomes Poseidon's chariotear so, Elian
Speaker 1: writes quote when Poseidon drove his chariot over the waves,
Speaker 1: all other great fishes, as well as dolphins and tritons too,
Speaker 1: sprang up from their deep haunts and gamboled and danced
Speaker 1: around the chariot, only to be left utterly and far
Speaker 1: behind by the speed of his horses. Only the boy
Speaker 1: favorite was his escort close at hand, and before them
Speaker 1: the waves sank to rest, and the sea parted out
Speaker 1: of reverence to Poseidon, for the god willed that his
Speaker 1: beautiful favorite should not only be highly esteemed for other reasons,
Speaker 1: but should also be pre eminent at swimming. But the
Speaker 1: story goes from here that Helios, the sun god, was
Speaker 1: jealous of the speed of Neriodes and transformed him into
Speaker 1: the snail with the spiral shell. And Helian says, commenting
Speaker 1: on the story here, that he doesn't know why Helios
Speaker 1: was angry at Nridies, but guesses that either Poseidon and
Speaker 1: Helios are enemies, or perhaps that Helios was jealous that
Speaker 1: the handsome guy was down in the sea. With Poseidon
Speaker 1: instead of flying among the stars with him.
Speaker 3: Yeah, I mean, really standard god drama right here.
Speaker 1: But exactly. But in this version at least, Nrides is
Speaker 1: known for being fast, right, so he's fast, and then
Speaker 1: he's trans formed into a snail. Something seems more fittingly
Speaker 1: ironic about that punishment.
Speaker 3: Oh yes, yes, you're right.
Speaker 1: Remember Aristotle actually mentions narrities when he's talking about the
Speaker 1: shells that hermit crabs occupy. But anyway, these snails today,
Speaker 1: they are a family of gastropods that are found in
Speaker 1: all types of water. They're found in freshwater, brackish water,
Speaker 1: and salt water. Their diet most of the time consists
Speaker 1: of algae that they eat off of rock surfaces and
Speaker 1: the waters that crawl around on a rock sort of
Speaker 1: scraping up algae and eating it. And they tend to
Speaker 1: be pretty small. They're sort of considered small to medium snails.
Speaker 1: So it is quite pitiable to imagine, as Gould describes,
Speaker 1: a population of hermit crabs where even fairly large individuals
Speaker 1: are trying desperately to cram into these tiny shells. Now,
Speaker 1: the one thing I said it was going to come
Speaker 1: back to was that nearte that Gould mentions by name
Speaker 1: in his essay the so called bleeding tooth, he doesn't
Speaker 1: say anything else about it. So I got curious about
Speaker 1: this as well, and I found a good photo with
Speaker 1: some interpretive text on the website for the Bailey Matthews
Speaker 1: National Shell Museum in Florida, USA. Rob I attached the
Speaker 1: pictures for you to look at here. And first of all,
Speaker 1: I gotta give credit to whoever named this, because they're
Speaker 1: right on the money. It does look like a pair
Speaker 1: of bloody teeth. Absolutely disgusting.
Speaker 3: This is easily the most disgusting shell I've ever seen.
Speaker 3: Usually I'm a big shell fan. Yeah, no matter what
Speaker 3: kind of creature lives inside it, Like show me the
Speaker 3: shell and yeah, it's generally pretty stunning, or even a
Speaker 3: very plain shell is pleasant to behold. This this is gross.
Speaker 3: This looks like misshapen teeth emerging from inflamed and recessed gums.
Speaker 1: It's what like the dentist would scare the children with
Speaker 1: on The Simpsons.
Speaker 3: Yeah, yeah, you'll see brochures with images like this. Yeah,
Speaker 3: your local dentist office makes me kind of want to
Speaker 3: make a fake brochure with images of the shell and
Speaker 3: just sort of slip them in among the other brochures
Speaker 3: next time I go.
Speaker 1: It makes me want to leave this session and go
Speaker 1: like brush and floss right now.
Speaker 3: Yeah, we can take five dental.
Speaker 1: Health anyway, so yeah, you can look these up. The
Speaker 1: bleeding tooth near eight. Anyway, This is on the inside
Speaker 1: of the shell orifice. You can imagine it's kind of
Speaker 1: a spiral and it's got the opening. So if you're
Speaker 1: looking at the opening, the side of the aperture that
Speaker 1: is closest to the central column or axis of the shell,
Speaker 1: that's where the bloody looking teeth are. And the museum
Speaker 1: page says that this is the species Narida pelloranta, and
Speaker 1: it's a snail commonly found on shores throughout the Caribbean
Speaker 1: and Florida. It reaches a maximum of about two inches
Speaker 1: or about fifty millimeters in size, and in an interesting
Speaker 1: parallel to the shell remodeling we saw in some land
Speaker 1: dwelling hermit crabs, the bleeding tooth snail will sometimes dissolve
Speaker 1: the interior surfaces of its own shell to give itself
Speaker 1: more space inside and also to make room for a
Speaker 1: kind of a water tank reserve, to make room to
Speaker 1: retain reserves of water inside the shell, which is apparently
Speaker 1: useful for the snail during low tide.
Speaker 3: Yeah. Yeah, this is essential to what we were talking
Speaker 3: about in the first episode here on hermit crabs, about
Speaker 3: the chemical and physical augmentation of the shells that hermit
Speaker 3: crabs use. And so most of the shells that hermit
Speaker 3: crabs are competing for have been augmented, have been remodeled.
Speaker 1: Yeah, and it's interesting that I think we've uncovered at
Speaker 1: least two different ways now, sort of initially hidden ways
Speaker 1: that you might not know about just by looking at them,
Speaker 1: that some hermit crabs have evolved the same at aptations
Speaker 1: to shell life as the snails that originally made the
Speaker 1: shells they inhabit. So the first example we talked about
Speaker 1: was hermit crabs evolving asymmetrically sized claws, so they can
Speaker 1: use one claw as an operculum, which means an aperture
Speaker 1: covering a door to close a hole, and they use
Speaker 1: that larger claw to close the whole of the shell
Speaker 1: when they retreat inside. And the parallel with the snails
Speaker 1: is that many snails have the same adaptation. It's part
Speaker 1: of their bodies. They often have a hard plate called
Speaker 1: an operculum that closes over the shell aperture when the
Speaker 1: snail goes inside to hide. So like the hermit crabs
Speaker 1: evolutionarily recreated that function with their claws. And now we
Speaker 1: see examples of both snails and later hermit crabs that
Speaker 1: inhabit the same types of snail shells, taking a calcified
Speaker 1: shell of a fixed size and then dissolving some of
Speaker 1: the interior surfaces of that shell to make more room
Speaker 1: or make it better suit their needs.
Speaker 3: Yeah, it's amazing.
Speaker 1: But anyway, so after this whole narratid digression, coming back
Speaker 1: to Gould and his essay, so he says that he
Speaker 1: saw all these hermit crabs in Bermuda trying to survive
Speaker 1: by cramming their big old bodies into the shells of
Speaker 1: narrotied snails which were way too small for them. But
Speaker 1: then he says, one day he came across one of
Speaker 1: these larger hermit crabs with a better fitting shell, a
Speaker 1: much bigger shell. And this was not from a narrotied snail,
Speaker 1: but in this case from a whlk. It was a
Speaker 1: species called Sitarium pica, commonly known as the West Indian
Speaker 1: top shell, and this is a larger variety of sea
Speaker 1: snail which is eating his food in many places throughout
Speaker 1: the Caribbean. But when Gould went in for a better look,
Speaker 1: he realized that the sitarium shell occupied by this hermit
Speaker 1: crab was no ordinary gastropod shell. It was a fossil. Yeah,
Speaker 1: a living crab inside a fossil shell. So Gould writes
Speaker 1: that it seemed the fossil had probably been dislodged by
Speaker 1: the tide from an ancient sand dune where the original
Speaker 1: shell was deposited roughly one hundred and twenty thousand years ago,
Speaker 1: probably deposited there by an ancestral hermit crab. So hermit
Speaker 1: crab takes the shell out of the water up to
Speaker 1: this area, it gets buried in sand, it gets fossilized,
Speaker 1: and then one hundred and twenty thousand years later the
Speaker 1: fossil comes out and a hermit crab claims it.
Speaker 3: That is amazing. I mean, you would hope that he
Speaker 3: would get those specially antique car tags for that shell. Right.
Speaker 1: So Gould continued to study the hermit crabs in the
Speaker 1: following months, and he saw that most of them were
Speaker 1: confined to these cramped narrative shells, but the few lucky
Speaker 1: animals to possess a welk shell always turned out to
Speaker 1: be living in a fossil. So Gould did some library
Speaker 1: research and he disc that he wasn't the first person
Speaker 1: actually to make this observation. He had been beaten to
Speaker 1: it by the Yale taxonomist Addison E. Verel in the
Speaker 1: year nineteen oh seven. So what on earth was going
Speaker 1: on here? Well? Gould found that veryl had had researched
Speaker 1: the same issue, and VERYL had gone back through the
Speaker 1: history of Bermuda to try to find references to these
Speaker 1: welks to see if anybody recorded ever seeing them alive.
Speaker 1: And it turns out that some of the earliest written
Speaker 1: records of the island actually do mention the welks. So
Speaker 1: here to read from Gould. Quote Captain John Smith, for example,
Speaker 1: recorded the fate of one crew member during the Great
Speaker 1: Famine of sixteen fourteen to sixteen fifteen. Quote one amongst
Speaker 1: the rest hid himself in the woods and lived only
Speaker 1: on wilkes and land crabs, fat and lusty many months.
Speaker 1: Is that fat and lusty? Is that describing the whelks
Speaker 1: and the land crabs or just the land crabs or
Speaker 1: the guy who is eating them.
Speaker 3: I think this is the guy eating them. I just
Speaker 3: imagine just laying about, fat and lusty, just stuffed with these.
Speaker 1: Creatures snail and crab for many months.
Speaker 3: Yeah.
Speaker 1: Wreck, that's so bad. Gould goes on to say, quote
Speaker 1: another crew member stated that they made cement for the
Speaker 1: seams of their vessels by mixing lime from burned welk
Speaker 1: shells with turtle oil. Okay, so some of the earliest
Speaker 1: references to these animals are people eating them and grinding
Speaker 1: them up and burning the shells to make cement. And
Speaker 1: then also the last evidence that veryl could find of
Speaker 1: living Satarium welks in Bermuda was quote from kitchen middens
Speaker 1: of British soldiers stationed on Bermuda during the War of
Speaker 1: eighteen twelve. So yum military rations including a lot of
Speaker 1: sea snail here.
Speaker 3: All right, we can definitely see where all this is going.
Speaker 1: Yeah, because apparently no record of them turned up in
Speaker 1: the many years since then. It appears that while these
Speaker 1: sea snails the welks still exist elsewhere, they were locally
Speaker 1: extinct in Bermuda. So Gould observes another one of these
Speaker 1: scenarios kind of like the post apocalyptic movie we talked
Speaker 1: about in the first episode, where in that case it
Speaker 1: was the land hermit crabs fighting over a scarce pool
Speaker 1: of these highly desirable, already remodeled shells because they want
Speaker 1: the remodeled one so much more than an unremodeled one,
Speaker 1: you know, fighting over those rather than spending a lot
Speaker 1: of time actually remodeling new shells, which I think you
Speaker 1: said was mainly the work of much younger crabs.
Speaker 3: Yes, yes, that's my understanding. So, yeah, in this case,
Speaker 3: they would be in a position to where the desired
Speaker 3: shells are no longer around or around and such short
Speaker 3: supply due to human interference that they have but one option, right.
Speaker 1: Right, So the shells they really want, or at least
Speaker 1: once they get larger, the shells they really want, are
Speaker 1: an extremely scarce resource. There are maybe some shells still
Speaker 1: kicking around within the hermit crab economy, though Gold says,
Speaker 1: you know, he never came across those, but he says
Speaker 1: that they're still recycling shells of the previous centuries from
Speaker 1: before these animals were wiped out. And these shells, you know,
Speaker 1: they're strong, but they don't last forever. They get battered
Speaker 1: around by the waves, they get knocked on rocks, they
Speaker 1: get damaged. Over time, stuff happens to them. So that
Speaker 1: supply is going down, and the only options they have
Speaker 1: other than that, which apparently those are already very rare,
Speaker 1: are these quote new shells which are actually fossil shells
Speaker 1: coming down from the fossil dunes like they come out
Speaker 1: of the earth sometimes, or these tiny narrative shells which
Speaker 1: are too small for them. So yeah, it's a kind
Speaker 1: of it's a kind of sad situation there. And he
Speaker 1: actually does make exactly the comparison that we made in
Speaker 1: the previous episode to kind of like a like a
Speaker 1: post apocalyptic Mad Max scenario where it's just this dwindling
Speaker 1: supply of original resources being fought over, and it probably
Speaker 1: means that the you know, the hermit crabs in this
Speaker 1: specific location do not have a bright future ahead. This
Speaker 1: essay is from I don't know, probably the late seventies
Speaker 1: or around nineteen eighty. I don't know exactly what their
Speaker 1: their status is now.
Speaker 3: Yeah, because you know, I imagine the fossilized shells were heavier,
Speaker 3: you know, they were at any rate, they would not
Speaker 3: be ideal, but they are close enough, and they're they're
Speaker 3: all that the crabs can upgrade to in this case.
Speaker 3: So that's that's fascinating. It's also one can't help but
Speaker 3: sort of put a fantastic spin on it and imagine
Speaker 3: the hermit crabs gathering and they they're like, the humans
Speaker 3: have have destroyed our pri shells. We have no choice
Speaker 3: but to retrieve the fossil shells that of course may
Speaker 3: resonate with ourcane powers. Well, that's fascinating. I had no
Speaker 3: idea that we had We had hermit crabs trooping about
Speaker 3: in fossilized shells. That's amazing.
Speaker 1: Oh and by the way, if you get a chance
Speaker 1: to read the Goold essay, the thing about hermit crabs
Speaker 1: is only the first half of it. The second half
Speaker 1: is actually an interesting sort of meta story about science
Speaker 1: because the second half is about another relationship, one that
Speaker 1: is alleged to have existed between the dodo and a
Speaker 1: plant that had an obligate relationship with the dodo, and
Speaker 1: how that allegedly would have affected the plant when the
Speaker 1: dodo was driven to extinction by human activity. But that
Speaker 1: story actually has a PostScript in the essay because it's
Speaker 1: then later research came along to challenge the suggestion that
Speaker 1: it was the extinction of the dodo that affected the
Speaker 1: plant in the story. So overall, it's an interest essay.
Speaker 1: You want to, I guess, find the version with the
Speaker 1: PostScript that hashes out all of the bait and controversy
Speaker 1: about that second story.
Speaker 3: All right, for the last phase of this episode, I
Speaker 3: want to dive a little bit more into mythology concerning
Speaker 3: Hermi krab. So we've discussed crabs in the show before, obviously,
Speaker 3: and we've touched on the times surprising lack of supernatural
Speaker 3: and divine crabs in global traditions. We touched on a
Speaker 3: few examples, the more notable examples in our twenty twenty
Speaker 3: one episode on crabs eating weird Stuff. I can't remember
Speaker 3: what title we went with on that that it might
Speaker 3: be the actual title, but we talked about the various
Speaker 3: things that crabs eat and the curious ways that they
Speaker 3: eat the stuff. You know, they basically like take it apart.
Speaker 3: It's like reverse three D printing with their tiny feelers
Speaker 3: and enough parts. But in that for instance, we also
Speaker 3: mentioned another example. It's not really an example of a
Speaker 3: mythology about a lobster, but the invocation of mythology and
Speaker 3: the naming of in this case, the squat lobster Kiwa hirsuta.
Speaker 3: This is actually a species that I mentioned briefly in
Speaker 3: one of the previous episodes, and it's named after a
Speaker 3: Maori see god. So again not a direct connection to mythology,
Speaker 3: but like an invocation of mythology. But I was wondering
Speaker 3: once more about all this. I was like, okay, are
Speaker 3: there any myths or folk tales involving the hermit crab?
Speaker 3: And once more not. A lot of examples came up,
Speaker 3: and you can, you know, you can probably tease that
Speaker 3: apart different ways, that hermit crabs are just ubiquitous in
Speaker 3: certain areas and therefore not deserving of such treatment, or
Speaker 3: in other areas they're just not known and therefore they're
Speaker 3: not invoked. Or you know, there's plenty of room too
Speaker 3: for things to just become lost. Not everything that that
Speaker 3: indigenous peoples and ancient people's thought and believe have been
Speaker 3: passed down to us. But I did find some interesting
Speaker 3: thoughts about how hermit crabs maybe just maybe fit into
Speaker 3: the Mayan pantheon.
Speaker 1: Oh interesting.
Speaker 3: So of note is a particular God depicted in the
Speaker 3: Mayan Codeses, those folding books written by the pre Columbian
Speaker 3: Maya civilization in Mayan hieroglyphic script that survived colonial destruction,
Speaker 3: and this particular God is often cataloged as God In.
Speaker 3: That is not what worshippers have said God would have
Speaker 3: called this God, but historians and researchers would classify them
Speaker 3: as such. So God In but also known under the
Speaker 3: names Bakab as well as sometimes the name Palutan. Now,
Speaker 3: according to the article Maya Creator Gods by Ka Bassi,
Speaker 3: God In and the Mayan Creator God God, It's Zamna,
Speaker 3: which is also known as God D in this classification system,
Speaker 3: these may be different incarnations of the same God. Furthermore,
Speaker 3: it seems that there were four different incarnations of God in,
Speaker 3: one for each cardinal direction, and these are often referred
Speaker 3: to as not just the Cab but the Bacabs, but
Speaker 3: also they are all the Bacab. Essentially, this is like
Speaker 3: a fourfold God, and so this particular God is associated
Speaker 3: with four directions, four colors, four cosmic pillars, but also
Speaker 3: with the Earth's interior and with its water reserves. Now,
Speaker 3: as Bassie points out, there are various visual depictions of bacab,
Speaker 3: often as a kind of like human with almond shaped eyes,
Speaker 3: sometimes with a water lily headdress, other times a net
Speaker 3: bag headdress. But other times this god is depicted as
Speaker 3: wearing or inhabiting a turtle shell. Sometimes they take on
Speaker 3: avian features. They are also sometimes presented as an old
Speaker 3: man or perhaps an old possum. They also are sometimes
Speaker 3: depicted as quote wearing a spiral shell or emerging from it. Now, Joe,
Speaker 3: I did not include images of this for you here
Speaker 3: in our outlined because these are these are very hieroglyphic
Speaker 3: in nature, and they don't necessarily read easily to the
Speaker 3: untrained eye. But the Bessie does include various examples of
Speaker 3: what they're talking about here now in this paper, the
Speaker 3: researchers has not mentioned crabs or hermit crabs at all.
Speaker 3: But I did run across some musings by doctor Nicholas
Speaker 3: Helmuth on a website that is mayathno zoology dot org.
Speaker 3: This is a This website is a project of the
Speaker 3: biodiversity educational organization f l A ar meso America. He's
Speaker 3: an expert in Mayan iconography out of Guatemala. He discusses
Speaker 3: that there are various representations of God in slash Pahutan
Speaker 3: slash bacabre. There's the turtle shell emergent variant, and then
Speaker 3: there's this version where the God is within a shell.
Speaker 3: Sometimes it's described as a spiral snail shell, other times
Speaker 3: it's described as a conk shell. A conk, will remind you,
Speaker 3: is a variety of c snail, known for its shell
Speaker 3: as well as sometimes for its meat. It's often used
Speaker 3: in a lot of you'll find it in like chowders
Speaker 3: or stews, sometimes fried up as well. So the author
Speaker 3: here points out that while the shell is often glossed
Speaker 3: over by researchers, you know, people will says it's a shell,
Speaker 3: you know, maybe a snail, maybe a conk. I mean,
Speaker 3: we don't know. But he points out that okay, it
Speaker 3: would be It would be nice to know. It would
Speaker 3: be it would be whove our understanding of mind culture
Speaker 3: to specify snailshell or conk shell, both of which would
Speaker 3: have been known to the Mayans. He also stresses that
Speaker 3: certainly the Mayans and the Aztecs alike, we're capable, you know,
Speaker 3: very much of creating imagined combinations of beings. So it's
Speaker 3: it's not one of those situations where there has to
Speaker 3: be this one thing that directly feeds into the idea,
Speaker 3: and then of course there are many other sorts of
Speaker 3: shells to consider. But you know, it's basically it's an
Speaker 3: interesting question coming from an individual here who is, I
Speaker 3: believe you know, on one hand, very interested in myn iconography,
Speaker 3: but also devoted to various projects that involve classifying and
Speaker 3: chronicling the biodiversity of the region. Anyway, he stresses that
Speaker 3: a great deal of additional research needs to be done
Speaker 3: in this area. But he ponders whether the model for
Speaker 3: God in might have been a hermit crab, if not
Speaker 3: for the God entirely, at least for one phase of
Speaker 3: the deity, one of the four aspects.
Speaker 1: Of bakad Ah. That's interesting. So yeah, so like because
Speaker 1: if you see a spiral shell, one that you might
Speaker 1: be to to to assume it is supposed to be
Speaker 1: associated with the animal that creates the shell originally, but
Speaker 1: the shell is equally associated with the animals that inhabit
Speaker 1: it after the original animals are dead.
Speaker 3: Yeah, yeah, so this this got me really excited. But
Speaker 3: then sadly he doesn't have much to say about the idea,
Speaker 3: because basically it was like, well, you know, maybe this
Speaker 3: is something we can look into later. But it was
Speaker 3: just enough to sort of, you know, to inspire me
Speaker 3: a little bit and think, well, yeah, what are the
Speaker 3: possibilities there? And does it mean like that the god
Speaker 3: occupies different housings like the turtle shell and then the
Speaker 3: snail or conk shell. I don't think that's necessarily the case,
Speaker 3: or more likely that like just one phase of the
Speaker 3: entity is perhaps based on a hermit crab. And he
Speaker 3: also points out that like he's like, I can't be
Speaker 3: the only person who has thought of this idea, and
Speaker 3: yet I can't really find any other references to it.
Speaker 3: And I looked around. I couldn't really either. But I
Speaker 3: did find mention of the hermit crab's mythologic significance in
Speaker 3: a paper titled late post Classical Ritual at Santa Rita Corrazol, Belize,
Speaker 3: Understanding the Archaeology of a Maya Capital City. This is
Speaker 3: by Diane Z. Chase and Arlen F. Chase. This is
Speaker 3: published in Research Reports in Belizean Archaeology. So Chase and
Speaker 3: Chase point out that they're basically this paper deals with
Speaker 3: an analysis of depictions of various animals in Mayan iconography.
Speaker 3: They point out that there are several animals that seem
Speaker 3: to represent the underworld and the surface of sort of
Speaker 3: the surface level of our reality, like the borderland between
Speaker 3: the the I guess you could call it the natural
Speaker 3: world or the visual the visual world and the world
Speaker 3: of the unseen, and furthermore that these animals could take
Speaker 3: on supernatural significance as entities that can travel between those
Speaker 3: worlds or travel at the very barrier of those worlds.
Speaker 3: They specify the turtle, and of course we already talked
Speaker 3: about the turtle significance in a Mayan iconography depicting this
Speaker 3: particular deity, but also the cayman, the shark, specifically the
Speaker 3: shark's fin as it breaks the surface of the water.
Speaker 3: Like here's an organism that is literally in both worlds
Speaker 3: at the same time. And they reference the hermit crab,
Speaker 3: so they point out that, Okay, the hermit crab does
Speaker 3: not really live at that boundary point. It's not like
Speaker 3: the fin of the shark where it's poking through or anything.
Speaker 3: It's not like the turtle coming up for air. But
Speaker 3: they do stress that hermit crabs across many species, of course,
Speaker 3: are found both on the shore and underwater. Plus, as
Speaker 3: we've discussed, we know that terrestrial hermit crabs are still
Speaker 3: intrinsically bound to the ocean. Well, I mean, the reproduction
Speaker 3: depends upon it, so they are not one hundred percent terrestrial.
Speaker 3: They are still creatures of the ocean that live upon
Speaker 3: the land. So they reference the creatures as well in
Speaker 3: comparison to various ceremonial urns, the lids of which are
Speaker 3: not merely lids, but represent the surface of the visible
Speaker 3: world or this barrier between our visible world and the
Speaker 3: world of the unseen, which in this case would be
Speaker 3: like the interior of the urn, the interior of this vessel,
Speaker 3: you know, just as the surface of the water, both
Speaker 3: from the standpoint of you know, a surface versus aquatic life,
Speaker 3: as well as just symbolic thinking. Is this barrier point? Ah?
Speaker 1: That is interesting and yeah, and the hermit crab not
Speaker 1: only is an animal that could inhabit a kind of
Speaker 1: boundary environment, but also crosses from inside to outside in
Speaker 1: that way, you know, crosses from the inside of its
Speaker 1: shell to the outside to crawl around.
Speaker 3: Yeah. Yeah, So I'm left trying to imagine the hermit
Speaker 3: crab is kind of a psychopomp, kind of of an
Speaker 3: like a creature that is here to guide you through
Speaker 3: to the underworld. I mean that's I don't think that's
Speaker 3: what the authors were directly getting at here, but still
Speaker 3: this idea of the hermit crab is this kind of
Speaker 3: creature with an innate understanding of the threshold between our
Speaker 3: world and the next. You know, is this creature that
Speaker 3: travels both sides. And like I said, I think I
Speaker 3: referenced in the first episode. You know, I saw the
Speaker 3: terrestrial hermit crabs in Belize, and then when I went
Speaker 3: in Snorkeling, I also saw at least one aquatic hermit
Speaker 3: crab underwater, And so there is kind of a sense
Speaker 3: of like, hey, you're under here too. You guys are
Speaker 3: all over the place. You get around, you know what
Speaker 3: it is to travel between worlds.
Speaker 1: And apparently across time as well. Sometimes living in the
Speaker 1: house forged one hundred thousand years ago.
Speaker 3: Yeah, No, it is interesting to think of all this
Speaker 3: like commared to those other animals are just reference Like,
Speaker 3: you know, the sea turtle, for instance, is very majestic
Speaker 3: to behold in the water. Can imagine this is an
Speaker 3: interdimensional dimensional traveler. Likewise, the cayman and the shark may
Speaker 3: take on even sinister qualities like yeah, of course these
Speaker 3: are creatures that have ventured into the underworld. But the
Speaker 3: hermit crabs, you know, they just seem very busy. They
Speaker 3: seem too busy to really waste much time in instructing
Speaker 3: you about the barrier between worlds.
Speaker 1: Well, Rob, I have greatly enjoyed this exploration of hermit crabs,
Speaker 1: and I feel like we may have to come back
Speaker 1: to them because I know there's a lot of stuff
Speaker 1: we didn't even get to. Yeah.
Speaker 3: Yeah, again, this is a thriving area of scientific research.
Speaker 3: New discoveries are taking place, new papers are coming out
Speaker 3: all the time, So yeah, we might return to the
Speaker 3: world of hermit crabs in the future. We'll definitely return
Speaker 3: to the world of crabs. You know, it ain't the
Speaker 3: holidays unless we're talking about crabs. All right, We're gonna
Speaker 3: go ahead and close it out here. We'd love to
Speaker 3: hear from everyone out there if you have observations concerning
Speaker 3: hermit crabs, if you have insight on any of the
Speaker 3: topic we've discussed in these episodes, write in. We would
Speaker 3: love to hear from you. Just a reminder that Stuff
Speaker 3: to Blow Your Mind is primarily a science podcast, with
Speaker 3: core episodes on Tuesdays and Thursdays. We do listener mail
Speaker 3: on Mondays, we do a short form episode on Wednesdays,
Speaker 3: and on Fridays we set aside most serious concerns to
Speaker 3: just talk about a weird movie on Weird House Cinema.
Speaker 3: Sometimes there are giant crabs involved. We'll also remind you, hey,
Speaker 3: if you haven't rated and reviewed the podcast somewhere that
Speaker 3: allows you to do that, go pop in there, give
Speaker 3: us a nice helping of stars, and let's see if
Speaker 3: you listen to the podcast on an Apple device or
Speaker 3: through Apple Podcasts or what have you. Maybe just pop
Speaker 3: in there and make sure that you're still subscribed and
Speaker 3: that you are in fact receiving downloads.
Speaker 1: Huge thanks as always to our excellent audio producer JJ Posway.
Speaker 1: If you would like to get in touch with us
Speaker 1: with feedback on this episode or any other, to suggest
Speaker 1: a topic for the future, or just to say hi,
Speaker 1: you can email us at contact at stuff to Blow
Speaker 1: your Mind dot com.
Speaker 2: Stuff to Blow Your Mind is production of iHeartRadio. For
Speaker 2: more podcasts from iHeart Radio, visit the iHeartRadio app, Apple podcasts,
Speaker 2: or wherever you're listen to your favorite shows.