Speaker 1: Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2: Hey you welcome to Stuff to Blow your Mind. My
Speaker 2: name is Robert.
Speaker 3: Lamb and my name is Joe McCormick. And we're back
Speaker 3: after the holidays. All right, I guess you've already been back,
Speaker 3: rob I'm back for the first time now.
Speaker 2: Yeah, that's right. I left a little early and then
Speaker 2: and then I came back to you know, scramble together
Speaker 2: a few episodes. But now it's time to return proper
Speaker 2: with a true core episode of Stuff to Blow Your Mind.
Speaker 2: But we're ringing in the new year once more with crabs,
Speaker 2: because of course, crab content is suitable for any holiday,
Speaker 2: and there is an abundance.
Speaker 3: Of it, you know. I don't know if it's just
Speaker 3: the name of Christmas Island that that created this correlation,
Speaker 3: but I think we tend to do crab content in
Speaker 3: the winter. Have you noticed that that's not on purpose,
Speaker 3: at least not on my part.
Speaker 2: No, this is this. I think the Christmas Island crab
Speaker 2: thing kicked it off a bit a while back. That's
Speaker 2: part of it. For sure. There's something maybe holiday centric
Speaker 2: about crabs. It also helps that sometimes my family and
Speaker 2: I travel during the winter break and go somewhere where
Speaker 2: crabs are abundant. And yeah, I'm excited to talk about
Speaker 2: crabs once more because over the holidays, my family and
Speaker 2: I were fortunate enough to once more visit Glover's Reef,
Speaker 2: a partially submerged atoll located off the southern coast of Belize.
Speaker 2: Tremendous fun. We stayed on a small island all week.
Speaker 2: There were other humans, certainly, but we spend as much
Speaker 2: time as possible getting into the water to snorkel to
Speaker 2: check out the fish and the coral. But the predominant
Speaker 2: land organism was, without a doubt, the terrestrial hermit crab.
Speaker 3: So this is a holiday with crabs underfoot.
Speaker 2: Yes, I mean, I don't think anyone ever stepped on one,
Speaker 2: but they were everywhere. Most hermit crab species are aquatic,
Speaker 2: as we'll probably touch on several times during this episode,
Speaker 2: but I'm going to be talking mostly about the terrestrial
Speaker 2: variants like those that I encountered on this island, that
Speaker 2: still depend on the ocean for reproduction, but which live
Speaker 2: most of their lives on land, and that comes with
Speaker 2: various complications and innovations. And also they're very visible, you know,
Speaker 2: you don't need a snorkel, you don't need a dive
Speaker 2: suit to engage with the world of the hermit crab,
Speaker 2: because on places like this they are everywhere and they
Speaker 2: are widespread. You don't also don't have to go to
Speaker 2: Belize to encounter hermit crabs, terrustrial hermit crabs, even they
Speaker 2: are out there.
Speaker 3: So roughly, how big were or how big was the
Speaker 3: range of the ones you were seeing? Is are we
Speaker 3: talking like silver dollar size or hand size? Like what
Speaker 3: are we dealing with here?
Speaker 2: Yeah? The size differential is one of the things that
Speaker 2: makes hermit crab watching in the wild so fun because
Speaker 2: you never know exactly what size you're going to encounter.
Speaker 2: Like some of the very small ones, you know, oh
Speaker 2: so cute, it's the size of a or something. You know,
Speaker 2: it's very small. But other times it'll be like, I'm
Speaker 2: probably exaggerating to save the size of a catcher's met
Speaker 2: but at least the size of a very large fist,
Speaker 2: you know, just a big chonker of a hermit crab.
Speaker 2: And as you're going as we were going about on
Speaker 2: the little pathways on the island, you know, they would
Speaker 2: be moving around pretty much all the time. That they're
Speaker 2: very busy. They're constantly trooping about, they're scavenging, they're competing
Speaker 2: for shells. Though I don't think we ever directly observe this,
Speaker 2: but clearly it is happening. And if you come across
Speaker 2: one while it's say, crossing the sandy path, they'll suddenly stop,
Speaker 2: and then if you get a little bit closer, they'll
Speaker 2: retreat into their shells, and as they do that, that'll
Speaker 2: cause them to roll over onto their back, and then
Speaker 2: of course they cap the shell opening with their larger
Speaker 2: claw and then give them enough time and then get
Speaker 2: back up and they continue on with their business. So, yeah,
Speaker 2: there's just something magical about hermit crabs, at least to
Speaker 2: someone like me who doesn't get to observe them all
Speaker 2: the time. But but even the team on the island here,
Speaker 2: they seem to find a certain amount of joy in
Speaker 2: the creatures, despite how accustomed they were to their presence.
Speaker 2: I heard that one of the cooks brought some shells
Speaker 2: for the crabs with her from the mainland, with the
Speaker 2: names of each of her children written on them, and
Speaker 2: then and then would enjoy like running into various crabs
Speaker 2: who would claim these shells and make them their homes.
Speaker 3: Oh, that's funny. It's like when people write funny things
Speaker 3: on a dollar, you know, it's like, are you expecting
Speaker 3: to encounter this again?
Speaker 2: Yeah? Yeah, And yeah. There's just something they're like little
Speaker 2: like biomachines, you know. There's just something about how industrious
Speaker 2: and relentless they are as they scavenge the terrain. For instance,
Speaker 2: at this place that we were staying, this a place
Speaker 2: called Off the Wall. The communal dining area at the
Speaker 2: place has a sand floor, and Jim and Kindred, who
Speaker 2: run the place, told us that first thing in the morning,
Speaker 2: when you go in there, the sand is completely devoid
Speaker 2: of human footprints because during the night the crabs have come,
Speaker 2: the hermit crabs have come, and so in the morning
Speaker 2: they are only crab tracks, and not even the slightest
Speaker 2: crom left behind because they have come and claimed everything.
Speaker 3: Crab wipe.
Speaker 2: Yeah, so I love it. After experiencing all that, I
Speaker 2: was like, well, we've got to find some more things
Speaker 2: to talk about with hermit crabs. We've talked about them before,
Speaker 2: but now we're going to go in a little more depth.
Speaker 3: Well, it turns out I think hermit crabs are very
Speaker 3: interesting and there is a lot we can talk about,
Speaker 3: so I guess we will start with the basics. What
Speaker 3: are hermit crabs are hermit crabs crabs? The answer is
Speaker 3: sort of. Hermit crabs are decapod crustaceans that means decapod.
Speaker 3: They're ten legged invertebrates with a hard exoskeleton that grow
Speaker 3: by molting, so they shed their old exoskeleton and emerge soft,
Speaker 3: and then a new exoskeleton hardens when they need to
Speaker 3: get bigger when they grow bigger, but they are considered
Speaker 3: distinct from what are called true crab. True crabs belong
Speaker 3: to the infraorder Brachyuria. Hermit crabs belong to the related
Speaker 3: info order animura a n O m U r A.
Speaker 3: They're close cousins to true crabs, but different. Other animurans
Speaker 3: or false crabs include the Lithodoidea or the king crabs,
Speaker 3: and the Porcelainidae, which are the porcelain crabs. And one
Speaker 3: thing animurins generally have in common is that okay, so
Speaker 3: these decapods all have five pairs of legs ten legs total,
Speaker 3: and in the animurans, the last pair of legs farthest
Speaker 3: away from the head is fund sized, so these animals
Speaker 3: are still decapods, but a lot of them look like
Speaker 3: they have only eight legs instead of ten, or maybe
Speaker 3: six legs and two claws. Those front front legs, the
Speaker 3: chelli or the claws are legs, but in crabs they're
Speaker 3: often claw shaped, but they look like they have only
Speaker 3: eight legs instead of ten because the hindmost pair is
Speaker 3: tiny and often hidden or tucked away under another body part.
Speaker 2: Yeah, and we'll get back to this particular detail later
Speaker 2: on in our discussion. If not this episode, then perhaps
Speaker 2: a second episode.
Speaker 3: So animurans have tin legs a lot of times it
Speaker 3: looks like they only have eight. Hermit Crabs belong in
Speaker 3: the taxonomic superfamily Pagurroidea, and with a few exceptions, they
Speaker 3: are mostly notable for exactly what you're thinking of their
Speaker 3: dependence on externally scavenged material for armor and shelter. Usually
Speaker 3: this armor is a shell that once belonged to a gastropod,
Speaker 3: such as a snail, a periwinkle, or a whelk. Though
Speaker 3: there are some animals in the family that don't need
Speaker 3: scaven shelter at all. We can talk about those in
Speaker 3: a minute, and there are a few that rely on
Speaker 3: things other than mollusk shells. One example cited in a
Speaker 3: paper that I'll get to in a minute is the
Speaker 3: discorso Pagurus schmitty, which takes a shelter not in a
Speaker 3: gastropod shell, but in empty polyheat worm tubes. The hermit
Speaker 3: crabs that do rely on external mollusk shells have bodies
Speaker 3: that are actually shaped by this need. So while true
Speaker 3: crabs have hard exoskeletons covering their entire bodies, hermit crabs
Speaker 3: have what you might call non calcified abdomens. So the
Speaker 3: front facing part of a hermit crab's body the head,
Speaker 3: the thorax, and the front pairs of legs and claws.
Speaker 3: These all have hard exoskeletal coating like any other crab.
Speaker 3: But the back part of the hermit crab, the abdomen,
Speaker 3: and what you might call the tail or the telson,
Speaker 3: this doesn't really resemble a crab body at all in
Speaker 3: a lot of species. It looks kind of like a
Speaker 3: curly fat worm, and it does not have a hard exoskeleton.
Speaker 3: The abdomen is flexible, soft and vulnerable. It is covered
Speaker 3: in an external coating, but it's just very thin and soft.
Speaker 3: It's very uncrab. This is the part of a hermit
Speaker 3: crab that curls up inside the externally sourced shell.
Speaker 2: Yeah, so if you're just encountering hermit crabs out in
Speaker 2: the wild, or even seeing them in an enclosure somewhere,
Speaker 2: you're probably not going to see this part of the
Speaker 2: organism with its abdomen inside the shell. As we've been discussing,
Speaker 2: it actually walks on its second or in third pairs
Speaker 2: of legs. The first pairs are modified to form pinchers,
Speaker 2: and its fourth and fifth pairs of legs are small
Speaker 2: and specialized to grip the inside of the shell. It
Speaker 2: also has appendages called europods at the end of its
Speaker 2: abdomen to aid and securing that shell. So, you know,
Speaker 2: all these things aiding to sort of grip and hold
Speaker 2: on to that shell that it has taken on as
Speaker 2: its shelter. The larger left europod hooks the central post
Speaker 2: of a shell, and they can also use this europod
Speaker 2: to hold on to other things when they are out
Speaker 2: of the shell. I've read about how they can attach to,
Speaker 2: say like a tree or something, and it can also
Speaker 2: use it to maintain balance.
Speaker 3: Yeah, so I think it's interesting that the hermit crab
Speaker 3: is an animal. Its body is shaped in a for
Speaker 3: double purpose. So the front end of it is shaped
Speaker 3: for facing the external world. It has the chelli, it
Speaker 3: has the claws like many other crabs you would think of,
Speaker 3: but the back end of it is shaped entirely for
Speaker 3: holding on to this piece of mobile shelter. And the
Speaker 3: concept of mobile shelter, while not completely unique, is pretty
Speaker 3: unique and what makes the hermit crab interesting to read
Speaker 3: a quote from a highly cited paper on hermit crabs
Speaker 3: that I was looking at by a biologist named Brian Hazlet.
Speaker 3: The paper is called the Behavioral Ecology of Hermit Crabs.
Speaker 3: Hazlet writes, quote, many animals utilize exogenous shelters, but almost
Speaker 3: all eight hundred species of hermit crabs are mobile while sheltered.
Speaker 3: The combination of mobility and protection afforded by this lifestyle
Speaker 3: must contribute to the large numbers of these crustaceans found
Speaker 3: in virtually all marine environments as well as in tropical
Speaker 3: terrestrial shores. So Hazlt is sort of saying the hermit
Speaker 3: crab plan is a successful plan, clearly shown by the
Speaker 3: diversity of these species found all around the world. That
Speaker 3: This is a plan that works because sourcing shelter from
Speaker 3: outside the body that you can take with you when
Speaker 3: you move works really well. But it also comes with costs,
Speaker 3: and we'll talk about those costs as we go on.
Speaker 3: One thing I think to understand is that in general,
Speaker 3: while a hermit crab can leave its externally acquired shell
Speaker 3: and it can survive for some time outside of its
Speaker 3: external shell, the acquisition of a shell for external armor
Speaker 3: is not optional for a hermit crab a nice to have.
Speaker 3: It is essential for survival in the wild, and the
Speaker 3: hermit crab's evolution has been shaped by the need for
Speaker 3: these externally sourced shells.
Speaker 2: Yeah. Yeah, this is not just somewhere it goes to
Speaker 2: sleep at night like. It has to have this with it.
Speaker 2: And if it does not have the shell, then it
Speaker 2: is highly vulnerable to predation exposure. It very well likely
Speaker 2: will not survive without it.
Speaker 3: Right, So I want to turn to a paper I
Speaker 3: was reading for a general overview of hermit crabs and
Speaker 3: related species. This was an overview published in the journal
Speaker 3: Current Biology called hermit Crabs by Mark Briefa and Sophie L.
Speaker 3: Moles in two thousand and eight, and they're going to
Speaker 3: paint the picture here of the kind of hermit crab
Speaker 3: family tree. So there are currently more than eight hundred
Speaker 3: known species of hermit crabs. Most of these species live
Speaker 3: in the ocean their marine, with a few exceptions. One
Speaker 3: is a species called Clibinari fontic cola, and this is
Speaker 3: the only known freshwater hermit crab which lives in Vanuatu,
Speaker 3: that's a volcanic archipelago in the Pacific. And there are
Speaker 3: other freshwater and a murans, but they are not hermit crabs.
Speaker 3: So this is the one freshwater hermit crab out there.
Speaker 2: I should throw in that the hermit crabs that we
Speaker 2: were observing in the wild, I believe are the Caribbean
Speaker 2: hermit crab. And this is a variety that's common to
Speaker 2: the West Atlantic, Belize, Southern Florida, Venezuela, and the West Indies.
Speaker 3: Yes, and the ones you were observing, you were saying
Speaker 3: were terrestrial or semi terrestrial, right, they spend a lot
Speaker 3: of time on land.
Speaker 2: Yeah, these were land boys. We did see one variety
Speaker 2: and I didn't identify this one one variety of aquatic
Speaker 2: hermit crab out law snorkling. But yes, the ones that
Speaker 2: I'm mostly talking about here are the hermit crabs, the
Speaker 2: terrestrial hermit crabs.
Speaker 3: So there are about a dozen species of land dwelling
Speaker 3: or semi land dwelling hermit crab descendants in a family
Speaker 3: called Sinobotids. This family includes one famous species that has
Speaker 3: shed its need for an externally acquired shell altogether, and
Speaker 3: that is the coconut crab or robber crab. We've talked
Speaker 3: extensively about these before, but the coconut crab is the
Speaker 3: largest land dwelling invertebrate in the world. It can have
Speaker 3: a leg span of up to one meter and can
Speaker 3: weigh almost five kilograms or about ten pounds. They live
Speaker 3: mostly in coastal areas throughout the Indian and Pacific Oceans.
Speaker 3: I think we talked a good bit about coconut crabs
Speaker 3: in our series on the Christmas Island Crabs that we
Speaker 3: did several years back. This was the animal where we
Speaker 3: were talking about the field notes of Darwin from the
Speaker 3: Voyage of the Beagle, where he's like, you know, they
Speaker 3: make really good eat, and you boil the fat under
Speaker 3: their tail and it makes a quart bottle of limpid oil.
Speaker 3: And then he also tells a story about how they
Speaker 3: locked one inside of a biscuit tin with wire and
Speaker 3: using its claws it was able to essentially like rip
Speaker 3: the tin out and escape the box.
Speaker 2: Oh man, there's a whole horror movie for you right there. Yeah,
Speaker 2: it would be Charles Darwin and crew on the Beagle
Speaker 2: having to fight off the killer coconut crab.
Speaker 3: They come and they just find the empty box. They're like,
Speaker 3: it's loose, No one knows where it is.
Speaker 2: You know, As long as we're throwing around Charles Darwin quotes,
Speaker 2: there's another place in the Voyage of the Beagle where
Speaker 2: he mentions hermit crabs. This is not a particularly insightful quote.
Speaker 2: It's just a mention, but I still had to drag
Speaker 2: it out. Quote. In every part one meets hermit crabs
Speaker 2: of more than one species, carrying on their backs the
Speaker 2: shells which they have stolen from the neighboring beach.
Speaker 3: Stolen.
Speaker 2: And yes, there is a fair amount of shell theft,
Speaker 2: as we'll get into. As long as you're thrown around
Speaker 2: quotes unrelated, I want to throw in this quote from
Speaker 2: Aristotle from the History of Animals.
Speaker 3: Is he gonna tell us where they come from?
Speaker 2: Yes? Yes he will reveal at the time non controversial
Speaker 2: hypothesis on crab origins. Quote, the hermit crab grows spontaneously
Speaker 2: out of soil and slime and finds its way into
Speaker 2: untenanted shells. As it grows, it shifts to a larger shell,
Speaker 2: as for instance, into the shell of the nearites or
Speaker 2: of the strombus or the like, and very often into
Speaker 2: the shell of the small cirrix. After entering a new shell,
Speaker 2: it carries it about and begins again to feed, and
Speaker 2: by and by, as it grows it shifts again into
Speaker 2: another larger one.
Speaker 3: Okay, I give Aristotle half credit on this. I think
Speaker 3: he's a bit wrong on the spontaneous generation out of
Speaker 3: slime and soil, but he correctly observes the shell shifting
Speaker 3: behavior of hermit crabs, which is a major feature of
Speaker 3: hermit crabs society that we'll have to talk about later
Speaker 3: in the episode.
Speaker 2: Yeah, he's absolutely wrong on spontaneous generation. We don't everally
Speaker 2: have to drive that home, but in a weird way, like,
Speaker 2: in a very general way, the idea of like matter
Speaker 2: becomes crabs, nature becomes crabs. Maybe not that far off,
Speaker 2: as we'll discuss later on.
Speaker 3: But apart from the coconut crab. There are various other
Speaker 3: species of hermit crab that live basically would live their
Speaker 3: adult lives on land, though they still usually live out
Speaker 3: part of their life cycle in the water, with females
Speaker 3: releasing larvae into the sea, and apart from these exceptions,
Speaker 3: hermit crabs are marine species.
Speaker 2: Absolutely. We'll come back to some of the ramifications of
Speaker 2: this in a bit now.
Speaker 3: According to Brifa and Moles, there are five families of
Speaker 3: hermit crabs, and it breaks down like this. You've got Pagurity,
Speaker 3: which are the right handed hermit crabs, and you've got diogeneity,
Speaker 3: which are the left handed hermit crabs right handed, left handed.
Speaker 3: What does that mean? We'll come back to that. Then
Speaker 3: you've got senobitity, which are the land hermit crabs, You've
Speaker 3: got parapagurity, which are the deep sea hermit crabs, and
Speaker 3: you've got Pilo chelady, which are symmetrical hermit crabs. Though
Speaker 3: the more than eight hundred species of hermit crabs display
Speaker 3: different local adaptations and behaviors, for the most part, it
Speaker 3: seems like hermit crabs are take what you can get foragers,
Speaker 3: which is true of many true crabs as well, but
Speaker 3: hermit crabs. For the most part, they will eat bits
Speaker 3: of dead organic matter, both animal and vegetable. They will
Speaker 3: eat live prey when they can catch it. Like true crabs,
Speaker 3: most hermit crabs are not very picky about food. Whatever
Speaker 3: they can get in their mouth, they're probably gonna eat.
Speaker 2: Yeah. Yeah. Both times that I was in believes there
Speaker 2: was a lot of fun to be had, especially with
Speaker 2: the kids, of leaving something out for them with permission
Speaker 2: of course, like I'm talking about the like like a
Speaker 2: cracked coke cannot and then seeing the hermit crabs eventually
Speaker 2: swarm over the material.
Speaker 3: So while foraging for food is of course essential for survival,
Speaker 3: so is foraging for shelter. We will have more to
Speaker 3: say about this as we go on, but obviously a
Speaker 3: huge part of the hermit crab's survival revolves around acquiring
Speaker 3: a good shell to live in, and the majority of
Speaker 3: these shells come from as we've said, mollusks like snails,
Speaker 3: but hermit crabs don't have to fight the snail for
Speaker 3: its shell. They generally move into the shell that is
Speaker 3: left behind after a snail dies. Also, finding a shell
Speaker 3: is not a one time pursuit. Hermit crabs grow larger
Speaker 3: throughout their lives, which means they need to trade up
Speaker 3: for bigger shells, which can lead to very interesting mass behaviors.
Speaker 3: More on that later. One thing the authors of this
Speaker 3: overview point out is that the gastropod shell filled by
Speaker 3: a hermit crab is not only a hard surface to
Speaker 3: protect the soft part of the body, the soft abdomen,
Speaker 3: it also forms a kind of shelter against the external environment.
Speaker 3: Now what kind of shelter against the environment would a
Speaker 3: hermit crab need. One example I recall from some documentary
Speaker 3: footage I saw years ago, was the idea that, you know,
Speaker 3: a hermit crab that's on land is under the hot sun,
Speaker 3: and if it's got soft body parts exposed outside of
Speaker 3: the shell, it could quickly sort of bake and dry
Speaker 3: out without the shelter and moisture provided by a shell.
Speaker 2: Yeah. Absolutely, Yeah. There again, they have to keep in
Speaker 2: mind that even though they are terrestrial, they are linked
Speaker 2: inherently to the ocean, and especially I when you're dealing
Speaker 2: with tropical heat environments. Yeah, they've they have to use
Speaker 2: that shell also to protect themselves and carry around some moisture.
Speaker 3: So I think it makes sense to look at a
Speaker 3: hermit crab's external shell in two different ways that both
Speaker 3: have some truth to them. On one hand, you could
Speaker 3: look at the external shell as an out sourced exoskeleton.
Speaker 3: It is, you know, it's like doing the role that
Speaker 3: would normally be done by the hard kiteness outer skeleton
Speaker 3: of a true crab. But another way to think of
Speaker 3: it is that it's like a portable burrow. And this
Speaker 3: is the point that Brian Haslitt was making in that quote.
Speaker 3: I read earlier about the idea of mobile shelter. Lots
Speaker 3: of animals find holes to hide in and rocks or
Speaker 3: other objects with recesses to provide a protective home. Hermit
Speaker 3: crabs find protective recesses that can actually come along anywhere
Speaker 3: with them. Now, I wanted to come back to the
Speaker 3: concept of asymmetry, which we already mentioned. Rob. You brought
Speaker 3: it up earlier, and it came up in the idea
Speaker 3: that there are these different families of hermit crabs, the
Speaker 3: right handed hermit crabs the pagurady, and the left handed
Speaker 3: hermit crabs the diogeneity.
Speaker 2: Yeah, this is all very important because we think about
Speaker 2: the asymmetry of the crab in this case, and the
Speaker 2: lines up with the asymmetry of the shells that they
Speaker 2: are probably going to be inhabiting.
Speaker 3: Right, So, one thing is that hermit crabs have a
Speaker 3: directional curve in the abdomen. The abdomen can kind of
Speaker 3: curl in a spiraling direction one way or the other.
Speaker 3: But there's also an important difference in the size of
Speaker 3: the claws. And from what I could tell, it was
Speaker 3: the claw asymmetry that was primarily used to sort these
Speaker 3: animals into the different families. One claw is often bigger
Speaker 3: than the other in hermit crabs. Now why would the
Speaker 3: animals be asymmetrical in this way. Well, so, the gastropod
Speaker 3: shells are most often inhabited by hermit crabs also have
Speaker 3: right handed or left handed spirals as you're saying, rob
Speaker 3: and the abdomens are curled so that they fit into
Speaker 3: the chiral shell. Meanwhile, one claw is often bigger than
Speaker 3: the other, so it can function as what the authors
Speaker 3: call an operculum, which in general means a structure that
Speaker 3: closes an opening or an aperture, but in the context
Speaker 3: of gastropods like snails, it has a specific meaning. A
Speaker 3: lot of snails are able not only to retract the
Speaker 3: soft parts of their bodies into their shells when threatened.
Speaker 3: They actually have a movable hard plate that they can
Speaker 3: use to close the door, essentially to block the opening
Speaker 3: of their shell behind them after they retract, like a
Speaker 3: solid trap door. And this is the snail's operculum. And
Speaker 3: the interesting thing is it seems that hermit crabs evolved
Speaker 3: claw a symmetry at least in part to fulfill the
Speaker 3: same function as the operculum of the snails that formed
Speaker 3: the shells that the hermit crabs take over after the
Speaker 3: snails die. So Abrifa and Moles write that a hermit
Speaker 3: crab can use its larger claw to close off the
Speaker 3: aperture of its shell after it retreats when threatened. And
Speaker 3: this connects to what you were talking about seeing, rob
Speaker 3: where the hermit crabs, you know, they might flip over
Speaker 3: on their back and then cover up the opening of
Speaker 3: the shell with one claw, maybe the bigger claw.
Speaker 2: Yeah, exactly, Yeah, I got to see this happen so
Speaker 2: many times. It's like, imagine some sort of futuristic crab
Speaker 2: that has evolved to use abandoned human portagoons or you know,
Speaker 2: portable toilets like you see at concert venues as its home,
Speaker 2: and then it has evolved its larger pincher to be
Speaker 2: the exact shape needed to serve as the door of
Speaker 2: that portagon.
Speaker 3: I thought you were going to say it has evolved
Speaker 3: a claw that can say either vacant or in use.
Speaker 3: I guess it would never want it to say vacant,
Speaker 3: so it says in use on its claw.
Speaker 2: Yeah, I mean, and maybe it wants people to go.
Speaker 2: That's how you get mimics. That that's exactly how you
Speaker 2: get mimics.
Speaker 3: So anyway, you end up with these asymmetries. You have
Speaker 3: right handed and left handed hermit crabs, the pagurids and
Speaker 3: the diogenids, respectively. There are also what are known as
Speaker 3: symmetrical hermit crabs called the pilocelids, which do unlike the others,
Speaker 3: they have hardened exoskeletons on their abdomens, though they do
Speaker 3: still hide in burrows like in you know, recesses in
Speaker 3: wood or rock that are thought to leave these burrows
Speaker 3: to feed. So they're related animals, but they live somewhat
Speaker 3: different lifestyles. Now we need to talk more about the
Speaker 3: selection of shells among asymmetrical hermit crabs and how that
Speaker 3: important biological need shapes hermit crab behavior and even what
Speaker 3: you might call hermit crabs society. One thing you might
Speaker 3: naturally wonder about with hermit crabs and the selection of shells,
Speaker 3: is is one shell as good as the next? You know,
Speaker 3: is any shell just as good as another? And the
Speaker 3: answer is no, not at all, in multiple ways. One
Speaker 3: big factor is, of course size. A shell that is
Speaker 3: too small or too large will greatly reduce a hermit
Speaker 3: crab's fitness, and studies show that when a hermit crab's
Speaker 3: shell is too small, for one thing, just increases mortality.
Speaker 3: Too small a shell means the hermit crab is more
Speaker 3: likely to die, but it also has less room to grow,
Speaker 3: and females with smaller shells produce fewer offspring, So it
Speaker 3: is not good for a hermit crab to have too
Speaker 3: small of a shell. However, it doesn't just want the
Speaker 3: biggest shell possible, because if the shell is too big,
Speaker 3: that increases the energy cost of carrying it, So you are,
Speaker 3: you know, massively wasting a lot of energy lugging around
Speaker 3: a shell that is heavy and too big for you.
Speaker 3: It's kind of like, I don't know, being encumbered in
Speaker 3: d and d or something. You know, you've got too
Speaker 3: much of a load. This is harming your ability to
Speaker 3: do everything else.
Speaker 2: Yeah, absolutely, So finding.
Speaker 3: A shell of just the right size is crucial, and
Speaker 3: that right size will change throughout the hermit crab's life
Speaker 3: as it grows.
Speaker 2: Yeah, so let's get into this a bit more like
Speaker 2: it's such an important aspect of the hermit crab, and
Speaker 2: it's you know, it's the first thing we think about
Speaker 2: really defines almost everything about their social interaction. And it's
Speaker 2: interesting to think about hermit crab society, or at least,
Speaker 2: you know, think of them as social organisms because we
Speaker 2: call them hermit crabs, which is a bit misleading because
Speaker 2: in human history and into sort of common usage, what
Speaker 2: is a hermit. A hermit is someone who withdraws from
Speaker 2: society and or civilization. So it might lead you to
Speaker 2: believe that hermit crabs are also loners in a certain sense.
Speaker 2: They are, but you know, that doesn't mean that they
Speaker 2: don't have interactions with others of their kind. In fact,
Speaker 2: they have a lot of interactions and they're very complex.
Speaker 2: So don't be too literal in thinking that a hermit
Speaker 2: crab is an actual hermit. In the same way that you
Speaker 2: wouldn't think that a king crab actually rules over decapods
Speaker 2: or something, right, and thissue is decrees. Yeah yeah. As
Speaker 2: Mark E Lydra pointed out in an article for Natural
Speaker 2: History Magazine back in I Believe twenty nineteen, hermit crabs
Speaker 2: live actually highly social lives, absolutely full of drama, just
Speaker 2: way more drama than you you'd expect your local human
Speaker 2: hermit to have, I'd wager.
Speaker 3: Yeah, I mean, I guess unless hermits were like constantly
Speaker 3: fighting one another to try to trade clothes.
Speaker 2: Yeah, or a pillar. You know, if you have your
Speaker 2: your pillar developers, it'd be like, no, I want the
Speaker 2: I want the taller pillar.
Speaker 3: Yeah, I'm gonna do exactly. I'm gonna bang my pillar
Speaker 3: on your pillar until you give me your pillar, unless
Speaker 3: I decide I want my old pillar back.
Speaker 2: So the various dramas that they encounter and instigate includes,
Speaker 2: but is not limited to, according to Elidra, commotion of
Speaker 2: social aggregations, UH, intergenerational inheritance of homes, life or death,
Speaker 2: competitive struggles. So the author points out that, in contrast
Speaker 2: to a lot of other social organisms you might think about,
Speaker 2: terrestrial hermit crabs socialize with non relatives and this is
Speaker 2: crazy to think about. The reason he points he points
Speaker 2: out is that while they spend most of their lives
Speaker 2: on land, we're talking about terrestrial hermit crabs again, not
Speaker 2: the aquatic ones. They spend most of their lives on land,
Speaker 2: but they are born in the sea. That's where the
Speaker 2: larva larvae are released. They become mixed in the ocean,
Speaker 2: and then they land on far flung shores via the tides.
Speaker 2: So I want to read this quote from Eldra. He says, quote,
Speaker 2: By the time an immature crab first arrives on land,
Speaker 2: it is therefore far away from any of its relatives,
Speaker 2: encountering instead only an assortment of non kin. Moreover, because
Speaker 2: the abundance of terrestrial hermit crabs on short stretches of
Speaker 2: beach often measures in the hundreds of thousands or even
Speaker 2: the millions, each crab is but a stranger within a
Speaker 2: vast crowd.
Speaker 3: However, you know, if you think of a human analogy,
Speaker 3: imagine a bunch of very selfish humans are thrown into
Speaker 3: a mix of you know, they're all living together beside
Speaker 3: one another, and not amongst their kin, just amongst strangers.
Speaker 3: And you know, maybe imagine they're not. Uh, they're not
Speaker 3: very nice people, they're not very inclined to be helpful
Speaker 3: to others. They still might find reasons to hang out
Speaker 3: around one another, even if they're mostly selfish. And one
Speaker 3: of those reasons might be the need for trade or
Speaker 3: an economy of sorts exactly.
Speaker 2: And what are they gonna have an economy of sorts about?
Speaker 2: What's gonna be the shell?
Speaker 3: Of course?
Speaker 2: I also like how this idea, it kind of matches
Speaker 2: up with the you know, the the huge stereotype that
Speaker 2: one encounters of big city life, particularly in movies from
Speaker 2: like the seventies and I guess into the eighties as well,
Speaker 2: Like nobody's related to each other in the city. You
Speaker 2: go to the city, it's just everybody's for themselves. You're
Speaker 2: gonna you're gonna lose your shell in that big city.
Speaker 2: And I guess it's kind of kind of that way
Speaker 2: with the crabs here. But anyway, the shells that they use,
Speaker 2: like you're saying, yeah, these are scavenged from dead mollusks,
Speaker 2: but this is also key, Uh, they have been remodeled.
Speaker 2: These are remodeled homes. Elidra points out, Uh, the crabs
Speaker 2: you when they have when they have a fresh shell
Speaker 2: that is gonna like this is okay, something has died.
Speaker 2: The snail has dyed, and now I'm going to make
Speaker 2: this shell into a home. You can't just put it
Speaker 2: on and wear it out. No, No, you need to
Speaker 2: use chemical secretions to weaken the shells calcium carbonate, as
Speaker 2: well as additional physical sculpting via your appendages. You're going
Speaker 2: to change the shell into something that absolutely suits you
Speaker 2: and absolutely suits your purposes.
Speaker 3: Right, So, this is another way in which one shell
Speaker 3: is not necessarily as good as any other. Size matters
Speaker 3: a lot, which is a sort of inherent feature of
Speaker 3: the shell, but also the remodeling condition of the shell
Speaker 3: matters a lot. There are shells that have been recently
Speaker 3: renovated and that's much more desirable than a shell that
Speaker 3: is a real fixer.
Speaker 2: Upper right, right, And this is unique to terrestrial hermit crabs,
Speaker 2: and we'll get it more into why in a second.
Speaker 2: But yeah, as Lighter points out, it's absolutely necessary for
Speaker 2: terrestrial hermes because they can't depend on water buoyancy to
Speaker 2: help them carry that shell around. It's just the basic
Speaker 2: reality of living out of the water. And some of
Speaker 2: these shells can be quite hefty for the crab, and
Speaker 2: so by reducing the shell mass, they're lowering the energy
Speaker 2: cost of just traveling across land, and they do a
Speaker 2: lot of traveling. Additionally, shell remodeling increases the internal space
Speaker 2: in the shell, allowing not only more room for the crab,
Speaker 2: but more room for increased water reserves to keep the
Speaker 2: organism from drying out. Like we mentioned earlier, the importance
Speaker 2: of this being a way to help them sustain themselves
Speaker 2: when they are living times in very hot environments. He
Speaker 2: also points out that while aquatic hermit crabs would conceivably
Speaker 2: benefit from shell remodeling as well, because even though you
Speaker 2: have buoyant sea, lighter shells could still be a benefit. Right,
Speaker 2: more internal space could still be a benefit. However, aquatic
Speaker 2: hermit crabs have to contend with shell expert predators in
Speaker 2: the ocean, organisms that are highly evolved to bypass shell protection. Therefore,
Speaker 2: it would be a mistake to sacrifice any of your
Speaker 2: shell's protection in order to get any of these benefits. Meanwhile,
Speaker 2: on land, the terrestrial hermit crabs have far fewer shells
Speaker 2: specialists to contend with, and Lidra points to various research
Speaker 2: that's shown that like your average predator that would be
Speaker 2: messing with a hermit crab is just not going to
Speaker 2: have like the byte power or the not going to
Speaker 2: have the tools necessary to crack open even a partially degraded,
Speaker 2: a partially remodeled hermit crab chosen shell. Now, Joe I
Speaker 2: included a photographer. This is from Lydra's paper and an
Speaker 2: example of an unmodified versus a modified shell. The central
Speaker 2: axis is often removed, but the shell again retains protection
Speaker 2: against the bite strength of terrestrial predators.
Speaker 3: Yeah, and one thing you can see in this picture
Speaker 3: is that a lot of the effort in the remodeling
Speaker 3: seems to be focused on the interior of the shell,
Speaker 3: sort of like expanding the interior cab and making more
Speaker 3: room there and smoothing it out.
Speaker 2: Yeah, and certainly removing some of the additional protection of
Speaker 2: the shell. But again it's apparently not going to matter
Speaker 2: for terrestrial variants. Now, like we said, one of the
Speaker 2: huge factors in hermit crab societies is of course the
Speaker 2: need for these shells, and the fact that as the
Speaker 2: crab grows and molts, they'll need to abandon smaller shells
Speaker 2: in favor of larger shells and as Liger points out,
Speaker 2: there's something really interesting about all of this quote. Over time,
Speaker 2: remodeled shells have come to dominate the housing market of
Speaker 2: terrestrial hermit crabs. Exhaustively sampling these housing markets, I have
Speaker 2: found few unremodeled shells, and also few shells that are
Speaker 2: still in the process of being remodeled. Most shells have
Speaker 2: already been completely remodeled. Remodeled shells present a superior home, and,
Speaker 2: as with any superior resource, it is understandable that terrestrial
Speaker 2: hermit crabs should prefer remodeled shells over unremodeled shells. However,
Speaker 2: over evolutionary time, a mere preference has transformed into an
Speaker 2: absolute dependence. As remodeled shells accumulated, terrestrial hermit crabs came
Speaker 2: to specialize in living in them, to the point that
Speaker 2: life in unremodeled shells became nearly impossible. My field experiments
Speaker 2: revealed that after an early life stage, most terrestrial hermit
Speaker 2: crabs cannot survive in unremodeled shells for even a single day.
Speaker 3: Wow, Okay, I did not realize that.
Speaker 2: Yeah, yeah, because you know what's the current hermit crab
Speaker 2: to do? If you need a shell, well, you could
Speaker 2: remodel your own shell technically, but most crabs simply can't
Speaker 2: do this anymore, in large part because they end up
Speaker 2: too big to access the inner parts of a fresh shell.
Speaker 2: So only the smallest immature hermit crabs actually can get
Speaker 2: in there and do this, which paradoxically often means that
Speaker 2: they're left with oversized shells. But as such, all terrestrial
Speaker 2: hermit crab individuals highly prefer a remodeled shell over a
Speaker 2: fresh one. Even even if they can fit inside that
Speaker 2: fresh shell and conceivably remodel it and make it their own,
Speaker 2: remodeling the shell is still a last resort. Ledra stresses
Speaker 2: that this is this is the only factor that ensures
Speaker 2: the continued creation of remodeled shells. That some crabs, hermit
Speaker 2: crabs are going to be put in a position where
Speaker 2: they have no choice wow, because I mean, they can
Speaker 2: do other things too. It should not like if a
Speaker 2: hermit crab is left without anything and there, and we'll
Speaker 2: touch on how this occurs in a moment, they may
Speaker 2: use something like a bottle cap and that might buy
Speaker 2: them a little time, but they need a shell. The
Speaker 2: thing is, you don't just find many emptied remodeled shells.
Speaker 2: He points out that on a given beach, the only
Speaker 2: empty remodeled shells you're likely to find are the ones
Speaker 2: that have been physically compromised in one way or another,
Speaker 2: so like they're broken, they don't actually protect the hermit
Speaker 2: crab anymore, or they're clogged with a rock something like that,
Speaker 2: they're no longer functional. The competition for remodeled shells is intense,
Speaker 2: and they're just you're just not going to As a
Speaker 2: hermit crab, you are not going to find them out
Speaker 2: there unless you're extremely lucky. As such, hermit crabs have
Speaker 2: to remain vigilant at all times, always looking out for
Speaker 2: a bigger shell, because either you need one or you're
Speaker 2: about to need one, so you need to always be looking.
Speaker 2: And also you have to be peeking over your shoulder
Speaker 2: because there's probably someone eyeing your shell that is looking
Speaker 2: for a slightly bigger shell, and they're trying to decide
Speaker 2: if it's worth trying to take it from you.
Speaker 3: Right, So this leads to the fact that hermit crabs
Speaker 3: very often get into well, I guess there's some debate
Speaker 3: over how exactly to characterize these encounters, whether they are
Speaker 3: purely agonistic fights, or whether you might consider them in
Speaker 3: some way a kind of trade or negotiation. Maybe we
Speaker 3: can talk about that some more in the next episode.
Speaker 3: But they get into these encounters that lead to shell swapping.
Speaker 2: Yeah, they're the very least aggressive negotiations. Yeah, but you
Speaker 2: know so, I'll continue to categorize them as battles. But yeah,
Speaker 2: give with that caveat in mind. Basically, what seems to
Speaker 2: be happening is one crab will attempt to flip the
Speaker 2: other on its back and force its opponent out of
Speaker 2: their shell. But as Lijra points out, this kind of
Speaker 2: thing can last hours, and it might just end in
Speaker 2: a stalemate. It might just end in everyone just going
Speaker 2: home or carrying on with the shell they had two
Speaker 2: hours ago. And that alone, I think that's pretty fascinating.
Speaker 2: Most animal competitions and struggles are fascinating. But it's the
Speaker 2: onlookers that make this even more interesting. Elijra writes. Quote.
Speaker 2: As bystanders gather at the site, and as the moment
Speaker 2: of evictioneers order emerges out of the chaos of commotion
Speaker 2: in the aggregation, the crabs array themselves literally into a line,
Speaker 2: each holding the shell of the crab ahead of it.
Speaker 2: This social formation emanates from the pair of antagonists, with
Speaker 2: the line of crabs there after being size ordered from
Speaker 2: biggest to smallest. Because if a crab is forced to
Speaker 2: give up its shell, the winner will leave its shell,
Speaker 2: and this will set off what's called a vacancy chain.
Speaker 2: All of the onlookers will have a shot at leveling
Speaker 2: up their current shell situation to a new one that
Speaker 2: is slightly bigger.
Speaker 3: You can find video of this online. By the way,
Speaker 3: there are multiple documentaries that have captured versions of this,
Speaker 3: and it's amazing to see they literally do just organize
Speaker 3: themselves in a size ordered line where they're each grasping
Speaker 3: the shell of the slightly bigger one, like feeling around
Speaker 3: on it, trying to make sure that it's what they want.
Speaker 3: Because the whole process, by the way in which hermit
Speaker 3: crabs sess a shell where the qualities they want is
Speaker 3: interesting on its own. There seem to be some visual
Speaker 3: processes going on. They you know, look at a shell
Speaker 3: to assess from a distance whether it's something they would want,
Speaker 3: but that's never enough. They have to inspect it physically.
Speaker 3: They like feel all over it with their antennae and
Speaker 3: their and their chelly, you know, the claws and the legs,
Speaker 3: and then usually they will want to sort of like
Speaker 3: dip into it with their legs and maybe their abdomen
Speaker 3: to see if they fit right, and they may end
Speaker 3: up changing their mind and wanting to go back to
Speaker 3: the previous shell, though obviously that could be a tricky thing.
Speaker 3: If a bunch of hermit crabs are lined up all
Speaker 3: trying to level up at the same time, it is
Speaker 3: an amazing thing to see.
Speaker 2: Yeah, to your point about like sizing up the shell,
Speaker 2: trying it on, Like sometimes you have a situation where
Speaker 2: you remember the asymmetry of shells and and hermit crabs here,
Speaker 2: and sometimes you have a you have a like a
Speaker 2: like what a left handed crab trying to get into
Speaker 2: or right handed shell or vice versa, and that's going
Speaker 2: to be a situation where the crab is going to
Speaker 2: quickly realize this does not fit, this is not the
Speaker 2: shell I want to live. We may come back with
Speaker 2: more details on that regarding the left right handedness in
Speaker 2: hermit crabs and shells. Now Ldra again points out that
Speaker 2: all this competition is based again not on kinship, but
Speaker 2: on selfishness and competition, and he has this wonderful part
Speaker 2: in the paper where he says that it's what's kind
Speaker 2: of the antithesis of something like a US social ant,
Speaker 2: you know, where all the ants in a colony are kin,
Speaker 2: and they work together to ensure the success of the colony,
Speaker 2: the success of their genetic line. But that is not
Speaker 2: the case with the hermit crab, and Lidra writes the
Speaker 2: following quote. If in an alternative world, interactions in terrestrial
Speaker 2: hermit crabs were among close kin rather than strangers, then
Speaker 2: the crab's social lives might be different, with individuals potentially
Speaker 2: being more interested in the queathing their finest shell to
Speaker 2: a close relative than in stealing the coveted shell of
Speaker 2: a stranger. Now, there have been plenty of other researchers
Speaker 2: and also science journalists and writers and so forth that
Speaker 2: have commented on all of this. Elizabeth Preston wrote all
Speaker 2: about this topic for The New York Times in twenty
Speaker 2: nineteen in an article titled even hermit crabs have wealth inequality.
Speaker 2: This was based on a twenty twenty study. This is
Speaker 2: because the New York Times paper came out a month
Speaker 2: before the twenty twenty study. This was in a December publication,
Speaker 2: So that's why the dates would seem to be in
Speaker 2: the wrong order here. But that particular paper was a
Speaker 2: comparison of wealth inequality in humans and non humans by
Speaker 2: Chase at all. This was a study that, as I recall,
Speaker 2: received a fair amount of mainstream attention at the time, because,
Speaker 2: of course, wealth inequality is always a topic of interest
Speaker 2: among human beings, and crabs are inherently interesting. You can
Speaker 2: throw hermit crabs into any study and it's going to
Speaker 2: be fascinating, even if there's not really connective tissue there.
Speaker 3: Well, is there connective tissue here?
Speaker 2: To a certain extent, it seems to okay, I mean,
Speaker 2: so in the study, Chase and his co authors gathered
Speaker 2: around three hundred hermit crabs on Long Island Beach and
Speaker 2: took away all their shells, which, okay, for science, I
Speaker 2: will allow this, but you know, obviously I can't help
Speaker 2: it sympathize because this is literally all these crabs care about.
Speaker 2: The researchers weighed and measured the various shells, and then
Speaker 2: they considered how they were distributed across the sample population
Speaker 2: of hermit crabs. And this is a quote here from
Speaker 2: that article by Preston. Quote the distribution curve they found
Speaker 2: peaked around medium sized shells, then dropped as the shells
Speaker 2: got larger, before tapering off very gradually through the largest shells.
Speaker 2: Of all, this matches the shape of wealth distribution curves
Speaker 2: in many human societies, so it's interesting. But at the
Speaker 2: same time, the New York Times article, of citing anthropologists
Speaker 2: Monique Molder, points out that we shouldn't get too carried
Speaker 2: away comparing hermit crabs to humans in this scenario, because,
Speaker 2: first of all, there are plenty of other factors involved
Speaker 2: in human inequality. You know, it's one of those it's
Speaker 2: often described as a wicked problem. You know, it's complex
Speaker 2: enough that you can't just point to necessarily. There are
Speaker 2: certainly large factors, but there are multiple factors. And Molder
Speaker 2: here who again as an anthropologist, speculated that vacancy chains
Speaker 2: are probably also not the only factor in terrestrial hermit
Speaker 2: crabs as well. I mean, you know, there are other
Speaker 2: factors as well into how they are dealing with each other,
Speaker 2: even on the basis of their shells. Still, you know,
Speaker 2: we can't help but compare ourselves to the hermit crabs. Again,
Speaker 2: part of it is just that hermit crabs are that interesting,
Speaker 2: and we as human beings are that self absorbed. Why
Speaker 2: we can't help but see ourselves in the crabs. We
Speaker 2: can't help but anthropomorphize the crabs, and you know, especially
Speaker 2: when we see them, you know, in a very complex fashion,
Speaker 2: struggle over limited resources like this. That again, I think
Speaker 2: if you're just casually aware of hermit crabs, you might
Speaker 2: not realize that just any shell, it's not a situation
Speaker 2: where any shell will do, and it is a situation
Speaker 2: where the shells have been augmented, and therefore it's competition
Speaker 2: not just for random garbage left over by dead snails,
Speaker 2: it's competition for mostly previously augmented shells, like the products
Speaker 2: of a hermit crab civilization, if you will, Well.
Speaker 3: That's funny if you think of it as like more
Speaker 3: fighting over fighting over a limited pool of finished goods
Speaker 3: rather than creating new goods. It's almost like a human
Speaker 3: post apocalyptic scenario.
Speaker 2: Exactly.
Speaker 3: Yeah, it's kind of Mad Max.
Speaker 2: It's kind of Fallout, right. It reminds me that in
Speaker 2: at least some of the Fallout games, you do encounter
Speaker 2: a giant hermit crab that is using what some sort
Speaker 2: of like a bus or something like a school bus
Speaker 2: for its it's abdomen. I can't remember offhand, but I
Speaker 2: remember when I would when I would play those Reasons
Speaker 2: fall game, I would occasionally encounter that that creature and yeah, yeah,
Speaker 2: I mean it's it's it's interesting. Where are they getting
Speaker 2: all these school buses? So what are they changing about?
Speaker 2: I guess they're taking all the seats out? Yeah?
Speaker 3: Is it a right handed bus or a left handed bus?
Speaker 2: I don't know. Yeah, And are they sizing up from
Speaker 2: different buses? Like they start with a like a shorter bus,
Speaker 2: then they go to a full sized school bus and
Speaker 2: they're going to like a megabus, then it's a double
Speaker 2: decker bus. Those are only that's only on Fallout London propertly,
Speaker 2: but you know you could go wild with the scenario.
Speaker 3: Well, hey, we've got more hermit crab stuff to talk about,
Speaker 3: so join us again next time.
Speaker 2: That's right, we have some more content lined up regarding
Speaker 2: the hermit crabs. We're going to fish around for a
Speaker 2: bit more. Because I'm hermit crabs. There's a lot of
Speaker 2: research out there. That's one of the reasons I felt
Speaker 2: pretty secure and going in and discussing them again, even
Speaker 2: though we've discussed them in the past, because there's constantly
Speaker 2: new hermit crab research coming out and there are some
Speaker 2: remaining mysteries and controversies about hermit crabs, so we'll get
Speaker 2: into all of that in the next episode. In the meantime,
Speaker 2: we'll remind you that Stuff to Blow Your Mind is
Speaker 2: a science podcast with core episodes on Tuesdays and Thursdays.
Speaker 2: That's the main event. You can also tune in for
Speaker 2: a short episode on Wednesday, a listener mail episode on Mondays,
Speaker 2: and on Fridays. We set aside most serious concerned to
Speaker 2: just talk about a weird movie on Weird House Cinema.
Speaker 2: If you listen to us on Apple or an Apple device,
Speaker 2: what have you going in And just make sure that
Speaker 2: you're still subscribed to the show, that nothing's changed there,
Speaker 2: make sure you're still getting downloads worth a check. That
Speaker 2: helps us out. And hey, as far as just rating
Speaker 2: and reviewing, we haven't beat the drum about this in
Speaker 2: a while, but hey, if you haven't rated and reviewed
Speaker 2: the show before, why didn't you do that? Throw us
Speaker 2: a good five stars somewhere. That also helps us out
Speaker 2: in the long run.
Speaker 3: Huge thanks as always to our excellent audio producer jj Posway.
Speaker 3: If you would like to get in touch with us
Speaker 3: with feedback on this episode or any other there, to
Speaker 3: suggest a topic for the future, or just to say hello,
Speaker 3: you can email us at contact at stuff to Blow
Speaker 3: your Mind dot com.
Speaker 1: Stuff to Blow Your Mind is production of iHeartRadio. For
Speaker 1: more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,
Speaker 1: or wherever you listen to your favorite shows.