From the Vault: Crab Content is King

the crabs with a third episode. That's right, we did as we should have. So this originally published November. Here it is Welcome to Stuff to Blow Your Mind, production of My Heart Radio. Hey welcome to Stuff to Blow your Mind. My name is Robert Lamb and I'm Joe McCormick, and we're back from the break. We thought the best way to jump right back in would be to do

more crabs. That's right. We had we'd just recently done a couple of episodes about crabs eating strange things, and we had some we had some crab run over anyway, so we thought, well, what what's what better than to go ahead and just jump right back in two more crabs. Crab overflow. Did you happen to eat any crab over the break rub? I went crabbing with my son and my and my brother in law, um, and they did

catch crabs and they were excited about them. I ended up not eating any of the crabs, just because I don't know, I just wasn't feeling it. It's a lot of work. Uh, you gotta be you gotta want it so um. So I abstained from the consumption of crabs, but I did get to observe some crabs. In my experience, I feel like it's always kind of embarrassing to eat a crab. You're just sitting there working on it, you know. I guess it's all of the the intense concentration it

takes to like crack the pieces and stuff. You're not really following the conversation of the tap able very well. It's you're in your own world. Yeah, I mean, it definitely is one of those activities that that puts you in the It feels like you put you in an archaic mindset. You know, you can imagine yourself, you know, you know, picking apart a carcass on some sort of primordial shore. Uh sort of a situation, and and therefore you do get in the zone. You get in the

crab zone, right. Um, But I don't know that. This this year, I wasn't feeling it, so I did not have any crab but I was. I was in New Orleans, uh, and I did enjoy some some very nice food, uh, some very nice drinks. I made it over to Latitude once more and had some some drinks at beach bum Berries. Oh do they do anything with tiki turkey puns for for this time of year? Well, no, they get into the sip in Santa things. So there were some Christmas ones.

I had a Christmas Eve of Destruction, which was very nice. Okay, okay, but we gotta talk crabs. That people want crabs. Yeah, let's get into crabs. So um, you know, in our in our most recent episodes on Crabs, I did dish out a little bit of crab mythology, and I mentioned how crabs don't often seem to have central rolls and myths and folklores for various reasons. But but that doesn't

mean they don't have some very fun cameos. And of course I do hold out hope that there are some some other crab myths and legends out there that I just don't know about. And so as always, if I'm missing something, right in and let us know now. In The Eight Immortals cross the Sea, an important Chinese work of the Ming dynasty, you basically have the story of these eight powerful humanoid beings using their various powers to cross the ocean and kind of show off as they're

doing it. Okay, I'm trying to is this something we've talked about on the show before or similar to it, or or a lot of these beings sort of uh, overlapping with the animals of the Chinese zodiac. I believe we've talked about the immortals before, but I don't think we've really looked at this particular work, okay, uh. And you might be thinking of the Chinese zodiac origin story about the the animal race where they have to cross a great river, so so this is different than that.

But basically these are these are super beings. They have superpowers, and so they're showing off as they crossed the ocean, and crossing the ocean also entails outsmarting and overpowering the

Dragon king. As this is his domain. And we have mentioned the Dragon King on the show before, but it's said that the Dragon King is served by quote, shrimp soldiers and crab generals, as this is the sea after all, And and I believe these these these sort of shrimp soldiers and crab generals also show up in tales of the Monkey King when when he encounters the Dragon King or the Dragon king soldiers. What is it about crabs that puts them in commander rolls? Don't? I mean, you're

gonna put the shrimp in the commander roll? I mean it seems like a no brainer, right, But the thing is that in these stories the shrimp and the crabs are generally seen as ineffectual. So you have this saying that emerges from these tales. Any you have references to shrimp soldiers and crab generals. This has just become become a way of referring to ineffective soldiers. Uh so I

kind of like that phrase. Okay, So would this be kind of similar to when people say tin soldiers like t I N I think so, yeah, I think this would be this would be a version of that in Mandarin. Now there's another Chinese crab myth that I was reading about that that was really fascinating me, and I wasn't really able to get quite to the bottom of it. But it pops up in yang and and Turner's Handbook

of Chinese Mythology. It concerns the Yellow Emperor, and there are a lot of stories about the Yellow Emper and this one just happens to involve crabs. A lot of these emerge from from zin Jung in the Non province, and this one seems to have as well. And in this particular tale, the Yellow Emperor's attendants find a nice cave for him to visit in the owners So this is just just a really nice cave. It's cool, uh, you know some water there. You can rest very comfortable.

Except they're way too many mosquitoes and other unwanted vermin living in the cave. So the Yellow Emperor just kind of casually mentions like, geez, I wish someone would drive these creatures away. Whish somebody would wipe these creatures out so I could enjoy this cave, because otherwise it's a great place to spend the summer. So what happens when an individual of great power casually mentions the desire well, oftentimes U uh, somebody will see an opportunity, and that's

what the crabs living in the cave do. They hear this and they decide, well, let's do it. So they drive all the unwanted creatures out of this wondrous cave, and as a reward, the Yellow Emperor is said to have given these crabs an extra set of legs. Quote. Thereafter, only the crabs in the local pond have tin legs. Wait, I'm confused. Okay, so do you know anything about how this connects to to biology, because so crabs are decapods

that should have ten legs, right right right? Yeah, this is where I really started scratching my head a bit, because yeah, that decapod crabs are quite literally ten legged crabs. So what would these other crabs have been? Well, I guess it seems to get complicated because technically decapods can have as many as thirty eight appendages, and generally the pereiopods are walking appendages or what we very loosely refer to as legs, and there are five pairs of those.

But at the same time, many common crabs, such as ghost grabs, they do run around on four pairs of legs and sometimes actually only employ three pairs in running, and the fifth pair of legs or the claws, which we humans often go ahead and at least think of as hands, right, because we can make we can make a little crab claws with our hands, and so we kind of feel like those are the crabs hands, right, Yeah, And if you want to get really technical, I mean,

crabs have all kinds of bilaterally symmetrical pen dig is that you could imagine our legs or have evolved from legs at some point. So you know, crabs have jaw legs in their mouths, the uh, the maxilla peds that help them eat and uh and yeah, so so yeah, it's true. Even though they will typically have ten legs or leg like appendages, some of those could be seen

as other things. Like you're saying, you know, a person looking at a crab's claws as well, those aren't legs, those are hands, or looking at maybe the swimmer legs says those aren't legs, those are fins. Yeah. Yeah, because some crabs have paddles for their their hindmost pair of legs, so you can at least imagine a scenario in which someone might not count those as being part of the leg count. But um, but yeah, I'm not really sure how to exactly interpret this story that maybe there's something

missing in translation. Um, you know, I looked around at a few papers about extra leg genetic abnormalities and some crabs, so maybe that's not out of the question either. Uh, maybe there's just something particular about the crabs in this cave environment or or even you know, is it sometimes the case and accounts like this in legends. Maybe it's not even describing a crab, it's something else, and the legend comes down to, you know, describing why does this

thing look a little different than what we're used to? Well, because it did something wonderful and therefore was gifted extra appendages. Okay, what number of appendages? Does it become not that useful to have more of them? You know, if you've got if you've got two arms, having two more arms, that seems like a real upgrade, right, like Goro has got

a real advantage over a regular human. But once let's say you already have uh ten bilaterally symmetrical appendages, if you get two more, is I mean, is that really an upgrade or do they just get in the way at that point, Yeah, I guess this is usually a question that that evolution natural selection solves over time. Right if if if appendages are not needed, well then they're just a drain on the the economy of the body, and therefore there's a there's a possibility they're going to

disappear year over time, that they're gonna a trophy. So

I don't know. But anyway, coming back to the story you were telling, I love that detail about the Yellow Emperor just sort of idly saying, oh, I wish someone would get rid of all these mosquitoes, because it kind of reminds me of the Actually don't know if this is historically solid, but the at least the at least legendary tale of the death of Thomas Beckett, the Archbishop of Canterbury, who when Henry the second supposedly said he was like mad at him, I guess, and said, you know,

won't someone rid me of this meddlesome priest? And uh, it wasn't given as an order. He was just kind of musing about how mad he was. But some nights happened to over hear him and they're like, well, okay, I guess we gotta go kill this guy and they did. Yeah, basically seems to be the same situation here. Now I'm out of my depth on this, but I also can't help but wonder maybe part of the idea of the story is the crab has so many legs anyway, and therefore it's not much of a reward. I don't know.

It makes me wonder, but I couldn't find out. I looked around. I couldn't find any other strong sources, you know, in in English on this. But if anyone out there has any details about strange crabs in a non province, crabs from the caves, and crabs with extra limbs right in, I would love to love to have more clarity on this. While you were telling the story, I was hit with a with a tremendously bad pun. Should I say it? Should I not say it? I don't know. It was

little pinchers have big ears. That's good now, Uh, yeah, it's good now. There are there are other crab tales to be found in Chinese mythology. For instance, they are fairy old myths to be found throughout various myth cycles of China among different ethnic groups about the separation of heaven and Earth. Uh. This is of course something you see in in other myth cycles as well. Uh. And in Chinese traditions, sometimes there is a sky tower or sky pillar connecting the two, and sometimes an an moll

is to blame for severing this tower or pillar. And apparently in some tellings it is a crab that does the snippet. Ah. Well, that would make sense. Yet again, when there's something to be snipped in a myth, sometimes the crab will fill that gap. Yeah. Now another one

that I was reading about. This one. This is another you know, very old mythological tale, and it's the story of of woman Cho, of whom there are I think three narratives in the Classic of Mountain, Mountains and Seas, and as Zann Barrel explains in Chinese mythology in an introduction, the written versions of these tales UH date from the first century b c. E. And the first century see and they tell of a time during which quote, there are two people in the sea, but we only meet

one woman Cho, who is strongly linked with the crab. And it seems like she may either take on the form of a crab or she has a crab that is her attendant, and it seems like this might be a crab of unusual size. And the reasons for this seemed to include the idea that okay, you've got the land and the and you got the sea, and you have the crab, which kind of has a dual nature. Like the crab lives on both. It can scamper on the beach, but then it can scamper beneath the waves,

it can swim in the water, and so forth. Yeah, the dual nature is right there in its body. It's it lives in the ocean, but it walks on its legs. But then the crab also does another interesting thing. It molts, It sheds it's it's old shell and grows a new one. And this was seen as a kind of regeneration that might allow the crab to live forever. And it was also associated with cycles of the moon, and of course the moon has strong connections to the idea of immortality

and Chinese mythology as well. Oh, that's very interesting, and it makes me wonder why we have commonly adopted the metaphor of the butterfly as the you know, the the important image from nature of something going through a transformation and then uh, and then coming out something new. I mean, I guess the difference there is that a butterfly looks very different than the than the larval stage that went into the pupa. But uh, but when a crab comes

out is just bigger. So maybe that is a better metaphor. I don't know now. Woman Chow is also known as Woman Cho corpse, corpse deity and Uh. This is connected to drought and the time of the Ten Sons, the time in Chinese mythology we've mentioned on the show before, Uh, when there are tens sons in the sky and they are burning up the earth, as related in the Shanghai Shan quote. Woman child corpse was born, but the Tin sons scorched her to death. That was north of the

land of Men. She screened her face with her right hand where the Tin sons are up above. Woman Cho lived there on top of the mountain, so she's she's scorched and burned by the surplus suns, perhaps seemingly especially her hand because she's shielding her eyes with that hand.

But then she is later reborn in brilliant green, so she has renewal, she has drought survival, but she has also connected to these observations of the crab and the idea that the crab experiences this sort of periodic renewal

as well. Now, another area concerning crabs that I was looking at kind of comes back to stuff we've talked about already about the you know, the idea that the crab design is a winning design, that it's emerged independently multiple times, and that according to some eventually everything will become a crab. Right, that's kind of the meme. Yeah, I think the more modest phrasing is that other crustaceans that are not necessarily crablike inform have repeatedly evolved into

crab like forms multiple times in the history of life. Yeah. So earlier this year, Doug Johnson wrote a fun article for Ours Technica titled on Earth things evolve into crabs?

Could the same be true in space? Uh? And so that part of this article is the author's generally summing up some of these ideas we've we've discussed already, But then he gets into this this issue of alien life because if we follow the logic that aliens might be humanoid, because that's what we see emerge as a dominant intelligent life form on our own world, then we might go as far as to wonder, well, if crabs are a popular form on this planet, wouldn't it make sense to

see crab or crab like bodies crab morphs if you will on alien worlds as well. I want to believe so. Um Johnson reached out to one of the authors of the paper I referenced in our previous crab episode, Joe wool for researcher at Harvard University's Department of Organismic and Evolutionary Biology. The article was how does a crab become a crustacean? And I have to say absolutely love this

quote from her. This is something she told to ours technical and in the the the interview quote there is no clear cut reason why being a crab is better than not being a crab. But if you say that too loud, the crabs in the cable here you and then they'll turn into something else. True. But I love this this quote because there's an absurdity to it, obviously, but it also does ring absolutely true and betrays a

deeper understanding. You know, we don't have an answer in human reason and human language to the question here, but evolution provides its own answer, and the answer seems to be the crab form itself um in various examples. However, Johnson talks to Charles Marshall, director of the University of California Museum of Paleontology, and Marshall points out that all in all, it's a fairly narrow group of species that

have become crab morphs on our planet. Um that you know that we shouldn't we shouldn't get too excited about this, this idea. It's like, well, crabs are everywhere, so they

must be in space. Like there's like, ultimately, it's still a situation where the crab form has evolved as an answer to specific questions posed by our natural environment, and not say universal questions, right, And I think the other half of that, uh, The other important point highlighted by by Marshall's observation here is that it's not just that the natural environment creates some pressure that encourages crab like forms, but that it's also certain morphological starting places that if

you're starting with a genome that codes for a certain kind of body plan, it's easy to get from there into a crab like form, and that body plan is like other certain types of especially marine arthropods, you know, certain crustacean types, right, I mean, like, for example, you can you can look at that the hands of various organisms, right, Like to get something like an extra finger or an extra thumb, it has to come from somewhere. You know,

there has to be a starting point. It's not just you know, suddenly thumb sort of a situation exactly so. And maybe you know, another billion years, we could find that all kinds of mammals on Earth have evolved thumbs, because it turns out it's really useful for all kinds

of animals. But you're not going to really find uh, say, crabs with thumbs, right, because they don't really have the morphological building blocks to start with to make thumbs, right, But I mean they do, they do sometimes have access to thumbs, because we do mention that they will show down on a cadaver. Yeah. Um, then again I want

just to doubt what I just said. I mean, I guess depending on how expansive your definition of thumb is, you could say that a crabs claws, the pinching motion provides some of what a thumb is good for, right, That a thumb can help you you know, close your hand over an object in order to manipulate it, obviously

with much more dexterity than usually a crab can. But I can see why we might look at the crab body and think, well, this might be good in in space because we look at the way the crab moves on land and through water, and it's easy to extracolate

that toum like a micro gravity situation. Right. So, in the same way that you have some crabs on Earth who's whose rear most pair of legs has turned into swimmer legs, a little paddle legs to help them move through the water, you could imagine a crab whose final pair of legs has turned into ion thrusters. Well, I wouldn't go that far, but um I will say add that.

I think another aspect of all of this is that, you know, we we tend to think of like crab more of popping up everywhere and imagine them in the future and another planets, because we do take a lot of delight in these organisms. I mean, they're weird, they're stealthy, they're efficient, they're kind of funny to look at. Uh, they're amusing to watch in the wild, and of course

we like to eat some of them. Uh, so we have a vested interest in their existence, and that's always a great way to wind up as a noted animal for humans. Is it something that we eat or is it something that can eat us? And uh, you know that the crab kind of checks off both boxes, Uh,

with some caveats on the the consumption of humans. That's a very well observed But I want to come back to crabs eating strange things, were being attracted to eat strange things at least, uh, And I wanted to do that by looking at a study I came across from just this year, looking at hermit crabs. Now we've mentioned hermit crabs a number of times in this series. Now, hermit crabs are decapod crustaceans. They're not considered to quote

true crabs. I can't remember if we've said that already, but they belonged to the group and Amura meaning the false crabs, rather than bracky Era, which are supposedly true crabs. But hey, you know they're they're close enough there crabs. And so the study that I was reading about that I wanted to talk about was actually just published earlier this year. So in and It was by Jack Greenshields, Paula. Shermocker,

and your Hartigaie in the journal Marine Pollution Bulletin. The authors here start by noting that bunch of research has identified a problem of marine life being in one way or another attracted to plastic waste. So we've talked before about some of the problems with plastic trash in the ocean. We discussed this somewhat in our interview with Christine Figner as it regards um, you know, the interactions between plastic

waste and sea turtles. But plastic trash in the ocean is not just a sort of accidental collision problem, right. It's not just that a turtle happens to randomly swim into a bunch of plastic six pack rings that are floating along on the surface of the water. In many cases, it appears that animals that live in the ocean are actively attracted to plastic waste. That it is it is getting their attention in one way or another and disrupting

their natural survival behaviors. And there are debates about the reasons for this. There are, of course, no doubt, different reasons when it comes to different types of plastic waste and different animals. So, for example, in some cases, visual mechanisms have been proposed maybe who knows, maybe a plastic bag drifting through the water looks like a delectable jellyfish and so forth. But in other cases the mechanisms can

remain more obscure. And in this study, the authors were investigating a strange phenomenon in a hermit crab species called Pagurus bernardus, which is the common hermit crab or the

soldier crab. This is a species that's native to the Atlantic coast of Europe and along the northern coast of Europe, basically the coast of Europe, but not really the Mediterranean uh specifically, this study I think was looking at the waters off of the eastern northern coast of England, so off of a place called robin Hood's Bay in North Yorkshire.

I was actually listening to a radio interview on the CBC with Paula Shermacher, one of the authors of this study, and it was addressing the question of why were hermit crabs chosen for this study, and Shermocker says that hermit crabs are sort of a good model species to study She identified a few reasons. They're small, they're very curious, and they have quote a very diverse appetite, which I think goes with a lot of the things we've been

saying so far. That you know, there are plenty of crabs out there, both true crabs and crab like animals, false crabs that that are not super picky when it comes to food types. They'll take what they can get, and hermit crabs often appear to fit that bill. They have a they have diverse diets and appetites. Yeah, I

love that tidbit about hermit crabs, uh says. They they're they're interested in things that smell like food, but they're also interested in the site of another hermit crab appearing to eat something, so that that alone is is enough of a cue for them, right. But so, this research team was based out of the University of Hull in England, and what it found was that hermit crabs were attracted to the smell of a plastic additive known as olyamide. Now,

oleamide is an organic compound. It's used as an additive agent in numerous plastic products. I was digging around trying to find out more about exactly what it's used for, And it looks like most often olyamide is used as a quote slip agent uh, and so this would be something that is added to a polymer to reduce the coefficient of friction on the surface of the material, basically

to make the polymer more slippery. I also saw one of the authors here, I think it was in that CBC interview saying that it helps in some ways make the plastic more malleable. But it seems like the major use of it, from what I could tell, was to make plastics less grippy, to make them them a little slicker to the touch. And so you might wonder, well,

why would you want that? Sometimes I think that's a desirable characteristic of plastic on the consumer side, But it also looks like slip additives are just important on the manufacturing side, especially with products involving thin plastic films like plastic bags and thin plastic food wrappers and packaging and things like that, and that adding these slip additives helps make it easier to like extrude the materials and then wrap them up tightly. But ollamide is also a a

natural fatty acid. It's a natural organic compound that you know you'll find it in our bodies. It apparently has something to do with the regulation of sleep in in humans, and so I think has attracted some attention as a possible sleep aid, though I can't vouch for whether those UH alleged uses would be valid or not. But at least olamide naturally seems to play some role in the regulation of the desire for sleep in the human body. But again, it's also being used as this additive to

help lubricate our plastics. And it turns out when you put oleamide into plastics, only amide can sometimes leach out from that plastic into the environment. So what happens if you're a hermit crab and you are crawling along the ocean floor and you happen to stagger into a big junkyard of plastic waste that is flooding the water with low concentrations of oleumide. Well, according to this study, surprisingly,

if you're a hermit crab, that gets you really excited. UH. The authors of this research found that exposure to low concentrations of oleamide dispersed in water will cause an increase in the respiration rate of hermit crabs, and that this is a standard biomarker sign that that indicates excitement and attraction.

Speaking to CBC Radio, Poulishrmacher again, one of the authors characterized the hermit crabs reacting to the oleamide as almost hyperactive, and so the question would be, why why do they get so excited and stirred up when they smell this plastic a additive. Well, basically it seems that they're reacting to olamide the same way they react when they smell a really exciting food stimulant. So this research was done

in controlled conditions. But if if this in fact bears out into the natural environment, what you'd have to imagine is you've got some piece of very well lubricated plastic trash that is leaching oleamide into the sea water, and then a hermit crab smells it and then it kind of powers up, gets excited and heads toward the food source, only to find an inedible piece of plastic at the end of its hunt, which obviously is not great for the hermit crab, is because they should be spending that

energy hunting for real food rather than than plastic that they can't really get nutrition from. So why would this compound used in polymer manufacturing cause a hermit crab to react as if it smelled food. Well, again, I think the answer is not known for sure, but the authors seem to have a pretty strong suspicion on that front, which is that only am i'd is chemically similar to olaic acid, which is a chemical that is released by

the rotting bodies of dead arthropods. Of course, hermit crabs are arthropods as well, you know, these these related creatures with exoskeletons. So a hermit crab may well smell a plastic food wrapper that's been you know, tossed into the ocean's litter, and then it literally starts heavy breathing at the thought of the ripe dead body of an arthropod cousin that that it might be able to feast on. Because again, hermit crabs are scavengers. And this is what

the authors call an old factory trap. All right, yeah, well this this makes sense. Yeah, it smells like shrimp death or a crab death or or what have you. They're going to be interested and go over there and check it out. And even if it's not, I mean, even if they want you know, didn't actually consume any of the plastic. Like you said, this is wasted energy, this is wasted scavenging that that should be spent on

more lucrative endeavors. Right. So yeah, So to come back to the original question, that this is one indication of another way plastic waste in the ocean could be harmful to wildlife and showing a mechanism of attraction. In this case, it could attract these hermit crabs by way of additive leaching, possibly on the false promise of rotting kin flesh. Now, as to the question of whether the hermit crabs actually end up eating the plastic, whether they find it, I'm

not sure about that. This study was just looking at them responding to the smell as if it were food. I don't know whether they would actually try to get it down the gullet or not. Another thing that I thought was worth flagging is there was an interesting case of miscommunication and some early science reporting about this study because a number of early articles about the study incorrectly claimed that the that the hermit crabs were sexually aroused

by the smell of the plastic additive. That is not true. That is not true of her crabs. That seems to have been a miscommunication based I think out of the university press office where this study came from. But while this is not true for hermit crabs, it does appear that olamide is a constituent of the sex pheromones of some other organisms like cleaner shrimp. So you know, you

can't rule out all possibilities. Maybe there are some Arthur pods in the ocean that would have some kind of sexual response to plastic additives than now, I was looking up more on the relationship between olamide, oleic acid, and decomposition, and uh I was reading a few things that actually reminded me of something we've touched on on the show before, which is the fact that oleic acid played a role in some classic research on ants by E. O. Wilson. Robert.

I don't know if this rings a bell for you, but uh so, back in the fifties, EO. Wilson, the Great Entomologist, was studying harvester ants and their waste disposal behaviors,

and so many ants have tremendous waste disposal capabilities. So ants will sometimes create a midden in or around their nest, basically a trash heap where they dump their garbage and the makeup of this midden can vary, but it will include everything from feces, to debris removed during nest construction or other behaviors, to the dead bodies of fellow ants

from the colony. So you come across a dead ant in the colony, you want to get that out of there, and so the ants will take it away to to the midden or in some cases just away from the nest, but in other cases to this this trash heap and the middens containing the bodies of dead ants have sometimes been referred to as ant graveyards or ant cemeteries. They are somewhat creepy to look at. They're like a spider's

web without the web. The process by which social insects remove dead relatives from their test is known as necrophoresis, and that that comes from necro meaning dead and phoresis meaning carrying or transport. But to bring this back to EO. Wilson in this somewhat famous story from the history of entomology, when EO. Wilson was studying this death transportation behavior in harvester ants in the nineteen fifties, he started to wonder how the ants could tell that one of their number

had died and needed to be removed. What what was it that triggered the undertaker behavior in a certain in a certain subset of ants a certain period after another one of them had died, And so Wilson he figured that this likely was caused by by some kind of smell, a pheromone of some kind. In this case, it's something that would actually come to be known as a necromane.

And he studied a bunch of different compounds that that could be released by a crushed or decaying dead ant, and he eventually found a winner, which was our old friend from from just a bit earlier, oleic acid. So, according to this story, he then tried an experiment where he got a bit of oleic acid and he dabbed it onto a live harvester ant to see what would happen. Okay, so this is one of these compounds released when an aunt is dead. Now an aunt is alive, but it's

got this stuff all over it. And sure enough, he reported that eventually the tainted ant was grabbed by other ants and then treated as a dead aunt. So it was alive and kicking, but it was carried off to the midden for disposal. So basically he framed an aunt. Yes, he hung a sign on it saying I am a corpse, and the other aunts were like, okay, time to time

to get to work. Um. Now, I think the happy ending of the story, if I recall correctly, is that after the ant spent a while cleaning the oleic acid off of its exoskeleton, it successfully rejoined the colony. So it just had to get all this stuff off of it. Yeah, I had, um, I remember reading about this or or

we're seeing it covered in one the documentaries about Wilson. Um. I think one of the things I love about him is that, like, he clearly has a tremendous amount of love for ants, but it's a love that is based in how they actually function as organisms, more so than like anthropomorphism, because it's easy to love ants and you know, think in terms of of armies and you know, very human models of what they're doing and why they're doing it.

But but Wilson, you know, I wouldn't go as suppost well, I would go as far as to say that Wilson like speaks and understands their language because because that that is a predominant area of a lot of his study, he understands how they communicate and and and and in doing so he has this this understanding of what they are and you know how they function. Oh, I totally agree. That comes through when you hear him talk about aunts. Yeah, that he he loves ants, not not by anthropomorphizing them,

but loves aunts as ants. Let ants be ants. They're really good at it, and they're really the ast at it. I mean if you actually part of the problem is if you try to love ants by anthropomorphizing them, by imagining them as tiny humans, then their behavior becomes monstrous, Like humans should not be doing what ants do, but ants should do what ants do. Ants are great at doing ants. By the way, if you want more content

on ants, we did a series about ant wars. Uh I guess it was last year, but you can find those those episodes. I think there are three or four of them in the archives. But so anyway, for for these harvester ants, oleic acid seems to trigger an instinctual behavior that says, hey, this object is filthy, rotting trash. Maybe you know it's some kind of garbage or it's a dead one of you, so it just needs it needs to be out of here, get it out of here,

and take it to the midden. Now, in contrast with the other study with hermit crabs, I thought this was just funny because in so in these harvester ants, oleic acid means you know, I am dead, take me to the graveyard, and in hermit crabs, oleic acid and possibly only am I to because it is chemically similar, causes the reaction of you know, commence your heavy breathing. The buffet is now open. But in either case it appears

to have something to do with death and decay. Is just the question of like, does arthropod death and decay signal to you a sort of an affection risk, something that's like whatever this is, it's it's it's not something we want in our colony, we need to get it out for hygienic purposes. Or does it signal something is potentially delicious and you know you're not going to miss up a chance to get some lunch. And apparently the use of alic acid is a type of signaling molecule

conveying information about death and decay among arthropods. Doesn't stop there. Because I was looking at a study from two thousand nine published in the journal Evolutionary Biology by Yao at All called the ancient chemistry of avoiding risks of predation and disease. Uh. You know, so a cockroach can smell a dead or crushed cockroach nearby, and the researchers determined that it was primarily by the presence of a couple

of fatty acids linoleic acid and oleic acid. Again, like we've been talking about using these, uh, these molecules as necromaneques, and the authors here separate the responses to these necromone cues into into two main categories so that they talk about what we were just talking about, the the necrophoric behavior of advanced to use social insects like ants, bees, and termites that will smell oleic acid or linoleic acid on on a dead member of their nest and then

use that as a behavioral trigger to get that thing out of the nest or into the midden safely away from the activity of the other members of the nest. Uh. So that's necrophoric behavior. But then there are plenty of other arthropods like cockroaches apparently, uh, these would be classified as maybe semi social species that practice necrophobic behavior instead, so that's just avoiding the smell of death of their own kind. And the authors here were looking at the

question of how where does this come from? You know, lots of different arthropods seem to have this behavioral response to these compounds. And so the authors say, quote, we hypothesize that necromones are a phylogenetically ancient class of related signals, and predicted that terrestrial isopoda that strongly aggregate and lack known dispersants would avoid body fluids and corpses using fatty acid necromones. These again would be things like like oleic

acid or linoleic acid. And so the researchers here found that indeed, these these isopods were were repelled by several things, so crushed conspecifics. They were also avoidant of non crush just intact corpses of their own kind and alcohol extracts of the bodies of their own dead. And then they write, quote, as predicted, the repellent fraction contained olic and linoleic acids

and and authentic standards repelled several isopod species. And then I think they also did some tests in other organisms tent caterpillars and fall web worms, and found that these creatures would would also tend to when they were siting their nests, they would avoid sites that smelled like the body fluids of their own conspecifics. And then finally the researchers found that just plain olaic and linoleic acids were

strongly avoided by these creatures. So there are diverse types of arthropods across, you know, widely varying categories of life, that all seemed to have this necromone response. They smell olaic acid or linoleic acid, and that signals to them

some kind of get away from this reaction. And the researchers here traced this back to aquatic ancestors of all these existing creatures uh that that lived probably more than four hundred million years ago, they say, at least four hundred and twenty million years ago, and this pre dates the the divergence of Crustacea and hexapoda, So modern terrestrial insects and crustaceans, which would include crabs, an ancestor tracing back to before those different categories of life split off

from each other, probably developed this response. Though of course, at some point along the way, some creatures started reacting to oleic acid as as something to to be chogged down on. Wow. So there's you know, there's plenty to be concerned about with with with our over alliance on plastic,

especially single use plastics. But in this we see a way that that plastics can end up um interfering with this, uh, with with the with the olfactory language of decomposition that is so rooted and established in the natural world, the hugely widespread chemical language. Yeah, that affects insects and and and crustaceans and and there are different responses to it.

But if the researchers in that of your right, it's at least one of these chemical additives commonly used in plastic just happens to start saying words in this ancient language, and that kind of confuses that could potentially confuse all kinds of organisms. It's kind of like an alien probe

or land on Earth. And it was it was, you know, just it was carrying out some sort of you know, function unrelated to human beings, but it also emitted a signal on an audible signal uh in English that said half off on electronics, um, you know, and and people would be then be drawn to it and they might be disappointed when they reach it and find out that it's it's just you know, terraforming the planet or something

and not offering discount electronics. What what do you say on Earth that makes some people think, you know, death and decay, stay away, and makes other people think delicious? Um all you can eat buffet? I mean really that you don't have to go much further than that. The smell of packet French onion soup mix angels to some devils to others. You know, all right, all right, you never noticed that, Like some people smell that and it's just like the eyes go wide. It's delicious, and then

I don't know, sometimes it just smells like armpits. Maybe hot dog water would be another example, you know, you know, depending on like you know, so many things. It's it's context, right. For many people, that's gonna it smells like, you know, a day at the ballpark. Other people are gonna be like, that's just that smells like like sausage meat has been soaking in there and and you know, in there for a day or so in a cart. How to hermit

crabs react to hot dog water? I bet well, I bet yeah, I bet they I bet they they're very interested. They want to know more about it. All Right, well, we're gonna go and close the uh, the the crab trap on this one, but but we'll be back in the future, who knows what. We'll probably be back with more crab content at some point. Uh. They're probably not for for Thursday, but in the meantime, we'd love to

we'd love to hear from everybody out there. What are your thoughts on uh, some of the myths and legends we talked about here, some of the environmental issues, and of course the behavior of crabs. Um. Oh. And on an unrelated note, I also just want to signal out another really fun thing to do in New Orleans that I did not know about until this previous break. Music

Box Village. UM really fun place. It's like a imagine a like a kind of Junkyard playground environment where everything is a musical instrument and um and uh and uh adults, children, you know whoever, everyone when there is invited to sort of make sounds on it uh and creates this wonderful communal experience. They're also performers there. I just had a great time with it, so I just felt like I should I should share this, I should share this with

the world. If you're not, if you're not familiar with it, I never heard of that. Yeah you can. You can look at up at music Box Village dot com. In the meantime, if you would like to listen to other episodes of Stuff to Blow Your Mind, you know where to find us. Uh Stuff to Blow your Mind podcast feed It's anywhere you get your podcasts. You get core episodes on Tuesdays and Thursdays, listener mail on Monday's, Artifacts on Wednesdays, and on Friday's we do Weird House Cinema.

That's our time to set aside most serious topics and just talk about a strange film. Big thanks as always to our excellent audio producer Seth Nicholas Johnson. If you would like to get in touch with us with feedback on this episode or any other to suggest topic for the future, just to say hello, you can email us at contact at Stuff to Blow your Mind dot com. Stuff to Blow Your Mind's production of I Heart Radio.

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