From the Vault: Crabs Eat Everything Around Me, Part 2

of the Feast of Crabs. If you haven't heard part one, you should probably go back and listen to that one first. But I'm ready to jump right in. Yeah, we're gonna We're gonna continue with our exploration of various uh accounts of crabs eating curious things, eating things in curious ways, and so forth. This is kind of our they kind of tradition during the holidays towards the end of the year to dive into a crab related topic and see

what it has for us. Now, we haven't talked a lot about mythology and folklore in in our crab journey thus far, and you know, part of it is. When you look around, crabs often don't have central roles in um in myth cycles. I mean there I think there's some exceptions to the rule, but a lot of times it's stuff like, uh, like Hercules is fighting the hydra and then a crab shows up and tries to to to nip at his heels and he dispatches it and goes back to fighting the hydra. That sort of thing.

Oh yeah, that sounds it was. So that's the crab cancer, right that became the constellation name from, or that has the same name as the constellation. I mean, he still gets a constellation out of the whole affair. But it's you know, it's it's it can feel little bit disappointing if you're really into crab uh anatomy and into crab monster movies, UM, it can be a little a little bit of a letdown, Like, come on, you can't Hercules have more of a battle. Can't he just battle the crab?

That sounds fun to me? Oh wait, I just had to look this up because I wasn't sure if I was remembering it right. But yeah, he he gets the constellation basically because Hara hates Heracles and the crab like bites him on the foot, and then Heracles kills the crab and Hera's like, well, good job biting him on the foot. I'll put you in the sky forever. The Greek gods. Well, I do have a fun one that I found though, that I want to share with everybody.

This one I discovered in the book Japanese Mythology A to Z by Jeremy Roberts. I looked around to try and find some of the places as well and didn't offhand. Um, I'm sure it can be found other places, but this is the only place I was able to find find it. I'm going to retell it for you here, but I'll stress that Jeremy roberts telling of it is is going to be more dramatic than mine, So definitely go to that source if you want to see it for yourself.

So that's how it goes down. A young girl, uh buys a crab from a fisherman in order to save the crabs of life. She's doing, you know, the basic thing that a lot of little kids will do, where they suddenly, you know, they'll feel sorry for a captive animal or a food animal, and they want to to save it, and so that's what this girl does. She buys the crab, lets it go. Meanwhile, her father is in a similar scenario. He's trying to save a frog from a snake. I'm not sure why, but he's trying

to do this. He's like, no, snake, you do not get to eat this frog. I'm not gonna let you do it, and the snake finally is like, okay, look, I'll spare the frog's life, but you have to let me marry your daughter, and dad agrees. So we don't know anything about this frog. It's not special, like it wasn't his brother who got turned into a frog or something.

There has to be more to this story. Um know, I've been reading a lot about various yokai recently, and you know, with with those Chinese ghost stories, there's often some hidden meaning. You know, maybe it comes down to a turn of phrase, you know, something that's not going to be obvious in a pure English translation, or it's something metaphorical, etcetera. So I don't know exactly what is going on here, but I think it can't just be the fact that Dad just loves frogs and loves frogs

more than he loves his daughter. Um, but at any rate, this is the scenario we find ourselves in. Okay, So what happens? Well that night the snake arrives, but arrives in human form and tries to claim his bride. And so Dad at this point has not even warned his daughter about what he agreed to. Uh. So he's he's able to buy a little time. He's like, look, look, just come back in a few days, and the snake agrees. So Dad has a little opportunity here to talk with

his daughter. He tells her what has happened, and she is rightfully horrified. She hides away in her room in she praised to the gods for delivery from this uh, this snaky fate, and the gods do not answer her prayers because they're too busy putting crabs in the sky. Perhaps, yeah, it doesn't see that the gods are are listening to her. And meanwhile, you know the the The two days pass and here comes the snake again. Only this time the snake has come in its serpentine form. It's an animal form.

It enters her room, and just when it seems that she is completely abandoned to this fate, a thousand crabs burst through the door and consume the snake, just you know, completely deflesh it a thousand crabs. And so I guess the idea is like this is that that she spared the crab earlier and so she had she had a friend in the crabs, And or you could also look

at it like the gods did actually reward her. They were listening, and they allowed all these crab saviors to come and yeah and yeah, save her from this snake and she marries this warm of crabs. I don't know, maybe, but but I love this because it's also like, oh man, this is something you could have, like a swarm of crabs tearing tearing an enemy apart like that should be in a film somewhere somehow, this whole thing could be adapted into some sort of like a weird horror tale. Yeah,

crabs are not usually the hero of a story. Yeah, this this is maybe the only one I've really been able to find so far. But hey, if you know some good crab hero stories out there, right in because we love to hear from you, because yeah, generally it seems like crabs are going to be a minor character. Uh you know, let's think of Disney's a Little Mermaid, right, the crab is just there to be a friend to arial the Mermaid. Uh. I guess maybe he comes through

a time or two. But he's he's not the focus, he's not the he's not the big central hero. But you know, I think it's a kind of mechanically intuitive pairing to have snakes and crabs together in a tale like this. Yeah, it does seem like it's some thing that storytellers around the world have come back to a few times. Um. For instance, there's this crab snake duology

in the Aesop fable The Snake and the Crab. Also, speaking of Disney movies, it factors into Disney's The Sword in the Stone, which is a King Arthur movie that I imagine a number of you have seen and they're familiar with. It's an otherwise in my opinion, it's it's kind of a boring film. It doesn't have a lot going on, except it has this fabulous wizard battle between Merlin and this this evil witch who I think was created for the Like. It's not Morgana or anything, it's

just it's just this witch that he battles Mab. I think her name is Mimm Mim. Yeah, I think you think you're right. So anyway, it's a battle between between two magic users and the whole the rules of the battle are that they have to fight each other. Uh, No one can turn invisible. You can only transform into real world animals, not into of fantasy animals. And we're

going to see who who winds up on top. So it's a fabulous sequence where they jump in and out of various animal forms and there and you know, generally trying to counter each other. And in this it actually reminds me a lot of of of another of a Japanese story about foxes that are engaging in a similar competition, magical foxes who are transforming themselves into different forms, and like one transforms into this and the other transforms into something to sort of uh counter that, and it just

keeps going. And in this case, one of them transforms into a snake and the other transforms into a crab in order to of course clip that snake in half if it can. Yeah, this comes back to that mechanically intuitive pairing I was talking about, where I think people just have a natural tendency that goes like this. So first step, you see a thing that is longer than it is wide, and then the second step you automatically

think about cutting or snipping a cross wise. So snakes are naturally long and crabs have by logical scissors on their legs. Yes, um, I also yeah, them is great in this. But also I have to say that Merlin has a wonderful animated mustache as long as we're we're focusing on November mustaches here, and it makes sense right because we think of the like the mouth parts of a crab, it's easy to to imply some sort of a mustache going on there as well. Oh yeah, it

fits right in there. Now I want to say something else here. I thought that this is worth noting about the crab, the crab form, and about how the crab is just ultimately this winning design. In fact, it's such a winning design that, according to a two thousand twenty one Harvard University study, the crab like body plan evolved at least five times independently in both true crabs and

false crabs. So that's at least five cases of carconization. Uh. This is a term that was coined by evolutionary biologist l. A. Bora Dale in nineteen sixteen. And on top of this, the Harvard study points out that the crab body has been lost at least seven times, so this would be a process that they referred to as d carcinization. So, um, I love this idea. I mean this kind of falls into I think a popular meme about everything becoming crabs, about how, given enough time, the crab form will be

the form of everything because it just works so exceedingly well. Now, I do enjoy that meme. I guess technically, if we want to be pedantic, it's about certain types of arthropods, Like you've already got certain a certain body plan to start with, and if you're starting there, things that are like, you know, lobster ish or something in one way or another often are shaped by their environment to become more crab like. But yeah, yeah, thumbs up to the meme.

So the first crab I thought we might talk about here today, uh, sometimes referred to as the Yeti crab or the hoff crab, it's its actual name is is perhaps a better suited for this interesting creature. Now there are a few different varieties, uh, but the one of the first that was really discovered that really set the trend is Kiwa Hersuta. Kiwa is the name of the Maori sea god and then Hersuita is Latin for Harry.

So Kiwa Hersuta was discovered by a team from the Monterey Bay Aquarium in two thousand six along the Pacific Antarctic Ridge south of Easter Island. And it is a is a wonderful looking creatures. This pale, hairy looking crab, kind of elongated looking. I would say it looks a little bit like, you know, some sort of a lobster perhaps, but it has no eyes and it lives on hydrothermal vents. So this discovery gave us not only a new species,

but a new genus, that Kiwa genus. And there are other Ciwa crabs that have popped up, including Kiwa ty Larry found off the Southern found in the Southern Ocean off of Antarctica. And this species is probably my favorite, as in my opinion, it's a little more cute looking,

it's less elongated, and it's more it's more plump. It looked um, I don't know, it just looks like like like it it it belongs in a cartoon, you know, yes, And it's a great example of the kinds of things we were just talking about, with these sort of converging forms of different types of of marine arthropods. Because technically the Kywa genus are not true crabs. I think they are a type of lobster or lobster related organism. But there it's they're super cool. I mean, they're also focusing

just on tylery. Here it has a tiny habitat, a mere thermal envelope of a few square meters deep along the East Scotia Ridge. Um it's here that they live by these black smokers. These are vents, These a chimney like vents that spew dark water that reaches temperatures of

roughly seven degrees farenheight or three degrees celsius. They live in heaps here, sometimes like six thousand crabs per square meter, and they're cramped in here because outside of this narrow proximity to the black smokers, the ocean is extremely cold. Uh so they're they're this fascinating example of extremophile life suspended between boiling eruptions and chilling darkness. Like this is

the niche that they've carved out for themselves. It's also interesting to imagine how they would spread between one vent to another. You know that you almost have to imagine their lifestyle is like a uh, you know, living on these tiny islands in a way. Yeah, yeah, so yeah, they're so they're on these little little islands and uh

and they're they're jocking position here. So you tend to find like the older, bigger crabs are are are towards the center, towards the heat, and the adolescents are having to to scramble for position on the outside. Meanwhile, the hot sulfur rich zone is is likely too much for their eggs, so the females seem to have to crawl off into the colder, darker waters to brood and they likely die there. They likely just don't have the energy. They spend all their energy going out to do that

and they can't make it back. But the females. Then this releases a vast quantity of larvae into the water column, and some of these end up finding distant vents, others returning to their own vent um. So you have this is how we end up with with with with the larvae from from a particular hydrothermal vent location potentially ending up at other vents. Yeah, like a lot of organisms

in the ocean. They've got this sort of broadcasting method of reproduction that allows allows uh the organisms to spread in their in their larval forms. Yeah, I was reading a great article about this in on the BBC website by Jonathan Amos wrote about them in two thousand and eighteen and points out the first of all, the last common ancestor of all these various Yeti crabs probably live thirty to forty million years ago in the eastern Pacific.

And so what we have here are these different far flung ancestors due to the successful colonization of hydrothermal vents by dispersed larvae UM and so the other. Then the crazy thing about all this too is once they have found a place to thrive, that doesn't mean that this is a forever home UM. In Amos's words, these various events quote switch on and off through time. So event that has this thriving population of of of Vietti crabs around it may just suddenly turn off and then everything

around it just dies in the cold um. And then it may turn back on later uh, and then it's a place that the larvae can can can can arrive at and life can sort of begin again until such time as it just turns off. Returning to the island analogy, you have to imagine like a small island that has a thriving ecosystem on it, and then suddenly it just gets like a dome clamped over it that turns it into a sub zero freezer. And then at some point maybe the dome is suddenly lifted and it's exposed to

the sun again. Yeah, yeah, and so this is why any given species of yetti crab has to ultimately maintain multiple footholds at different events to survive. But it also drives home the delicate how just how delicate these event environments are, because um, if human activity wipes out, you know, potentially, just like it seems like just one or two of these vent habitats, they could potentially limit a given species holdings to an unsustainable level. Um. I don't know that

researchers have really worked out. I mean we we I don't think we know enough about like you know, all the different places that they live. But yeah, it's it. Basically the idea is we we we don't know just how delicate the situation is if they're depending on vents that may again turn off and back on again at

any given moment. They have to have a foothold in a certain number, and if you start digging into that number through deep sea mining or some other human venture, then yeah, you potentially put them in in an unsustainable place. Won't someone think of the dear crustaceans. I mean, they are so cute. I mean it is uh probably easier than than with a lot of arthropods in the ocean to generate sympathy for them because they look kind of like, yeah,

these pale, fuzzy ticks. Uh, that doesn't really folks sympathy, does it. But they yeah, they're they're like plump and cute and I don't know, they're good well, also, Tylery, especially if you look at a picture of them from a from above, it also kind of looked with the pale colorization, it looks like a human skull from above, like there's a human skull with skull cover colored legs and claws coming out of it, which again doesn't sound very cute, I guess, but um, but but it makes

it makes it a very interesting creature to look at. Now, I should again stressed that we have different varieties, and they have some different um different features. For instance, tay leery have special spikes for scaling up those chimneys of the black smokers. Meanwhile, there's a species found near Costa Rica which is Kiwa pura vita, which doesn't have claws

at all. Um, So you have they have different varieties, but what they seem to all have in common is their namesake, hey, which isn't here at all, but set which they used to collect bacteria growing around the hydrothermal vents and also to grow it within these what if it's sometimes referred to as gardens on their bodies, and then they use their delicate mouthparts to scoop up and

consume the bacteria. So they are you know, they're they're walking around growing their own food, collecting their own food, and then growing it on their own bodies. It's pretty great. Thank well. This actually connects directly to a couple more examples I wanted to talk about. So the first one is connected by the idea of these deep sea dwelling UH crustaceans that can be found around hydrothermal vents. So I came across another report of interesting crab feeding behavior.

This this was from a short twenty six article and New Scientists by Sam Wong, and the subject of this, uh, this right up was video footage that had been captured by a robotic deep submersible that was based off of the Schmidt Ocean Institute's ship, the foul Core, and it had been exploring life around deep hydrothermal vents in the Pacific at a depth of thirty meters so way way down. This was in the Marianna region. Well, well, I have to slow down there. That it was called the foul Core.

So it was named for the wish dragon in the Never Enning Story. I don't know, what's awesome? So well, yeah, I don't know this foul Core in the Never Earning Story named after something else? Or is that original to the book? I don't know offhand, So I cannot answer your question. But that is its name, all right? Or are you gonna apply to set sail on the foul Core? Now? No, probably not, but I but I applaud the naming. Uh

either way? Well, so, anyway, the submersible based off of this ship was um capturing footage of crabs that were that were around these hydrothermal hotspots, and this particular species

was known as austin O Graya william See. Apparently not a whole lot is known about them, but they inhabit these hotspots, and like many other deep sea creatures, they tend to be pale and lacking eyes and so as to the diet of these crabs, they have been observed eating some regular things like snails and algae, but they have also been observed engaging in brutal cannibalism. You can find some video footage of this. Uh. It's it's of

a particularly frenzied quality. It's just sort of like a big murder puddle of pale crabs ripping legs and claws off and and running away with them. Uh and and and of course, in addition to eating other things in their environment, but on this expedition, footage was captured of these crabs doing something a little gentler. They were appearing to groom one another, eating bacteria off of the shells

of con specifics. So, for example, you can see one crab going up to an the crabs leg and just sort of picking at it, just picking it, not pulling the leg off and running away with it, as they might be wont to do in another situation, but just sort of like grazing along the outside of the leg, getting some of this, uh, this bacterial matting off of the surface of the of the exoskeleton. And this is really interesting behavior. It makes me wonder, like, what does

this indicate about the the nature of the crab. Is it possible this could have some kind of social role within crab society, like the social grooming behaviors of primates. I mean, on one hand, that seems kind of unlikely because these are you know, these are crabs. They're not they're not social mammals, um, you know. So it could just be that bacteria is delicious and here's some right now on on my on this neighbor's leg. But I

guess we don't know that this kind of thing. I'd be interested to see more research about, like could there be a role for some type of social grooming within these within the deep see Arthur pod communities. Interesting interesting Now I have in the background here, Joe, I had to do some quick research, and first of all, I can confirm that the RV Falcore is in fact named after the wish dragon in the Never Ending Story. Um

it was. It was originally called the c Falc, but then it was retro fitted um later um and I believe two thousand nine or so, and then it was renamed the foul Core. Now the name Falcore. Incidentally, Falcore is the English uh name for the wish dragon in the English translation of Michael Linda's The Never Ending Story.

In the German the name is fukor uh fu c h you are derived from the Japanese term for lucky dragon fukur you uh if I'm saying that correctly, And apparently it was changed in the English translation because, um, the name future sounds too much like an English language swear word. Okay, well, I I feel very educated now, Um the way, did they change the name of the type of dragon in the movie because I remembered it from the movie as being a luck dragon? Is it

a wish dragon in the book? I might have accidentally said wish dragon just now, but he is he is a luck dragon? Okay, wish dragon is a is a is a different film that I've also watched recently. We watched all the dragon films in Okay, we'll steady sailing to the Falcore. But let's get back to the world

of crabs. What else did crabs eat? Okay? Well, so we talked about them growing bacteria on themselves and eating it off of themselves, and then in some cases performing grooming like behaviors where they graze bacteria off of each other. But I want to move on to another parallel finding. So Okay, if you are even the slightest bit crab curious, you probably know a bit about the type of crabs known as spider crabs. This involves many different species, all

belonging to the super family known as magoid data. They're called spider crabs I think because their legs can get very long and spind lee, so in some cases they actually do look like spiders. One of these animals, maybe the most remarkable spider crab, is the Japanese spider crab or macro Kira camp Ferry, which is the largest extant arthropod in the world. So this is an ocean dwelling crab that still exists today. It's not some you know, devonian,

your riptoride, giant sea scorpion or something. You can find these out in the ocean still, and the largest one on record had a leg span of around three point eight meters or more than twelve feet, and it weighed something like forty something pounds, So these things are enormous. They're mostly legs, so you know, they're not like a solid mass that big, but if they spread their legs out, it is it is bigger than human body. Yeah, you can often find spider crabs at at aquariums and they

always need to look at. I mean, they don't do much. They're they're they're they're not really action packed, but they're very impressive specimens. But there's actually another interesting thing about this superfamily, the Majoidea. About three quarters of the species in this superfamily are examples of what is known as decorator crabs. Decorator crabs are animals that live in symbiotic relationships with many different kinds of sessile organisms by attaching

those organisms to their exoskeletons. Rob, I've got some images for you to look at. Uh. There are many different kinds that live in relationships with many different kinds of other species, but generally, a decorator crab wears other plants or animals as clothing on the outside of its shell as a form of camouflage to blend into its surroundings, and it does this by hooking these other organisms onto little bristles on its exoskeleton called ct S E T

A E, which I've seen compared to velcro. So this might be a sort of natural precedent for for velcrow technology. There are lots of different kinds of other creatures that get roped into this. Some particular species of decorator crabs, uh prefer algae, some prefer sponges, some look for certain briozoans, and some like anemonies that can sting. Oh yeah, I think yeah. There's been some some interesting studies we've probably talked about in the show before about these uh, these

anemone wielding crabs uh, and then what what? They usually have one on each claw and then if one gets taken away, they can care one in half to have to again that sort of thing where these the boxer crabs, Yeah, I think so. Well, yeah, so that example in particular of anemon ees that can give you a hint that sometimes these decorations on the outside of the shell do more than simply camouflaged the animal as it hides among the rocks and the other flora and fauna populating the

sea floor. Some of these decorator crabs select organisms that play a specific defensive role. So I was looking at a table of findings of this sword published in a book called Animal Camouflage, Mechanisms and Function edited by Martin Stevens and Semi Merlita. And this was from Cambridge University Press in two thousand eleven, and it lists a bunch of different examples of different types of majoid crabs, along with research identifying their preferred decorations and possible reasons for

that preference. So, for example, there is a type of crab known as the Innocus philangium or the leeches spider crab. It appears to prefer a type of brown algae known as dick yota dick atoma for the parts of its body most exposed to predators. And it turns out that this species of algae is not only good camouflage, it is chemically noxious. So it hides that this crab hides the vulnerable parts of its body behind something that predators

would probably find disgusting or even poisonous. Uh. Maybe, like if you were trying to, you know, protect yourself from tigers by covering your back in bottles of bleach, you know, a tiger gets in there and starts biting it's it's not gonna want any of that. Also along these lines, there's an Atlantic spider crab called stin O c o ops for cot Us that preferentially attaches a species of

stinging anemony to its carapace. And in both cases these decorations would appear to provide additional defenses beyond just masking the body in the environment. But the crab from this list that I wanted to focus on has a different relationship with its preferred decoration organism. It likes to eat

its own camouflage. So the animal in question is known as noo Mithrax ursus, or the hairy seaweed crab, and I think the Latin name of its of its species ursus, implies that it's also known as the bear seaweed crab or sign bear. And folks, I just want to say, off the bat, this is a beautiful crab. In some cases it looks like a cartoon animation of a crab being electrocuted. It's got like animated electricity lines all around it. Also sometimes it looks like a burst of fireworks from hell.

It is just a gorgeous Arthur pod and I can definitely see where the name comes in because it it is it looks like it's furry like the bear, you know, yeah, totally. Um. So, it has some natural hairs that that stick out from its exoskeleton. But it's also generally well actually not in all environments, but in some environments it covers itself in uh in in these decorations that give it this additionally

hairy look. So according to an entry, I was reading about it from the Museum's Victoria database the Australian Um Natural History Museums. Uh these are found in rocky shores and reefs around New Zealand and Southeastern Australia, and I was further reading about this this species in a in a research paper published in the New Zealand Journal of Marine and Freshwater Research ch in nineteen ninety four by Chris Woods and Colin McClay called masking and Ingestion Preferences

of the spider crab no no mythrax Ursus. And what the researchers here say is that in laboratory tests, specimens of this crab not a mithrax Ursus, were found to have preferences when it came to which organisms they would mask with. So it wasn't just any algae, there are certain kinds of algae they like to put on their shells, and specifically it was types of branched algae like how

op terrorists specific era and coralina office analis. And I actually just want to read in full a part from the introductory section of this paper that describes the process of attaching pieces of algae to the body, because I found it really fascinating to picture this routine as the crab does it. Uh, and so as a note to help understand what I'm about to read here, the words chilly and cheli peds refer to the clause. The cheli are the claws and the chelipads are the claw legs.

Pad isn't foot so the author's write quote. The masking behavior of in Ursus begins with the selection of a clump of algae. The crab then selects a single piece of alga, using the chili in a cella over cella technique to correctly measure the piece of algae to the required size. So they're measuring it out using their claws

as a as a as a ruler. Basically, this piece of alga is then snipped off using the cheli and transferred to the mouth parts, where the cut end is roughened and trimmed of any projections, while the uncut end is held by both chelipeds. Okay, so holding it in the claws and then chewing on the snipped end, putting it in the mouth parts to chew on it. Then once you've chewed up the cut end, good uh quote, one cheli pad is then used to transfer the piece

to a part of the body. Attachment is accomplished by rubbing it against the hooked set so that the end becomes entrapped by the city. If the algal piece does not attach it first, it is transferred back to the mouth parts to be manipulated, and then taken back to the side of attachment and rubbed against the hook set until it attaches. If the piece of alga fails to attach after a number of attempts, it is discarded and a new piece is selected. I don't know why, but

I found this kind of surprising. Something seemed kind of complex and and crafty about this process. Yeah, I mean it. It's it's a process that may seem, you know, out of beyond the the abilities of what we might might

generally attribute to a crab. But then again, we think about the way they eat, which we discussed in the first episode, and it does sound like a natural extension of that, Like, this is an animal that is very that excels at taking things apart um uh you know I usually so it can fit those things in its mouth uh and can consume it. But this is kind of a specialized version of the same thing, manipulating living things, um, and then using the pieces of that thing that you

have manipulated. It ends up being this kind of kind of like biomancy that the crab practices. Yeah, totally. I just love that detail about it chewing the snipped end of the alga in order to roughen it so that it attaches to the velcrow on its back. Now, another interesting fact this paper mentions is that there is a

lot of turnover in the crabs algae mask. Apparently not to mithrax Ursus replaces a good ten to twenty of its algae cover every twenty four hours, So that would mean, you know, every roughly five to ten days, it's got a new coat of algae on it. And apparently decorator crabs that use algae in particular can be very strategic

about its benefits as camouflage. For example, previous research, so not this study, but other studies they cite, had found in some decorator species that when you put a crab in a tank where it is surrounded by algae that doesn't match the color of the algae on its current mask, it will basically strip itself of the old algae and redecorate itself with the new algae to match its environment.

And also research has shown that when given the option, crabs will tend to stay hidden within masses of algae that match the color of their existing mask. So these crabs can distinguish between different types of masking materials and they can make calls about masking and hiding behaviors to maximize the camouflage effects. Wow, that's really it's really impressive. Yeah, it's it. It goes beyond just this near sort of automatic behavior that's taking place with anything that it happens

to come across. Right, So, yeah, it's not just sort of like rubbing up against a bunch of algae and getting it stuck on there. It's picking the algae that will that will do the best job of camouflage. But the researchers in this study found a different kind of discrimination in the selection of the masking material when it came to Noto Mithrax ursus. They found that the algae species the crabs preferred to mask with where the same

ones they preferred to eat. So, if you make like a ranked list of all of the algae that the crab will go to first to eat, which ones does it like to consume the most, that is going to be the same as the list that it will choose to put on its carapace and on its legs. So in a way, here it looks like the camouflage is

doubling as food storage. This crab is hiding behind a mask of its own lunch, so the algae on its back will help it blend in with its environment, make it look like a bunch of seaweed rather than a crab, so predators are you know, are less likely to spot it. But then also it can eat that seaweed. It can eat that algae if it gets hungry. It's like if we were to imagine a like an army sniper in

one of those gilly suits. But they insisted on only camouflaging themselves with their favorite leafy greens, so that they could snack on it whilst while stalking, you know, and and waiting on their their target to appear. This gilly suit is a super food kale only kale gilly suit. I love it, though, I guess it does make me wonder maybe there is an answer to this. I'm not sure, but it makes me wonder which way the adaptation goes? Like, how how did it end up matching the food preferences

and the masking preferences? Um? So, like, was it because a certain type of algae was the best, you know, provided the best camouflage cover, the animal evolved to prefer eating that kind or was it the kind that's most delicious and nutritious it evolves to prefer for masking. M Yeah, that's a great question. Yeah, the crabs are silent on

the matter. Thank you, thank you. All Right, up next we have this will be a shorter little section here, but this is something you you you pinpointed and then I followed up by looking at a source on it. But this is the idea of crabs eating This is so much crabs eating something remarkably different, but crabs doing it in a way we didn't expect. And that's crabs

eating quote unquote eating through their gills. Yeah, this is interesting, so circumventing the delicate mouth parts that you don't even have to raise a jaw leg for this meal. Right. So this concerns the invasive or at least invasive in um uh North America, and I believe in Africa as well. Uh, the the invasive green shore crab, which we've discussed on

the show before. I believe in their native European waters, they are sometimes harvested for food, and there have been efforts in North America, where it is certainly invasive, to encourage its use in cooking. You know, what are some culinary uses for this? And I think there have been some some ideas of using it as like a uh

you know, like like a soup base and so forth. Um, that's the same tactic you see with like invasive lion fish, hinging on the fact that if you really want humans to make a species disappear, make them desire that species for some reason or another, such as making it an ideal main course at a dinner. Sure. I think we've actually covered the green shore crabs in a different capacity

on the show before. I don't remember what it was though, So u has pointed out in a two thousand seventeen study from the University of Alberta, the green crabs are pretty snazzy consumers in their own right because they can again quote unquote eat by absorbing nutrients, specifically the amino acid um loose sign across their gills. And this was the first demonstration of crustaceans being able to do this.

Now that the crabs are notoriously hearty, as you often see with an invasive species um, so their bility disability might enable them to survive long periods between meals. So I don't have anything to eat, but I can absorb some some necessary amino acids, or it might help them cope with changes in salinity. So offsetting salinity changes via the amino acids that they can absorb just straight through

their gills. Okay, so they would not be fully like sucking in chunks of food through their gills and eating like that. It's it's specifically getting these particular amino acids, these particular nutrients out of the water around them as they breathe. Yeah, so you know that's again why we put eat in quotation marks here. I guess it's kind of like our humans eating when we absorb vitamin D via sunlight that sort of thing. Are we are we eating when we get a you know, some sort of

a vitamin injection or something. Yes, okay, I've got something I was wondering about. Rob You may have seen. Uh, it's a very popular genre of internet video, uh, feeding crabs human food. You know, I don't really think I've seen any of these. What kind of foods are they eating them in these videos? Oh? Everything I've seen. I

think I've seen crabs eating pizza. I've seen crabs eating you know, fruits and vegetables and chips and all the giving crab derrito is probably I don't remember all the specifics, but you know, I've seen a good bit of this in my day. Clearly, it's funny to look at, you know, it's crabs. It's kind of it thinks it's people sort of thing, right, exactly. A crab eating a derrito is inherently comedic. I don't know if it's good for the crab though. Then again, lots of crabs are scavengers. You know,

they'll eat what they can get. Um, So, so I guess I'm not too worried about the crabs. But but but I just wondered, is there anything interesting to cover about the phenomenon of crabs eating human food? All right, so we cannot speak for all crabs. We will not speak for all crabs. But one fun place, uh to look for some answers that I thought would be to look to the realm of hermit crabs as pets. Joe, did you ever have a hermit crab as a pet? I did not, did you. I've always wanted one, but um,

it's never been permitted. I'm always like that looks that could be a great pet. And and and whoever is in my life is always like, I don't know if you need that, and they're they're probably correct. So you mean your family now is preventing you from getting hermit crabs? Right? I think it's the end. I think the argument is a hermit crab is either too much pet or not

enough pet. So it's either a situation where like, uh, you really, you know, ask yourself, do we have space and time for this creature to live in our life as well? Or it's a question of is there something more exciting we could have, like a lizard, And that's like, that's where we are now we have a we have a leopard gecko. We skipped over hermit crab and went

straight to leopard gecko. This is a vertebrate household, so to be clear, there are more than one thousand hermit crab species, and you can roughly divide them all up into marine hermit crabs and terrestrial hermit crabs. Uh. So you're you know, you're your sea dwellers and then you're land dwellers. And there are a few different species that are popular pets from either category, but the ones most likely to encounter human food are of course those terrestrial crabs.

So I thought I might look at some terrestrial hermit crab feeding guides for some ideas. Okay, so I went to the spruce pets. This is I think it's from

the same people do like the sprucey heats uh. And they point out that commercial hermit crab diets are probably the best way to go if you're feeding a hermit crab, because these are balanced and they contain everything that they might need because in general, you know, matching up with pretty much everything we've been talking about here, they're going to have a very diet. Their opportunistic land roving omnivore.

So they're gonna eat a little bit of this, a little bit of that in the natural world, and you need a food source that reflects that they're on the seafood diet. I seafood. I eats it pretty much. Yeah, So they recommend I'm going to roll through a lot of foods here. They recommend such fresh foods as mango, papaya, coconut,

fresh or dry it. And I have to add that I can certainly back up the coconut suggestion because um, I got to watch a whole bunch of hermit crabs go absolutely crazy over a busted open coconut once and it was it was amazing. It was a feeding frenzy where you seeing the wild hermit crabs. I believe this

was in Belize, if memory serves. Oh okay, alright, But in addition to this, apples, apple sauce, bananas, grapes, pineapple, strawberries, melons, carrots, spinach, watercress, leafy green lettuces, but not iceberg lettuce because you know the the nutrient issue there, uh, broccoli, grass leaves, strips of deciduous tree bark, unsalted nuts, occasional peanut butter, raisins, dried seaweed crackers, unsweetened cereals, plain rice cakes, plain popcorn

on occasion, freeze dried shrimp, freeze dried plankton, Brian shrimp, fish, food flakes, and much more. Okay, so it looks to me like this, Uh, this list of suggestions from this website is suggesting a wide range of different kinds of foods, but seems to be avoiding things that have added sugar or salt. Yeah. They point out that the crabs may seem very interested in salty and sweet snacks like chips and sweet breakfast cereals, but these are to be avoided.

They say also stay away from dairy products, which makes sense when would when would a crab get a dairy product in the natural world? Um? And they say that the hermes are generally gonna be game for fresh or dried fruits of any kind, but some experts advise against highly acidic or citrus foods, so like, maybe don't give them a limon or a tomato. Also, starch veggies like potatoes are to be avoided. Um as well as again low nutrient iceberg lettuce. What I all this hating on

iceberg lettuce? I? Love iceberg lettuce. I'm gonna go out on a limb right here. I'm gonna say iceberg lettuce is awesome. I mean it, iceberg lettuce can be awesome. But the question is what are you getting out of it? Well, I don't know what you're getting out of it nutrient wise, but it's delicious, crunchy, crunchy goodness. All right, fair, fair enough,

Just keep it away from the hermit crabs. Um. Now, Also, hermit crabs require calcium, So remember that bone nawing we mentioned from the last episode involving other crabs kind of plays into into this scenario. Uh, calcium addition probably not gonna come as a surprise too many pet owners out there. I know with our leopard gecko, we have to we have to shake its crickets up in a bag with a calcium powder to ensure there's getting enough calcium, and then also leave some calcium out for it in a

little tiny dish. Um. But with crabs you can end up using reptile ready calcium supplements like this. But also you might end up using something like crushed oyster shells or cuttle bone as something that they can use to get their their calcium. Oh yeah, okay, So tying it back to the last episode, I was just remembering the

suggestion this was not proven, but it was. It was hypothesized that maybe one reason duck built dinosaurs had been eating a bunch of crustaceans that might have been crabs or some of their you know, related crustaceans that have these these hard shells, was that they were looking for certain nutrients types of protein or specifically calcium as part of their breeding and reproduction cycle. Yeah. Now one more, one more note from this spruce article because it's just

it's so crab. I love it. They say, quote hermit crabs are able to find their food in two ways, by smelling the food and by seeing other hermit crabs eating hermit crab dietary peer pressure. Yeah, so they might be like I detect food over there, or it's like that hermit crab is eating something I'm in, I'm gonna go, I'm gonna go try and steal some of that. All the hermit crabs, like Billy gets to eat iceberg, lettuce,

Billy gets to eat pizza. Yeah. But obviously, I, like I said, I do not have a hermit of a pet hermit crab. I've never had one. I've just gotten to observe some in the wild and you know, look at them in pet stores. So if there are any hermit crab enthusiasts out air and you have particular thoughts on this, if you can tell us, uh, you know what foods your hermit crab prefers the most, which ones you you like to give them? Definitely right in and

let us know. I'd I'd love to hear from that. Really, anybody out there with with crab expertise or crabs pertise, Uh, you know, right in, have you ever had part of your body eaten by hermit crabs? What was that like? Hermit crabs do? They just have a lot of character? I love I love watching them. Yeah. Actually I recall one Nature documentary segment. I honestly don't remember what it was from, but I think it was something narrated by

by Attenborough. Um. But it was a segment that was showing hermit crabs forming a chain of shell trading, so like they were all trying to trade shells to get a bigger shell, and they formed up in a line

essentially to each switch into the next one's shell. Yeah, there have been essentially like biology economics article that have looked at this, like how do they go about, um, you know, trading up on their their shell size and then you know, because if one leaves its shell for a bigger shell, then that opens up a shell for another growing hermit crab to take advantage of it. It's

it's really fun. So the adaptation there, I guess would have to involve the hermit crab observing when a bigger hermit crab is likely to be leaving its shell for for a bigger one. So yeah, that would take some kind of social observance kind of like what you're talking about with the hermit crabs watching other hermit crabs eat. Yeah, I mean I think also they're they're all about stealing as well, So it's it's a it's a crab kind of a crabby crab world. But who comes up with

these rules? You can steal somebody else's shell, but you can't eat iceberg. Let us. Now, they will eat the iceberg. It's not that they don't want it. I think I think the idea is like they will eat it, but it's just they deserve better. Okay, coming up soon, we're gonna do a whole episode on iceberg let us. It will be about how iceberg let us is the king of foods. It's amazing. I know that what iceberg let us must not occur in nature. Whoever created the strain

of vegetable is really deserves great credit. All right, well, we're gonna go ahead and close it out there, but yeah again, right in, we'd love to hear from you. Let us know if there are other examples of curious crab cuisines that that we were not familiar with. It didn't have time to cover here. We will mention it in an upcoming listener mail episode. Also, yes, hermit crab owners,

right in and tell us all about your babies. In the meantime, if you would like to listen to other episodes of Stuff to Blow your Mind, you can find us in the Stuff to Blow your Mind podcast feed

that it gets found anywhere you get your podcasts. Just you know, make sure you subscribe and you can get everything, including our core episodes on Tuesdays and Thursdays, our listener mail episodes on Mondays are artifact short form episodes on Wednesday, and then on Friday you get Weird how Cinema that's our time to just talk about a strange film of one sort or another. Huge 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 a topic for the future, or just to say hello, you can email us at contact at stuff to Blow your Mind dot com. Stuff to Blow Your Mind is production of I Heart Radio. For more podcasts for my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listening to your favorite shows.