323: Banana Slug

Thank you. Hi there, everybody. It's Ellen Weatherford. And Christian Weatherford. And this is Just the Zoo of Us, your favorite animal review podcast, where we rate your favorite animals out of 10 in the categories of effectiveness, ingenuity, and aesthetics. We are not zoological experts, but we try our best to bring the most interesting and accurate information that we can. And we're also coming to you from the land of the reigning champions. Super Bowl winners. This is my first time ever being in a city that won a Super Bowl while I was in it. Same, same. It's very exciting for me. As someone from Jacksonville, where not only did that never happen, it was never even a distant possibility. They did pretty good this year. For a while, it was nice because I was just keeping a very casual eye on how some teams were doing. I was like, oh, nice. It was a good weekend. Seahawks and Jaguars did pretty good. Yeah. But then a couple weeks ago, not so much. That's okay. Well, everything's coming up Seattle right now because we won the big game, the very big football game, which people who have listened to this podcast know I've never in my life spoken on. I've never watched it. i've never cared about it but this time oh yeah we were tuned in we used my mom's login to a streaming service and we did watch it we did and we did the whole thing we had chips and dick and our neighbors came over and watched it with us like we had the full like american super bowl experience yeah to give ourselves credit i was fully prepared to pay for our own subscription I wasn't. But then I saw that we were still logged in as them. Because they were here like a year ago and I guess logged in for something, to watch something, and then never logged out. So we were still logged in to my mom's account. I'm really hoping they didn't try to use it themselves and had some sort of problem because we were using it. Oh, did anyone watching the halftime show notice that on the screens for Bad Bunny's show, they had this like logo of a little mascot that looked like... to me i think it was a cokey yes which was very exciting for me i love those little guys i saw confirmation on that on several instagram reels oh good cokey mentioned i mean obviously the cokey was going to be mentioned yeah it was all about puerto rico which was really really cool uh we did an episode on the cokey very very early on it was probably like one of our first like in the double digits of episodes yeah yeah um but yeah we had a lot of fun the seahawks won that was great for us I've been loving seeing all the Osprey content. That's been very exciting for me. It's fun seeing all this like go Ospreys, like Osprey hype, because that was our college mascot. Yeah, yeah, yeah. Who famously didn't, I don't think still doesn't have a football team. It's so funny that you say that, because that specifically is in this episode. Is it? Yes, I will be mentioning that specifically in this episode. In fact, sports mascots are a fantastic tie-in to the animal I'm talking about. Great. I was just thinking, like, I'm the only one at this point who doesn't know what that animal is. That's true. Well, but also I was thinking about a few things. First of all, Seattle just won the Super Bowl, so, like, a lot of local pride. I'm thinking about, like, an animal that is, like, a local icon, something you're going to find around here. And also, this time of year is now, you know, mid-February. which is supposed to be winter. As I'm looking out the window, it is like extremely sunny and weirdly warm out today. But this is supposed to be the time of year for this animal to come out. What do you think I'm going to be talking about? What do you think it could be? Something you'd see out and about in the wintertime or in the rainy season. We've seen them before. Here? Yes. We've seen them on our street. Is it a bird? It's not a bird. Oh, God. Opposite direction. you're looking up look try looking down okay is it earthworms oh you're getting closer you're getting closer i'm drawing a total blank i'm sorry banana slugs we didn't we have not talked about banana slugs yet really yeah huh okay now okay my mind went there for a moment i was like no we've already done that surely nope we have not it's hard to tell though because we've done over 320 of the years now it's yeah it's getting closer and closer to a coin toss as to whether we've done an animal or not. Now, banana slugs belong to the genus Aerolimax. There's a few different species. I'm just going to be kind of looking at the genus as a whole. The one found in our area is the Pacific banana slug, and it is probably the most common banana slug, but they are found all over the West Coast. There's a few different species, and these were submitted actually like last year. So sorry, I wanted to kind of wait for like the time of year when they tend to be out more. I wanted to wait for the timing because this is kind of slug season right now. It should be at least. This has been a weirdly warm and dry winter for us, so I have not seen banana slugs out as much as I normally do. But last year, these were submitted by Garrick Hachay from Vancouver, Canada. I'm getting my information from a lot of different sources that will be cited in the episode description, including the U.S. National Park Service and a KQED article by Mallory Pickett titled Banana Slug's Secret of the Slime. So I'm going to be talking a lot about slime today. Okay. This is going to be a slime-heavy episode. It's real slime hours today. To me, the most immediately obvious noticeable trait of the Pacific Banana Slug, the first time I saw one, is its sheer size. we've seen these out and about in the wild and we've seen big ones yeah like when i see like a fully grown big one i always try to make sure i take a picture with my hand next to it so you can see like these things are the size of your hand yeah it can get up to a max of like 10 to 12 inches long massive slug and they're also really like thick and bulky too you know what i mean they've got a lot of heft to them because in florida i feel like the garden variety slug was very little Very tiny. We had some larger slugs that were like, I remember finding one that was like a snail eating slug. Oh. And that one was a little bit bigger. But yeah, you really don't get those huge slugs. And actually, this is one of the largest terrestrial slugs. They're going to be found in forests, particularly on the forest floor. These are ground dwellers. You'll find them in the leaf litter, under logs, stuff like that in forests along the west coast of the United States in Canada. And they belong to the taxonomic family Aereolimacidae, which are a family of terrestrial slugs. And I'm not going to dwell on taxonomy here because there's nothing particularly interesting about it in this case. And I mentioned this a little bit in the Sea Angel episode a few months ago, but like slug is not a taxonomic category. It's more of a morphological description. It just means a gastropod without a shell. So for example, like these banana slugs are more closely related to things like garden snails than they would be to a sea slug, like a nudibranch or something like that. It's convergent evolution that different branches of the gastropod family lost their external shells multiple times. It doesn't necessarily mean that they're related to each other. And I think that that probably has to do with the fact that they do like live on the forest floor they have to like crawl underneath stuff so if they had a big shell on their back it would be getting snagged on stuff and like it would hold them back i feel like so they kind of had to make some trade-offs there because the shell for gastropods tends to be their like first line of defense right you got no hard parts on your body right that's super snackable right you're a little you're just a grub you're just like a soft bodied and very inviting little thing wiggling around and you're very very slow too yeah that's the thing because it wasn't an anime moment like where they take off the weights and they were weighted like these are only holding me back yeah no uh they are still extremely slow and in fact banana slugs are even slower than like a lot of other types of of snails wow they are particularly slow even among snails and slugs. So I'm guessing the benefit really lies in not having to use resources to make the shell. That's true because the shell, you know, the body has to make the shell, right? So the body has to be dumping a lot of like calcium. I think it's calcium carbonate. I think that the body is making the shell out of. So like your body is spending a lot of metabolic energy and nutrients and stuff to make that shell. So if you don't have to make that shell, then that's going to free your body up to do a lot more cool stuff yeah but it also leaves you defenseless especially if you're also really slow and you can't escape from things very well so this brings me to the first category that we rate animals on which in this podcast is effectiveness physical adaptations things in the animal's body that let them do a good job of the things that they're trying to do and i'm giving banana slugs a seven out of ten okay the slime here is really the slugs bread and butter a lot of this conversation is going to be about slime. And I mean it quite literally when I say it too. You're making a face. I don't like those words in that order. Slime bread and butter. It's like a slime toast. Like not enough slime spread over too much bread. That's how I feel. Yeah, sometimes, some days. Banana slugs really use the slime for nearly every aspect of their life. It's helping them in every department of slug life. First of all, what a lot of people might know, and what you might notice is that when you see a slug crawl somewhere, right, there's always going to be that little shiny trail of slime behind them. So do you know why they like drop slime underneath them when they're crawling around? I have a guess. What's your guess? Just to lubricate the ground for themselves. Yeah, really. It is a lubricant. Like say they're crawling across a sidewalk, right? The concrete is going to be bumpy and scratchy. Anyone who's ever walked around on concrete barefoot knows it doesn't feel good. And especially if you're tiny, you know, you're only 10 inches long and soft. It's a mobile slip and slide. It's a mobile slip and slide. So it fills in all of those little crevices and sharp edges and corners in the ground and gives them a smooth surface to crawl across. Because they're basically dragging their body, right? They can't like pick their body up and take a step. they have to drag across the ground. So it's reducing the friction so that they're not getting the bottom of their body all scratched up. It also absorbs moisture from the environment around them. It helps protect them from drying out. For example, during the summertime, which is the dry season, they will sort of shrink up a little bit and coat themselves in this mucus. And the mucus absorbs moisture from the air, from the soil, from everything around it, and keeps the slug's body from drying up even when they're going, you know, months at a time without much rain. Does it stop them from losing the moisture they have? Or does it have to allow that passage, like, to be able to pull in air, I wonder? Yeah, so it's basically forming, like, a barrier between their skin and the air around them so that they're not losing their own moisture to the air around them. But still somehow absorbing moisture from the outside. I'm going to talk more about, like, the structure of the mucus in a minute because it is very interesting. Please tell me it's not salt gates. It's not what? It's not salt or sodium gates. I would not. I would never do that to you. If I never hear about sodium gates ever again in my life, it'll be too soon. I love you, sodium gates, but I do not want to learn any more about you. I'm sorry. You are very difficult to understand. But another thing it helps them do is it protects them from predators. It is very unpleasant. Like I mentioned, it absorbs moisture from the air environment around it. Like it just sucks up every little bit of water and moisture it can. So can you imagine popping one of those bad boys in your mouth? It's counterintuitive. How so? I guess for something that has that property, you would like what you're imagining from a touch and seeing perspective. Something rough, something crumbly, something like a dry sponge. Right. But then this starts off just wet. It looks wet and gushy. It looks like a gusher, right? Like you're going to pop it in your mouth and it's going to be like hydrating, right? But instead it just gives you like the worst cotton mouth you've ever had. It's the worst of both worlds. Yeah. Bad texture, bad moisture. It's all around bad. It's a bad time. It's really nasty. I have heard because I saw a few different sources say that it has like a numbing like an anesthetic effect basically that like when you come into contact with it it like numbs the skin that it touches but then I was reading this interview by Lookout Santa Cruz with a University of California Santa Cruz researcher named Janet Leonard who I will be talking more about this interview later it's fascinating she's a researcher who has been working with banana slugs for decades and one of the things they asked was if it's true that kissing a banana slug makes your lips tingle which i guess is a common thing i didn't grow up in this area so this seems like one of those things that like kids do like how like kids in florida would like put lizards on their ears and fingers and stuff like that like i feel like it's one of those things that like you grow up hearing about okay so they asked her if it was true and she said well students are always talking about this and so eventually i tried it and it is sort of a funny feeling but i don't think it's really anything special chemically i think it's just that they've got a very stiff mucus as it dries out your lips it sort of feels funny but i would be cautious about kissing a wild banana slug because they're famous for eating both poison oak and death angel mushrooms. You pick one up from the field, you don't know where it's been. The one I kissed was one that had been in the lab for a long time, and I sort of knew what had been eating. Have yourself a little toxin as a treat. Listen, as someone who regularly eats capsaicin, which is meant to be like a hostile toxin. That hurt a little bit. I'm going to do that again. can you make it hurt more just a little more you just a little bit more like i want it you want it butting up against that pain threshold that's like like you you definitely recreationally poison yourself yeah yeah so well it's not a pleasant feeling it's not something that anybody likes i would imagine that if you swallowed this like mucus saliva it would probably do some damage to your gastrointestinal system yeah just from drying you out right wasn't there a story of someone in australia who swallowed a whole slug on a dare and then like died from it i don't know i i mean i doubt it was this type of right yeah i guess um but i will talk a little bit later about possible culinary okay uh uses for the slug but also this is not like a perfect predator defense because it is just the mucus yeah if you can get the mucus off or somehow avoid the mucus there's nothing else preventing you from eating the banana slug so what raccoons will do that's so funny that's where my mind was going really what do you think they do they wash it right oh no it's not washing it i mean i'm sure they would but it's not washing that they'll do when a raccoon finds a banana slug but that was a good idea yeah but the raccoons will roll the slug around like with their paws okay and coat it in dirt so they just like make a little corn dog out of it and it coats it with dirt and kind of like neutralizes the mucus and then and then they eat it and it's fine or maybe it just like i think it's a combination of coating it and also like just scraping some of the mucus off. Yeah. So like if you're clever, you can figure it out, right? Yeah. Yeah. Like, I don't like this mucus. Dirt, however. Love that. That's the seasoning, baby. That's a little bit of dirt. So those are the kind of the things that the purposes of the slime. But there's something really interesting going on like when you really zoom in on the slime and like what it is, what state of matter would you describe? Do you think this slime belongs to? Like, how would you describe the state of matter it belongs to? I'm going to take a wild guess here. Okay. You've got like a 33.3% chance of getting it right. Maybe. Well, before you said that, what I was going to go with was probably like a non-Newtonian fluid. That is pretty much what it is. It pretty much is a non-Newtonian fluid. So what's interesting is that it is not totally solid or liquid. It has a structure called liquid crystal. In a liquid, the molecules are kind of loosey-goosey, bouncing around, going anywhere they want, really. Freely moving molecules. They can't go up into the air like a gas can. Sure. But they can spread to fill a container. They're not locked into one shape. as opposed to in a solid where the molecules are all kind of locked up together in place. They're organized. They have a structure that they have to stay in. So the molecules that make up the banana slug slime, they're called mucins. And they start off not as a liquid. They start off as dry granules, like little grains of rice. But then once those granules come into contact with water, they rapidly expand. and like explosively grow. They can absorb water, mixing it together with the granules to make a sort of solution, expanding in volume by up to like 50 or 100 times in milliseconds, like less than half a second, which reminds me a lot of the hagfish slime that we talked about a long time ago. Hagfish slime does something like that. The proteins are basically stored in this sort of condensed brick form inside the animal's body, right? Because the animal is not going to be storing gallons and gallons of slime in its body. It's a small animal. It literally does not have space for that. So instead, it just kind of stores the concentrate and then just uses the water around it to fill it out. Okay. Which is really interesting. So in the KQED article about this research, It was featuring an interview with a researcher named Christopher Viney, who was working on figuring out the molecular structure of this mucus. And he describes the structure of the mucin strands as being, this is a quote, semi-ordered like braided hair instead of tangled together randomly like a bowl of spaghetti. so if you imagine like the little individual strands of mucin like being fiber materials if you have something like a bowl of spaghetti they can go anywhere they want they're behaving a little bit more liquid they're going to spread out right yeah whereas with braided hair or a rope they can still bend they can still flex they can still move around but they're staying in a consistent structure so it's organized and structured but it can move around a little bit It has properties of both a liquid and a solid. You know what this is making me think of? What? Gelatin. I'm not very familiar with how gelatin works. Is it like this? I don't know at a molecular level, but just, I guess, from a visual is what's making me think of. Well, you mentioned non-Newtonian fluid, right? Something that has both properties of solid or liquid, depending on how you're interacting with it, basically. When you apply pressure to it, that changes its sort of state of matter. So the slug's mucus can actually act as either a lubricant or an adhesive, which are contradictory, right? Something that is a lubricant should not be adhesive and something that's adhesive should not be a lubricant. Lubricants are supposed to make you go more. Adhesives are supposed to make you stop going, right? So how can the same substance act as either a lubricant or an adhesive? Because if you've ever seen a slug do something like crawl up a tree or get stuck on a stick, you pick up the stick, the slug stays stuck to the bottom. Like I've done, specifically. Is it a difference in the direction of force? It has to do with the locomotion of the snail and how they move. Because the slug slime can even support suspending the weight of their entire body. as in they can make like a rope of slime and hang from it it's not the mating thing that you're probably thinking of that's leopard slugs oh future episode because i love them for that but this is just like if they've gotten up a tree and they want to get down without having to climb all the way down the tree very very slowly they can like rappel down basically with like yeah it's really cool it's a batman move for sure more like spider-man i guess that man would do it he would so to understand this a little bit i was reading a paper from mit because mit has built a biomimetic robot called robo snail good that is meant to mimic the movement of they call it snails but it doesn't have a shell so this also works for slugs too um but they were specifically looking at the movement of slugs and like their use of mucus how they are able to move through the mucus while using it as both a lubricant and an adhesive this is a quote from the paper they're talking about the way that the slug if you've ever looked really really closely at a slug crawling the muscles of their foot kind of undulate yeah they make like like waves that like move forward in these sort of wave patterns and they say as each wave propagates forward the interwave areas so the areas between each muscular wave, must adhere to the substrate to prevent the snail from slipping backwards. Conversely, the moving portion of the foot must be allowed to slide freely forwards. This is only possible if the interstitial fluid possesses a finite yield stress. In the interwave regions, the fluid is unstressed and acts as a solid, gluing the foot to the substrate. In the wave regions, the snail must provide sufficient stress to induce the non-Newtonian fluid to yield a lubricating layer for the wave. So that was a lot of complicated words. A little difficult to parse on the first read. But basically, the snail, or in this case the slug, has to use its muscles in a wave pattern so that some parts of the foot are pressing down against the mucus and making it liquid. while other parts of the foot are staying still and leaving it solid. So it's basically alternating solid liquid, solid liquid, solid liquid. So it's able to move and stay stuck at the same time. It's like they're alternating points of pressure so that they can take advantage of both the solid and liquid states of their mucus. Yeah, yeah. Which is wild. It's so neat, isn't it? Anyone's ever made like oobleck? oh yeah done that as like a school assignment or something i don't know i mean you just did it for fun have you ever done that before uh yeah i was also gotten some like as a swag thing at a conference once what a weird thing for a conference to give out like you weird nerds will love this but like you know with oobleck if you hit it fast enough it acts more solid but if you touch it slowly then it acts more liquid yeah it's kind of that concept like the way that you interact with it and the pressure you apply to it changes how the substance behaves yeah which is fascinating to me so they they built robo snail and then they built robo snail too like a second design of it that was made to move vertically up walls and on ceilings um and they actually used a synthetic compound called lapinite instead of mucus but that reminded me a lot of the uh gecko robot that finley got for christmas which uses like which is like a fan or something it's a vacuum a vacuum Like it's like a little vacuum that like sucks it up against the wall. And it's so lightweight that it can keep it stuck to the wall, but you can put it like on a, it is remote controlled. So you make it skitter around the wall or the ceiling or whatever. How fast does the robot move? I would imagine quite slowly. I think this mechanism won't work if it goes faster. You probably have to go really, really slow. That's probably what keeps them slow. Huh? Yeah. If they went any faster, they would be like stiffening up the mucus too much and not able to. So I guess being slow kind of helps them here, like helps them take full advantage of... They don't have a choice. Yeah. Not like physically. Well, I mean, probably physically too. I mean, they probably has, you know... They could not become faster without having a new mode of locomotion. Yeah, without breaking the mucus. Yeah. Yeah. Well, the mucus would be too sticky. Like they wouldn't be able to get... They wouldn't be able to go forward on it. Huh. Yeah. Isn't that interesting? It is. especially when you see them like upside down or like going up the side of a tree you think about things like needing momentum to go like up vertical services like that but that's not what they're relying on so they actually have to go really slowly so cool but that's not the only example of biomimicry of slug slime they have been the inspiration for quite a few projects one of them has been slug slime surgical glue in 2017 researchers at harvard published a report on a designed for a surgical glue that was based on slug mucus that successfully patched up holes and stopped bleeding in pig heart experiments so it was a substance that was able to adhere to wet surfaces that was the thing that they were most like trying to get it to do was sticking to wet surfaces it's difficult to do that and when they applied this like slug slime inspired glue to holes in a pig heart, it was able to stop the bleeding. So it was both like sticky enough and strong enough to do what they needed it to do. So that was an interesting application of that But also an architect named Ilaria Mozzolini and a biologist named Shauna Price worked together to design a greenhouse that lined with silicone bladders So if you imagine a greenhouse where instead of like glass panels, it's these green rubbery looking pouches and the silicone bladders capture and store water inside that's been released later to water the greenhouse. So I'll show you a picture. It looked really cool. Here you go. Here's a picture of it. Huh. And that's grabbing water from like the atmosphere? I think so. I think that's what it's supposed to be doing. It's like absorbing or at least capturing just like rainwater and then storing it in the bladders. And then like later on when you need it, when it's not raining, then using the stored water to water the plants inside. There's a similar thing in Star Wars. Oh boy, tell me about it. It's called moisture farming. Wasn't that what they were doing on Tatooine? Tatooine, yeah. Wasn't that from like the first episode, wasn't it? The first, yeah, the first movie and all that. So yeah, the idea there is like very arid planet. So the moisture they have to capture from the atmosphere. You know where else they do that? Where? Arrakis in Dune. Oh, yeah. Well, something similar to that. But yeah, this is a banana slug. And this greenhouse was specifically like inspired by banana slugs, which you can see in the color too. It has that like yellow green color. Nice. Which definitely feels like you're like inside a banana slug, which is pretty cool. And just a quick little aside. I was reading this article. It was this old article from 1993 from the University of Washington magazine titled Emerging Biotechnology Promises to Transform the Materials We Use to Work and Live. And that was one of the ones that was citing the researcher Christopher Viney that I was talking about earlier. And the quote from this article that I was delighted by, kind of an aside, a little throwaway sentence, they say, And if mucus makes such an ideal highway for slugs, light rail might someday be replaced by slime rail. Give me the slime rail. I would ride it every day. We've already got the station, baby. Would you ride the slime rail? Yeah. I mean, you probably wouldn't even be able to tell the difference. That ride would be so smooth. So smooth. but then you run into the speed problem yeah that we have already established that like you are there's a speed cap on that otherwise the slide stops working i mean it's still faster than i5 but wouldn't that be i would love to see like science fiction with some sort of like slug based train system like like a slime trail that slugs just like high speed slug maybe like the slugs are normally like really really slow but then they get on their like slime trail and then they zoom like something like that i don't know someone who writes science fiction do it yeah make it fun yeah make it fun take my idea make it good another thing about just to go back to like the don't put them in your mouth thing in addition to the fact that they eat things that are poisonous and you could be you know accidentally getting poisonous substances on you banana slugs are also often carriers of the rat lungworm parasite which can cause meningitis in humans so it's not worth it fam no i know you think it's gonna i know i know you think you're built different it ain't worth it it's a weird animal to name after an edible fruit i know right and they look the part too they look so edible they're yellow and they and some some of them have the little brown speckles on them like that's like the best kind of banana a slightly overripe one like they look it's it's triggering the the primate fruit specialist brain that's like no gotta beware the strange banana yes i'm always saying that been saying that let's take a quick break to hear from our friends in the maximum fun network and then we're going to talk about ingenuity aesthetics and some other fun stuff for banana slugs Hey Alexis. Hey Ella. What animal has the most teeth? I would guess a shark. A snail. No, snails don't have teeth. They have thousands and they are freaky looking. No, I don't want that to be true. Okay. Did you know that the hippocampus in your brain is named after the half horse, half fish sea creature found in Greek mythology? I didn't know that, but we're meant to be doing animal trivia and hippocampus isn't a real animal. Well, that doesn't matter on comfort creatures. You're right, it doesn't matter at all. Comfort Creatures is a cozy show for lovers of animals of all shapes and sizes, real and unreal. If that sounds like your cup of tea, then join us every Thursday for new episodes on MaximumFun.org. Are you a celebrity? Are you searching for meaning, connection, and a little levity these days? Hi, I'm Kumail Nanjian, actor, writer, and yes, a celebrity too. And I've got four words for you. Bullseye with Jesse Thorne. Are you tired of junkets, red carpets, sick of the endless spicy snacks you have to eat? Do you want to connect with someone who gets your work and laugh with you a little? Join me, Andre 3000, Tom Hanks, Tina Fey, and many more and become a guest on Bullseye with Jesse Thorne from NPR and Maximum Fun. the next category that we rate animals on is ingenuity behaviors clever strategies things the animal is doing to navigate its world or solve problems that they face so what we got so i'm giving the banana slug a three out of ten okay i mean they're singularly minded i fear sure they just kind of go and they just hope for the best there's a lot of vibes happening for the banana slug. Not great, even really sensory perception. They're just kind of hoping for the best. I mean, when you're living on that kind of time scale, like I mentioned, like, their top speed is like 30 feet per hour. So like, they're not getting anywhere fast. They're operating on just a very slow down time scale. So they're not going to be exactly quickly reacting and thinking on their feet. It's just kind of a lot of going forward and hoping that works. They will follow each other's slime trails. So if they come across a slime trail that has the right sort of pheromone cocktail in it to suggest that it is a good potential mate, they will follow their trails to go find each other when they are going to mate. Now, on mating for banana slugs. And I'm going to talk a little bit about reproductive anatomy here. I'm going to use clinical terms, but just know it's coming up. So banana slugs, like a lot of other types of snails and slugs, are simultaneous hermaphrodites. Do you remember what this means? Meaning possessing reproductive qualities of both male and female at the same time. Right. Yeah. Because we've talked about some sequential hermaphrodites, which is having phases of life at which they could be reproductively male or reproductively female. Yes. But these, all the time, they could go either way at any time. And what's interesting is that so banana slugs can even fertilize themselves. They don't need a partner. They could fertilize themselves if they wanted to. They have the equipment for both. Yeah. Or if they do find a partner that they want to mate with, they could fertilize each other reciprocally. As in, everyone's walking out of this encounter pregnant. Everyone's getting fertilized. It is a trade, a fair trade of reproductive material. And this can look different between different species. So in some, it happens all at once. They are simultaneously at the same time fertilizing each other. In some species, they take turns. So like you get me, then I get you. Yeah. They do have to line up their corresponding organs with each other. Like if they're going to be doing it at the same time. Sure. And they're both on the right hand side. So they have to do this like. One's upside down. I mean, well, it's on the ground. They're not like they're not suspended from the air like banana, like leopard slugs. But they have to do this sort of like they have to like curl around each other in this like spiraling sort of like yin and yang shape. Okay. Like so that they can line up the right sides of their body like against each other flipped around. Yeah. Which actually looks kind of cool. Like I think it looks neat to see. And this process takes a very long time. Imagine. Hours of courtship. and then further yet more hours of sealing the deal. They are taking their time. They are not in a hurry here. And then, so I mentioned earlier that interview with the researcher Janet Leonard. She really specializes in studying slug reproductive biology and behaviors, things like that. She keeps a collection in her lab that she calls the Banana Slug Ranch. like she has just like hundreds and hundreds of banana slugs okay what did you think i meant weren't stressing i did think that yes in what context that's why i was confused well she basically keeps a bunch of banana slugs and like watches them and studies their behaviors and their reproductive biology and one of the things she talked about in her interview is something called apophilation. So in some species of banana slugs, following the act of mating, they're basking, they're in the afterglow, they're cuddling, and they might need a little snack. Okay. As you do sometimes. And they might just reach over and chew on their partner's phallus oh and chew it off yeah just the whole thing clean off wow specifically just that part of the body though it's not like they're like cannibalizing each other okay it's specific to the reproductive anatomy uh-huh and remember they both have it So it's just that one turns on the other, I guess, and chews theirs off. The researcher said in her interview that it's still not understood why they do this. It's just a thing they do sometimes. So does it grow back? I have to hope so. I have to assume that it grows back. I don't know. I hope so. How strange. Yeah, and this is also not the kind of animal that mates with the same partner. Yeah. Like, sequentially, like, would have any reason to want to, like, you know, some animals will do some sort of, will have some sort of behavior that controls their partner's, like, ability to reproduce with others. But this doesn't seem like it would help with anything. Does this stem from, like, maybe a viewpoint of seeing them as competition? See, I don't know, because any slug could be competition with any other slug. Right. But I mean, to us, that seems odd and cruel to do it after mating. But to them, they're like, well, I got what I want. Now you're just another thing for me to compete against. Then I think that would be a more widespread behavior. It's still pretty rare. It's not a thing that they do all the time. It's a thing that they do like every once in a while. It's rare. At the other end, maybe they're just not smart enough. It's just they just don't have the faculties there. They're like, oh, there's a thing near me that I think I would want to eat. I fear it is that. It's giving praying mantis. They just happen to be hungry at that time. It's giving praying mantis a little bit. It's not a sort of like that she wants to eat her partner after they're done mating. It's that he's in melee range and she's taking an attack of opportunity. Like the part of the brain that registers him as a partner is just not functional. and was just like, okay, you're a thing I can eat. Is this behavior specific to banana slugs? That's the only type of slug that I know of that does this. Okay. I think it's funny that it's the one that we call the banana slug. I see it. Clearly, they think they taste pretty good too. And they do actually eat either their own slime or other slugs' slime, which is kind of like a reduce, reuse, recycle approach there. Yeah. You know, because they are still like, it still is costly to the body to be producing mucus that you just kind of put out into the world and then leave it behind. So it's kind of their way of like bringing those mucins back into their body so that they can recycle them. I wonder if the resources involved are the kind of thing where like they can just run out of slime or if they run out of whatever that resource is, that's just enough to die. I figure if they have run out of slime, something else catastrophic has probably also happened. So like the circumstances that would lead to that happening probably would have killed the slug already. Sure. Yeah. It can't be good. Yeah. You know, like if you're overly stressing a slug and making it overproduce mucus. Because if they're still alive and they can no longer produce slime, they're not going to be able to refill that resource. Oh, what's the point of living? If I can slime who am I Yeah At what cost Yeah So they do have a little bit of an infinite slime glitch if they can manage to eat either their own slime or someone else so that brings me to aesthetics for banana slugs just how nice they are to look at i'm giving them an eight out of ten okay they're pretty darn cute if you've ever gotten real up close and personal with one as i tend to do when i see them i like to like crouch down on the ground and get a million pictures and what do you think? I think they're very cute. Is there any reasoning behind the coloration specifically? You know, at first I didn't think so. Every time I saw a banana slug, they're like this bright yellow, up here at least, they're like this sort of yellowish green color and they tend to have these like dark brown or black spots on them, which to me, especially in the areas where I usually see them, where they're usually against like brown and green, it seems very conspicuous. Like, it's obvious. You're going to see them. But then I saw them. It was on the West Hilobos Wetlands Boardwalk Trail. And it was in the fall. And one of the rhododendron trees that was growing over the trail had been losing its leaves. Those leaves were the exact same color as the banana slugs. And the same shape. where as I was walking down the trail that had all of these fallen rhododendron leaves everywhere, I kept over and over again, I kept stopping because I thought I saw a banana slug, but it was just one of these leaves. So it's kind of camouflage working in the opposite direction where I'm mistaking the leaves for the slug. And so then I saw it. I was like, okay, that actually does work pretty well as camouflage, but then that would only be for like a tiny portion of the year and only for like a specific type of leaf, right? So like, I can't imagine that they would have adapted their entire body to camouflage into like such a specific circumstance. But I do think, I mean, maybe there could also be some aposemitism going on because they do have that unpleasant slime. So it could be a little bit of like a warning, like brightly colored, like, hey, don't eat me, I'm going to be kind of gross. Yeah. Could be something like that. Yeah. So this is usually where we talk about conservation status for animals. These are not evaluated and they're not known to be particularly threatened. They seem to be doing okay, but they are very ecologically important. So they are decomposers. They help clean up the forest floor. If something is rotting, something is dead on the ground, slugs are really good at coming in and breaking that material down. And that is really important for things like redwood saplings. Redwood trees don't just spawn into existence, you know, two, three hundred feet tall. They have to start out teeny, teeny, tiny. And in order to break through all of the vegetation, all the, you know, nettles and vines and stuff on the forest floor, they need some of that to be cleared away. And slugs are really important for that. They're really, really, really important for the health of redwood forests. So I wanted to throw in a couple of fun little things. First of all, that same researcher I talked about a couple times already, Janet Leonard, she mentioned a long out of print cookbook featuring recipes for cooking banana slugs. Really? Yes. So apparently this is something you can't really get anymore. But she mentioned that she had got her hands on a copy. And this is her quote about this cookbook. cookbook she says the story is that back in pioneer days especially farther north in washington and oregon some of the french and german pioneers who were accustomed to eating snails at home would get banana slugs and eat them in times of hardship and she goes on to say but my favorite recipe from the cookbook is the banana slug daiquiri the story with a daiquiri is that you blend up the banana slugs and then throw away the blender okay it's like it's like if someone was like here's a recipe for a grilled cheese sandwich yeah you put cheese on bread and you grill it and then you throw it away and you make a pizza instead all right so i thought that was kind of funny um i don't think i would eat a banana slug if confronted with one you've eaten snails though yeah i mean i've had escargot would you eat banana slug uh probably not wild ones well no don't do that that's a bad idea as previously discussed but if like if someone had one and they were like hey it's lived in a lab its entire life It is guaranteed to not poison you. Is it still alive when they're asking me? Like, hey, if you want to eat this, I will kill this slug for you. Oh, my God. What? Now I'm going to say no. Yeah, true. No, don't do that. But, okay, it's already died of natural causes. Of old age. It reached a fine old life and enjoyed a happy, comfortable, luxurious life. I'd say it's not about the years. It's about the miles. But, uh. That was about the yards, perhaps. Maybe. I don't know. Maybe. Maybe if I saw the end result, it was particularly appetizing. I'm imagining it's just drowned in butter, probably. I mean, that's the escargot way. Right? No, I do wonder about the toxins. Because plenty of toxins, like cooking the meat or whatever, doesn't usually get rid of a lot of those toxins. Right. Yeah. I wonder about that. Not good. Not worth it to me, I think. You're going to mess up your prions or something. I'm controlled by a zombie fungus thing. Did I ever tell you? I think you may have been there with me. The time that I accidentally isekied a banana slug. We were hiking. Maybe it was just me and Isaac. But we had picked up a walking stick, as you do. Just like a big, sturdy-looking stick that you just use for hiking. and uh probably hiked i want to say like two miles right with this walking stick and then realized that the walking stick we'd been using the entire time which we had picked up at the beginning of the trail yeah yeah had a banana slug stuck on it and then we were like well now i feel bad because we just accidentally like abducted this slug not only that but like took it farther than it ever would have been capable of traveling in its entire lifetime. If it had like traveled in a straight line its whole life, it probably couldn't have made it that far. Like if you just like, if some sort of giant incomprehensible creature just like grabbed you and then dropped you on the moon. Here you go, buddy. This poor slug. Okay, so as I teased earlier, the last thing that I would like to say about the banana slug is about the University of California Santa Cruz's mascot. Oh. In the early 1980s the University of California Santa Cruz UCSC joined the NCAA and at the time they had no official school mascot. Oh. They were unrepresented. Athletes at the school wanted sea lions to be the mascot. Like, they were really leaning into the sea lion thing. But the USC website writes, the wider student body would have none of it. And they continued to root for banana slugs. Even after a sea lion was painted in the middle of the basketball floor. After five years of dealing with the two mascot problem, an overwhelming pro slug vote by students in 1986 convinced the chancellor to make the humble but adored banana slug UCSE's official mascot. So basically they just mutinied. Like they tried really hard to like soft launch sea lions as the mascot. And the student body was like, no, thank you. I shan't be doing that. So I was reading about how like during sports games, the like students that were attending the sports games would like chant things like slime them. So they just like sort of homebrew their own like weird mascot that they just refused to recognize sea lions completely. And to this day, Sammy the Slug is their school mascot. and the chancellor of UCSC at the time, Robert Shinsheimer, wrote in response to the vote. As is well known, I would prefer a mascot with more spirit and vigor. However, the students are entitled to a mascot they desire and with which they can identify. I also suggest that it would be most desirable for our biological scientists to begin a program of genetic engineering research upon the slug to improve the breed. The potential seems endless. This is where you lose me, Robert. What are you talking about? He's like, maybe we could make a better banana slug. He's like, if they're going to be our mascot, we might as well make him cool. Sounds like a book in a series you're reading. Call it Children of Slime. the new book is coming out soon i'm so excited oh my god so it's just you can hear him coping like as he's writing this he's trying so hard he's so he's like seething like i can't believe i got stuck with a stupid banana slug maybe they can genetically modify it to something i will accept maybe we can fundamentally change it as an animal give it lasers or something cool i don't know and and i they have this sort of like slogan that i you'll see bounced around sometimes you see it like on t-shirts i see it in reddit posts a lot about the school this like little slogan they use sometimes for the banana slugs where they say no known predators oh that was actually a question i was thinking of like you were talking about their ecological importance is it a food source for anything particularly it's not an easy one like things will eat it but like it's a pain yeah like it's not fun nobody's having a good time there's not like an animal running around who's a specialized no no it's kind of you have to be in dire straits to take a slug but like something they'll do it but like they're not happy about it okay i think birds will like birds of prey uh i think are not as like affected by the mucus as mammals tend to be okay uh so i think birds will go for it but so so the no known predators slogan is unfortunately it is false sure but that was that reminds me a lot of the t-shirts we used to get from unf that said like unf like football oh yeah undefeated oh there's italian got it yeah yeah yeah that's what it reminded the no known predators they We went to a school that did not have a football team. There was no football team, but you could get T-shirts that said UNF football. And then underneath it said like undefeated. Which was funny. So that's Banana Slugs. Thanks, babe. I had a lot of fun. I learned a lot that I didn't expect to learn. Learned more than I wanted to about fluid dynamics. But c'est la vie, I guess. thank you dear listeners for listening and having fun with us spending this time with us if you had a great time i would love it if you left behind some nice words for us in a review on your podcast app of choice like like you're gonna like this one a highway man i'm a highway man uh who writes for the lemming myth did we not just follow one stupid person off of a cliff of knowledge. Really makes a thing. They write, awesome podcast. Thanks for clearing up the lemming misinformation. We did it. We did it. So thank you all. If you want to come hang out with us online, we're on Facebook, Instagram, Discord, and Blue Sky. 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