My Slimey Valentine: The Slug Life

listeners out there. And in fact, let's go ahead que up a little little Verry White just to sort of set the mood here, because you know, as humans, we live in this world of human sexuality, and we have all this baggage attached to it, all these thoughts about what is what is appropriate, what is taboo, what is

a little risque? Uh? You know? And that music playing in the background there by the way, that was a little Verry White with can't get Enough of Your Love Babe nine four classic or can't get enough of that slug love Now you're yeah with the slugs. The slug serves as an example of just how wild and diverse and to humanize hideous uh, sexual reproduction really is in in in nature and and maybe how sanitized it is in humans. I don't know. That's that's a value judgment.

I'll leave that for someone else to make. It shows us how much human baggage we bring to the situation. I'm going to tell you that some slug sex, in particular leopard slugs, and we'll talk more about them, kind of make human sex look a little milk toast, a

little vanilla. Yeah, I will. I will admit that as repulsed by slugs as I am, like, I feel like this deep in my James repulsion to them, not in my blue jeans, but in my actual genetic material, Like there's a deep like there in my ancestral enemy um that that I am avoiding because I know they will crush me. You think you have ancestral memories exactly of slugs. As repulsed as I am, I have to admit that there is some thing weirdly beautiful about it. If not beautiful,

then at least elaborate, Like it's it's elaborately grotesque. It's it's it's grotesque in a way that that that it becomes almost art. All right, So before we start talking about slug sex and all girding our loins for that, let's talk about slug anatomy. Because most slugs are hermaphrodites, they have both a penis and a genital opening, right, so when they have sex they can both fertilize and are fertilized. It's important to remember too that your coming

slug it's ancestor had a had a shell. It is descended from shelled gastropods. So if your rear end is in a shell, where do you think evolution has put all of your important bits right up there at the head. So it's from the head that the penis of a of a slug protrudes right out the side like a weird hat. Yes, and they yeah, I think about the penus being over there too, is over there too, so

so there's that. And again yes, this is because they are descended from snap the genital orifice, everything, the mouth, everything has to be upfront, has to be front loaded, because the rear is back there in the shell where Dr Doolittle rides. If you are a fan of that movie and really knowing all the stuff about snails makes

that even weirder. So keep that in mind when we're talking about some of the configurations that these slugs make when they are engaging in their reproductive efforts because again, all the business is pretty much over there on the head. Yeah, face to face sex, because that's where it's two faces going at it. Alright, various ways as well, discuss let's discuss one of the ways one of the strategies that

slugs approach reproduction. Yes, Now, it's important to to realize that what we're talking about here sexual conflict between among these creatures. And this is the idea that you have individuals in a species and they are competing with other individuals for mates. So they want to do whatever they can to ensure that their genetic material passes on and not the genetic material of rivals and other other individuals

that that their mate is mating with. So you see various methods in various animals, whether the uses you see, for instance, their sperm plugs, which you can you can look up, which it's it's about. I've got mine in there, so I'm just gonna sort of block it up so that nothing else is gonna get in there too. You see barbed penises in various creatures, especially in in in insects. I've seen them referred to as torture pholusis if you

want to hear more about that. Check out our our episode that we did on the penis and the evolution of the penis. Um you. So you see a lot of sexual competition evolution trying to to to game this scenario so that the the the mating creature has the advantage over all the other creatures that are mating with

its mate. I'm glad you cued that up because I think that it's it's important to keep this in mind when you think about um slugs in what seems sort of rough dealings with reproduction and of cour without anthropomising them, but um, we can't help to. But thinking of it in that context, I think helps you to better understand why, um it is maybe as dire seeming as it is, or I mean, it's a it's a brutal game with

high stakes. The stakes are high. They couldn't be any higher because ultimately, the genetic mission of this creature and any any creature is to pass his genes on. Yeah. So let's look at the sea slug, all right. According to I O nine author Robert T. Gonzalez, uh sex is initiated when one slug uses a syringe like organ

to gore its partner and that's where the stabbing comes in. Yes, and you you see the same activity in a number of air breathing land snails and slugs as well, So this is not particular to sea slugs, right, but in this particular instance, you've got that syringe like organ goring its partner and injecting prostate fluid into its body. And then they made a second time, this time with one slug inserting its penis into the partner's genital opening that

they made through the stopping. So these are two separate acts. Basically, one is shanking and the other sexing. Yeah, I mean the way I like to think of it is the the final knife fight in dune Um between Paul Trades and Uh and the Harcone and kid played by a Sting in the movie you know there, it's this this vicious fight when they have to counter each other's shields with their slow moving daggers, and at least one of the daggers this poison divider call. So it's that kind

of situation. There's kind of a it's like they're they're making love to each other, these snails, these slugs, but they're also trying to stab each other. It's it's it's often described by biologists is ultimately a joust sword fight because whoever gets their loved dart, which is the term that's often used for it, whoever gets their loved dart into their mate, they're going to increase the odds that their sperm is going to be victorious inside of that mate.

That's right. And you know, it is said that most slugs would probably perfer to be the shanker rather than the shanky. Evolutionary biologist Rulanda Lang describes the penis thus lee. The penis bears four to five large hook shaped spines at its base in a crown of twenty to thirty minute fine pointed spines at its tip, which are spread

like an anchor during mating. So there's still a question as to watch lugs will allow themselves to be penetrated beyond the amount needed to get the stores of sperm. Because this happens, right, they get the storm stores of sperm that they need, but they still engage in is what we think of as a very vicious act um and it doesn't really increase the reproductive fitness to do it,

but they still engage in it. So the idea is that perhaps the injections of prostate fluid might include nutrients that benefit the stab slug, So it's a bit of a trade off there. Yeah. And there was this old idea that the love dart was injecting calcium into the mate and therefore making a giving it a gift kind of a dowry, uh and staying here, here's some calcium

us this to create the eggs that we have created together. Um, But I think they've kind of shied away from that, going more in this hormonal direction that it's uh, it's enabling this better chance of survival for the stabbers sperm again, reproductive fitness being the most important thing. And just as the you described the penis and pretty horrific terms, uh, the love darts, which are also called gypso bellums, Um,

they vary a great deal as well. You can find images of these and they look like varying cruel harpoons, and and they're made of different substances. Sometimes it's calcium carbonate, sometimes it's cotton um, various shapes and sizes and uh, they can also vary between one and thirty millimeters in length. Um. Sometimes it's more of a just kind of a stab in the side like a prison shiving. Sometimes the love dart goes all the way through, uh, the the mated slug.

It's um, it's it's pretty fascinating and um it. We call it a love dart in English, but in Germany they call it a leaves field or love arrow. And there's some there's some people that that argue that the idea of Cupid and his arrow is ultimately um inspired by the love dart, even though the love dart again is just a it's a stabbing, more of a lance or a dagger in the side rather than anything that is actually a projectile. Yeah, and they do come in

in various shapes. Um. Some look like spears. I thought one actually did look like a graboid as well. So it sort of depends on this species most some have just one um dart sack. Some have more than one. Uh. And then after they have used it takes a while to grow it back to re reload the gun as it were. All right, um, let's take a quick break and when we get back, we are going to talk about the love lives of leopard flugs. And you really

don't want to miss this, Alright, We're back. Leopard slugs um now the very white yeah kes the berry wide again. The leopard slugs. They really make a show. They're they're really about putting on a show of their love for anyone who may be able to watch in stomach this nonsense. Yeah, alright, imagine these leopard slugs. They're nocturnal. They're grayish yellow with modeled black spots, hence the name leopard slugs. They measure about four inches long. Uh. Let's say that they're cruising

through the forest. They pick up a scent in another slugs trail. They read the love poem and that that slug slime. Yes, come on, I don't know, is that very when? And so they follow it. They find this other slug and they stalk each other in a circle, again using their scent trails. And then they say, hey, let's take this up to a more private area. They go up a tree. They find a nice little tree branch, and that's when thing start to get a little bit weird.

They begin to intertwine. It's quite beautiful. And as they are intertwining, they form a rope of mucus that comes down start to slay like imagine this rope of mucus extending from the branch, and then they continue intertwining together and they're suspended like that for a little while in this gooey embrace. Now, then the penises come out. That's right, as gonna say. If that's not the head, the side of their head, their penises are basically emerging, and they

begin to glow blue. Yeah, and these are these are large phouls is um comparatively um like for a human. It would be like a like a baby's arm coming out of the sides of your head, or no larger than a baby's arn't like a like an eight year old army. So now I'm asked to say, I'm a little bit g right that you used that analogy, but

it's effective to give you some idea of scale. So then these uh, these head placed penises begin to do the same, execute the same intertwining configuration right this embrace, and you see this glowing blue penises entwined and moving until they bloom into a pulsating blue flower like globe that's translucent. Yes, it's really alien and oddly beautiful to behold. It's it's it's really weird. Now, the reason that they're

doing this big light show, this big circus slay. Hey, look at us, you know, intertwined getting it on um is that they're passing sperm to and fro and that um, that sort of flower configuration because again there hermaphrodites. They're both male and female. And it's just amazing because I yea, this is this is the attempt to for alize each other. And it's amazing because it looks like this Toluly sculpture

rights class blown sculpture that's happening before your eyes. But my favorite part of this is that you have this entirely intricate, beautiful, disgusting display of reproductive fitness, and then there's just this unceremonious drop of one of them PLoP onto the fourth floor, Like you would think that they would have come up with a more elegant way to to end it. But it's quite it's quite a sight to behold. If you wanted to seat yourself, check out

I O nine h Sex Life of Leopard Slugs. Yeah, I believe they're embedding a video created by Discovery and BBC. Atinborough narrates it, narrates it, and I want Attenborough narrating well anything in the natural world, but especially slugs doing it because he's got that great wink wink, nudge nudge

with his voice that he does. So imagine it applied to this scene of beauty before you and I know what you're thinking, Well, that's where it ends, right, maybe this uh, and we're generalizing the entire vast buffet of slug sex in this. But you begin with a little gentle stabbing. Then you you go up into the trees and you you intertwine, and you intertwined penises and create a glowing flour and swap sperm and you think, well,

then then you're done. Right, not necessarily because in some slugs you see something that we call apophylation, which is, uh, maybe not as sexy as it sounds. This is when one slug choose the other's penis off. Occasionally we'll shoo its own penis off and swallow it. Yeah, that's auto apophylation, auto appophilation. Yes, So what is all this sexual cannibalism?

What is it about? Right, because we've we've encountered we've talked about sexual cannibalism before, where you have like the female will eat the male or part of the male following mating. Sometimes because Hey, the male was only there to mate, and then once he's done, there's no sense keeping him around. Might as well make a meal out of him, right, female or spiders right right? In this case though, these are these are amaphrodites. So what's what's

going on here? Well, these these banana slugs in particular, of course called banana fligs because of their yellow color and their occasional black spots. Uh, they're not entirely sure why the chewing is going on, but let me just kind of give you a little bit of information about these guys. Uh. They are the second largest slug in the world, so imagine that. Imagine that when you start to talk about the slug penis, which is usually the length of the slug itself. It is also the official

mascot of the University of California, Santa Cruz. Really, really, they're the banana slugs. Oh God, I assume they don't have a sports program like this has to be just like chess club or something. I don't well, but or the more mild school. I just can't imagine like a football mascot of the banana slug. I mean, it's better than a dog, I guess, but I mean it would inspire fear in the competitor, right, like I'm gonna chew your penis off. Yeah, if they really want all out

with it, I guess it would work. Yeah yeah, um okay. It's scientific name is dolly phallus, which means one penis. So what we find when we look at slugs getting it on is that again they find each other via the chemical traces in their slime trail. They make a bed of slime to cuddle on. Essentially, there's some head waving, they get very close to each other, and then they begin to actually, when I say they get close together, they're in a gangyang configuration. Um. Then they began to

gently bite gentital openings of each other. So what happens next is they their penises spring out from their heads and they insert the penises and the nearby genital splits, and then intercourse lasts for hours for hours, and then, with their multiple pairs of teeth known as the radula, sometimes one or both of the slugs gnaws the penis

off the other. This is the appiphiliation. So the idea at first was that they were doing this because the penis was getting stuck and I ran across that that theory that they were their intertwined is like, how do we get out of this? Well, we could bite through these penises and then they do. But but the but what we're really getting down to ultimately is again sexual conflict, right, yes, because it's not about that, because actually what happens is that the penis, when it is not erect, it's not

a problem for it to pull out. Okay, again, imagine this, This penis san is the length of the actual banana slug itself. So, uh, they do think it has to do with this idea of Okay, well, I'm gonna chew your penis off and I'm going to ensure that my sperm from now on is the main deal out there. I'm going to remove you from the playing field. Yeah, it's like, yeah, it's it comes down to sexual conflict

because every slug is both male and female. But then after the mating is done, Yeah, if you can, if you can bite the penis off of the other slug, then you have taken a male competitor off out of the out of the game, while leaving a perfectly functional female slug out there for what you know, for for

public use. So it's it's pretty amazing stuff. Yeah. Now I saw one of the videos that had the uh, the case of auto appiphiliation and uh, and this one was a situation where the slug engaged in sex and then they went off without chewing penises off, because sometimes that happens, like sometimes there's no penis chewing off and when a when a penis is chewed off again, it's still a perfectly functional female slug. So it really doesn't care.

It's kind of like, all right, you got me, but I'm gonna go on carry out out my business now. But in this one example, they were looking at the the slug had survived, its penis was still intact, but it had not retracted, and so the slug just turned and bit it off and ate it down. So they really weren't sure what to make of that. But maybe there's something not functioning there. It decided, well, I'm not just gonna walk around with this thing sticking the side

of my head. I look kind of stupid. I better eat it. Do you think slugs will could experience phantom limb I get the impression they don't. I get the impression there they don't really think that hard about it. You know that it's that it Ultimately it's like, uh, you know you got me, all right, good on you you ate my penis off. But but I'm still I'm still a functional female slug. I'm was I'm a hermaphrodite for goodness sake. So that's right. They can still engage

in the act. Yeah, yeah, and do so all right, I mean, guys, happy Valentine's Day. Um, you know, maybe you're going to go to an intimate dinner with your loved one and what you will talk about. Maybe you're going to an anti Valentine's Day party, and this is

also what you'll talk about. Right, Yeah, if there's a computer there, look up some some YouTube clips of this stuff and uh, and we'll try to include them on the blog post that accompanies this, uh, this episode, so you can cue them up and just just step back and enjoy some some good times, you know, play them very white in the background. Watch watch these slugs and snails stab each other with their their love darts. Watch

them make love on a tendril of slime. Watch them eat each other's penises off to keep them from doing anything behind their back and cheating on them or not that last part. You don't have to do that. No, no, no, don't do it. I'm just saying you can watch it happen. No, that's what I mean. You don't know if you're not into the penis chewing watching. Yes, yeah, and yes, but do not imitate any of this stuff except for maybe the if you want to try doing it in slime

I think is lovely. Yes, really, but you're gonna have a hard time getting getting polymers that are going to be that sticky that you can suspend yourself from some of you working in the lab, though you might get a source or two. Yeah. There. Slime has as we've discussed in our last episode, slime has a number of purposes. And if you want to know more about slime, do check out that episode trilogy of Slime and you'll learn

all about the various properties. Because slime is ultimately it's about it's about moving around, it's about look emotion, it's about communication, it's about defense, it's about offense. It is it is about protecting an organism against parasites and pathogens. It's really a remarkable substance and sometimes it is the backdrop for love, slugs for love and slugs. All right, well, I'm gonna, you know, read a quick bit of listener mail here if we'll call the uh the robot over

all right. This one comes to us from Eric, and this one's kind of suitable for a kind of a sexy episode. Uh. This is a response to our Undercover Cops episode about what happens when we layer our lives and fiction and what that does to our perceptions of self and reality. Eric says, I have a friend who is a female police officer who works undercover from time to time, primarily as a street prostitute. She gets very

into her role and it's quite convincing. She told me once, shortly after she started doing this work, a car with a very familiar face stopped to talk to her. She was horrified to realize it was her favorite teacher from when she was in high school. She told me she felt physically ill when she realized she was going to have to bust him, likely destroying his career. She was relieved when he told her that she was way too smart to be doing this and begged her to let

him help her. He even remembered she'd wanted to be a cop. When she realized he wanted to help her get off the streets uh cleaned up. She was happy to tell him that she was a cop working undercover. I don't think she has any trouble letting her prostitute self take over, as she only does this for a few hours a month. She did tell me it's a lot of fun, but I think she is slightly crazy. Eric, So there you go a little insight into the double

life of a of an undercover vice officer. It's always interesting, as always an area that has fascinated me. I can't imagine how you wouldn't be a little bit crazy from having that kind of job. I think all of this are various amounts of uh nuts and craziness, um, and that's what makes us human. But yeah, trying to keep

that up day after day it would be very difficult night. Yeah, because it seems like you've got to be the type of crazy to where you can just turn it on and off and it doesn't bother to you, or you've got to be the kind of crazy where it does kind of bother you a little because you've so become

the role that you're taking on. So anyway, thanks Eric, that was really interesting to hear about so if you if you have any time left in your Valentine's and you want to talk to us online, want to want to maybe a share with us how the how your Valentine's dinner went when you brought up the sex lacke of slugs uh. Then you can find us on Facebook

and tumbler. We are stuffed abow of your Mind on both of those, and we also have the Twitter feed Blow the Mind, and you can always drop us a line at Blow of the Mind at discovery dot com for more on this and thousands of other topics. Is it how Stuff Works dot com