Games, Oral, and S&M: Wildlife Gets Kinky

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Orange-throated male side-blotched lizard mating with one of his multiple partners
An orange-throated male side-blotched lizard, mating with one of his lady friends

You ever look at some critter outside and think, “I wonder how those guys get freaky?” Of course you do, everyone… oh, you don’t? Huh. I guess that’s just something us biology nerds do. And, look, we definitely do! But not because we’re weird perverts. Or at least, if we are weird perverts, that’s probably not the reason why. When you’re talking about ecology, wildlife management, or evolution, sex is everything. The way a species reproduces tells us everything from how to set up hunting seasons to how to recover endangered species. It determines how they evolve. And if they start having trouble reproducing, well, that’s the end for them. So, reproduction is one of the most important things you can learn about any organism. Granted, reproduction doesn’t always mean sex, but for the three examples we’ll be looking at today, sex is what’s going on. And it gets kind of weird.

If you live in the western US and you ever go out for a hike in a rocky, dry area, you might run in to a group of side-blotched lizards. These are cute little guys, about two inches long, grey or brownish in color, with a black or dark blue splotch right behind each of the front legs. When do you find them, you’re likely to find a bunch of them, flitting about the brush and boulders. They look ordinary enough, but you know what they say about the quiet ones. Turns out, side-blotched lizards are way in to sex games. Rock-paper-scissors, specifically. Not exactly the sort of sex game you were thinking of? Well, that’s because you’re not a lizard. For them, it works pretty damned well, since geneticists think they’ve been at it for millions of years now. The game in general, that is. Not, like, the same specific sex act. That… I mean that would just be inefficient.

Anyway. Here’s the deal. Males are split in to three groups, all conveniently color-coded. Some males have blue coloration on their throats. These blue males are the nice guys. They are loyal to their favorite lady and stay by her side. Like, really, right by her side. They establish a small territory for the couple, and then guard her relentlessly against any other males who might want to put the moves on her. This has the advantage of making sure that they definitely get to mate with their main squeeze, but on the other hand it means they don’t get to play the field, sow their wild oats, be a dirty rotten cheat, however you want to put it. They’re more likely to breed successfully with their chosen mate, but they miss out on the opportunity to father more offspring with different females.

Side-blotched lizard
Either a female or a yellow-throated male side-blotched lizard. Photo by me! © Cliff Hohman 2021

Then there are the orange-throated males. These guys are the hunky assholes, the bad boys, the jocks. They are bigger and more aggressive than the blue-throated guys, and are able to just muscle them out of their territory. Since they are able to control bigger territories than the blue-throats, they get to have multiple mates that live in different parts of their turf. The lady lizards are all like, “I know he’s bad for me, but have you seen the size of his tail? I just love a strong man with a big tail. Every time he beats up a blue-throat, it gets me all hot. And then I have to crawl under a rock, because that’s the only way I can regulate my temperature.” So, the orange-throats have a clear advantage over the blue guys, because they’re more aggressive and get the chance to breed with more than one female.

Then there’s the yellow-throated side-blotched lizards. These guys are scoundrels. They’re all about the one-night stand, and they’re not above sneaking in to the other guy’s home to do it. These guys actually pretty closely resemble females, and even behave like them. They don’t control any territory or claim any mates. Instead, what they do is hang out near some orange-throated asshole’s turf and act all meek and mild, making it clear they’re no threat to anybody. The orange-throats have to constantly patrol their territory and check to make sure their girlfriends aren’t cheating on them. But, the thing is, they can’t keep track of all the ladies at once, their territory is too big. Sometimes he’s off on the other side of a boulder, reassuring girlfriend #3 that he’d never cheat on her, no way, he just has to travel a lot for his job, that’s all. And that’s when the yellow-throated guy sneaks in and has a quickie with girlfriend #2, and then bails before he gets caught. The yellow-throated lizards are less likely to mate successfully with any particular female, but they do get to attempt it with many different individuals. The downside is, those damned blue-throated lizards are, like, joined at the hip with their mate. Yellow-throats never get a chance to have a fling with a blue-throat’s lady, since those guys only have a small territory to guard, and can keep an eye on the entire place all the time. Those blue-throated guys are a total cock-block.

I prefer sexy duck-duck-goose, myself

So there you have it, a sexy, endless game of rock-paper-scissors. They just use it for figuring out who gets laid, instead of which sibling has to tell their parents that they broke the kitchen window. Blue beats yellow, because they guard their mates constantly. Yellow beats orange, because they sneak in when nobody’s looking. And orange beats blue, because they can push the blues around and father more offspring. It’s a perfectly balanced system. And round and round it goes, each variety of male constantly winning and losing the game.

And the thing is, what color throat a male has, and the behavior that goes along with it, is genetic. It’s inherited. And that’s the key to this system. Orange-throated males have more orange-throated offspring. Likewise, blue males sire blue offspring, and yellow guys have more yellow kiddos. So, when one group starts winning the game more often than they lose, it means they breed more than the other groups. They pass on their genes to more offspring than the other two get to. That generation of babies will have a little more of the winning group in it than the last one. Then those guys grow up, and since there are now more of them, you get even more offspring of that color the next generation. It’s a feedback loop. Once one group gains momentum, they keep growing in size relative to the other two groups.

Side-blotched lizard
Just another side-blotched. Can see the blotch better here though.
Photo by Judy Gallagher, CC BY 2.0 , via Wikimedia Commons

But, each group is also vulnerable to one of the others. Imagine you’re playing rock-paper-scissors, except the players only ever play one of the options. You happen to be a rock player. If there’s lots of scissors players out there but not many paper players, you’re going to win a lot more than you lose. Once the underdogs start winning, they start their own feedback loop, and then they become more numerous and eventually become the new dominant color morph. Since side-blotched lizards have a fairly quick life cycle, you can observe these shifts in which color is dominant every four to six years in a population. Each group is dominant for a few years at a time, then it shifts.

But hey, it turns out, there’s more going on than just rock-paper-scissors. Because the ladies aren’t just helpless damsels. They’ve got their own thing going on. Female side-blotched lizards get to choose which males they hook up with, and they’re picky. Unsurprisingly, they like to pick healthier, stronger mates. But there’s a little more to it than that. Even though they’re female, they still inherit the genes for one of the male breeding strategies. This doesn’t alter their behavior or color, but they tend to prefer males of the same color as they have genes for. Unless their group is dominant. When their group is dominant, females all of the sudden start picking males from the underdog group. So, they’re kind of rigging the game. They’re helping to speed this cycle along, which ensures that the tipping point always happens and no group becomes such a small minority that they can never recover. The guys are all proud of themselves, they think they’re totally dominating the other lizards, but really, the whole time, the females were secretly picking winners and losers.

Of course, that’s not really kinky sex. That’s everything leading up to the sex, but the actual sex for the side-blotched lizards is pretty normal. For lizards, that is. Compared to humans, normal lizard sex is… well, look. Don’t ever do a google image search for “lizard hemipenis”. You will have nightmares.

And you thought you couldn’t get pregnant that way…

For an actual unconventional sex act, we can look to the various species of mbuna cichlids. Mbuna cichlids are a group of freshwater fish endemic to Lake Malawi in southeastern Africa. Endemic just means they’re native there and not found anywhere else. Though there’s many kinds of mbuna cichlids, they all tend to live along the bottom of the lake in rocky areas. And they pretty much all have a specific kink. They love oral sex. In fact, that’s the only kind of sex they’re into. But you’re wondering, how the hell can you reproduce that way? Well, humans can’t, but actually quite a few species of fish can manage it. It’s called “mouthbrooding.” Here’s how it works.

First, the cichlids pair off. How they do this depends on the species, but mbuna cichlids, like cichlids all around the world, tend to be very territorial. The males, generally, will stake out a territory and defend it, often violently. They will attack rival males, fish from other species, or really almost anything that strays in to their territory. They’ll chase the intruder right up to the edge of their turf and then come to a screeching halt. If you could screech to a halt under water, which I guess you can’t really. They really respect boundaries, is what I’m saying. In some species, the males will dig nests or shallow pits in the sand or gravel. Either way, they generally wait for a female to come along and decide that he’s got a nice home picked out. Usually he’ll try to entice her in by doing a little darting dance, or else a quivering display that looks like they’re having a seizure. They’ll try to get her either into their nest pit, over a nice flat rock, or into a little cave underneath the rocks, depending on the species. If she decides she doesn’t like him, he’ll tell her to fuck off just like everyone else and go back to waiting for another hot lady to come by.

cardinalfish (Apgonidae sp) with mouth full of eggs
Not a cichlid, but you get the idea. Cardinalfish Apogonidae sp.
photo by Christian Gloor from Wakatobi Dive Resort, Indonesia, CC BY 2.0 , via Wikimedia Commons

But if they click, they’ll swim up side by side at the spawning site. They may do the shimmy dance again, or swim around in circles. Eventually, the female will start laying eggs. Immediately after she drops them, she scoops them up in her mouth. Nothing weird about that at all. Next, the hotness happens. With her mouth full of her own eggs, she’ll swim up to the male’s genitals and nuzzle them. This is, apparently the term for fish fellatio, nuzzling. You’ll see it over and over again if you ever read up on it to research for a blog post. They’re not rubbing or stroking, they are definitely nuzzling. I guess. Anyway, this excites him greatly. Nothing is more sexy to a male mbuna cichlid than a lady with a gaping mouth filled with her own eggs. By the way, another phrase you should never google is “lady with a gaping mouth filled with her own eggs.” Actually… hmmm… I just checked and it’s actually fine, sadly. Anyway, the male fish feels that nuzzle on his junk, and he just can’t handle it any more. The camera zooms in, and he promptly squirts milt into her mouth, fertilizing the eggs.

Please don’t name your child “Milt”

By the way, “milt” is what we call semen if it’s from a fish. I don’t know why we can’t just call it semen. This is something scientists do all the time, and it can get a bit silly. They just can’t stand it when a term isn’t super specific. I mean, I’m sure there’s some functional difference between the sperm-containing fluid of a fish and that of a mammal. But, man, you could just call it all semen and we’d understand perfectly well. People wouldn’t get confused. Nobody would sit there and say, “But Dr. Copeland, what that male salmon just fertilized those eggs with can’t be semen! Yes, it serves the same function, but it has a somewhat different composition that is not at all obvious to me!” I have no idea why we have to have a special name for it. This is why scientists get accused of being elitists!

Anyway. Back to the fish smut. So the happy mbuna male fertilizes the eggs the female is holding in her mouth. What happens next varies by species. Sometimes she’ll go off on her own, because she’s a strong independent woman with a mouth full of sex and she don’t need help from nobody. Sometimes she’ll promptly go and do all this again with a different male. They just can’t get enough. In this case, she’ll have different groups of eggs in her mouth fertilized by different males, so the offspring all have the same mother but different fathers. Other species will stick around with the male for a bit. But in every case, they hold on to those eggs at least until they hatch. This can take weeks, or even months. During this time, eating is obviously going to be an issue. Some species will try to feed while they’ve got their mouths stuffed with eggs, but they won’t eat near as much as normal. Others will fast during the entire process. If it’s a species with a long incubation period, they can be seriously underweight and weakened by the time they’re done. The next time you have a child, just try to stop eating until that thing is born. You ain’t gonna like it. Cichlid moms are kind of bad-assed.

male mbuna cichlid of species Melanochromis loriae, with eggspots visible on anal fin
Male mbuna cichlid with eggspots on anal fin. Melanochromis loriae
Photo by Brian Gratwicke, CC BY 2.0 , via Wikimedia Commons

And the female mbuna generally don’t just leave the eggs in there and forget about them, either. They will periodically spit them all out and then promptly suck them back in again. This helps make sure the eggs are getting enough oxygen and fresh water, and is also a way to keep the eggs clean and to pick out any that are dead or infected with fungus. Eventually, the eggs hatch into little baby fish, which we call fry. BECAUSE OF COURSE WE CAN’T JUST CALL THEM BABY FISH! OH NO! WE WOULDN’T WANT OTHER PEOPLE TO UNDERSTAND WHAT THE FUCK WE’RE TALKING ABOUT SO WE HAVE TO COME UP WITH SPECIAL NAMES FOR EVERYTHING!

I’m fine, it’s okay. Really, nothing to worry about here. So… sometimes after they hatch, the fry will promptly leave the mother’s mouth and start swimming around in a little school near her. With other species, the mother will keep the fry in her mouth for a while longer. Once they’re loose, the free swimming fry will still swarm back in to mommy’s mouth whenever they’re spooked. So the poor mother will be half starved, and desperate to eat. But she can’t take her eyes off her kids, plus they’re constantly hopping back inside her mouth when they’re scared, so she can’t eat half the time anyway. Human pregnancy and childbirth sucks, but sometimes I think we could still have it worse.

Oh, and one last little detail. In lots of species, the male mbuna will have little white or yellow spots on their anal fin. Yeah, I said “anal fin”, it’s hilarious, let’s just get past it, please. As you might expect, the anal fin sits right next to the fish’s genital opening. These spots happen to be about the same size and color as the fish’s eggs, so they’re called eggspots. The thinking is, the female is desperate to gather up all her own eggs in her mouth before some other fish comes along and eats them. So when she sees these eggspots, she thinks they’re real eggs and tries to suck them in to her mouth, giving the male the chance to do his thing. Now… it’s not clear that this is actually what’s happening. I kind of hope not, for her sake. I mean, it’d be pretty embarrassing. It’d be like if a guy had a tattoo on his belly that said, “PUT MOUTH HERE” with an arrow pointing at his crotch, and then somehow that actually worked. There’s a lot of different species of these mouthbrooding cichlids, and they’re all a bit different, but most will still mate with a male even if he doesn’t have the eggspots. So, the jury is still out on that.

Snails do WHAT now?

But let’s face it, oral sex is tame. There must be some animal out there that really gets their freak on, right? Something that would make you say, “Double-you tee eff?” Well, buckle up, buttercup. How do you feel about… sadomasochism? Does a little pain get your juices flowing? Eh? How about stabbing? How about stabbing with a slimy, drug-coated dagger that you grew inside your own body? Hot enough for you? Do we need to take a break so you can go take a cold shower? Because that’s how some species of terrestrial snails do it. Yeah, snails. You never would have guessed that they were the freaks, would you? I’m telling you, it’s always the quiet ones.

Before we get to the stabbery, we need to have The Talk. The Snail Sex Talk. Because, believe it or not, snails are even freakier than I just made them sound. There are snails that live in the water, and snails that live on land. In this case, we’re only talking about the air-breathing terrestrial snails. These land snails are usually hermaphrodites. They’ve got both sets of genitals. The sausage and the taco. The dipper and the honeypot. The Millennium Falcon and Docking Bay 94. When they mate, they impregnate each other, and then both go off to lay eggs. Now, that may seem like a win-win. Everyone gets something out of it. But… it gets more complicated.

Helix pomatia snails, busy impregnating each other
Helix pomatia snails, busy impregnating each other
Photo by Janek Pfeifer CC BY-SA 3.0 via Wikimedia Commons

See, these guys often mate with multiple partners before laying eggs. And sex is always about passing on genes. Whatever helps to pass on the most genes to the most offspring is what natural selection will select for. From the perspective of the snail as a father, this means having as many eggs as possible fertilized by their sperm. But from the female perspective, when their eggs are fertilized by a variety of different males, it increases the odds that at least some of them will have good genetics. If one father is a genetic dud, you at least haven’t doomed all your offspring. So, there’s an evolutionary conflict between males and females here. That’s not all that unusual, only this time, male and female are the same thing.

So what happens is, these land snails have an internal reproductive system that’s a little more complicated than you’d expect. They get inseminated more or less like you’d expect… other than the part where they’re both getting it at the same time. But once they’ve delivered their sperm, the receiving snail has the ability to only send some of it off to fertilize eggs internally. The rest of the sperm gets diverted to a special chamber where… it gets digested. I shit you not. These guys have a special little stomach just for sperm. This allows them to save some of their eggs for the next partner, so no one male can fertilize them all at once. So, okay, great. The female half of the snail is doing what makes the most evolutionary sense for it. But what about the male half? Well, many species of land snails have a secret weapon. Or, really just a weapon. I mean, everyone knows about it, it’s no secret. They have love darts.

All of the sudden, Cupid’s arrows don’t seem romantic

A love dart is also called a gypsobelum, and see my above rant about scientists coming up with new names for stuff when it’s not really necessary. But we’ll let the mollusc nerds call them that. You and I will just call them love darts. These are basically just what they sound like. Long, thin, pointy darts. In some species they are straight and narrow, in others they’re curved, bladed, or barbed. Often they’re made of calcium carbonate, the same thing as the snail’s shell is made of. Other species have darts made of chitin, the material an insect’s exoskeleton is made of. Either way, these things are surprisingly big compared to the size of the snail. If humans had them, they’d probably be a foot long. And they have these things tucked away along with their genitals. They’re basically giant crotch daggers. Or throat daggers if you like, because by the way, snails have their junk up by their heads. Because you really needed this to get weirder.

When two horny snails meet, they tend to do a little dance where they feel each other up and decide if they like each other. Snail eyes aren’t that great, so using touch to asses the worth of their potential partner is pretty much how they have to do it. When they’re getting ready to do the sex, they will try to stab each other with their love darts. Now, these things don’t shoot into the air like a proper dart. The snail lovers wait until they’re pressing up against each other, so the dart goes directly from one and in to the other. But they do get squeezed out with a lot of force. A lot of force. They can go all the way through the snail’s body and poke out the other side. It must hurt like hell. We don’t really know, but damn! Because their eyesight is crap, they actually end up missing a fair amount of the time. But when they do land a hit, the other one fucking knows it. Once they’ve each taken their shot at the other, they do the sex, they inseminate each other, and then the function of the dart comes in to play.

barbed love dart from a Monachoides vicinus snail
Love dart from Monachoides vicinus
Photo by Joris M. Koene and Hinrich Schulenburg, CC BY 2.0 , via Wikimedia Commons

Because the purpose of the dart isn’t that snails are actually in to S&M. The potential pain and the obvious physical damage are not advantageous to either one. In fact, snails that don’t get stabbed by love darts will live longer than those who do. So why go to all the trouble? Because they’re a drug delivery system. These darts are covered in a special mucous that gets spread on them right as they leave the body. This mucous contains chemicals that immediately affect the part of the reproductive system that controls whether the sperm gets consumed or sent to fertilize the eggs. It causes contractions in the other snail that help to squeeze sperm away from the sperm-stomach and towards the eggs. So a snail that successfully stabs their mate with a dart is helping to make sure that, even if their lover goes off and mates with other snails, more eggs will be fertilized by their sperm. Twice as many eggs, in fact. Plus, in at least some species, the dart drugs also make them less interested in mating, so they’re less likely to mate again before laying their eggs. Again, this helps to make sure that as many eggs as possible are fertilized by the dart-shooter’s sperm and not a rival.

Well, I told you it got weird. Sex is vital to the survival of a lot of species, and any sexual practice that helps it to be more effective at passing genes along will have a powerful effect on the evolution of that species. Sex can drive evolution just as much as the ability to find food or avoid predators. Doesn’t matter if it’s fun games or a gruesome sex dagger. If it means the genes are more likely to get passed along, then that behavior is going to get passed down as well. Just remember: what’s good for one species isn’t necessarily good for everyone. If you want to try out some games before sex, go for it. Oral sex? Sure, just be safe. But… as romantic as the term might sound, I really suggest you not try to do the love darts. If you notice a sharp bony object protruding from the flesh of your abdomen when you become aroused, you better just go directly to the hospital. As for mouthbrooding, I think that’s fine. Go ahead and carry your baby around in your mouth. It’ll be fine. Just put a video of it up on TikTok for me, because that shit’s gonna be huge with Gen Z.

MORE READING:
These Lizards Have Been Playing Rock-Paper-Scissors for 15 Million Years
Evolutionary game of rock-paper-scissors may lead to new species
Daddy Day Care Underwater
A love-dart at the heart of sexual conflict in snails

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