January 4, 2022
As the itsy bitsy spider crawls up the water spout, it dawns on her: her exoskeleton doesn’t fit. Is it a fashion emergency—or her moment to shine? This week, Dr. Maydianne Andrade joins Jonathan to share the ins and outs of spider growth, behavior, and reproduction.
Dr. Maydianne Andrade is a professor of Biological Sciences at the University of Toronto Scarborough, and president of the Canadian Black Scientists Network.
For more resources referenced in this episode, make sure to check out the work of Professor Karen Warentkin at Boston University, including the presentation Crossing boundaries, disrupting binaries: A queer perspective on studying behavioral diversity.
Many thanks to Dr. Senthurran Sivalinghem at University of Toronto for permission to use the amazing spider footage featured towards the end of this conversation.
And thank you to Dr. Jessica Ware for sparking our curiosity here! Dr. Ware’s episode of Getting Curious about cicadas, dragonflies, and other insects is a perfect follow-up listen.
Transcripts for each episode are available at JonathanVanNess.com.
Check out Getting Curious merch at PodSwag.com.
Listen to more music from Quiñ by heading over to TheQuinCat.com.
246 — Do Spider Exoskeletons Go Out Of Style? with Dr. Maydianne Andrade
Getting Curious with Jonathan Van Ness & Dr. Maydianne Andrade
JVN [00:00:00] Welcome to Getting Curious, I’m Jonathan Van Ness, and every week, I sit down for a gorgeous conversation with a brilliant expert to learn all about something that makes me curious. On today’s episode, I’m joined by Professor Maydianne Andrade, where I ask her: do spiders’ exoskeletons ever go out of style? Welcome to Getting Curious, this is Jonathan Van Ness. I cannot wait for today’s episode, it’s, like, seriously so major. It’s a long time coming. Who knew I was going to become a 30-year-old who was going to be obsessed with insects, arachnids and spiders? But it happened. And alas, let’s introduce our guest, who is Maydianne Andrade. Her research on spiders centers on how the reproductive behaviors of males and females evolve through the interaction of sexual and natural selection in variable ecological contexts, and how that shapes individual phenotypes and population level characteristics. She’s also the president and co-founder of the Canadian Black Scientists Network, also known as CBSN, with a PhD in neurobiology and behavior from Cornell University. Maydianne has over 20 years of experience in science and research, teaching and outreach. OK, first of all, that gave me chills on my thighs, like, your resume, like, you better. And I’m also, I wish people could see this podcast, and I’m sure you get this all the time. Your hair is so stunning.
MAYDIANNE ANDRADE [00:01:20] Thank you, thank you.
JVN [00:01:21] And your texture. I’m trying to do this thing where I’m trying to not compliment everybody on their looks because I was, like, trying to be more, like, you know, a journalist. But in this case, I can’t help it. Like, your hair is literally too perfect and too stunning on you, to, like, I’m a hairdresser at heart, first, I can’t help it.
MAYDIANNE ANDRADE [00:01:37] Well, you must know that when I was, when I agreed to be on the show, the first thing I thought is, “Oh my goodness, it’s Jonathan Van Ness. I have to do my hair and makeup.”
JVN [00:01:46] I mean, you’re, I mean, we’ll get it on social. I mean, it’s just, like. [CROSSTALK] I never offer, like, unsolicited notes on people’s hair any way. But if I did, there’s literally no notes. Like, they’re like, This is the most perfect hair like, get out of my face. I can’t even stand it . And the other thing that I just would be remiss if I didn’t mention before we get into spiders, your last name is very similar to the reigning Olympic gold medal-winning vault champion Rebecca Andrade, from Brazil.
MAYDIANNE ANDRADE [00:02:17] Maybe we’re distantly related. I hope so.
JVN [00:02:20] Me too. Me too. But here’s the thing: we were minding our own business on Getting Curious when some cicadas came to town last summer, it was, like, a smaller brood. Not this summer, but last summer, right? Then we met Dr. Jessica Ware. Then, ever since then, I’ve been obsessed with Dr. Jessica Ware and insects, spiders, arachnids, all, like, all of this nature. I do kind of think it’s somewhat Dr. Jessica Ware’s fault, because she’s so interesting and a fierce educator that I’m thinking that might be why I got so into it, but that’s how we met you. And also, she gave me her number, which I, I think she might regret, because now every time I see a spider or a bug, I FaceTime her probably, like, three times a week, which I don’t totally do to all of our guests, right? So, but in that spirit, I’m minding my own business in the house. My friend slash assistant Julie is in the front of the house. She finds a literal dead tarantula in our front doorstep.
MAYDIANNE ANDRADE [00:03:21] A dead tarantula?
JVN [00:03:22] Uh huh.. because we live in Texas, we live in Austin. And I’ve got a picture, I have a picture I can show you.
MAYDIANNE ANDRADE [00:03:28] Love to see it.
JVN [00:03:28] I FaceTimed Dr. Jessica Ware, and then we ended up FedExing it to the American Museum of Natural History, like, surrounded in paper towels so that we wouldn’t mess up the legs. But then she was, like, “I think it died molting,” and then I was, like, “Now I have to learn about exoskeletons of spiders and, like, spiders.” And then she was like, “Well, our friend Maydianne is, like, really the one.”
MAYDIANNE ANDRADE [00:03:50] Jessica’s amazing. And she’s definitely doing her job by getting you completely hooked on things with exoskeletons. I love that.
JVN [00:03:56] And I’m just going to give you a forewarning, like, don’t give me your cell phone number if you don’t want me to, like, like, we maybe just, I’ll, like, DM you, but that was famous last words, because that’s how it started with Jessica, too.
MAYDIANNE ANDRADE [00:04:06] So I actually keep tarantulas. When I was a graduate student, I had one for each member of my committee and I named them after my committee members. It was a way of making me feel more relaxed with my committee members, and I saw them grow up. So I started them off as little babies, and then I saved each one of their molt skins so that when I went out to do outreach for school groups, I could show them, you know, “Here’s the spider now,” size on my hand, say, “And here’s what it was like as a baby, and here’s every single stage of its development, from baby to what you see now.”
JVN [00:04:34] OK. I got to start at the beginning because now I’ll go off track. OK, so just to get us started on, like, spider basics because, like, I am literally no spider expert. And I would say, I’m kind of scared of spidies in a way that, like, you know, you know, like, the cicadas don’t totally scare me. And, like, the other ones like, you know, praying mantis, a leaf bug, like, spiders, I’m a little scared. So what is a spider?
MAYDIANNE ANDRADE [00:04:55] So spiders are air-breathing arthropods, which are things with, you know, external skeletons. They have eight legs. They make silk at all or can make silk at all points in their life cycle. And then they have fangs, which are held in these, these chunky things called chelicerae, which hold the fangs in place, and that basically are the key characteristics of spiders. But variations on that theme are huge. Right? It’s, it’s this huge group of organisms. We think there’s about 50,000 different species of spiders, they’re on every continent except for Antarctica. And they’re awesome. Like they’re they’re sort of top predator of the invertebrate world, right, of the things, the creepy crawlies that move around.
JVN [00:05:36] And they all have fangs?
MAYDIANNE ANDRADE [00:05:39] They all have fangs. Yeah. So they’re not all big fangs, but they all have fangs, yeah.
JVN [00:05:44] That’s what they get the most visceral reaction. Like, I’m down with everything until you see fangs, and then I notice I’m grabbing my arms. I’m rocking. I’m scared. I feel like there’s a spider behind me. So I’ve just got to deal with that. But that’s a separate episode. So basically, like bugs, insects, arachnids, isn’t it just that, like, one has six legs, the other one has? There’s so many differences. It’s not just their legs.
MAYDIANNE ANDRADE [00:06:06] No, but you, but that’s, that’s basically the biggest one to someone just looking at them. Six legs, insect; eight legs, spiders. Completely reasonable way to split them up. And insects also have three body parts whereas spiders have two. The word “bugs” is kind of a fun one because people apply that to everything. So you know, everything from viruses and bacteria right through to insects and spiders. So that is just sort of a fun term we use. It doesn’t really have a scientific meaning.
JVN [00:06:31] OK, I love that. And we think there’s fifty thousand. That’s OK. So, venomous spiders. Because you know how, like, with snakes, like, there’s some they have venom and there’s some that, like, constrict? So, like, like, are, because some spiders aren’t venomous, but then some are, right?
MAYDIANNE ANDRADE [00:06:47] Well, so all spiders produce venom, but not all venoms can affect humans or vertebrates. So I think that’s what people are thinking of, right?
JVN [00:06:55] Stop the presses! So literally all spiders are venomous.
MAYDIANNE ANDRADE [00:06:59] Oh, wait, wait, wait! There is a spider called the spitting spider, and the venom glands have been modified to actually create a type of silk that it actually spits out at its prey and sort of splatches them against the wall like Spider-Man. Yeah, it’s cool.
JVN [00:07:11] Scary! OK, so one other off the rails question, I’m sorry. Wive’s tale, tale as old as time? I don’t know if you, like, if y’all heard about this in Canada, but we say in America a lot. Is it true that daddy longlegs, which are, I think, six legs, not eight legs? Are they really the most venomous letter in the world? But they just don’t have things big enough to bite you? Or is that a lie?
MAYDIANNE ANDRADE [00:07:34] That’s a, that’s a lie. I’m sorry, I got. So why, you know? So first of all, yeah, they’re not spiders. You’re right, they’re a type of arachnid, but they only have one body part. And as far as I can tell, from the literature, that is just something people make up. If they don’t have fangs and they don’t use venom, why would they have venom? And why would it be the most, most deadly type of venom in the world, right? It just doesn’t make a lot of sense.
JVN [00:08:01] I need to do an episode on daddy longlegs.
MAYDIANNE ANDRADE [00:08:03] That would actually be cool.
JVN [00:08:04] Because do they, like, whatever, I can’t even deal with them right now. There’s just too much to go on with, just, spiders. So, you know, I first saw a tarantula living on Lake Travis, minding my own business in, like, May of 2020. And it was so big I looked over the balcony. It was, like, literally this big and then scurried under the rock. And I almost shit my pants, like, you would have thought that someone was going to kill me in the backyard. Like, Mark thought, my husband thought that there was someone there to kill me, but it was a spider. Then I saw one crossing the street about a week later, then I didn’t see one again, did not see one again until this past June. Another one. And then the dead one in our front door.
MAYDIANNE ANDRADE [00:08:45] Tarantulas, a lot of them live in burrows or places where you wouldn’t often see them. But when they are trying to mate, when males are trying to mate, they will start wandering and looking for females. So it’s possible that what you saw was basically a male looking for love. And that’s why certain times a year you might see them, but you might not see them very often otherwise.
JVN [00:09:05] That’s hot. OK, so wait, what about the, so what’s, like, their life cycle, like, they’re babies…
MAYDIANNE ANDRADE [00:09:12] Yeah. So like other types of things with a hard exoskeleton, they have to shed to grow. So you’re encased in this skeleton. You start to get bigger, because you’re eating and everything else. And then it’s, like, imagine, like you’re in a coat of armor and it’s got you constrained, but you’re growing, right? And you hit a certain size and you’re too big for that coat of armor and you break it off and then you basically expand once the coat of armor is gone. And so that’s one growth stage. So tarantulas go through multiple growth stages until they become sexually mature and after that, even because some of them can live for up to 25 years, 25 years, right? That’s amazing. So for people who go out and think, you know, “I’m going to kill a tarantula because it’s a bug and I don’t like it.” It’s, like, you’re killing something. It could have lived for 25 years. So, yeah, I know your mouth, so, it’s amazing. And so their body’s covered in these sensory hairs and as they age, some of those sort of wear off. And when they wear off too much, the tarantula will molt again and regenerate those hairs. So tarantulas actually can molt continuously throughout their life, their lifespan. But up until the time they become sexually mature, each life stage gets bigger and bigger and bigger.
JVN [00:10:18] So, oh, so they last longer. The skin or the, is it called skin or the exoskeleton lasts longer.
MAYDIANNE ANDRADE [00:10:23] The exoskeleton or molt skin? Yeah.
JVN [00:10:27] So, so, like, we have this basket outside of our front door that, like, we keep open, like, for delivery, and it was, like, the lid always stays open, and the tarantula was, like, underneath the lid, like, if you, like, because it was leaning up against the door and so if you pulled the lid back. He was, like, laying between the crease of the, the box and in the wall. And Jessica, because we did send it. She said that she thinks it is a boy. And, and so the, like, and it was okay, should I just show you a picture really quick so that we can just, like, rip the Band-Aid off?
MAYDIANNE ANDRADE [00:11:00] Oh, yeah, that’s cool. Oh, see those things hanging out the front, you see the very things that look like front legs. Those are actually called pedipalps. They’re the front appendages and they’re modified legs that are used for mating. That’s how you can tell it’s a male and I can see the little things on them that… [CROSSTALK]
JVN [00:11:16] Yeah, and then she said fangs, that why she said she thought it was a boy.
MAYDIANNE ANDRADE [00:11:19] Yeah, underneath, yeah.
JVN [00:11:20] She thought maybe he died molting and he was like, who, like went to go find a quiet, dark spot, and that’s why he was there?
MAYDIANNE ANDRADE [00:11:28] Yeah, that’s exactly what they do. So they, he, what you describe looks like it would have been a shady spot that might have looked kind of like a little burrow because some spiders will go into the burrows made by other animals that have been abandoned. Because it’s kind of a safe spot. When they molt, they’re super vulnerable. So what I just described with the sort of coat of armor bursting off, imagine that you’re kind of soft inside of that until you build your next coat of armor. That’s kind of how they are. So when they’re molting, they really need to go somewhere safe. And then it seems as if the humidity is too low or something like that, then it doesn’t happen successfully. They, their new coat of armor gets built while they’re still stuck inside the old one, and that can actually kill them.
JVN [00:12:07] So that’s what, OK, so, OK, OK, let’s slow this down, do all spiders molt or just tarantulas?
MAYDIANNE ANDRADE [00:12:21] So all spiders molt they, they grow. So when you see a baby spider, it looks like a tiny little perfect adult spider, basically. Then it sheds and gets bigger and bigger until it hits its adult stage.
JVN [00:12:24] Why don’t we see them, then? I feel like I don’t see, like, I don’t I don’t feel like I see little, do other animals eat them?
MAYDIANNE ANDRADE [00:12:31] Well, they’re tiny, they, if it’s a web-building spider it would be stuck in a web. And a lot of people, actually, when the spider is big enough, they think it’s a dead spider, but in fact, it’s a mold. So like when I go out and go to school groups, I take my tarantula skins and people are, like, “Whoa, you’ve got six tarantulas in that glass-fronted box.” And it’s, like, “No, they’re actually skins that you can basically reconstruct the spider from.”
JVN [00:12:51] Because actually, Dr. Ware, because I obviously immediately FaceTimed her like four times in a row, and then she answered on the fourth one. She was probably teaching a class or dealing with an emergency, and I couldn’t stop calling. And she was, like, I think I’m actually saying that to be funny. I think she picked up on the first try. Because that would be like harassment, four in a row. But I just, but, but she was, like, “Oh, actually, it might just be the skin.” And then when we got closer, she was like, “No, that’s like, that’s the, uh-huh. Yeah.” So, so, so how, so all spiders molt. But some only live for, like, a year, right? Like a season?
MAYDIANNE ANDRADE [00:13:25] Yeah, yeah. When the eggs hatch, usually that’s at the beginning of sort of their season. So for a lot of spiders, that would be the beginning of the, let’s say, the spring and they hatch, they’re babies. They can eat and capture prey right out of the box. They can build webs, usually if they’re web-building spiders right out of the box and they start eating and they start growing. If they’re one of these one-season spiders, then they become sexually mature before the end of the year. They mate. You know, if it’s a female, they produce offspring, and then they die. But lots of spiders also overwinter, so they can hunker down and spend the winter at whatever growth stage they’re at or egg sacs overwinter. So spiders produce eggs typically in these little balls that they cover in silk and that whole egg sac can overwinter and then hatch at the beginning of the season and then go through that again.
JVN [00:14:14] OK, yes, ok, ok, ok, ok, ok that makes sense. So with a tarantula, and I swear to God, we’re going to get to mating today. [CROSSTALK] I swear we are. But I just have so many questions. I’m a nightmare. So well, how old for a tarantula on their first one? And I need to know, like, what happens with their insides, like, with the, when they…
MAYDIANNE ANDRADE [00:14:33] Right, so the age when they molt really depends on how much they’re eating. So development requires X amount of nutrients. And essentially we have evidence that for some species, it’s kind of a decision when you’re going to molt. So let’s say the animal’s in a food-constrained environment and it’s just getting very little food through its whole lifespan. It’s basically a decision: “I’m going to become sexually mature within this time span, but I’ll be smaller,” versus, “I’m going to stay longer as a juvenile and keep eating to get bigger.” And so there’s evolutionary reasons why they may pick one or the other, but it’s kind of cool that they can do that flexibly. So the total time really depends how much they’re eating. Like, the tarantulas that I had, one of them that I had was one of the largest species that that we know of that can grow to the size of your hand, can be, like, six ounces and size, which is about six times heavier than a mouse, which is amazing. And notice I said ounces and not grams. I did that just for you guys in the states. And so anyway, when they get to a particular size, when they become sexually mature, then investment has to shift into their gonads, right, into producing sperm or eggs. And so that’s really a decision, if you know what I mean? But if you have to be a particular size to survive or to get a mate, then you need to keep investing and keep growing. But the tarantulas I had, this really large one, it took about a year and a half to become sexually mature from the time I had it as a little baby, I fed it quite well, though.
JVN [00:15:59] So that one exoskeleton lasted that whole time, like, a year and a half?
MAYDIANNE ANDRADE [00:16:03] No, no. Sorry. And then it grew probably once every two or three months, it would shed its skin, so it is literally doing it multiple times. So really, when I have the spider, that, this really large one the size of your hand, I would have, like, eight molt skins for its development. And then after that, when he becomes an adult and it only molts when, let’s say it’s sensory hairs degrade, then it would only be every once, every couple of years or so.
JVN [00:16:27] So do spiders have, like, you said, air-breathing. So do they have, like, lungs, kidneys, livers.
MAYDIANNE ANDRADE [00:16:36] So their guts are very different from ours. They do have book lungs, they’re called. And so they, you can think of them kind of like our lungs, but they don’t only breathe from those lungs. They also have ways in which air can kind of make their way, its way into, into the body cavity otherwise. But the main thing is that they use oxygen. But unlike us, where we have, you know, the lungs are pumping and you’ve got the blood vessels going in and out. They have these sinuses, big gaps where we call it hemolymph. Their, their equivalent of spider blood just sort of pools there and gets oxygenated. And so they look very different. They do have a little bit of tissue that pulses like a heartwood. And in fact, in some species, you can actually see through their exoskeleton and see the pumping, which is super cool under the microscope. So they’re very different from us internally. They don’t have kidneys and livers. They have places where they put waste. But it’s not, you know, being filtered out by a kidney.
JVN [00:17:33] Do they poop?
MAYDIANNE ANDRADE [00:17:34] They have little places where they store fat. They definitely poop. Everybody poops. I think there’s a kids book called that, which I love, and, but their poop is this sort of dried up white stuff. So if you’ve ever had a spider web in your house that you’ve kind of missed for a while, you’ll notice there’s this kind of white, dried up, crystalline stuff around and that that’s a mixture of old and pee.
JVN [00:17:54] So what else do they have about, like, the, they store, they store waste and then there’s, like, there’s a pumping tissue, but it’s not really, like, a heart.
MAYDIANNE ANDRADE [00:18:01] Yeah, we just call it a contractile organ, like, it’s, it’s just pumping tissue that helps to move that, that spider blood around the body. But it looks, they look very different from us. So when you look at a female spider, they have a really big abdomen, right? The largest part of the spider. It’s almost entirely filled with eggs when she gets to be sexually mature. So a lot of that space fills up with eggs. Of course, there’s space for, for the venom gland in the head. There’s space for the spinner, for the, the silk-building glands in the back end of the body because the silk comes basically out of the bum. But otherwise, like, a lot of that space fills up with eggs.
JVN [00:18:39] Ah, and then you know how, like, now we’re going to be getting into mating. I’m excited. So you know how, like, like, is there, are boys or girls ever more venomous or less venomous than each other? Or does it depend by species?
MAYDIANNE ANDRADE [00:18:56] So I know black widows better than other species, as far as I know, males and females have venom that have the same composition, that may be different in other species, that I have to check, but I suspect not. What is different is a couple of things. One is how much venom they release when they and if they bite you. The other piece is the size of the fangs, so that, that’s where that thing you hear about, about daddy longlegs comes into play. So, for example, in my lab, we’ve got generations of black widows. The males are about the size of a rice grain. The females are the size of kind of a large marble. And the female’s fangs can get to your skin. The male fangs? Probably not. So males release less venom. They’re less dangerous in general, females, though, you’ve got to watch out for because they produce more venom, especially if they’re mad at you. So females can produce and release different amounts of venom, depending on the situation.
JVN [00:19:47] So if they feel threatened, like, they might release more?
MAYDIANNE ANDRADE [00:19:50] Yeah. So for example, in our lab, we take away the females’ egg sacs because we’re mean, no, because that’s how we rear them. So the female produces egg sacs once a month, or sometimes once every two weeks. We take the egg sac out and put it in a new cage so that we can rear up her babies. Females do not like that. So whereas mostly black widows, they’ll sort of hang back and be retiring. They will actually try to bite the tweezers we’re using to remove the egg sacs. So they’re very, very maternal.
JVN [00:20:17] Oh my god.
MAYDIANNE ANDRADE [00:20:18] I know, it feels a little mean. I know.
JVN [00:20:21] Do you ever let one? Do you ever feel bad and, like, let one keep, keep one?
MAYDIANNE ANDRADE [00:20:26] That only happens accidentally, because what happens, so, females are kept in my lab in these clear plastic cages so that we can see the female as we’re doing what we need to do, feeding her, et cetera. Once there’s babies and a female, if you open the lid, you know, it’s, there’s a real risk of an escape. Whereas if we have got a cage with only babies or only adult females. We know exactly how to deal with it. So none of them escape because if a black widows population shows up in our building, they’re going to know who to come talk to.
JVN [00:20:56] Oh, so once the, so once the mom has egg sacs in the same thing, she wants to leave?
MAYDIANNE ANDRADE [00:21:02] No. So it’s more that the spiderlings will be trying to leave. And so it’s very hard to deal with both the adult female and the spiderlings as the spiderlings are trying to come out. Whereas when we deal with just spiderlings, we know that that’s going to happen.
JVN [00:21:17] So how long, in the case of black widows, do they, like, what’s, like, the gestation period of the spider sac?
MAYDIANNE ANDRADE [00:21:24] So the, the eggs are packed into the sac and there’s between, say, 50 and 300, depending on the species, which is super cool, pretty small, like a little tiny cotton ball. They hatch inside the egg sac after about a month or month and a half, depending on the temperature, and they actually live inside for one growth stage. So to me, this is completely fascinating. And after this, you should really Google “black widow spider hatching.” The egg sac has, like, 300 babies packed in there, and they’ve hatched, right? So they’re actually juveniles and they’re like eating off their yolk sac or whatever, not eating, but getting nutrients from that. And then one spider, and I don’t know why, one spider will cut a little hole in the egg sac, and they all come pouring out. And literally, in some cases, we have to do, we call it a cesarean. We have to open the egg sac because no one has cut that little hole and we can see that they’re, they’ve hatched inside because it gets kind of dark and we’re worried they’re gonna get trapped inside. And we’ve actually had cases where the spiderlings are trapped inside because presumably no one cuts the hole, no one comes out.
JVN [00:22:25] And then they die?
MAYDIANNE ANDRADE [00:22:27] And they die inside the sac. Yeah.
JVN [00:22:29] Have you ever had some, like, some of them die, but some of them lived?
MAYDIANNE ANDRADE [00:22:31] Yes. Like when some of them eat their siblings inside the sac?
JVN [00:22:35] Oh, so that happens?!
MAYDIANNE ANDRADE [00:22:36] That does happen, sometimes, yeah, yeah.
JVN [00:22:38] Does that happen even in, like, a healthy sac where one does open it? But some of them were just like, “Sorry, I got hungry, couldn’t wait?”
MAYDIANNE ANDRADE [00:22:44] That’s a good question. I don’t think so. So the way the spiderlings work in general, and you see this on the, on the web as well, these web-building spiders are sit-and-wait predators, which means without stimulus, they kind of just sit there, conserve their energy, and then when prey hits the web, they kind of get activated. So when they’re inside the sac, as far as we can tell, they’re basically in the sit and wait kind of posture. Once the egg sac opens, they come pouring out. But on the web, if, let’s say a fly comes in there, juveniles, the spiderlings, they, they are pretty indiscriminate and where they throw their silk, let’s just say that. So they all pile on this, this spider. And if, if brother, sister, whatever is in the way they’re wrapping it up and they’re eaten brother or sister as well as, as the fly. So you do see some, some cannibalism that way.
JVN [00:23:31] Oh, OK. So, OK, OK. Oh, OK, so, so many things in my head that are all, like, coming, rushing in at the same time, I can’t even stand it. OK, so with how, so how do they, how do spiders, like, and I guess they’re all different and we are obsessed with black widows, how do they, like, select their mates?
MAYDIANNE ANDRADE [00:23:57] Ah! So spiders, spiders have very few neurons. I’m going to start with that, right? So we have a brain, we have all the sophisticated cognition and spiders with only a few neurons can still make really sophisticated decisions about their mates, basically for web building spiders, and yes, I’m obsessed with black widows, they make their decisions based on scent and based on vibrational signals. So they actually don’t see very well when they’re web-builders, and they can smell females from a distance. So a male spider will develop on a web that’s independent of females, right? They’re carnivores, they tend to be independent, and then they get the scent of a female sort of coming towards them once they become sexually mature and they actually make a beeline for the female using kind of the pheromone or the perfume plume that comes from that female’s web. So they track them down that way. For black widows what’s really important, though, for a male is they can actually smell whether the female has said recently or whether she’s likely to be hungry, particularly in species where the females are cannibalistic and kill males who approach and try to mate with them.
JVN [00:25:01] Oh, I was going to ask you about that. Like, so, like, is there, like, a praying mantis vibe to a lot of spiders? Meaning they’ll eat after they, like, they’ll kill their, their baby daddy?
MAYDIANNE ANDRADE [00:25:11] Yes. And so well, and sometimes they won’t even let him become the baby daddy. Right. So we have some black widows where the female attacks before, I won’t say before mating, because, of course, if the male’s dead, there’s no mating, but the male comes to court and the female will kill him during courtship. There’s other species where it never happens during courtship, but it happens during the mating itself. Like, the species that I started studying as a Ph.D. student, the male actually has this movement where he twists his body onto the female’s fangs, and while she’s chewing on him, he continues to transfer sperm and is fertilizing eggs. So it’s this amazing behavior. And then in other species, after the male is done, he has to run like crazy, or the female is going to try to eat him then.
JVN [00:25:52] So with that, what was that species that you started studying in PhD school?
MAYDIANNE ANDRADE [00:25:55] This is the Australian redback, which is the Australian black widow.
JVN [00:26:00] So the Australian redback male knows that he is going to off himself at the end.
MAYDIANNE ANDRADE [00:26:06] That’s, I mean, to the extent the spiders can know. Yeah. And the other piece, of course, that’s weird is males have two copulatory organs in spiders. We have even got into the weirdest part yet. The male will approach the female, insert one of these organs and do this twist. So the female starts to eat him. Then he goes back on the web and courts her again, and comes back with the second organ, mates again, and then she finishes him off during that second copulation.
JVN [00:26:30] And that’s only the redback ones? [CROSSTALK] Do all this, so no other spiders do that, that’s just specific to those ones?
MAYDIANNE ANDRADE [00:26:36] Ah, well, so, among the black widows, which is 30 species worldwide, we know now that there are three species where the female eat the male during mating at different places in their evolutionary sort of family. And so that’s one of the things we’re really interested in in my lab is how does something like that evolve?
JVN [00:26:51] Why, do they do it because, like, they need more nutrients while they’re making the babies? Or, “This takes a lot out of me, mister. So I’m going to eat you.”
MAYDIANNE ANDRADE [00:26:59] Yeah, you know, it’s not that clear. The interesting thing is that in the two species where the male is basically offering himself, like, there’s definitely a distinct behavior where the male moves his body into the female’s fangs. And so we think it’s basically the male enticing the female to eat him. And she actually lets the male mate for longer if she does take him up on this offer. So it seems as if he’s maybe transferring more sperm as a result? So it’s beneficial for the male, at least in those species. One of the critical pieces, though, is that males, a lot of males die while searching for females in the first place. So it’s like you finally get to a web. And if your chance of dying, if you looked for another female is, like, 85 percent, but there’s something you can do right now that would increase how many babies you have, then, then males do it. And so that seems to be what’s happening in these systems.
JVN [00:27:46] Oh, because if that, if that spider already spent all of his energy finding that one,if he’s, like, “If I go find another one now, I probably won’t make it. So I just got to do something to make sure that I have babies now.” Okay!
MAYDIANNE ANDRADE [00:27:56] And also there’s predation, right? Spiders need their web to be really good at fighting off predators and things, and they, the male doesn’t have that when he’s searching for a mate.
JVN [00:28:05] Oh, OK, and then you know, you said, like, “web-building spiders,” how many other, like, categories is there?
MAYDIANNE ANDRADE [00:28:12] So there’s tons of categories of spiders. I’m definitely just talking about web-builders. There are wandering spiders, there are jumping spiders. There are all sorts that don’t actually live in webs, right? So they actually are active hunters that move around. [CROSSTALK] Oh! But I’ve got to say, so if you were to see a jumping spider under a microscope, it’s like a teddy bear. They have big, forward facing eyes, they’re kind of I don’t call them hairy, I call them furry, they look furry. They have all sorts of amazing colors. And then on top of it, jumping spiders are probably the most impressive for mating because males do a song and dance to convince females to mate, literally, like, shaking their legs around. And there’s all colors on their legs and waving their abdomen and then vibrating. And if you were to watch it, it’s, it’s totally incredible.
JVN [00:28:58] And they don’t have webs?
MAYDIANNE ANDRADE [00:29:01] They don’t make webs. They make, they still have silk because jumping spiders. So, OK, I’ll tell you, we talked about, a little bit about phobias. A lot of people are afraid of spiders. Tons of people. I think it’s like flying, snakes, and spiders are right up there, and they always tell me that the spider jumped or chased them. And I have to say, jumping spiders are really one of the only species or group of species that can jump. They do jump, and they jump incredibly long distances for how small they are. But they, the only way they use silk is they, they anchor a little line so that when they jump, they have basically a safety line behind them.
JVN [00:29:35] Oh, and then do they chase, are they notorious for chasing or were they just imagining it?
MAYDIANNE ANDRADE [00:29:41] They don’t chase people, but they chase their prey. And actually, that’s the other thing about jumping spiders is that they stalk prey like cats do, so they can actually anticipate where an insect is walking and sort of cut it off at the pass sort of thing or hide behind things to catch it. So they’re, they’re really sophisticated, even though they don’t have that many neurons.
JVN [00:30:01] I’m so sorry that I’m giving you, like, all these, like, random questions, but Maydianne, I just read this article and it was talking about like these spiders that eat other spiders and they and they were. And now I’m realizing they were coming for the web-building spiders because they do this thing to them where they, they’ll hit their, they’ll find the web, and then they hit it to make them think it’s a fly. And then when the spider light comes out, like, “I’m going to get the fly,” then the other side is like, “raaaaw,” and it, like, kills them.
MAYDIANNE ANDRADE [00:30:28] Yeah, that’s awesome. Absolutely. So spider, there’s spiders that, the one you were talking about or the ones you’re talking about. Yes, they can mimic the vibrations that a prey item would make in the web. And that is exactly what they do. And some of them actually specialize in killing web-building spiders by doing that. There’s others that actually can mimic ants, and they mimic them, like, so exquisitely that people sometimes don’t realize they’re spiders. Even people who study them, even to the point of, you know, ants have like antennae that they sort of move around. The spider will hold up its front legs and do the same sort of thing as if it’s an ant. It mimics the chemicals on its body and then it can just go into those nests just, like, mow through a whole bunch of ants.
JVN [00:31:08] That’s amazing! [CROSSTALK] And then they do all of the different kinds have, like, the whole thing with, like, how they choose their mates and but they are, do they all kind of have different because it’s, like, the, the, the, the jumping ones have, like, their little song and dance and then the other ones are just, you know, kind of have to, like, come up to the web and hope they don’t die.
MAYDIANNE ANDRADE [00:31:32] Yeah, it’s all over the map again. And I should say the diversity is incredible. So the jumping spiders, as I say, elaborate song and dance, all sorts of colors. Wolf spiders, which are another type that there’s an active hunter, they also have a song and dance, but it’s, it’s much more subtle. And then some web-building spiders, like the black widows I study. They will court females by vibrating the webs, and they’ll do that for, like, eight hours before the female does or does not accept them as a mate. There’s other species where they basically sneak up on the female kind of ride around on her because they’re tiny, really tiny males compared to females, and they basically try to sneak a mating while the female’s busy eating. And that’s to avoid cannibalism as well. So, and then, we were talking about molting earlier. There’s some species where the male just waits ‘til a female is molting and then sneaks in there. So, you know, oh, those ones don’t get caught. They’re like, “We’re investing all our time in doing the sneaky thing as opposed to courting.”
JVN [00:32:28] Ew, so, like, consent’s not always a thing in spider culture. And it’s and it doesn’t seem like it’s like buying for them. They just kind of are doing it to have babies. And then my other question with the black widow families or, like, the redbacks and the black widow families. Do the boys ever mate but survive? Like, is there ever one who’s like, we’ve ever observed? It was, like, “I’m not twisting myself in those fucking fangs. I’m going to get in, I’m going to get out. And I’m going to try to live to see another day.”
MAYDIANNE ANDRADE [00:32:58] Yeah, for sure. There’s some species where males do mate multiple times, and so they would be trying to avoid being cannibalized, basically at all costs. And in fact, they will not bother to go to a female if they can tell she’s hungry. So black widows, western black widows, southern black widows. As far as we know, they can tell if the females are hungry from her, her pheromones, from her perfume. And they’ll avoid those females if they have a choice at all. And that way, they can survive and mate again. I should say, too, that when we’re talking about all the different kinds of spiders, there’s actually some that are reversed, in the sense that males build a big burrow and then the female comes and tries to convince the male to let her use the burrow to lay her eggs in. And if the male doesn’t like her, he eats her. There’s some awesome work from South America. Yeah, so it’s pretty cool.
JVN [00:33:46] It goes both ways, that’s, OK, now I would just be like, I must agree to this. Have we ever observed it like, you know, intersex spiders, that just, like, developmentally, like, don’t develop either which way?
MAYDIANNE ANDRADE [00:33:56] You know, that is really interesting, and that’s the problem with the work we do. And actually, there was this great talk by by one of my colleagues who talked about how, what queerness can bring to, especially to behavioral studies, because we tend to look at averages. And sometimes all the interesting stuff is not in the averages. It’s when you start looking at something that’s different or at the extremes, right? Which is basically what I do. Sexual cannibalism is one of the extremes, but it lets you understand all these other things. And that was their point was that, in fact, you know, if you take a queer lens on behavior and start saying, “OK, sure, I may have only seen this once or twice in the lab, but really, I’m selecting for average behaviors, what’s actually going on in the field?” We don’t know. We don’t know. So that’s the, that’s the kind of exciting thing about starting to build in some complexity. Just like I feel like we’re finally doing kind of socially, right, to understand that things are way more complex than the averages we used to talk about.
JVN [00:34:48] I know, which is just kind, of I mean, it’s really interesting and amazing, but it is annoying for, like, even, I’m as queer as they come. But like I do love, like, a nice, clean box. Like, sometimes you just want a definitive answer. But I just, the older I get, the more I think it just is never, ever like that. So with those Australian ones, right? And, and the black widows that you study? Is there ever because do to the black widows in your lab, do the boys do that twisting, “I’m going to shove myself in your fangs,” thing?
MAYDIANNE ANDRADE [00:35:14] Some of them do, and some of them don’t. Species wise? Yeah. Oh, some species do, and some species don’t.
JVN [00:35:19] Oh, and you have all the species that your lab?
MAYDIANNE ANDRADE [00:35:21] Well at one point we had eight different species we’re working on right now. We’re down to just a couple, but yeah, we have more than one in the lab.
JVN [00:35:27] So my question is, is in the same species as there ever is. So is there some way to do the twist and, “I’m serving myself to you.” And others were, like, “No, lady, I don’t want to die.”
MAYDIANNE ANDRADE [00:35:38] Gotcha. Yeah, for sure. There is variation. And so in one species, it’s really extensive variation, like, maybe 80 percent of males do the twist and 20 percent of males don’t. And they think that some of that variation depends on whether the female seems to be worth investing in. In the black wid-, in the redbacks, the ones from Australia, it’s almost every male that does this. So that seems to be less the case for them. But yeah, the cases where it’s sometimes they do, sometimes they don’t, then we can really start probing, “OK, what makes you decide to do that or not?” And that’s really interesting.
JVN [00:36:11] And then have we ever seen, like, in, like, the Jurassic Park, like, petrified sap or whatever? Has there ever been, like, like, how do we know about this evolution? Is it just like fossils or like, how do we know? Like how they, like, behaved?
MAYDIANNE ANDRADE [00:36:25] So, behavior is hard to capture in the fossil record, but some of it’s there. So like we have really ancient, especially in amber, spiders with their webs and prey in amber, like not a lot of them, but enough that it’s just like, “OK, we know for sure that orb weavers developed really far in our evolutionary history.” Otherwise, some of the techniques we use are actually looking at modern species, what we have for the fossils. And then now with molecular techniques, they can say, “OK, their, their genome looks like this. Here’s how it differs with their relatives.” And they can actually use sort of mathematical techniques to predict how far back it goes in time, right, “From these species, we know that this thing evolved at this rate so that we can infer something like this.” And then if we know what we’re looking for, you can start looking in that period in the fossil record to see if you can find some fossils.
JVN [00:37:15] I’m so relieved that you just said orb weaver, because my husband would have been so fucking pissed if I didn’t ask about this. So in addition to the huge tarantulas that we’ve seen, I was again this other day. All these stories start the same with spiders. I was minding my own business and I was getting these ghost, I was getting these ghost peppers off because I just, like, fierce ghost peppers…
MAYDIANNE ANDRADE [00:37:39] Are you growing ghost peppers?
JVN [00:37:40] Yeah, yeah, yeah. And these fuckers, excuse me, I don’t mean to talk about them like that, I had these gorgeous bushes planted since May, and they are still producing so many peppers and still flowering on December 1st. [CROSSTALK] These three, but, like, but last year, almost it was dead by like October, November. Like, these ghost peppers are like, I just must have picked, like, the right spot because I can just fill it up. Like, I really like their major. But that’s where this orb weaver was, and it was huge. I was, like, getting my things in this, I’m actually getting chills on my thighs again, just thinking about it, because the thing was, is that my face was maybe six inches from this spider because I didn’t, I didn’t even see it. I was so focused on the ghost peppers. And then I was, like, “Oh, that’s not.” And then I was, like, it literally was, like, right here. And it was like. And it was like, and it was yellow, it had, like, a yellow butt–
MAYDIANNE ANDRADE [00:38:32] Black stripes? Or was it all yellow?
JVN [00:38:33] Yes, I think it was, I don’t know, I don’t remember. I feel like there are some black. I feel like there was some yellow. But what I remember the most once I realized how fucking close I’ve been to it in the middle of the web, there was this like. [CROSSTALK] Yeah, yeah, yeah. Uh-Huh. And then a few days later, it was gone. And I was like, because there was this big storm and I was, like, “Oh my God, it’s gone.” And then two weeks later, I’m pretty sure I saw the same spider with the exact same web in a different part in the garden, like, it rebuilt. What was that, can you tell us what I saw?
MAYDIANNE ANDRADE [00:39:04] That’s awesome, you’ve actually just described what it is. That’s amazing. So what you describe sounds like argiope, which is one of the big web-weavers. You know, the concentric circle webs that we find in North America and there’s a bunch of different species, but they’re all a lot of them are the bright yellow summer silver, and a lot of them build what we call web decorations or stabilimentum, which looks like a squiggle, a dense squiggle of silk in the web. There is a huge debate in the spider communities, and there are spider communities, about what the function of that squiggle is. Some people think that it actually attracts prey to the web, it has a particular reflectance that attracts prey. Some people think it helps keep the spider cryptic because the web is otherwise invisible. You can see the spider. But if it sits sort of at the end of the stabilimentum, it’s harder for the insects to see. And so they still crash into the web, so it’s not entirely clear what it is, but just from what you described. I think it’s probably an Argiope. And the other thing is that female orb weaving spiders take down their webs, usually at night and then rebuild them during the day. Some species eat the silk, some species don’t. So that’s probably what you saw. And certainly they can tell often when a storm’s coming the, the, the barometric pressure changes, and the spider will change its behavior, probably hunker down and then may have moved maybe to a better spot where Jonathan isn’t breaking the web with his face and then we’ll end up with a new web.
JVN [00:40:27] Where do they, where will they hide in a storm? Will they dig a hole? Do they go into, like, a different hole or something?
MAYDIANNE ANDRADE [00:40:33] I can’t tell you for sure.
JVN [00:40:35] They come inside! They come inside, they go in the house!
MAYDIANNE ANDRADE [00:40:39] They might! No, they probably can, so spiders could, just like it depends on where they usually live. So spider webs usually have a refuge, a sort of denser area of silk that is often off the web, which is where they hang out when they’re not on the web. And so they can actually build themselves, like, kind of a little cocoon-like thing and attach it to something. So that might be a plant. It might be towards the base of the plant. If it’s an animal that lives usually in a burrow, that they would probably go into its burrow and hide out there. Can I tell you one cool story about spiders in their burrows?
JVN [00:41:07] Please tell me everything.
MAYDIANNE ANDRADE [00:41:10] So, I worked on black widows in British Columbia, and there is a little area of relic desert there. Most of it’s been watered into, you know, fruit orchards or whatever, wineries. But there’s this area that’s like the desert and the spiders build their holes in its burrows. And I didn’t realize how deep under the ground they were until one year there was a fire in that area and the fire was so hot that it could actually warp PVC, you know, plastic, that deep dense plastic tubing. As soon as the ground got cool again, the spiders were back up. The black widows were back up, so they were in some sort of burrow that was deep enough that the incredible ground temperatures of a forest fire did not kill them. Which, to me, is completely remarkable. Like, they can just, so if they can, if they can, they can survive that, they can survive a storm. You know what I mean?
JVN [00:41:56] Yes. Yes, yes. Again, all spiders molt. So even those orb-weaving ones, even those ones that dig. But then if they only live a year, maybe they just don’t molt as many times as, like, a tarantula does.
MAYDIANNE ANDRADE [00:42:11] And they don’t molt once they become an adult. So tarantulas and those really long to live ones, they can molt again later, but these other ones that you’re talking about that live for a year, they’ll have whatever, however, many stages of their life are sometimes five or seven molts, become an adult, and then that’s it. They no longer grow, they longer molt.
JVN [00:42:28] So then, what made you obsessed with spiders?
MAYDIANNE ANDRADE [00:42:31] So I was afraid of spiders as a kid, I’ll admit that. And I, when I started studying, deciding I wanted to study something that was as an undergrad. At first I wanted to be a doctor. A lot of us do, when we like biology. And I started learning that there was a thing called research, and it was fascinating and especially behavior. So I started working in labs to figure out what I wanted to do. And really early on, I was, like, “I don’t like working with vertebrates. I feel like I don’t want to keep a vertebrate in a lab and I don’t want to manipulate them in any way.” So I knew that I wanted to work on invertebrates and then spiders are just, like, the most fascinating thing. I started my master’s degree and my supervisor sent me a paper that was about that twisting behavior. And, you know, the deal was sealed. I thought I was going to do something else later. But I just, I’ve been working on black widows ever since, so…
JVN [00:43:20] I get it, they’re just so cool. So, and then, what about it? So what has been, because you’ve been doing this, even researching for…
MAYDIANNE ANDRADE [00:43:30] Let’s say, do I have to tell you? 30 years, 25 years?
JVN [00:43:35] Wow! What has been the thing that, like, so you told us the fierce story about how they survived the fire. What’s been the most surprising revelation or, like, delightful, like, thing?
MAYDIANNE ANDRADE [00:43:46] OK, I’ll tell you that one of the things that we find most exciting and interesting right now, or I do, this is work with a bunch, and I always, I’m saying I, but it’s always with graduate students, my fantastic, amazing graduate students, we’ve discovered, so I’ll say we, we’ve discovered that not only can males smell females from a distance, but they use information about whether females are nearby from that smell to change how they develop. And if they smell a lot of females nearby, they actually become sexually mature faster so they can get out there and beat competitors to that female. But if they don’t smell any females nearby, they actually slow down their development and just spend more time eating because they are going to have to search further for females, so that what that actually means is they’re changing their gene expression to change their development as a function of what they smell about their current environmental context, about the challenges they’ll have as an adult. So I think that’s super cool.
JVN [00:44:40] What about eyesight? Do they see well?
MAYDIANNE ANDRADE [00:44:44] Jumping spiders see really well, they, they actually have image-forming eyes, which if you again Google “jumping spiders” or if you get one on your hand, jumping spiders are very innocuous. If you look at them and move your head, they’ll actually move their head and track you, which is amazing because they can actually form images with their eyes. But outside of jumping spiders, spider vision is really variable, and web-building spiders can’t see well at all, kind of dark and light. And that’s about all.
JVN [00:45:12] Because tarantulas don’t build webs.
MAYDIANNE ANDRADE [00:45:16] They don’t, they line their burrows, usually with silk, but they don’t build webs, and a lot of their ability to move through the environment is based on vibrations and scent. So most spiders have that even if they don’t have vision.
JVN [00:45:32] And then. Oh, God. Tarantulas, they are just, by God, they are just a lot, that is just that. It’s just and then and then the orb weavers, how long do they live? Are they, like, a three-year spider or, like, a one-year spider?
MAYDIANNE ANDRADE [00:45:46] A lot of them are, like, you know, Charlotte’s Web kind of one-year spiders. Yeah. So they’re, they’re not typically living for more than one season. Yeah, so sadly. Oh, and I thought of something else! Can I tell you one more thing about the latest things in my lab? [CROSSTALK] Ok, so I described how the spider develops basically inside this shell. When a female is about a week away from becoming an adult so that molt, final molt before becoming an adult, the black widows, inside she has created all her, her genital apparatus, so the place where she stores sperm, and the place where she will eventually mate through, her genital openings. Male black widows can actually find females of that stage, and they will open up the exoskeleton and actually mate with them, even though they’re not formally sexually mature yet. And then when the female molts and becomes an adult, she doesn’t need to mate at all. So it’s like they’ve moved, everything’s moved to an earlier stage. Males are so competitive that they have developed this competition to find females even earlier than before they become mature. And maybe that’s actually creepy now that I’ve said it out loud because people say weird things about that, anyway.
JVN [00:46:54] Ah! But we also read that you, that the lab takes care of 50,000 spiders.
MAYDIANNE ANDRADE [00:47:03] Yes. Yes, at a time.
JVN [00:47:04] How does this?
MAYDIANNE ANDRADE [00:47:05] We have this huge operation.
JVN [00:47:08] How big is that room? Is it just, like, spiders wall-to-wall?
MAYDIANNE ANDRADE [00:47:11] Yes, it’s spiders wall to wall. So we have this rearing facility that’s just, like, shelf upon shelf, and tray upon tray, with these boxes of spiders in, in all of them are spiders of different developmental stages. Basically, we have a huge operation, at least huge for me. We have eight to 10 assistants who put in about eight hours a week feeding spiders and cleaning their cages. And the thing about spiders is that they are carnivorous, right? They’re, they’re predatory. So you have to keep them one per cage once they reach a certain size. So as babies, we have these 300 babies, and then when they get a little bit bigger, they get to two or three molts, we separate them into individual cages and then we just have this machine of feeding them, and it’s all live prey. So one room has flies and crickets and mealworms. A couple of other rooms have spiders, tray upon tray upon tray of spiders. And then, yeah, we need those for their experiments. So I estimate 50,000 or maybe a bit more when we’re really at full speed. The pandemic has slowed us down a bit, but…
JVN [00:48:11] Is there ever a spider who, like, just doesn’t want to eat the prey? They just want to be friends with them? Or do they always eat them?
MAYDIANNE ANDRADE [00:48:15] They always eat them. They always eat them. And actually, I do feel sorry for the flies, sometimes because we use fruit flies, drosophila, and they are fed to the babies. So the babies are, like, maybe 200 in a cage initially. And what we do is chill the drosophila so that they’re basically asleep, put them in the web, and they wake up, like, in what I imagine would be a fly’s worst nightmare, which is you’re already in a web and as soon as they start moving, the spiderlings get them, so.
JVN [00:48:43] Sad for the, that’s okay, it’s life. And then, like, and then here’s another question I had a minute ago: has there ever been, like, like, like, in fact, like, could a tarantula and an orb weaver have a baby? Or could like a, or could like, could it be, like, do, do we have, like, a gorgeous, like, different kinds of new spiders that are, like, of two other spiders?
MAYDIANNE ANDRADE [00:49:07] Yeah, hybrids. There are, but it’s never, like, orb weaver and tarantula. That tends to happen when the species are fairly closely related already. So among black widows, for example, you can have hybrids. In fact, in Texas, the western widow and the southern widow overlap and there’s some hybrids there. So there’s some people studying that. They do sometimes enter mate, and sometimes those hybrids don’t do so well, right? They they kind of are the end of the line. And in some cases, they, they, they do OK, and they might create a new species, basically from those hybrids.
JVN [00:49:39] Do we know about any species that are, like, that did good? And they wer, they’re, like, the cool new, like, one?
MAYDIANNE ANDRADE [00:49:46] Yeah, historically. So if you study sort of the evolution of some of these groups, you can infer or you can take a look at the, the genes of two different species that are closely related and maybe a third species. And then you can figure out the ways in which it might have been a hybrid that actually then became its own species. But you pretty much have to figure that out from tracking backwards in time through the genetic footprint basically of intermating.
JVN [00:50:10] As a spider expert. Yeah. What spider are you seeing and you’re, like, “Fuck, I’m scared! I’m not staying in this house!” Or like, like what one do you see that you’re like, you know, you’ve ever come, like, which one is, like, the fucking most dangerous that we, like, interact with that, like, if you see what like, is it the brown recluse?
MAYDIANNE ANDRADE [00:50:29] So to be honest, I’m not afraid of the ones that can kill you or give you a sore. The really big ones are just really hard. The really big orb weavers are the ones that kind of get me. And I think it’s because I don’t like walking into webs. I mean, no one does, right. But, like, in Australia, there’s some orb weavers that are, like, the size of your hand, and they’re big and the web is strong and you walk into it and you don’t know where that giant spider with its relatively long fangs is. In fact, I once, we collected some once, or some people collected some and sent them to us, and I was…
OK, maybe I shouldn’t say this, but I’m going to say this, so we were allowed to drive them across the border with our permits, but I had to drive down to the states, get the shipment of spiders, and then process them in my hotel room. I won’t tell you which hotel, but which means taking the spiders out of the little cages because they were, they were shipped the way you described, like, you put cotton on them and pressed them down, but you need to move them out of that. So I was transferring them into separate cages, and these were these big orb weavers the size of your hand, from the south. And when they land on the table, it’s like you can hear the skittering of them, like, walking. Do you know what I mean? And it’s just-
JVN [00:51:36] Well, no, because ours was, mine was, ours was dead.
MAYDIANNE ANDRADE [00:51:39] Oh, yours were dead. I think it’s the sound. And then, yeah, it was. It was a lot.
JVN [00:51:45] No, because we just wanted to send it to Dr. Jessica Ware. It was more on the FaceTime it was, like, “This is like if you collect that, we can, like, to make it a specimen in our gorgeous, like, things. And then you and Julie will be, like, in the Museum of Natural History.” [CROSSTALK] Exactly. Yeah, yeah, that’s cool. So we, so we had to, like, put it in there with like. So I cleaned out this like guacamole to-go container and I cleaned it out and I watched it out. And then we put, like, paper. And by we, I mean, Julie, cause I obviously didn’t fucking do it. I was, like, too scared. I oversaw, it’s like they said, “I oversaw.” I was too scared. Julie is like the one who had the cajones to actually do it, but she put, like, paper towels between the legs would be, like, perfectly preserved. But yeah, you were just getting the spider to stretch its legs and stuff because it had been, like, all cooped up. Yeah. So you were just doing the spider a solid. But it was huge.
MAYDIANNE ANDRADE [00:52:30] It was huge. It was huge.
JVN [00:52:34] Did it try to bite you?
MAYDIANNE ANDRADE [00:52:34] No, it didn’t. I think any, anything I felt was completely in my own head, right? That’s the thing with spiders. Most of the time it’s in your own head. Unless it’s a Sydney funnel web, then it actually is trying to bite you.
JVN [00:52:44] A Sydney funnel, what’s that?
MAYDIANNE ANDRADE [00:52:45] Sydney funnel webs are another one of those species that can hurt people, like, the venom is venomous for, for human beings, but they’re aggressive, so they will come up to you if you sort of interrupt them when they’re doing their thing, whereas other spiders try to get away. So, yeah, Sydney funnel webs are not fun.
JVN [00:53:00] Where do those live? Sydney?
MAYDIANNE ANDRADE [00:53:01] Sydney, everything bad, everything dangerous is in Australia as far as I can see.
JVN [00:53:06] Yeah. So are they, like, a house dweller? Those Sydney ones…
MAYDIANNE ANDRADE [00:53:10] They are a tunnel dweller. But some people say that Sydney’s actually got just riddled with tunnels of these things all over the place. And so the Sydney funnel webs could pop up anywhere. So, you know, I don’t like to vilify spiders, but that’s the one that I would be that I would be definitely backing away from.
JVN [00:53:27] OK, got it. So if there is anybody, there’s been several times in this recording, it’s actually when you say fangs where I just feel a little creepy crawly. My hoodie could be a little longer and I’ve noticed that I really kept pulling it down a lot like I didn’t want an imaginary spider to, like, crawl up my back. So if there’s anybody listening to this that are just, like, scared of a spider, is there anything we can do to kind of help assuage their fears?
MAYDIANNE ANDRADE [00:53:49] So I do just tell people they’re not aggressive. Most spiders, most spiders, like, 99.99% of spiders are trying to get away from you. I mean, imagine something relatively as big as a human is to a spider, right? There’s not much they can do to you, so they’re trying to get away from you. The other thing is, I used to tell people, learn a little bit about them, like, and it sort of relaxes you. They don’t care about you. They’re trying to go about their business. But then I did have a friend who said, “Yeah, I learned about them, and then I learned that there’s usually one within a meter of my hand at all times. And it didn’t help,” you know? So maybe just be confident they’re not trying to hurt you.
JVN [00:54:22] Is that statistic true? That whole, like, one every, like, three feet?
MAYDIANNE ANDRADE [00:54:27] Well, so that was basically derived by estimating how many spiders there are in the world and then dividing it by the landmass, basically. So it’s an average, again, this thing about averages, but there’s, there’s spiders in a lot of places where you wouldn’t expect it to be spiders. I would agree with that.
JVN [00:54:43] And now our final, I think this is the final question, you did, you did really good unless you have, like, and if there’s anything that you need to like. What? Is there a spider behind me? What!
MAYDIANNE ANDRADE [00:54:51] There’s a video I want to show you, I can show you. And then you can hear the vibration signals if you want to hear it later. But we can ask your question.
JVN [00:54:57] I’m, I’m dying to hear it right now.
MAYDIANNE ANDRADE [00:55:00] Okay, so why don’t I show you the video? So these are videos, I’m sharing sound. Yep, so here we go. So that is a laser, a recording from a laser being shown on the web, and the male, you see how it’s body’s moving up and down. He’s making those vibrations on the female’s web to kind of say, “come hither.” And then I want to show you this one and then I will stop, but, so these are two males competing for this female. These are black widows. This male is bigger than this male. And what we find is, like, the little guys, as soon as they detect there’s a big guy on the web, will retreat. And what you’re going to see in this video is the little guy starts courting that sort of vibrate, “bom bom bom bom bom.” The big guy will make a vibration that makes the small guy stop, and then the female will just say, like, “Shut it all down,” and you’ll hear the difference in the sound that they produce. So let me show you. OK, so that’s a little bit of female vibration, that’s a little male now moving in. And that big male made a move. Now listen for the female to say, “OK, you guys cut it out.” Coming in. There’s the female, so it’s like an order of magnitude louder than what the males are doing, right? And so what we find is the males compete on the web, but the female at some point is just, like, “Look, guys, shut it down. Like, I don’t want you interrupting the vibrational sort of environment on the web because that interferes with prey capture.” So anyway, what they’re saying to each other is fascinating.
JVN [00:56:31] Did she make it? Did she go with one of them at the end of that?
MAYDIANNE ANDRADE [00:56:35] In the end, she did. She mated with the bigger guy.
JVN [00:56:38] And then did he kill himself for her?
MAYDIANNE ANDRADE [00:56:41] Not in this species, he got away, and he could actually mate another day.
JVN [00:56:44] Ah! Oh my gosh, that is so fierce. Wait, and so, is there, what is, like, what are these working on in the lab now? Like, what are you guys doing these days?
MAYDIANNE ANDRADE [00:56:56] So all sorts of things. One thing is we’ve started working on false widows, which are related to black widows, and we don’t know much about them at all. So that’s like a whole new thing. And they don’t court for as long, and they sort of pull the female around while they’re mating. So we’re trying to figure out what’s going on there. But the other piece, the really big piece, is asking about how, so two of the black widow species are invasive, and they’re, one of them in particular is found all over the world now and others aren’t invasive. So we’re asking what makes the difference between those things and is it related to how flexible they are in their mating? Because, you know, when an animal invades, they have to, like, establish themselves, produce lots and lots of babies, and then be successful in that new place. And part of that is finding a mate. So we’re kind of interested in how that plays out.
JVN [00:57:40] Oh, yes, OK. I think. I felt like I should have another question that, like, I thought of, but I didn’t have a pen and I didn’t write it down, which just makes me devastated. Let me just, like, wrap my brain for one more second. Sure. Reproduction. What did we miss? We talked about reproduction. We talked about silk. We talked about dead spiders. We talked about, oh, it’s right there. Oh yes. Oh yes, I remember! OK, so you know how you were saying that spiders use other animals’ burrows? Has there ever been like a tarantula? It’s like, “Oh, this will be a nice place to molt!” And then they actually go into, like, a currently used snake burrow and then the snake kills the spider?
MAYDIANNE ANDRADE [00:58:18] I would imagine there has been. I’m trying to think of, I’ve seen reports of that, but for sure, there’s got to be right because snakes. I don’t know if it’d be snake, it might be a rodent. Some rodents will eat spiders and things like that as well, like, little mice and stuff. So I would guess, yeah, there’s got to be missteps sometimes. But I would also say that depending on what kind of spider it is, it could actually kill the critter that’s in the refuge, right? So black widows, for example, could kill a small mouse or a snake or a lizard that’s inside something that they’re trying to inhabit.
JVN [00:58:50] Cause, have we ever seen a black widow or a spider, like, eat a snake?
MAYDIANNE ANDRADE [00:58:54] Yes, I have. I’ve seen it in the field. You’ll see pictures of it on the internet and people will say, “Oh, that’s fake.” And it’s, like, “No, I’ve actually seen it.” I’ve seen spiders eat black widows, eat snakes, and also small skinks, reptiles.
JVN [00:59:08] So was that a big female black widow, then? That would eat a little snake?
MAYDIANNE ANDRADE [00:59:12] Yeah, it’s an adult female. The venom affects vertebrates. Like, that’s the amazing thing about black widow venom. One piece of it is specific for, for invertebrates, for things like insects. One part of the venom is specific to vertebrates and can take a vertebrate down. And that’s what makes them so dangerous. And that’s, like, seems to have been, have evolved specifically for that function.
JVN [00:59:33] If you get bitten by a black widow or is it kind of like with spider bites, like, you have to get to the doctor, like, other has to, like, right away if it’s, like, a really venomous spider?
MAYDIANNE ANDRADE [00:59:42] With black widows, luckily, it doesn’t have to be immediate. The venom has its effects develop slowly over time. So if you get to the doctor, say, so, and a lot of people can just sort of ride out the symptoms. But if it starts to become painful or if you’re bitten near the heart or something like that or near an air passage, then you might want to get to the doctor sooner. Like within a few hours. But the venom effects develop over a sort of hours or days. In the, so I’ve been in, in my lab for 21 years now, raising, like, 50,000 spiders a year. And in all that time with, you know, many, many students going to my lab, there’s been one person who was bitten and that one person was not paying attention to our protocols. But that person said that they felt very ill for about four days and they did go to the emergency. But they, they just said, “You need to ride out the symptoms.” They said it was like the worst flu they’d ever had for about four days.
JVN [01:00:34] And then, OK, I think, I think, I think we did it. Where can people find you? Are you on Twitter? Do you use the ‘gram? Where do you, like, talk about how much you love spiders?
MAYDIANNE ANDRADE [01:00:46] I am on Twitter, and I’m @WidowWeb, which, which I grabbed early, or my, my website is www.maydianne.ca. Or you can find me at blackscientists.ca.
JVN [01:01:02] Yes! I had so much fun. I can’t even stand it. Thank you so much for taking your time and educating us about spiders more. And just thank you for being, like, a fuckin’ fierce ass scientist, gorgeous Black woman, honey, you’re amazing. And I just love, like, I just love all these, like, fierce lady scientists in my life. I can’t even help. I just am so obsessed.
MAYDIANNE ANDRADE [01:01:25] And I’ve got to say your podcast is amazing. I just, I thought, have you, is there any woman scientist you haven’t interviewed? And they’re all just right on point. So just thank you so much.
JVN [01:01:35] Well, girl, excuse me, doctor, of course. And, and I guess it’s actually, like, how would you encourage other young people, young women, young non-binary people that you were mentioning, like, that queer lens of science and how important that is? I mean, even for me, like, being a hairdresser, like, I didn’t know exactly, like, how to go about doing that. How would you, if someone’s listening to this and they’re, like, “My cousin or my kid or me or whoever, I think, I think I want to become a research scientist.” How would you tell people, what do you need to do to make that happen?
MAYDIANNE ANDRADE [01:02:10] I would say the key thing for people who may not be, like, the average person, right? For whatever reason, the thing that you want to do, you don’t see anyone like you doing it. You need to have a support network, whether it’s your family, your found family, your friends who are just saying to you, “Yes, yeah, you can actually do that.” And you may have to weather microaggressions, you may have to weather people thinking you can’t do it, but you need someone who’s on your side saying, “You can do this.” And just saying that to you consistently. And that’s what, I don’t like social in some ways, but that’s what I like about social. If you get into the right environment, the right group, you tap into the right group, then you also get some of that from that because you can start saying, “Oh, like, OK, maybe I don’t see anyone in my neighborhood doing it. But in California, there’s someone who’s like this who is just like me, who’s doing this awesome thing. And, you know, obviously I can do it too.” So a lot of it is confidence, unfortunately, but some of that can be fake it ‘till you make it.
JVN [01:03:05] Yeah, I love that saying, I’ve used that in my life a lot. Thank you so much for your time. I appreciate you so much. This was just so much fun. Thank you so much for coming on Getting Curious, and we just love you so much. Thank you.
MAYDIANNE ANDRADE [01:03:17] Thank you so much for inviting me. I really enjoyed it.
JVN [01:03:21] You’ve been listening to Getting Curious with me, Jonathan Van Ness. Our guest this week was Professor Maydianne Andrade. You’ll find links to her work and the episode description of your listening to the show on. Our theme music is Freak by Quin, thanks so much to her for letting us use it. If you enjoyed our show, please introduce a friend, honey, and show them how to subscribe. You can follow us on Instagram and Twitter @CuriouswithJVN in our socials are run and curated by Middle Seat Digital. Our editor is Andrew Carson. Getting Curious is produced by me, Erica Getto, and Zahra Crim.
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