In their second Bonus Episode, the guys interview Dr. Sebastian Kvist, one of the leading leech researchers in the world (and overall amazing person!). Dr. Kvist holds a dual appointment as Professor of Ecology at the University of Toronto and Curator of Invertebrates at the Royal Ontario Museum.
After learning more about Dr. Kvist's background (01:54), the guys dive into the leeching process (12:06), Dr. Kvist's current research (21:01), and the affects of climate change on leeches (29:33). Then they reflect on life lessons derived from leeches (33:23) and the ethics of leech farming (40:51) before hearing about Dr. Kvist's favorite leechy films (45:57).
We’re always looking to expand our pond -- please reach out!
Series URL: www.theleechpodcast.com
Public email contact: theleechpodcast@gmail.com
Social Media:
External Links:
Credits:
Evan 00:27
All right everyone. Welcome back to The Leech Podcast, the most visceral podcast. The Leech Podcast is a show about movies that suck the life out of you but also stick with you. They may even be good for you – like a leech. I am Evan Cate. I'm joined as always by Aaron Jones and Banks Clark. How are you guys?
Aaron 00:49
Doing great, my brother.
Banks 00:51
Good day to be here man.
Evan 00:54
Awesome. Well, this is an extra special podcast. Today, we're having an interview with Dr. Sebastian Kvist, who is coming to us over the interwebs and has very graciously agreed to talk with us about leeches and his work as a professor of Ecology and Evolutionary Biology at the University of Toronto, as well as the Curator of Invertebrates at the Royal Ontario Museum. So, welcome to the show, Sebastian!
Sebastian 01:24
Thank you so much, everyone. Thanks for having me. This is, you know, really an honor to be here. But it's also really, really fun to be talking to some fellow leech enthusiasts, I guess. I'm really happy to be here, thank you. [Haha! Absolutely.]
Evan 01:40
We are honored and we are definitely leech enthusiasts and becoming more so every day. So Dr. Kvist, would you please just tell us a little bit about yourself and how you came to be doing what you're doing?
Sebastian 01:54
Um, yeah, sure. I, you know– born and raised in the south of Sweden. So I lived there most of my life. And I think I always knew that biology was something that was close to my heart, zoology in particular. I remember going to the fishmongers when I was a kid, and I could just sit in the fishmongers for hours just staring at these fish, right? Because they looked so weird, you never see these things normally. They're under the surface, you don't get to see them. So I remember, you know, sort of loving biology pretty early on. And then I started taking marine biology when it was time to choose, you know, my college education. So I got my undergrad in marine biology, and then I did a master's degree in biology. And when it came time to do my thesis, I, I decided to try to go with a professor that had taught a couple of classes that I took, that I really, really liked, and so I wanted him to be my advisor. He just so happened to work on earthworms. And for of you who don't know that – well, that's probably even more esoteric than leeches, right? – but for those, for those of you who don't know, earthworms and leeches are super closely related; they're cousins.
Aaron 03:10
So, earthworms kind of suck on earth, and leeches suck on blood?
Sebastian 03:16
Well, one of the crazy things is that leeches actually are earthworms. But they sort of spring up, they come from a lineage of earthworms, but they're the only earthworms, of course, that feed on blood. So blood feeding's actually happened, you know, throughout evolution, it's happened on multiple occasions within leeches, but only within leeches. There are no other of those organisms – with which leeches are related – that feed on blood. And when I say that, when I say they're relatives, I talk about earthworms, and also bristleworms or polychaetes, that mainly live in the ocean. They're the closest relatives of leeches, and none of them feed on blood. So bloodfeeding is sort of exclusive, within that group of animals, to leeches. Yeah, so that's all of my masters. And then I got into a program at the Richard Gilder Graduate School at the American Museum of Natural History in New York to do my PhD. And again, I chose my advisor, and it was a guy that's really well known for leech research. And it was a bit of an easier transition, because I'd worked on earthworms. And I thought that I was going to continue working on earthworms but I actually transitioned into leeches when I got to the MNH (Museum of Natural History) so that sort of put me on the path to leeches. There's nothing more interesting about it, except, I will say you know that the more you know about something, the more you start to love it and so whereas I didn't, you know, love leeches, maybe when I started, when I ended, I definitely did, and there's a lot that we can go over when it comes to leeches on why they're so interesting. So hopefully we'll do that. [Yeah!]
Aaron 04:55
That's amazing. So–
Evan 04:57
Yeah, we all have so many questions!
Aaron 04:59
We often make a joke on the pod that we used to teach together but now we leech together.
Sebastian 05:06
Yes!
Aaron 05:07
But it sounds like you, but you now, you leech and teach about the same thing.
Sebastian 05:13
That's right That's right. Leeching and teaching come together for me. It's true – it's Leech Teaching that, yeah – that's what I do.
Aaron 05:21
Amazing. So is this through the University of Toronto that you're doing that?
Sebastian 05:26
That's right, yeah. So I'm cross-appointed between the Royal Ontario Museum and the university. It's actually a quite a unique position. We're one of the few museums in the world that has that sort of a connection with a university. So you know, I'd like to say that we're a natural history museum, but we're also art and culture, and so we're a unique museum you know, in that sense already, and it becomes even more unique because we have this coupling with the University of Toronto. And yes, I teach there I'm a I'm a professor, an associate professor at the University of Toronto, and a curator at the Royal Ontario Museum, so it's sort of, I teach, and my students that I have, that I supervise, they get their diploma from the university, but there are a lot of the times they're stationed at the museum, right, so they get the best of both worlds, I'd like to say, yeah.
Aaron 05:40
Wow, so what do you– give us a title of one of your courses. You teach a course explicitly on leeches?
Sebastian 06:27
I don't, no, I wish did! I wish there was enough interest to teach a course on leeches. [Haha!]
Banks 06:35
If you could what would the title of that course be?
Sebastian 06:37
Aye yay yay! That's a tough one actually. It's a really good question, Banks. I think it would probably be something about bloodlust [ohh!] or bloodfeeding. You know, I think it would it would have to be something surprising. You know, people think that they– well, I shouldn't say that. People have a lot of knowledge when it comes to leeches – a lot more knowledge when it comes to leeches then several other animals that, you know, people don't interact with on a daily basis. But there's still so much that we don't know about leeches, and we have too few researchers in the world that study them, that there's so much that we don't know. So I think it would probably be a course that would, you know, let everyone know how little we know, but open people's eyes to leeches, I guess. So some sort of surprising– but bloodlust or bloodfeeding monsters or something like that. We can go with that, I think. Or 'Attack of the Giant Leeches,' something like that.
Banks 07:44
Ohh!
07:45
Are the Brazilian leeches the largest in the world?
Sebastian 07:49
Yeah, that's right. The Brazilian – so haementeria ghilianii. This is another thing about about leech animals is that they very seldom have English names, you know. Whereas a lot of other organisms that are a bit more charismatic, maybe, that more people study, more people, dare I say, care about? They have English names as well as Latin names, right? As you know, all animals in the world also have Latin names. And a lot of, you know, very few leeches have English names. But the Giant Amazonian Leech actually does have an English variety to its name. Yeah, that's the largest leech in the world. It grows to be over a foot [ohhh] and it lives in the in the Amazon basin. You know, humans don't really need to fear it because it normally feeds on Caiman and Anaconda and stuff like that.
Aaron 08:42
What? What? Anacondas? Good gracious you got to be gutsy to try and chew on an anaconda.
Sebastian 08:50
No doubt, yeah, but these these guys are really stealth, and the Anacondas probably don't even know that they're there. But yeah, leeches, you know – just imagine this though. Imagine that this leech is about a foot long. And leeches feed by two different methods. Either they make an incision with their jaws, right? So they have jaws with teeth on them. Or they feed with what we call a proboscis, which essentially is a straw, right? So imagine that, that you're at McDonald's and you get a coke, a fountain drink, right and that straw is about the same width as the proboscis in a leech that's maybe a foot long right? [Gasp] So imagine being fed on by a leech of that size. You know? So those leeches occur, they occur in North America as well of course, the, you know, relatives of those leeches that feed with a straw, but the one in the Amazon basin grows to be pretty large. So yeah, I actually, I was lucky enough to see one alive – not in the Amazon Basin, but in the lab in New York City. So that was fun.
Banks 09:59
Was it attached to somebody?
Sebastian 10:02
At the time it was resting on someone's arm. [Oh!] Yes. Yeah. So–
Banks 10:08
On?! On someone's–
Sebastian 10:10
Yes. Exactly. It was, it was resting. It hadn't attached, it wasn't feeding, but it was on someone's arm. Leeches normally take, you know, some species take up to an hour before they start feeding on you, on average. So they're not like mosquitoes, right? Mosquitoes land and they bite straight away. But leeches actually take a longer time, they like to try to find a really, really soft spot where the skin is really sort of thin. And where it can almost feel the blood under your skin. And– [Ohh!]
Aaron 10:44
It feels like this weird, sensual kind of romance you're describing that I don't like.
Sebastian 10:49
You know what? I think this is what makes people– what, you know, what scares people about leeches. And also what fascinates them, right, is that they get into your personal space without you knowing, and they take, you know, I don't want to be overdramatic about this, but your blood basically is your life, right? So they sort of take your life force, if you will. And I think that's how they've been portrayed in popular culture. You know, since, you know, 3000 years ago, when leeches were first started– you know, when they first started using leeches for bloodletting and other purposes.
Banks 11:25
They certainly get under your skin, geez.
Sebastian 11:27
Yeah, for sure. For sure they will. That's right.
Evan 11:32
So we are– I think we've talked before in some other pods about some of the process of how they suck the blood from your body and what's happening there. But can you just give us, for our listeners, like a one on one what happens? So the the leech grabs ahold of you? Maybe the proboscis? Maybe the teeth?
Sebastian 11:52
Yeah.
Evan 11:53
And what is I know there's a bunch of proteins that are secreted. And maybe it connects to what we're just talking about how you don't even know the leech is there, in some ways?
Sebastian 12:02
That's right.
Evan 12:03
So yeah, can you talk us through the leech, the leeching process?
Sebastian 12:06
Sure. Absolutely, yes. Yeah, so leeches are unique in the world, in that they have two suction cups, one at the back and one at the front. And there are other animals in the world that have suction cups, but none that are worm-shaped, that have a suction cup at the back and one at the front. And the back sucker, right, so if the leech attached, attaches to you, you don't always have to be worried, because it might be the back sucker that's attached to you. And normally that's the wider end of the leech. So it attaches with the back sucker – doesn't have a mouth there, there was no opening at all, so it doesn't feed with the back sucker – ut what it does then is it attaches with the back sucker, sort of gets its perch by holding on with the back sucker. And then it either uses, you know, three jaws normally – the normal medicinal leeches have three jaws – and they're lined with about 60 to 65 teeth on each jaw. So they're razor, razor sharp, right? Scalpel precision. They make an incision wound on your skin that sort of looks like, if you can imagine a Mercedes Benz mark, or a peace sign, depending on depending on who you are as a person, I guess, [yeah!] but sort of like a Mercedes Benz mark. Or they use a proboscis, just like we said, and the proboscis will make– will sort of push through the skin, go into the blood vessels, and they'll get the blood out that way. And yes, you're right, Evan, there are two things that happen when leeches feed on you. The first thing is that they have a local anesthetic in their saliva. And so you don't really feel the bite. I mean, you, a lot of the time you feel something, you feel the bite. But then the longer the leech feeds on you, the less you feel because it's sort of pumping you full with with local anesthetics. So I always think, you know, I've had leeches feed on me, maybe, I don't know, 250 times.
Aaron 14:02
Ohh, I had to ask about that!
Sebastian 14:06
Yeah. You know, I always think that it feels, if you're looking at the leech whilst it's starting to feed on you, you can feel it. But if you're not looking, if you're doing something else, and you're not seeing it, you probably won't feel it. And a lot of the time, the waters that they occur in, are pretty cold, right? So they numb you a bit, so you probably won't feel the leech biting. And then you know, the longer it feeds on you, the more of the anesthetic it injects into the wound, the less you'll feel. [Mmm.] The other thing that's happening at the same time as they're feeding, is that they're pumping you full of these proteins that we call anticoagulants, right? They're blood thinners. And these proteins are designed to keep the blood flowing so that the leeches can feed for prolonged periods. And people thought that the anticoagulants normally, or sort of almost entirely, was used by the leeches to be able to feed for extended periods. But what we also know now is that after the leech leaves the body, or leaves the blood, it's full of blood inside, right? And imagine if that blood clotted inside of the leech – it would turn into a brick and just fall to the bottom of the lake, pond, or ocean. So what it does is it lines– it actually has anticoagulants inside of its stomach as well.
Aaron 15:29
Oh my God.
Sebastian 15:30
That blood, when they feed, gets mixed with anticoagulants. So it gets pushed down into the stomach, is full with anticoagulants, and they keep that– they keep the blood flowing inside of their guts, basically, for extended periods, right? Because a leech can, can feed up to between five and ten times their body weight in blood every time they feed. And then they can go up to a year without feeding. So they need to keep this blood flowing for a year after they've fed.
Aaron 15:59
They're like– their whole body is like a refrigerator [that's right] you filled the fridge, you shop for groceries once a year, and then you shop when you're empty.
Sebastian 16:06
Once a year, once a year! And you fill up right? You have a fridge, and you buy five times as much groceries as you can fit in the fridge. So your fridge needs to be expandable. And that's exactly what their stomachs are. So they're segmented, right? There aren't too many animals in the world that are segmented, and leeches are part of this, one of the three major groups of segmented animals, a group called Annelida, which includes earthworms and bristle worms as well. And their bodies are segmented, and that segmentation allows their body to extend, and also allows the body to contract when it's sort of perching, trying to feed, when it's squeezing through different terrain in, you know, at the bottom of lakes and ponds. Or, for that matter – and I see your face here, Aaron [haha] – or for that matter when it's trying to feed from orifices, which some leeches are known to do.
Aaron 17:05
Ohh, like to creep into orifices, is that what you're saying?
Sebastian 17:09
Yeah, correct.
Aaron 17:10
Ohh, ohh, I don't like that at all. You said – I mean, I think – and maybe it was in our pre-conversation, you mentioned leeches being found in human bladders or animal bladders... inside?
Sebastian 17:22
Actually, a human bladder, yeah. So let's– I think, you know, if you don't mind, we'll take a step back and talk about the sort of less, less gross stuff, maybe–
Aaron 17:31
Okay, okay! [haha]
Evan 17:33
You gotta build up to it!
Aaron 17:33
Yeah, that's what I, that's what I was thinking, right? You got to lure everyone in. But yes, no, they're families of leeches that are sort of specialized on feeding on blood through mucous membranes of mammals, and these leeches occur in specific parts of the world. I mean, we know that they're quite numerous in South America. We know that there are some that also occur in Southeast Asia, and one of the problems for humans, I think, is that, you know, mucous membranes tend to occur where you don't want leeches. And they'll feed, you know– there's nasal hirudiniasis, mouth and throat hirudiniasis, that occurs pretty often in some parts of the world. [Eww.] And so yeah, you get to the doctor, and you have, you know, a pain in your throat maybe, or pain in your nose, and the doctor goes well– there's a leech up your nose or down your throat. *Gasp. Choke* And that's okay, right? And I think that that, you know– What?!
Sebastian 18:43
No, but it's not, by– you know– let me put it this way then. Imagine that there are other parts of your body where you have mucous membranes where you would definitely not want to have any leeches, right? Let's put it that way. [Okay, okay.] And so, you know, we hear about leech infestations of nasal passages and down throats, even behind eyeballs, not so much with humans, but with the birds quite a bit, leeches behind eyeballs. But then you hear a bit about, you know, vaginal hirudiniasis, anal hirudiniasis, and that's, that brings us to this bladder photo, where you know, a leech, there's an X-ray of a leech swimming inside of a human bladder. And it got there through the passage that you would expect, right? So someone was swimming in water, and a leech, you know, got in, I guess, made its way to the bladder, and lived there for not very long presumably, but long enough for the, you know, the doctor to get an X-ray of the leech swimming inside of the bladder.
Aaron 19:55
The leech is an invertebrate. If a leech is an invertebrate, the x-ray can't, there's like no bones to see?
Sebastian 20:06
Yeah, but there's– that's right! But it's actually, with a CAT scan, you can, right? Because it's differences in density. So it's a good point. So it's a difference in the density between the urine and the leech, and the– so I called it an X ray, but it's actually a CAT scan. And the scan itself is not great for that particular purpose. That there is no– there's no contrast, or there's not a lot of contrast between the bladder and the leech itself, but enough to know that it's a leech swimming.
Aaron 20:36
I was just curious, is it kind of– we're speaking in general terms here, but can you speak a little bit to your specific kind of research? It looks like from, what I was seeing, you've been involved with, like, study of the genome of the medicinal leech, you've been involved with– you mentioned birds, studying leeches even in bird nests of waterfowl? Can you kind of tell us kind of where you're interested, where you're working right now?
Sebastian 21:01
Yeah, sure. Absolutely. Yeah, no, I think, you know, it's– my research program has heavy focus on working on these these proteins that occur in the saliva of leeches, right? The anticoagulant. So I work pretty heavily on the anticoagulants. I also try to understand generally the evolution of bloodfeeding in leeches: how and when and where it started; how many times it's happened throughout evolution. You know, blood is low on certain enzymes and vitamins, so blood is pretty low on vitamin B (vertebrate blood at least). So the leeches that feed on– almost exclusively on– vertebrate blood, they need to get vitamin B from somewhere else, so they've struck this association with bacteria that provide them with the vitamins. So I study those bacteria as well. So my research program sort of focuses quite heavily on the aspect of blood feeding in leeches. But yes, just like you said, Aaron, we tend to do, you know, we tend to know quite a bit about various aspects of leeches, and this is where my students really come into play as well, because they have vast knowledge about different areas of leech research. And so we do study the behavior and the ecology of leeches as well. Now, of course, we're starting to get into genomics and transcriptomics, right? Whereas we used to, we used to sequence the DNA from just a couple of genes, we're now sequencing the DNA from the entire genome of organisms, trying to figure out what the genome looks like, which genes are involved in which aspect of the behavior. And yeah, so it's quite multi multifaceted, I'd like to think at least! It's quite a broad, you know– most people when I say that I study leeches, they think that it's pretty narrow, but when it comes to what we actually do research with the leeches, it is, it's quite broad, I would like to think at least. But the bread and butter that we do is trying to understand evolutionary relationships, right? So we sequence DNA, make these big data matrices, and then we try to figure out how every one's related to to each other. How were all the leeches related to each other? You know, are there certain aspects, you know– are all the green leeches, for example, are they more closely related to each other than than anything else? Are the leeches with jaws more closely related to each other than the leeches with the proboscis or the straw? Are the leeches that have 15 eyes more closely related than the leeches that have two eyes? You know, so stuff like that.
Aaron 23:36
Good gracious. I mean, so, I have so many questions, I feel like I'm being greedy here, but I'm– but like, now we're talking about, kind of, this data level research. Can you tell us a little bit about the field, like times you've– you've been bitten over 250 times?
Sebastian 23:54
Yeah, I mean–
Aaron 23:54
Tell us some stories from the field here!
Sebastian 23:56
Yeah, sure. Sure. Yeah, I mean, you know, one of the reasons that I've been bit so many times is because– that's what we try to do, right? I mean, the way that we do leech field work, and the way that we collect leeches, is that we put shorts on and we walk into the water. [Haha!] And it's actually it's quite easy fieldwork because the animals come to you rather than you having to hunt the animals. [Haha!] And so, you know, whereas doing field work in the Amazon basin, if you have a cut on your foot that, you know that's going to fester, it's not a good thing when you're in a really humid environment like that, but when you're doing leech research, that's actually not a bad thing. And so, yeah, so that's one of the ways that we collect leeches, is we walk into the water bare-legged and let the leeches come to us. So that's one of the reasons I've been bit so many times. The second thing is, you know, even– I guess some people would say, even crazier, right? Is that a lot of the time we bring these leeches back to the lab, and we keep them to observe their behavior, or we keep them, you know, to make sure that we have fresh DNA when we need it. And even though leeches can go up to a year without feeding, at some point, we need to feed them. And instead of, you know, now we've actually started, because we've had so many leeches in our in our lab recently, we've started getting cow's blood from the butchers, and you get sort of sausage casing and you feed the leeches that way, but when we only had a couple of leeches, it was much more efficient to just feed them ourselves. And so, you know, that happened. [Oh!] That happened quite a bit, too is that we feed the leeches ourselves in the lab. Yeah. So that, you know, that's one of the reasons, or those are the two main reasons, I'd say, that I've been bit so many times, yeah.
Aaron 25:47
Oh, do you have like– where's your favorite place to go when you're like, 'Oh, it's time for some research'? Where do you go? Where do you what do you enjoy going?
Sebastian 25:55
We, I mean, I enjoy that– one of the best things about this job is being able to travel the world, see new cultures, and meet new people, and just exchange ideas and knowledge, I think. And so I, you know, I do enjoy that part of the job immensely. And I've been lucky enough to do fieldwork on a couple of different continents so far. There are a couple of continents that are untapped for me still, and that I really want to do. Africa is one of those, and it's, you know, it's a bit of a logistical nightmare, but we're hoping that we can get collaborations going to be able to do that, in the not too distant future. My favorite, you know, there– I have so many favorite parts of the world to do fieldwork in. But I think that Canada, actually, you know, without being– trying not to be biased, seeing as I live in Canada. Canada is an amazing country when it comes to to leeches. You know, Ontario alone has 250,000 lakes and ponds, right? So a vast amount of water in this province. And with that water comes a lot of life inside of it. One of the things that thrives, you know, a lot in Canada is leeches. And so leech diversity isn't very high. There aren't too many species of leeches, but they are mega-abundant. And this is what I like to tell people, because it's something that not a lot of people know about, is that, you know, leeches occur on every continent. In every body of water where we've looked for them, we've found them. They don't only live in water, though – they also live on land. And so leeches actually occupy all three of the major ecosystems: the terrestrial ecosystem, so on land; in freshwater environments; and also in the ocean. There's a big radiation of leeches that live in the ocean. So there are only about 700 species of leeches, but they occur everywhere across the world. And so, you know, my favorite places to do fieldwork, I think, are probably in and around Ontario. I love getting leeches from here. I've been lucky enough to do leech fieldwork in a lot of places in Europe, but also a couple of places in Central America. And we're just sort of getting into South America pretty soon. So Panama was a really, really cool place to do leech fieldwork as well.
Banks 25:59
That's amazing, it really is.
Sebastian 26:15
So lots of really– I mean, I'm hoping that I'm not leaving anyone out here. But yeah, lots of places to collect leeches.
Aaron 28:28
I mean, it seems almost offensive to say that the Canadian leech would be better than a Swedish leech.
Sebastian 28:32
Yeah, that's right, yeah – but they are! [Haha!] There's– there are so many, I mean, you know, to each his own right? I– if anyone asked me if I have a favorite leech, I'd say yes. And, I'd explained to them that's a non-bloodfeeding leech, which is really weird– that also that lives in, you know, the Baltic region of Europe, right? In Slovenia, Croatia, and that area. And it's a really, really cool leech. I like it because of the coloration patterns and stuff. But yeah, there are some leeches in my mind, not that are better, but might be more fascinating than others.
Aaron 29:14
Wow.
Evan 29:16
So that leads to one of my questions, which is thinking about leeches existing in all sorts of different habitats all over the world. Just mindful of climate change, and what's happening with the planet in the big picture: how's that gonna affect leech populations?
Sebastian 29:33
You know, immensely, is the answer, and just like it will affect everything else. I think one of the things that we see with groups of earthworms is that they are technically not native to North America. They're native to areas around the equator. So the icecaps actually, sort of, when the glaciers, you know– at the heights of glaciation– these earthworms occurred around the equator, and then sort of stretched in as north as southern Mexico, probably, right? Where the ice caps didn't really, really form. And then when the icecaps retreated, the earthworms went with the icecaps, right, because they they got all this, this new ecosystem just opened up to them, right, that wasn't available to them before. And so they populated North America, right. So there are no native earthworms to North America – all of them came from Central America. And we are not– so we know a lot about that. But we don't know too much about how leeches have populated North America. But certainly, global warming is having an effect on the distribution of populations, right. So they are– we are seeing that leeches are moving northbound to areas where they haven't been seen, at least in that diversity or in those numbers, before. And the other aspect, I think, that's really important to think about is – and you know, most people might not think about this – is what global warming does to the prey of all animals, right? So animals need to feed on something. The animal itself might be resilient to changes in climate, but the prey or the food for the animals might not be. And so if those animals die out, because of global warming, then of course, the leeches will die as well. And so what we're seeing – and we're not entirely sure that we can tie everything to global warming, but certainly it's having an effect – is sort of this surge in, you know, fungal infestations in frogs, for example, and frogs dying en masse. And that probably will mean that leeches also will come down in numbers because they don't have the frogs to feed on, and they rely heavily on the frogs. Same with fish, of course. We know a lot about, about how climate change is affecting fish populations: warming of the ocean, the warming of lakes and ponds changes the ecology and the behavior of fishes. And that will also lead to, you know– that will probably be detrimental to leeches as well. So it's a really, really good point, Evan. And I think that there are lots of aspects of this that we haven't– that we don't yet know anything about. And unfortunately, we probably won't know until it happens, you know? But there are there are lots of lots of aspects of it.
Evan 32:43
Thanks. Banks, do you have anything you've been thinking about?
Banks 32:47
I do! So, you've been studying leeches for a long time, and, you know, I have a lot of family who works in, you know, both in research, in biology, conservation, and so you always hear these stories about how other species, sometimes the bigger-name species, they sort of teach life lessons. Right? You know, a good one is, you know, whales don't sing because they have some some answer to the world, they sing because they have a song, and things like– they're these things that people– in all of your years of study, have you come across any life lessons from the leech? [Ohh!]
Evan 33:21
Oh, great question!
Sebastian 33:23
That is a really, really good question, actually. You know what? I think that there are a lot of life lessons from leeches, and some probably more banal than others. I think– to be honest, this is sort of, you know– I'm talking about a deathly sin here, which you know, which is gluttony, I guess [haha!]– but leeches are gluttonous, right? So it might not be a life a life lesson, although I will say, you know, if you're an animal outside of human beings, then it might be a good idea to be able to feed as much as you can when you can. Right? [Carpe diem!] So leeches don't know when they're– yeah exactly, carpe diem! That's a good way of putting it– and that's exactly it– Carpe Diem, and Carpe Carpum, if they feed on carps, right? [Haha!] But, the sort of, you know– I guess the the gist of it is, you know, they feed up to five times their body weight when they can only because they don't know when the next meal is going to come around. I think the other thing – again it's not really a, you know, it's the– leeches aren't really, they don't teach you so many lessons that are actually good or that make you feel great [haha!] but, the other thing, of course, is, you know, if you're stealth enough, then you can come and go before anyone knows. So one of the, you know– people that do fieldwork in the tropical jungles of Southeast Asia, they'll know that– leech– you know they'll come home from a day in the jungle, they won't have felt anything during the day, and they take their clothes off, and they're just bleeding from several places of their– on their body, right. The leeches are long gone but they've been there and left without without them knowing. And those are the terrestrial or the land-living leeches– are really, really aggressive in that part of the world, and they'll just come, you know, they'll they'll go– they'll drop from the from the canopy, so they feel, they sense you, right? They sense your carbon dioxide, they sense the movement, and they'll just drop off from the canopy – drop down on you and then feed, and then leave before you actually know that they fed on you. So I don't know, Banks, I don't– those probably aren't good life lessons in general! [Haha!] But do they teach you something about biology? By all means, yes they do. Of course; of course they do. And I think, you know, one of the first things that people ask me is: how do you make leeches interesting to a to a general public? Now, we're lucky enough that leeches have been used for medicinal purposes for millennia now, but the other thing is, well, if you are interested in fish, which most people are, right? Because, you know, it sustains human beings, at the very least; there's lots of other really, really cool things about fish. Leeches are fish food; that's one of their main– the main roles that they play in the food web. And I guess the lesson here is: be stealth enough so that the stupid animals like humans don't notice you, but don't be stealth enough so that the fish can't find you, because then your role in the food web is gone.
Aaron 36:58
We were just– I was just doing some research on the lucrative trade in leech trapping to sell leeches as fish bait.
Sebastian 37:07
Yeah man. Though it is a, yeah, it's a– it's actually quite lucrative. So let me ask you this guys: you know, they– a lot of the leeches that come over from overseas, that come come to North America from overseas, they're not so much used for fishing; they're more used for for New Age medicinal purposes. [Hmm.] So how much would you guys pay for a leech? If, you know, if you had to venture a guess. Like, how much would you go, 'Oh no, that's too much for a leech'?
Evan 37:35
Hold on, [Oh wow], so is this just like on the open market, or is this like, if you go to a hospital and need a procedure?
Sebastian 37:41
Yeah, so at the hospital hopefully they're they're free right? Hopefully they'll help you out with that.
Evan 37:45
Maybe in Canada, not here!
Aaron 37:47
Yeah, American medicine!
Banks 37:48
You want a leech, I can get you a leech by 5pm!
Sebastian 37:51
You know what? That's exactly right. That's what I tell everyone: it's all, you need leeches? Yeah, I'll get them for you. But yeah, I definitely came at that from a socialist point of view. [Having lived in Canada for awhile now.]
Evan 38:04
No, I'm jealous, I'm jealous, I think that's great!
Aaron 38:06
I think that's like $25 for an medicinal leech? Maybe $5 for a thing of fish bait leeches? That's my guess.
Evan 38:15
I'm going $50 to $100.
Sebastian 38:18
Wow, you guys, I should be selling leeches to you! [Ohh!]
Banks 38:22
I was gonna say five bucks! Five bucks!
Sebastian 38:25
Yeah, see, you know, a lot of people think that it's a leech, right? They're not going to pay– definitely, you know, five bucks is normally the top level of what people people say. So I think that what you've probably heard or seen, maybe, is what they actually cost, right. So a leech a medicinal leech from Europe, getting shipped to Canada, can be, you know, up towards $20-$25 a pop. So imagine if you were bringing, you know, if you're bringing over, or if you're selling– let's put it that way– if you're selling, you know, 5000, 10,000 leeches? You're making a pretty good profit, right? [Good gracious.] Which is good if people need them, but what we need to realize is – and I can't stress this enough, it's a really important point – is that the European medicinal leech, which is the leech that is normally used for medical procedures, is actually red-listed by the IUCN, right [wow]. So it's CITES-listed, which means that there are restrictions on how you transfer it across borders, what permits you need to do so, and so that's a really important point, and you know, a couple of years back, I was contacted by the airport, basically the airport police out there. So Environment Canada called me up and said, 'Hey, we confiscated five thousand leeches in customs.' They came from Russia, and they were in a plastic bag with water, and he– so who knows how he got the water on the plane in Russia, but somehow they did. Anyway, so they called and they said hey can you identify these leeches, because we need to know if they're part of the CITES-listed species or not, and they turned out to be part of that– part of that, you know, those species. [Oh my gosh.] There are two different species that are CITES-listed and so, it's illegal, right? So that was illegal to bring those across borders then. And I'm not even sure that the person that brought them across knew that, and so, you know, it is important to point out here and hopefully some of the listeners will know now that leeches are red-listed.
Evan 40:36
Well, along those lines, are there other ethical leech practices? Leech, I don't know, leech farming– [or unethical!] – I mean, what should we know? Yeah, what is– can we hear more about how to take care of these leeches well?
Sebastian 40:49
Well, so leech farming is actually a big thing. And there are big farms in Europe that farm leeches for the purpose of selling them for New Age medicinal purposes. There are some companies, you know– some of these companies are more or less legit. There are some companies of course in the US that sell leeches legitimately to hospitals, and a lot of hospitals now use leeches for medicinal purposes. So they were used, you know, they've been used for millennia, but during the Middle Ages, they sort of hit the pinnacle of use, right? They were used to treat basically everything. And so if you had something, if something was wrong with you at that point in time, they normally attributed it to an imbalance of the humors, right? An imbalance– so there were four humors. They were black bile, yellow bile, phlegm, and blood, and the blood part, of course, you know, if you had a certain ailment or condition that could be attributed to an imbalance of blood, then you could stick a leech on it would take out some of the blood and balance out the humors. That was the idea at least right? So we know that that was hocus pocus, and we know that leeches, you know, you can't put leeches on and expect that they'll cure you from anything. But the– but leeches as therapeutical devices is just– we're just scratching the surface, I think. There's lots that's untapped. But I think, you know, because they have these really strong anticoagulants in their saliva– believe it or not, leeches have the strongest– the most potent anticoagulant that's known to man is in leech saliva. So that's why, you know, last time I was bit by a leech I bled for about 20 hours. My wife wasn't too happy! I slept with, you know– it bit me on the hand, so really superficial, there was a big vein there. It had– I slept with two panty liners, a tensor bandage, and then a nitrile glove on, and I still, you know, overnight, I stopped bleeding, which was great, but I was bleeding pretty pretty heavily even after 12-13 hours when I came home. [Oh my gosh!] Anyway, so the leeches have these super, super strong anticoagulants and that's why they're used in in New Age medicine, but also in, you know, authoritative medicine, if you will, in hospital settings. And because of this demand, because people– a lot of people think that leeches can help with any variety of condition. Because of that there's a bit of a high demand on leeches worldwide and because of that of course there there will be leech farms that sell leeches to you know, sometimes the highest bidder, and sometimes legitimately to hospital settings, right? So there is a demand for leeches worldwide. The way that you can go about, if you need leeches for any reason– I would suggest that you try to do a bit of research on the company that you're buying them from. Some obviously are a bit more legit than others, and see if you can, you know, scope out which those are before before buying.
Banks 42:30
Wow. It sounds like there's a market for leech smugglers, is what you're saying.
Sebastian 42:41
You know, so this is– this apparently wasn't the first time that they had confiscated this amount of leeches in customs in Canada. And kind of– the last time it happened, they didn't really know what they were, and so they just let them, let it– you know, sort of let let them go and come in with the leeches. I'm, you know– I'm sorry that they didn't call me and or my lab or, you know– or any of my students when it happened. But yeah, I think moving forward, it should be relatively difficult to get CITES-listed European medicinal leeches into Toronto airport. I would think–
Aaron 44:04
There's like a famous– There's a famous movement called 'Leeches Without Borders.' Have you ever heard of it? I'm just kidding.
Sebastian 44:51
That's it! Perfect. Exactly, exactly.
Banks 44:55
Oh my gosh.
Aaron 44:57
Sorry, bad joke. Gosh, what's next?
Evan 44:59
It does make me think that, maybe off air, Sebastian, we could talk about companies that we might reach out to that are doing it the right way, that we might want to ask to sponsor the pod.
Sebastian 45:10
Yep, absolutely, not a bad idea actually.
Aaron 45:14
Oh right, yeah, that's been a dream for a while now! We need to get that in motion.
Evan 45:18
So I'm mindful of your time Sebastian, so let's– you know, this is a movie podcast about– [haha!]
Aaron 45:27
I think we forgot– I forgot about the movies.
Sebastian 45:32
That's fair.
Evan 45:32
So you know, we've used this metaphor of 'the leech' to talk about films that we really love but are also painful and and medicinal in their own way, instructive. So I guess two questions: one would be, you know, does this metaphor, as a leech expert make any sense? And then two: if so, are there movies for you that are especially leechy?
Sebastian 45:58
Yeah, so first of all, I mean, this is, you know– one of the reasons that I really wanted to be part of this podcast was because I love that email that you sent, Evan. Where you know, you were talking about, you know, movies that the grip you, that stick with you just like leeches stick to your body right? But that also were kind of icky, and you know, maybe drain you, or or that you, know, or that you're adverse to, right? That you don't like? And I think from that point of view, that metaphor is absolutely perfect. I think, you know, thinking of movies that are yucky and icky, but also stick in your mind– I think we all have those movies. I think the, you know, the two that stick out for me– one is quite icky and the other one stuck with me, or sticks with me still, because it's just such a cult classic, I think. So the first one is 'Stand by Me,' right? And so a lot of people know 'Stand by Me,' and one of the reasons that I like to choose that is because most people have, you know, number one: most people have seen the movie. It's just, you know, one small scene in the movie, but it's normally very visceral to people; it's something that they remember a lot. When you ask people about, you know, what's your– 'Tell me one scene from stand by me,' they might, you know, 50% hopefully, will talk about the leech scene, right? Where they come out of this pond and they have leeches all over them. And I do remember coming out of ponds when I was a kid in Sweden and having leeches, you know, attached to me as well. Not that many leeches, not at those numbers, but definitely leeches on you. And of course, I mean, one of the things that makes that movie scene so great is that the leeches are actually in spots where you don't want leeches, right? I mean, that's one of the main things– is that the leeches get into your shorts, whether you want it or not. That's where they're– what they're designed to do. So I think that's one of my favorite scenes. And again, you know, it's the perfect metaphor, right? It's a– it's an icky and yucky scene, but it sticks with you as well. [Hmm.] And the second movie that I thought of is a bit more on on the nose. It's 'Attack of the Giant Leeches,' [haha!] which is a 1959 Classic. [Oh, wow!] Okay, so if you haven't seen this movie, it's about an hour long. It's– you can actually catch it on YouTube, which is good, right? So you can just find it on YouTube. It's about an hour long. It's from 1959. It's a classic in my world, right? In the leech research world, of course. One of the crazy things about it is, you know, these– that– I don't even know where to start with this. [Haha!] But there are people people are dressed up in these leech costumes under underwater, right? And so they're filming underwater, which was quite a feat in 1959, but you can definitely see the bubbles from the breathing package that the divers have on, right, so there's this leech swimming around – doesn't even look like a leech! – and these bubbles are sort of coming out of it. [Haha!] And it doesn't even look like a leech, it looks more like some sort of alien, so they so– I love how they they just went, 'You know what, let's create our own leeches?' And someone must have gone, 'Ah, do you want to make it sort of anatomically correct?' And someone else just went, 'Nah, let's not do that!' [Haha!]
Banks 49:37
That's great!
Sebastian 49:42
You know, they have teeth all over their body, they have really big jaws and stuff like that in this movie. So yeah, 'Attack of the Giant Leeches.' And we actually, we were lucky enough to put together an exhibit at the Royal Ontario Museum a couple of years ago now called 'Bloodsuckers,' and we detailed all, you know, all aspects of bloodsucking, I guess – both from a cultural point of view but also from a natural history point of view. And one of the things that we managed to get our hands on was an original poster of, you know, the 1959 movie 'Attack of the Giant Leeches,' so that was really fun for us, yeah, it was amazing, an amazing, you know, poster to see and to have in the exhibit, so that was really good. So those are probably two of the, you know– and there are more. 'African Queen' with Humphrey Bogart there's a– you know, when he comes comes out of a pond and he's just covered with leeches, as well. There there are quite a few scenes with leeches. Of course, 'Game of Thrones,' if you if you do remember, there's a leech scene there as well, and that made, you know– that made headlines, and I think that was really good, really good for the leech research community!
Aaron 50:44
Good PR, yeah!
Sebastian 50:45
Exactly! So yeah, there are lots, but I think 'Stand by Me' and 'Attack of the Giant Leeches' probably, you know– the two that come to mind for me.
Evan 50:54
Love it. Love it. Thank you, yeah.
Sebastian 50:56
Can I ask you guys if you have any any favorite leech scenes or any favorite sort of movies on the topic of bloodfeeding or bloodsuckers, maybe?
Aaron 51:04
Oh wow, I mean, gosh! I would say the– I mean the film that kind of got this podcast going is a movie called 'There Will Be Blood.' [Yeah.] Have you ever heard of that? [I have!] It's kinda– yeah it's about oil but it's also about [That's right] ahh, it's about blood! And so we're– we'll actually be discussing that film at near the end of the season.
Banks 51:27
One of our season finales!
Sebastian 51:29
It was actually, it was– did it win the Oscar, or was it just nominated?
Evan 51:33
Nominated. It lost to 'No Country,' but it was–
Sebastian 51:36
'No Country for Old Men' won that year! Yeah, great movies!
Aaron 51:40
One could argue, also a leechy film in its own way.
Sebastian 51:42
Yeah, that's right, yeah. I love– there's a scene in 'Family Guy,' sorry, we're going off topic.
Evan 51:48
No it's good, bring it on!
Sebastian 51:50
There's a scene in 'Family Guy' where Javier Bardem goes to the hairdresser. Have you seen this? [No, haha!] He sits down and he does it in like that accent too, and he goes– so the barber goes, 'What do you want?' He goes, 'Everything.' And he's like 'Oh, what do you mean?' 'Short in the long places, long in the short places. [Haha!] It needs to be both from the past and the future, something that a baby would do to their doll.' [Haha!] Anyway that's what Javier Bardem looks like in that movie!
Aaron 52:27
That's amazing.
Sebastian 52:28
Such a weird haircut.
Aaron 52:31
Have you ever seen the movie 'Parasite,' by chance?
Sebastian 52:35
Are those the big worms that live underground? No, that's 'Tremor,' right? They live underground?
Banks 52:40
That's right!
Evan 52:40
Tremor would be good!
Sebastian 52:41
Parasites, I don't think– oh, no, no, 'Parasite,' the one that won the Oscar! [Yeah, that's right.] Yeah, I haven't seen that yet. I have to see it, I don't know why I haven't.
Aaron 52:50
Oh, it's wonderful. It's– there's not any actual leeches or invertebrates in it. Ahhh, but it is leechy to the maximum degree.
Sebastian 52:59
I have to see it, I have to see it.
Aaron 53:01
It may be highest leech rating of the season so far!
Banks 53:05
Yeah, if you have average all the scores, that's right!
Evan 53:08
Yeah, so just to be clear, we give every movie one to four leeches as a rating at the end of every episode. So [I love this.] it's not quite the same as stars, you know? So some movies might only get one leech, but they're [yeah] excellent, well made films, so it's really about–
Sebastian 53:28
Because of course, you know, it might get more leeches– (ahh shit– that was gonna be such a bad pun)– if they suck more. [Hahaha]
Aaron 53:38
That is totally appropriate here!
Evan 53:40
We are not above bad puns, trust me.
Sebastian 53:43
Fair play, fair play, that's awesome.
Evan 53:47
So Sebastian. So you are Curator of Invertebrates, and you mentioned an exhibit that you have done. What is– what's the future looking like for you? Are there any projects that you want to plug or anything you're working on right now?
Sebastian 54:02
You know– what I would say is, there's nothing that is easy to plug at this point. There's no there are no exhibits on, you know, my work that's coming up. If you want to, you know, link somewhere to the Royal Ontario Museum, I'm sure that they would be really happy. And you know, that people can find the exhibits that way. I don't know how many listeners you have in and around Toronto, but but it would be cool. I'll plug it– I'll plug this as much as I can on my social, of course, and see if the ROM picks it up, which they hopefully will. Other than that, I mean there there are lots of research papers that are in the making. Nothing that really affects, you know, people's everyday lives, perhaps. So I– you know, whereas I really appreciate it, I think it might be a hard sell for for, you know, leech anticoagulants. And I don't know, I mean, maybe there's someone out there that's interested in it, but it might be a hard sell. But I appreciate the offer, though. I wish that there was an upcoming exhibit. You know what, I actually plugged –speaking of parasites – I plugged an exhibit, or I sort of pitched an exhibit, to the executive team at the ROM once, and it was called 'Human Parasites,' and it was just going to be basically all the parasites of human beings. And they thought it sounded really interesting, but then I also pitched 'Bloodsuckers,' at the same time so they went with that one. Let's do that one.
Evan 55:31
Understandable.
Aaron 55:32
Sounds like a winner.
Evan 55:34
Okay, so guys are there any final questions before we let Sebastian go?
Aaron 55:38
Gosh, I'm just so delighted by everything that I've heard.
Sebastian 55:43
Well thank you thank you so much for having me on. I mean, this was a real treat being able to talk about leeches in a way, in a manner, that you do want to talk about leeches, right? From the ickiness to all that fascinating stuff? [Haha!] And, you know, leeches are everywhere, they're used for medicinal purposes still in hospital settings in North America. They, you know– they have superm, super strong anticoagulants, and that's one of the reasons that we need them around, right? So, 'Be kind to leeches,' I guess is a take home message.
Evan 56:14
Aww, that is a good word.
Aaron 56:15
Be kind to leeches! That's going on a t-shirt, that's going on a t-shirt!
Banks 56:20
Be kind to leeches!
Sebastian 56:22
Not all leeches suck. [Haha!] Thanks, Evan. Thank you so much for having me.
Evan 56:28
So yeah, thanks so much, Sebastian, for being with us. Again, we are The Leech Podcast. You can find us @LeechPodcast on Twitter, @TheLeechPodcast on Instagram. Please contact us. We'd love to hear from you. And thanks again to Sebastian Kvist for being with us tonight. Thanks, everyone. We'll talk to you again soon.
Sebastian 56:49
Thanks, everyone. Thanks for having me.
Aaron 56:50
Cheers.