Ologies with Alie Ward - Smologies #11: SNAILS & SLUGS with Jann Vendetti

Episode Date: March 16, 2022

The SMOL version of an ep about smol precious creatures, we're talkin' slimy little angels with bellies for feet... literally! That's what gastropod means! We've got Dr. Jann Vendetti of the Natural History Museum of LA County to talk with Alie about snail-based beauty products, escargot, urban snails, thousands and thousands of teeth, and whether or not you should adopt a rabbit-sized pet snail. Click here for the full-sized, somewhat filthy versionSLIME project at NHM.orgMore episode sources & linksBecome a patron of Ologies for as little as a buck a monthOlogiesMerch.com has hats, shirts, masks, totes!Follow @Ologies on Twitter and InstagramFollow @AlieWard on Twitter and InstagramSound editing by Jarrett SleeperTheme song by Harold Malcolm

Hey, it's a puddle that was just a little deeper than you thought. Hallie Ward, here, another episode of Smologies. So Smologies episodes are just regular full-size oligies episodes, but we de-adult them, if you will, and we whittle them down to about 20 or 30 minutes. So the regular oligies episodes that you like, but are too filthy for kids or your grandparents, these are classroom-safe versions of them.

Also, they're small, so they're perfect for short little walks and commutes. Okay, speaking of small things, let's talk about slugs and snails. Malacology. So the study of mollusks and malacology comes from the Greek word for soft animal, and it deals with mollusks ranging from snails and slugs to bivalves and octopuses. So many.

There are a ton of malacological subsets, and adults, you can see the amazing toothology episode on squids, but there isn't a specific ology for snails. Lime ecology is a study of slugs, but snails don't get their own? What? So this episode is just a carnival of both slug and snail facts. And this guest is a curator at the Natural History Museum of L.A. County.

They did their undergrad in biology and geology at Colgate and went on to earn a PhD in integrative biology at Berkeley. So get ready for some belly-footing slime cruisers. Dizzying denticles and tiny, terrifying teeth. What snail slime is actually made of if I should put it on my face? Giant pet snails, prolonged snail snoozes, and more slime than any of us know what to do with. Oh, and because I'm not a giant fan of the word mucus,

you're going to hear it replaced with a soft chime instead. So every time you hear this, just think of the word mucus. You can do it quietly in your head, or you can say it aloud from the backseat, because you're not in my car. OK, on to the show. So let's get to know our goopy pals with museum mollusk curator, researcher, and malacologist Dr. Jan Vendetti. What's the difference between snails and slugs?

Yeah, I know that seems like an obvious question. It's a good question. OK. So I get asked that question a lot, and people often think that slugs are just snails that have kind of cast off their shell. Like, I'm done with this shell, and now I'll be a slug. That's not true.

So I've explained that snails and slugs are both, like you said, gastropods, but there's lineages, multiple places, multiple times a slug, so a slug is just the name for a snail whose shell is either absent or so small that the snail cannot retract into it fully. So there's things called semi-slugs that have like little, almost like vestigial shells, like this little dinky shell on it that it can't do anything with. It's just still there.

Others have an internal shell, which is like a little disc that sometimes you can even see when you're looking down at a sort of semi-translucent slug, which we have in Los Angeles from Europe. You can see like a little disc sort of in the middle of its body, and that's its tiny little remnant shell. So snails and slugs are both gastropods. Snails, obviously, what we usually call snails, have shells.

Slugs have a remnant shell or have completely lost their shell, but they can't regain it like during their life, and they have never lost it during their life. They were born that way. So hopefully that clarifies our most basic question about the difference between the two. But let's talk about one feature of a belly footer shell. Some gastropods have extremely elaborate denticles,

or you could call them teeth, that are at the margin of their aperture, so the opening of the shell, which makes their bodies able to get out, but very difficult for other things to get in. So an opening that's lined with little pokies. Now, what about how baby snails and slugs come into the world? Well, a lot of snails and slugs

have both male and female reproductive parts and can create offspring without a partner. So it has its advantages and disadvantages, as Dr. Jan explains. Why are more organisms not hermaphroditic or have both male and female reproductive parts? Part of it is that there is an advantage, but a bigger disadvantage to self-fertilize.

So sometimes if you have both parts, you can fertilize yourself. Oh my God, that's so narcissistic. So then you can make offspring that you were both the mother and the father. They're not clones, but they are your offspring with no partner. So that can be problematic

because you don't get variations. The scientific consensus generally is that if you are self-fertilizing, that's not a great system in the long run for genetic diversity. And when environments change, you always need genetic diversity, otherwise your lineage will just go extinct.

The more genetically diverse, not in all situations, but yeah, in most, the more genetically diverse you are as a population within a species, the better you are essentially equipped to handle environmental change, right? So if things change, some individuals, your environment changes,

some individuals in that group will be able to survive and then have offspring, right? So that's usually a good thing. So diversity helps make populations stronger. Next, the difference between snails and slugs that are land dwellers versus those water inhabitants. And it turns out they might be connected through one of the biggest evolutionary innovations

in biology. So squirming up onto the mud and then into the dirt. So many people have this question. Can you give me in a nutshell the difference between terrestrial and aquatic snails and slugs? What's the deal? Why can some of them hang out on land?

Oh, sure. So terrestrial means lives on land and obviously aquatic means lives in freshwater or if it's the ocean, we would normally call it marine. And then from the marine realm, different lineages have evolved. Most of them, like it was a big introduction once or a big evolutionary innovation

that one lineage evolved to be terrestrial. And then once they were terrestrial, they really sort of exploded in diversity. So there's a bunch of different pathways that they've taken to kind of, you could call it, invade these different ecosystems. And it's considered one of the biggest evolutionary innovations in the evolution of animals is,

and doesn't seem like it because not that many people think or talk about gastropods, but gastropods evolving or snails evolving from the ocean to the land is considered one of the biggest evolutionary innovations in history of life. Because it's so hard to do. I mean, your whole, your physiology has to accommodate oxygen instead and air instead of water,

which is a big, big difference. Can you imagine if it was just the air just had floating jellyfish in it? Just like puffing by. Flying jellyfish, yeah. Like nothing, like whoops, that jellyfish was hanging in the face. Way to go, slugs and snails.

You made it and you brought some wetness with you. So let's slide into slime corner. How do slugs and snails survive in arid or dry environments? Are they so thirsty all the time? Someone get them a juice box. What is it about terrestrial snails and slugs? Is it like a BYOM, like bring your own on land

and then just like cover yourself in a moisture layer and you're good to go? That lets them to survive when it went in like arid conditions at all. So if you have a shell and you're marine, then you have something you can pull into and keep yourself safe and from drying out. So it's like it had two different functions.

If the first function in the marine realm or where they're living in the ocean was for protection, its secondary function was to prevent desiccation. Whether it was necessary for that organism when it first evolved or not. So that allowed them, this is why we call it pre-adapt, which like I said has some kind of problematic implications. But the idea is that they had this trait already

and that trait ended up having a really important secondary function that allowed them to make this big transition onto land. So if you have a shell, your shell can be where you pull into and keep yourself from drying out. So that's what they do. So that's one of the reasons that that big evolution and innovation could happen in the first place.

That makes sense. But for slugs, they obviously don't have that. So you mostly see slugs in wet environments, which is why you see banana slugs in parts of the Greater Bay Area, because you've got lots of wet, foggy redwood forests where they get a lot of moisture. Comfy wet fog and organisms in their perfect niche,

just slipping and sliding and thriving. But what is the slipper stuff just laid on me, but not really, I'm good. So what is snail slime? It's mostly water. It's mostly water. And one way of describing it is as a liquid crystal. And this is outside of my realm of expertise,

but there's ways that it can be sticky and fluid very quickly and move from sticky to semi-fluid. The ability to do that can put you in a category as a biological product called a liquid crystal. PS, liquid crystal means that the molecules follow orderly patterns like a solid, but it flows like a liquid. So another liquid crystal, soapy water.

Wow, that's news to me. And it just helps from mostly mobility and protection. Yeah, that's right. So you can, as a snail or a slug, you could make multiple kinds of slime for various purposes, right? So your moving slime would be different than your protection slime, right?

So the cells on your foot would make slippery slimes so you could move around or very sticky slime to stick you to something. And then your body, right? The dorsal part of your body would make maybe chemical-rich, protective, unpalatable slime. It seems like risky to have essentially a trail of breadcrumbs leading to your location.

Like, hey, everyone, here is an actual map to find out where I'm hiding. So there's, yes, it does. That there's sort of, maybe if I could think of two reasons why that would be a good thing. One, it might advertise the chemicals that are in you that would be, so you could have anti-predator slime in your foot slime too that says,

predator, I smell disgusting. One way to cut off a conversation with someone you're avoiding? Smell disgusting to them. Easy peasy. But is slime dangerous to humans or could it serve a purpose for our dry, non-slimy exterior?

There is some research now that slug and snail slime can be healing for human skin in various ways. Right, yeah. And I, because that is one of the most asked questions from Patreon is snail goop really good for your skin. Matt's Clement, Lauren Egert Crow, Kabar Lee. Yep, so there's a lot of, South Korea has a lot of snail slime products.

A lot of Southeast Asia has a lot of snail slime products for, yes, for everything from like curing acne scars to just general beautification. I'm not a biochemist and this is more a biochemistry question, but there does seem like there is, there could be some benefit to putting something that is water rich on your skin, right? But I don't know how that would be very different

than like aloe or anything else that is like an emollient. Also, side note, don't eat any raw stales or slugs because they may carry rat lung worm, which is a worm that burrows into your brain and can kill you. So serious illnesses have happened in a few countries and even in the Southern United States, mostly in boys and young men who have been dared

by friends to eat a raw slug or snail. So please don't do that, cook them if you have to. It also can tell, so if you're a snail or a slug, you might have trouble finding a mate and your slime trail may be a path to you from somebody else who would be your potential mate. So it's like your breadcrumb trail that's your romantic breadcrumb trail.

Here I am. Because yes, snails and slugs need love too, but let's scoot along to their anatomy and the mysteries that you'll encounter if you stare a snail right in the face. Let's talk about their Martian googly eyes because like it's so weird. I feel like we're still used to it, but it's like.

Yeah, weird. You have two sticks that grow out of your head from moment to moment. And they can also pull them into their head and then pop them back out. And marine snails, most marine snails don't have that. Most marine snails, their eyes are on their face. And how are these terrestrial eye stocks even working?

And also, side note, don't they have crazy tongues? Yes, yes they do, yes they do. Right, so the eye is on a muscle and if you were to look at a snail and you were to poke at its eye stock, it'll pull its eye in so it can pull its eye in on a muscle first before the rest of the stock, right? So it's like having a foot in a sock.

Like you can pull your foot out of your sock and your sock is still there. So you, so they can do that. So they have, I think, an image forming eye, but there's no reason to think that they're making a lot of sense out of what they're seeing. What about the rear tongues? Yeah, the rear tongues.

So their tongues are called radula or one radula, two raduli. And I tell people it's like a cat tongue. So if you imagine, if you have ever been licked by a cat, right? It's that really rough tongue. So their radula is like a cat tongue and all of those little,

the bit that makes it extremely effective are little teeth, little teeth on the tongue. So it's like a strip that moves in and out and the mouth kind of shoots it out and scrapes and pulls it back in and shoots it out and scrapes and pulls it back in. So a snail tongue is made up of hundreds to thousands of tiny little teeth that have different shapes and sizes

depending on the species, thousands. So no more complaining about brushing teeth before bed. All right, humans, we only have 32 of them. That is 13,968 fewer teeth than the average garden snail. I'm getting tired just thinking about it. Speaking of which, do they nap Dr. Slime, as she's called, tells us more? You had mentioned hibernation

and I got this question, I feel like before, I even knew I was doing this episode, but why can they sometimes just hang out, sealed off in their shell for like months? Right, well, that's one of the reasons that the snails that can do that are good at living in environments where they didn't evolve and that can be very hot and dry,

that they survive because they can do that very thing, it's called estivation. So it's hibernation, essentially, and so they find a spot and they can put out a special that will stick their shell to a surface, so like the side of a house, and then they can pull their body back in and make another layer that covers their body

and has a little hole as an air hole, and then they can sit there and wait. I have one estimating, like I'm looking at it right now. It's sitting over there, I can show you. Yes, I see it in a jar. It's just like gone fishing. I love that you just have a jar with a snail in it. So a snail seals itself into its shell

during hot or dry periods, kind of like how you would barricade yourself indoors during the summer in Arizona, and there's like a tiny little hole and they're sealed off slime wall, kind of like a mail slot through which you would accept air or pizzas, even though snails are fasting. Once they have rained, then they'll find each other

and mate and find something to eat and then go back to estimating. So it's like there, I guess once they have enough resources, they'll just go to sleep and like they'll slow down their metabolism and stay like that for, yeah, they can stay like that for a really long time, which also extends their lives.

Like people have asked, how long do they live? And I said, they could live for five plus years? Really? I think so because most of their, especially if a lot of their life is just estimating, right? So they're not doing anything. They're just waiting. Five years?

I had no idea. I mean, spending most of your life napping sounds kind of nice, but you would miss so many birthday parties, so much cake, and you'd have so much mail piled up. Okay, let's get to your questions. But first here at oligies, we'd like to give away some money to deserving causes and this week we'll be sending some to a program called

Slime, stands for snails and slugs living in metropolitan environments. And it's a community science project that aims to catalog the biodiversity of terrestrial gastropods, land snails and slugs, you know that, in Los Angeles County and throughout Southern California. And that is through thenhm.org.

You can check them out. Or you can also listen to the episode grownups field trip that I did all about how volunteering at the NHM changed my whole life and caused me to make this podcast. I'll put a link in the show notes to find out more about Slime as well. That donation was made possible by sponsors of the show. Okay, your questions.

Here we go. Can I hit you with some Patreon questions? Yeah, okay. Sure. This is a rapid fire round. You can answer as fast as you want. Sarah Preston, great question. A few people asked this.

Where do all the shells come from? Are they making them? Are they finding them? What the shells going on? They're making, yeah, they're making them. So I say that it's like a turtle, right? So a turtle makes its shell and it lives in its shell and it's attached to its shell

and it can't somehow like cast it off and get another one. Snail is in that sense, exactly the same. It makes its shell when it's a little tiny baby, it has a tiny little shell. As it grows, it adds to its shell. So it's like a turtle. Like a turtle doesn't just, it's not like naked when it's born

and then finds the shell. It's the same thing with snails. They make their shell. So every shell that you've ever seen was made by a snail. Dustin Mills wants to know, are there fast snails? Yes, fast in certain aspects. Yes, cone snails, which are famous for having cone toxins, these special toxins that they use to kill their prey.

The way that they do that is they have a radula, right? The feeding structure that is evolved to be a spear type shape and they can in milliseconds shoot out the spear into fish, polykeet worms or other mollusks and that process of shooting it. Like if there's a fish, you've got to be pretty quick to catch a fish. So a cone snail that eats fish

can shoot out this barb in milliseconds and paralyze its prey almost instantaneously and then engulf it and eat it. So that's fast. That's real fast. Fast is most definitely relative in terms of terms. But next we moved on to the concept of eating snails and the French delicacy of escargot.

Please note that not all snails are created delicious when it comes to using them as a food source. Also really depends on how you prepare them. And like we said earlier, please, please never eat a raw snail or a raw slug ever. Two words, rat lung worm. Is that enough? It should be.

But what if they are cooked and they're safe? Mike Monakowski, great question. Is farming helix snails for escargot an environmentally sustainable form of agriculture? And do you eat snails? Con snails? Right, I don't. So helix, so he's talking about for escargot,

there's a couple of species that are, yeah, are good escargot snails that I've never eaten. One is our Los Angeles wet sidewalk snail. So in addition to making the slime that's used in snail beautification products, they also are a maybe second tier escargot snail. Is it environmentally sustainable? As a form of protein,

I would say probably more than other forms of protein. I mean, they can build up a lot of body mass on very few ingredients. They could also eat like refuse from, you know, they could eat, they could be instead of your compost bin, you could have snails thriving and eating your compost and then you could eat your snails.

That was kind of how the Cornuas Bursam wet sidewalk snail was introduced through California in the first place. Right, wasn't it Gold Rush? There was a Frenchman who in 18 somethings, I'm not sure if it was for the Gold Rush, could have been. Fact check this story and yes, is delightfully endearingly, bizarreingly true.

A Frenchman in California who asked his, someone in his family, his mother perhaps, to send him snails from France to California because he wanted to have a supply of snails to eat. And so he made an enclosure for them so he could breed these snails to have them whenever he wanted. And the little babies are just millimeters big

and crawled out of the mesh or presumably whatever structure he had for them. And then that was one of the ways that snails were first, perhaps the first way that snails were introduced to California. But they, this same snail has been introduced all around the world and lives, I mean in South Africa, New Zealand, Australia.

It's really good living where people live. I have a colleague at the museum who collects snails at night around Los Angeles and feeds them cornmeal for a while to like clean out their system. And then I guess sautes them up, steams them, however, it eats them. My mom used to do that.

My grandma, my great-grandma nun, she used to do that. She would send my mom and my aunt out to the graveyard with a burlap sack and they'd have to take the muni in San Francisco with this dripping, oozy sack of, and then she'd feed them cornmeal. She was like- Were they in North Beach?

Was this like Italian grandma from North Beach? Yeah, awesome. Literally lived in North Beach. That's where all the Italians live. Yeah. And so my mom would have to- That's amazing. She said she was mortified as a teenager.

She'd be taking the subway with a burlap sack full of just- It's messed up. And then- But you don't eat gastropods. I mean, I have not the escargot variety, but I have on a couple occasions, but it's not like I don't seek that out to eat. It's for any particular reason.

It's just not really my thing. Not your jam too, so chewy. Yeah. Very chewy. Snails and slugs have this rich history as a source of nutrition, but do they make good pets? It's possible, but there is one specific kind of snail

you should avoid trying to keep as a pal. It's a gals. G-A-L-S. Skype a scientist has a great question. Oh. Is there any good reason that I should not have a giant African land snail as a pet? A catena follica.

Yes, there are many reasons. Okay. There are many. The only places that those snails, they're called giant African land snails, which are nicknamed gals, G-A-L-S. Hey. So gals are potentially highly, highly invasive

and highly destructive in environments where there isn't a cold winter that can kill them off. Oh. So yes, the short answer is you should absolutely not. And if you do have them, the answer is not, oh my gosh, I have them. I'm going to let them loose in like Echo Park and then I don't have them anymore.

The answer is call, like contact me at the museum or somebody from USDA. And what is that when you give up, you can give up your snails without any... Oh, you have impunity. Yes. I believe you are just, you can say I have these. I'm not supposed to have them.

I'm not going to let them loose in Griffith Park or anywhere else. I'm going to give them to you. Somebody who's going to deal with them. Right. So that they do not become an agricultural pest. Yes. Please do not unleash an agricultural pest

upon your local ecosystem. Your ecosystem is like, please no, please, we can't take it. So safe surrender is a thing or better yet, just don't try to domesticate a giant African lance now, despite how cool they look. Now, as we are rounding third on this podcast, you know, I always want to know what makes ourologists love their jobs so much.

And what is your favorite part about your job? Or do you have a favorite moment in malacology where you discovered something or you were in Hawaii on a bluff and found a species? Anything crazy like that happened? I would say it's not one moment. It's, I think like a lot of scientists, if you get to do the work that you like to do,

and this sounds sentimental, and I don't mean it to sound as sentimental as it's going to sound. But every day, almost literally, every day, there's something new that I learn that is amazing to me. And it wouldn't, I understand it wouldn't be amazing to everybody, right? But I think that you know when you're in the right kind of job,

when something that you encounter as part of your job is, is awesome. Like this is amazing. And I didn't know anything about that. Like I am, I've had training for a decent number of years. I've worked on a bunch of different species. And still there are so many stories about evolution that you can see in organisms

that are just absolutely like breathtaking. So it's a really, in that sense, it's a really amazing. Every day there is a potential for something to be absolutely mind blowing. Just mind blowing indeed. And it seems like so many of ourologists get into their respective fields for the same reason. Okay, let's have the recap.

So we learned that snails and slugs are both belly footers. Snails have shells, slugs have a remnant shell, or we're born with that one. They have thousands more teeth than you do. They can have offspring with or without a partner. And for more on that, you can listen to the full length episode is suitable for adults.

Malacology, the full version, we'll link at the show notes. We also learned about the evolutionary leap of sea slugs to land slugs. That was a big, cool one. We learned that snail slime is mostly water and it's sometimes described as a liquid crystal. And if you're gonna eat slugs or snails,

do not eat them raw. We learned snails can hibernate like bears, but it's called estivation. And there are many, many, many reasons why you should not have a giant African land snail as a pet. So thank you, Dr. Jan Vendetti for sharing your love of snails and slugs with us. And thank you for tuning in all you new smallgites.

These fresh, clean little episodes are out about every two weeks. You can find more at alleyword.com slash smallgies. You can listen to the full Malacology episode that has much more detail and adult content. The full episode also has more on Dr. Slime's journey and that's available on alleyword.com or in the show notes.

There's a full list of credits for this episode. That can be found there as well since we like to keep things small around here. And if you listen to the very end of the show, I give you a piece of advice and this is one that I just learned in the last 12 hours. Apparently if you wrap the top of your banana stems, they sometimes come wrapped in plastic

but you can wrap them in foil or beeswax cloth and that traps the ethylene gas in your bananas which tells the rest of the banana to ripen. So by trapping it, your bananas stay fresher longer. So you wrap your tops, there you go. Isn't that bananas? It's bananas. Okay, until next time, smallgites, bye.

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