How many teeth do snails have?

by / Jun 01, 2022



This post is edited from an episode of the Is That True? Podcast, where host Arionne fact-checks different kid questions. Today’s episode answers the questions of how many teeth snails have and how long they sleep for, questions submitted by Leo and Yousef. 

Arionne: So, in this episode, we’re actually talking about snails … AGAIN! If you heard our episode on snail noses, you’ll know that snails are super interesting. If you haven’t heard it, no worries! You’ll definitely know after this episode. And once we learn some new facts today, just ask your grown-ups to scroll back to episode two. It’s called “On the Nose.”


But today, we’re talking about a totally different snail fact. But it’s just as interesting! And, it’s from TWO of the friends we’ve talked to before. The first is LEO!


Leo: Hi. My name is Leo and I am 8 years old and I live in Pasadena, California. 


So, another fact about snails is that they can sleep up to 10 years in a row. Isn’t that crazy? Oh, and I researched that. 


Arionne: Leo! You are a researching machine, my friend! That’s such a cool fact. The next fact we’ll talk about today is from our friend Yousef, who told us about monarch butterflies. You can look for that episode, too. It’s called “Warning Colors” and it was our very first one.


Yousef: My name is Yousef and I’m 8 years old. And I live in Illinois. And did you know a snail has more than a thousand teeth? 


Arionne: A thousand? That’s really a lot of teeth. I’m so excited to investigate these two new facts. AND hear from a very cool scientist about some groundbreaking work related to snails.


But first, let’s talk a little bit about how I found someone to help us figure things out.


The scientist is named Dr. Mandë Holford. Dr. Holford’s research is both chemistry AND biology. So you know she’s super smart. Her lab is called the Holford Lab. There, they investigate the power of venom—like the kind of venom that snails have.


So snails? They move REALLY slow. But even though they are slow, some snails are extremely dangerous because they shoot out a venom that kills the animals that try to eat them. Even though snails don’t try to eat people, their venom is very dangerous for us, too.


But Dr. Holford’s work is all about taking something dangerous and then making it actually be able to help people. I talked to her about Leo’s fact AND Yousef’s fact, and also about the groundbreaking (that means new!) work she’s doing with venom. 


Dr. Holford: Hi, my name is Mandë Holford. I'm a killer snail chemist. I work on venomous Marine snails.


Arionne: Remember: Dr. Holford studies what she calls killer snails. She studies how they can help people.


Dr. Holford: I study how they evolve their venom over time and how we can use the compounds in their venom for potential, um, therapeutic development, basically looking for new drugs for treating pain and cancer. 


Arionne: That is really cool. Really amazing. So I definitely will want to ask you more about your work, but, um, our first fact is, is it true that snails can sleep up to 10 years in a row?


Dr. Holford: I'm not sure about 10 years. I know that some of them can sleep for three years. And the average [snail] mostly can sleep anywhere between 10 and 13 hours at a time. 10 years, I haven't heard before, but they are very, very long, I mean, good sleepers for resting their metabolism when they need it. 


Arionne: So is it true that snails can sleep 10 years? Maybe not quite THAT long. But they can sleep for YEARS.


Arionne: Our next fact: is it true that a snail has more than a thousand teeth? They didn't say what kind of snail they were thinking about, but that seems like a lot of teeth to me. 


Dr. Holford: It's a lot of teeth and they do have a lot of teeth. Especially our snails, like we work with Marine snails, they have it's called the radula. It's a false tooth and they have lots of them. They produce them in, at something called the radular sac and they produce them sort of like if you think of the machine gun, how they line up all their bullets. So that they can fire them out one by one by one and keep using them.  


So, yes, they’re single use. In our case, our snails, the, um, cone snails to terebrids and turrids they use their radulas to harpoon, um, their prey or predator with venom. And so they shoot out those harpoons, or we call them harpoons, the false teeth, the radula um, on a single use basis. 


So they don't recover them after they've used them. So they have lots and lots of teeth in order to be able to shoot out venom when they need it.  


Arionne: So it is true that snails have A TON of teeth. But also, they have so many to protect themselves. They actually shoot their teeth out at their predators. A predator is an animal that preys on other animals. That means they try to eat them!


But shooting teeth at certain predators doesn’t work because they have hard shells to protect themselves. That’s where the venom comes in. Especially when we’re talking about the marine snails that Dr. Holford works with.


Dr. Holford: For our snails, the fam our snails are from the family Conoidea, and they are— the predators for them are mostly lobsters and crabs who have, who can crack the shells of our snails.


And because lobsters and crabs have, you know, the exoskeleton, the radulas that we were just talking about, those false teeth, they can't penetrate, the skin let's say of the lobster and the crabs. And so they're the biggest predators to our snails. Our snails, they prey on fish, worms, and other snails. 


And so the fish, the worms and other snails, they can find a soft body area in which they can deliver that harpoon or radular tooth that's filled with venom. And have themselves a meal basically. And so that's why we call them killer snails because they actually are lethal to fish, snails, worms and also humans.



Arionne: So the venom helps protect them and hurts their predators. BUT ALSO, it hurts humans. So we need to be careful around snails.


There are certain species of our snails that are quite lethal to humans. So if you got envenomated, that's the big word for if you got stung by one of these snails, it could cost you your life. 


Wow. And so. With your research, you have, you know, found a way to really discover how these scary snails that can be really dangerous, can also really help people. Can you talk a little bit about that? 


Dr. Holford: Oh, yes. ‘Cause I like to say it's venom can be both a superhero and a super villain. So our killer snails will keep you up at night cause they're a little scary, but they can also help you because the compounds in their venom turns out that they're very good at manipulating signals and in particular, they can manipulate malfunctioning signals like in diseases and disorders.  


So if I were to pinch you on your finger, um, there are things in cells in your body called neurons. So one neuron [will] signal to another neuron to your brain and your brain will go  "Ouch! Get away," and send another signal back. And then you would try to get away from me. And what we found is that certain peptides in the venom of certain molecules in the venom of the snails are very good at suppressing a pain signal. And so they will prevent that signal from getting to the brain. And so you'll never feel pain or, or you won't feel that particular kind of pain. And so, um, that's how we were able to use components within the venom to help us find new drugs rather than using all of the venom cocktail.  


If we used all of the venom cocktail, then yes. For sure we would kill you. But if we tease out individual things in the cocktail that can manipulate—let's say for example, a pain signal and turn it off— then now we've got something that we can use as a drug. 


Arionne: Dr. Holford’s research is revolutionary — that means it can change a lot of things. And it’s revolutionary because a lot of the medicines we use now to control pain are not always the best for our bodies.


Dr. Holford: Oh, sure. If you were in a situation where you got hurt really bad, like for example, if you have chronic back pain and, um, what we usually prescribe for that are things that are opioids and, uh, like morphine, which has a really bad side effect of being addictive. And so some people then get hooked on their pain medications as you might've heard. So what we're trying to do is find molecules that can help with the back pain, but without being addictive so that it doesn't become a disease for you in trying to figure out how to treat your pain.


So if you've got a chronic pain that just does not go away and it's preventing you from doing things like walking or lifting or carrying heavy things, or even just, you know, wanting to get up and out of bed. Then we were trying to find compounds that can help you get up and get out of bed, but without being addictive so that you feel like you're hooked on it and you need it all the time.


Arionne: Got it. So this is a much safer alternative to those things. 


Dr. Holford: Yes. 


Arionne:  Got it. Are there any just great snail facts that you just love? 


Dr. Holford: I love to share the fact that snail shells are so ubiquitously collected all over the world. You can go to any natural history museum and for sure you'll find shells on display or for sure in their collection.


Arionne: Wow, fantastic.


Dr. Holford: I was like, I love the idea that you can have shells that are so prized and so well loved that they become, um, you know, items to acquire and in nature. And for us, it's nice that now the venoms are starting to outshine the beautiful shells. And we also care about what's inside of the venoms as well as we care about what's on the outside. 


Arionne:  Yes. Yes. That is so interesting and amazing. And I look forward to continuing to watch your work as everything evolves and continues to be really groundbreaking. So thank you so much, Dr. Holford. 


Dr. Holford: Thank you guys. It's great to chat with you. I love to talk about snails all the time.