Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lambin. Today we have a vault episode for you. Of course, this is going to be our second episode in the four part Life in the Hypogean World series. So without further ado, let's dive right.

Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lambin. Today we have a vault episode for you. Of course, this is going to be our second episode in the four part Life in the Hypogean World series. So without further ado, let's dive right.

In Welcome to Stuff to Blow Your Mind production of iHeartRadio.

In Welcome to Stuff to Blow Your Mind production of iHeartRadio.

Hey, welcome to Stuff to Blow your Mind. My name is Robert.

Hey, welcome to Stuff to Blow your Mind. My name is Robert.

Lamb and I am Joe McCormick. And hey, we are back with part two of our series on cave ecosystems and Hypogean biology. Cave biology. In the last episode, we talked about some of the characteristic features of cave ecosystems and then we ended up discussing how lightless cave environments shaped the evolution of a creature called Astianax Mexicanus, or the blind Mexican cavefish, also known as the Mexican tetra, of which many populations have adapted to life in subterranean waterways by losing their eyes and the pigments in their flesh. We ended up kind of doing a deep dive on the evolutionary logic of this why an animal population that once had eyes and skin pigment would adapt over many generations to lose those traits in a cave. So if you haven't heard part one yet, you should probably go back and check that one out first. But we are back again today to talk about some more elements of cave biology. Specifically, one of the things I wanted to get into we didn't really have time for last time, was something else about blind Mexican cavefish, which is, if they have no sight, what do they do? How do they navigate their environment and forage for food?

Lamb and I am Joe McCormick. And hey, we are back with part two of our series on cave ecosystems and Hypogean biology. Cave biology. In the last episode, we talked about some of the characteristic features of cave ecosystems and then we ended up discussing how lightless cave environments shaped the evolution of a creature called Astianax Mexicanus, or the blind Mexican cavefish, also known as the Mexican tetra, of which many populations have adapted to life in subterranean waterways by losing their eyes and the pigments in their flesh. We ended up kind of doing a deep dive on the evolutionary logic of this why an animal population that once had eyes and skin pigment would adapt over many generations to lose those traits in a cave. So if you haven't heard part one yet, you should probably go back and check that one out first. But we are back again today to talk about some more elements of cave biology. Specifically, one of the things I wanted to get into we didn't really have time for last time, was something else about blind Mexican cavefish, which is, if they have no sight, what do they do? How do they navigate their environment and forage for food?

And this is key because they've got to eat something. These are extreme environments that are generally regarded as not being the most bountiful places to scrape out a livelihood as an organism.

And this is key because they've got to eat something. These are extreme environments that are generally regarded as not being the most bountiful places to scrape out a livelihood as an organism.

Right, and there might be some advantages to living in the cave if you are a fish like this, Like there might be fewer predators than you would encounter in the world above, but there are also fewer food resources, so you know, you have to have to kind of like shift your specialization.

Right, and there might be some advantages to living in the cave if you are a fish like this, Like there might be fewer predators than you would encounter in the world above, but there are also fewer food resources, so you know, you have to have to kind of like shift your specialization.

Yeah, Like, if I was to decide, again this is a non evolutionary example, but if I was to decide I am going to now live in my local Ikea store, well, you know, I've got to figure out some new things. Right, It's going to be easy to find a bed when the lights go out, but I'm going to have to deal with the night security. My diet is going to consist entirely of Ikea food. So if you like Lingenberry, yeah, yeah, make sure you don't have a Lingenberry allergy for sure.

Yeah, Like, if I was to decide, again this is a non evolutionary example, but if I was to decide I am going to now live in my local Ikea store, well, you know, I've got to figure out some new things. Right, It's going to be easy to find a bed when the lights go out, but I'm going to have to deal with the night security. My diet is going to consist entirely of Ikea food. So if you like Lingenberry, yeah, yeah, make sure you don't have a Lingenberry allergy for sure.

Yeah. So I wanted to explore this question of how do blind cavefish since their surroundings, and so I was looking into this and I discovered that apparently one major sense mechanism that they rely on is what's known as the lateral line system. And this is not a sense that is unique to blind cavefish. The lateral line system is found in lots of aquatic vertebrates, even those that can see. Though in blind fish there are usually enhancements to this system. So it's a sense that they already have, but it gets stronger in the cave evolved variants. As a side note, I always really enjoy imagining types of senses that humans don't have, Like what it would be like to have a different kind of sense, you know, like electro reception or magnetic perception or something like that. And this sense in particular, I'm very excited to try to imagine because it's very spooky trying to imagine it. It's something about it feels almost kind of Halloween. This might make more sense once I explain it. So, the basic function of the lateral line system is to detect movements in the water surrounding the animal through high sensitivity to changes in water pressure. This system it runs along the length of an animal like a fish, so there'll be sort of canals of the lateral line sensing organs around the head of the fish and then running lengthwise along the body. The system uses sensory organs known as neuro masts, which contain little hairs suspended within a kind of jelly filled capsule that bends in response to changes in water pressure and flow. And then these little hairs are connected to nerve cells that are strung along the lateral line system like Christmas tree lights. Sometimes the neuromasts are exposed to the water on the outside of the skin. They're just right on the outside of the skin, but other times they are contained within a kind of duct or canal that is just under the surface of the skin. And either way, the purpose of the lateral line system is to detect vibrations, movements, and objects within the water by sensing these little changes in water pressure and flow. So with this system, an animal can get feedback about its own movement through the water, for one thing, but it can also sense the presence of currents and nearby solid masses, either moving or stationary, by the way they displace water as the fish moves through it. And this is coming back to what I was saying a minute ago, something about trying to imagine this is. Oh, it's very evocative and a little bit scary, almost so imagining living in a place of dark water. But you can sense objects around you by the way they move the water, or by the way they change how the water moves around you.

Yeah. So I wanted to explore this question of how do blind cavefish since their surroundings, and so I was looking into this and I discovered that apparently one major sense mechanism that they rely on is what's known as the lateral line system. And this is not a sense that is unique to blind cavefish. The lateral line system is found in lots of aquatic vertebrates, even those that can see. Though in blind fish there are usually enhancements to this system. So it's a sense that they already have, but it gets stronger in the cave evolved variants. As a side note, I always really enjoy imagining types of senses that humans don't have, Like what it would be like to have a different kind of sense, you know, like electro reception or magnetic perception or something like that. And this sense in particular, I'm very excited to try to imagine because it's very spooky trying to imagine it. It's something about it feels almost kind of Halloween. This might make more sense once I explain it. So, the basic function of the lateral line system is to detect movements in the water surrounding the animal through high sensitivity to changes in water pressure. This system it runs along the length of an animal like a fish, so there'll be sort of canals of the lateral line sensing organs around the head of the fish and then running lengthwise along the body. The system uses sensory organs known as neuro masts, which contain little hairs suspended within a kind of jelly filled capsule that bends in response to changes in water pressure and flow. And then these little hairs are connected to nerve cells that are strung along the lateral line system like Christmas tree lights. Sometimes the neuromasts are exposed to the water on the outside of the skin. They're just right on the outside of the skin, but other times they are contained within a kind of duct or canal that is just under the surface of the skin. And either way, the purpose of the lateral line system is to detect vibrations, movements, and objects within the water by sensing these little changes in water pressure and flow. So with this system, an animal can get feedback about its own movement through the water, for one thing, but it can also sense the presence of currents and nearby solid masses, either moving or stationary, by the way they displace water as the fish moves through it. And this is coming back to what I was saying a minute ago, something about trying to imagine this is. Oh, it's very evocative and a little bit scary, almost so imagining living in a place of dark water. But you can sense objects around you by the way they move the water, or by the way they change how the water moves around you.

Wow, I mean, we're getting right back into that Gollumn territory, you know. I'm imagining Gollum sensing that that goblin that has come down and is washing its hands in the water and so forth on this lightless underground lake. And to your point, it is so alien to try and imagine this. I'm in the water a fair amount. I swim laps most morning, though swimming this morning, and it's still you know, it's a very visual exercise. You can set you can feel things in the water, obviously you can, and Lord knows, there's a lot to see and feel in a ymca pool. You know, there are people doing exercise classes, there are people swimming laps next to you, sometimes very often in the same lane with you, and you pick up on those movements, but nowhere near this level of detail. You know, this is like compared to what we have. This is like a second site.

Wow, I mean, we're getting right back into that Gollumn territory, you know. I'm imagining Gollum sensing that that goblin that has come down and is washing its hands in the water and so forth on this lightless underground lake. And to your point, it is so alien to try and imagine this. I'm in the water a fair amount. I swim laps most morning, though swimming this morning, and it's still you know, it's a very visual exercise. You can set you can feel things in the water, obviously you can, and Lord knows, there's a lot to see and feel in a ymca pool. You know, there are people doing exercise classes, there are people swimming laps next to you, sometimes very often in the same lane with you, and you pick up on those movements, but nowhere near this level of detail. You know, this is like compared to what we have. This is like a second site.

Yeah, I kind of ghostly vision through which you can sense things around you by the way they move the water against your body.

Yeah, I kind of ghostly vision through which you can sense things around you by the way they move the water against your body.

Yeah.

Yeah.

So anyway, the astianax fish, the Mexican blind cavefish apparently compensate for their lack of vision by having a more sensitive lateral line system than their surface dwelling cousins, and this helps them navigate, forage and survive in their lightless environment. But this way of living depends not just on heightened sensitivity to water displacement, but also on changes to behavior. For example, one thing I was reading about is that when preparing to mate, apparently male and female blind cavefish engage in this in these patterns of exaggerated movements of various body parts like the mouth and the gills, and these movements are thought to perhaps help the mating partners find and identify one another without visual cues, does some sense, like moving around in the water more so that they can locate one another. Of course, the fish also have changes to their metabolism to allow them to survive in a place where food is less abundant than it is on the surface, so they are thought to have slower metabolisms to need less food energy. But also I was reading about an interesting twenty seventeen study published in PLUS one by some researchers associated with the University of Cincinnati, and this was on the role of a symmetry in blind cavefish evolution. We actually did a whole series on asymmetry and animals a while back in which we talked about fiddler crabs and such, you know, fiddler crabs having one claw much much bigger than the other. But we talked about a lot of examples in the animal world, and I remember that being a very interesting series.

So anyway, the astianax fish, the Mexican blind cavefish apparently compensate for their lack of vision by having a more sensitive lateral line system than their surface dwelling cousins, and this helps them navigate, forage and survive in their lightless environment. But this way of living depends not just on heightened sensitivity to water displacement, but also on changes to behavior. For example, one thing I was reading about is that when preparing to mate, apparently male and female blind cavefish engage in this in these patterns of exaggerated movements of various body parts like the mouth and the gills, and these movements are thought to perhaps help the mating partners find and identify one another without visual cues, does some sense, like moving around in the water more so that they can locate one another. Of course, the fish also have changes to their metabolism to allow them to survive in a place where food is less abundant than it is on the surface, so they are thought to have slower metabolisms to need less food energy. But also I was reading about an interesting twenty seventeen study published in PLUS one by some researchers associated with the University of Cincinnati, and this was on the role of a symmetry in blind cavefish evolution. We actually did a whole series on asymmetry and animals a while back in which we talked about fiddler crabs and such, you know, fiddler crabs having one claw much much bigger than the other. But we talked about a lot of examples in the animal world, and I remember that being a very interesting series.

Yeah, that was a fun one for sure. You know, some of the outrageous examples in some of the less obvious examples of asymmetry.

Yeah, that was a fun one for sure. You know, some of the outrageous examples in some of the less obvious examples of asymmetry.

Apparently there is a bit of hidden asymmetry in the blind Mexican cavefish as well. So let's see. This study was by Amandicaate Powers Aeronym Davis, Shane A. Kaplan and Joshua be Gross, published in Plus one in twenty seventeen, and it was called Cranial asymmetry arises later in the Life History of the blind Mexican cavefish Astianax Mexicanus. And so we were talking in the previous episode about how in some of these cavefish populations the fish are not without eyes from the very beginning. Rather, they do grow eyes initially in embryonic development, but then the eyes go through what's called regression where they are absorbed and disappear as the fish grows, and then the bone around the eye socket collapses in by the time the fish as an adult. Young cavefish apparently start life with fairly symmetrical bodies, and the surface variants in the rivers above where there's plenty of light also have fairly symmetrical bodies even as adults. But the young cavefish start out fairly symmetrical, and then as they mature, a mismatch develops in how the bones on either side of their skull take shape, and this asymmetry in their cranial bones seems to match a difference in behavior between the cave variant of the tetras and the surface variant still has eyes. The surface variant, when you place it in a fish tank, will swim in more random patterns or will just kind of float without moving in the shaded portions of the tank. The cave variant, on the other hand, will just keep it'll keep swimming in circles around the edges of its tank, and this matches with the fact that has been observed in the wild. In its natural environment, the cave variant will tend to follow the rocky walls of the pool where it lives, swimming counterclockwise around these boundaries in an endless loop. And one of the studies authors, Amanda Powers, was quoted in a press release about the research, explaining quote, you could see how asymmetry might be an advantage in navigation. They tend to swim in a unidirectional circular motion around their tanks to explore their surroundings. Having asymmetry in their skull, we think is attributed to handedness. If their skull is bent to the left, they could be right handed. They're feeling the wall to the right with their sensory structures. Oh wow, Yeah, so it seems that the cavefish have a type of developmental handedness that correlates to a navigation behavior where they follow the walls of their natural enclosure in this slow, counterclockwise lapping motion. Though I think it's still not fully understood how this system emerges, if it helps them survive how, we don't fully know yet, but it's interesting to imagine why. Another interesting sort of unrelated thing that I was just reading in this press release, also quoting the same author of the paper, I mean powers, talking about how she and colleagues went into the caves to observe these fish, and she says in this article quote, whenever you would touch the surface of the water with your finger, a swarm of cavefish would come right up to it. Not many fish would do that. These cavefish have zero predators, so they're not afraid.

Apparently there is a bit of hidden asymmetry in the blind Mexican cavefish as well. So let's see. This study was by Amandicaate Powers Aeronym Davis, Shane A. Kaplan and Joshua be Gross, published in Plus one in twenty seventeen, and it was called Cranial asymmetry arises later in the Life History of the blind Mexican cavefish Astianax Mexicanus. And so we were talking in the previous episode about how in some of these cavefish populations the fish are not without eyes from the very beginning. Rather, they do grow eyes initially in embryonic development, but then the eyes go through what's called regression where they are absorbed and disappear as the fish grows, and then the bone around the eye socket collapses in by the time the fish as an adult. Young cavefish apparently start life with fairly symmetrical bodies, and the surface variants in the rivers above where there's plenty of light also have fairly symmetrical bodies even as adults. But the young cavefish start out fairly symmetrical, and then as they mature, a mismatch develops in how the bones on either side of their skull take shape, and this asymmetry in their cranial bones seems to match a difference in behavior between the cave variant of the tetras and the surface variant still has eyes. The surface variant, when you place it in a fish tank, will swim in more random patterns or will just kind of float without moving in the shaded portions of the tank. The cave variant, on the other hand, will just keep it'll keep swimming in circles around the edges of its tank, and this matches with the fact that has been observed in the wild. In its natural environment, the cave variant will tend to follow the rocky walls of the pool where it lives, swimming counterclockwise around these boundaries in an endless loop. And one of the studies authors, Amanda Powers, was quoted in a press release about the research, explaining quote, you could see how asymmetry might be an advantage in navigation. They tend to swim in a unidirectional circular motion around their tanks to explore their surroundings. Having asymmetry in their skull, we think is attributed to handedness. If their skull is bent to the left, they could be right handed. They're feeling the wall to the right with their sensory structures. Oh wow, Yeah, so it seems that the cavefish have a type of developmental handedness that correlates to a navigation behavior where they follow the walls of their natural enclosure in this slow, counterclockwise lapping motion. Though I think it's still not fully understood how this system emerges, if it helps them survive how, we don't fully know yet, but it's interesting to imagine why. Another interesting sort of unrelated thing that I was just reading in this press release, also quoting the same author of the paper, I mean powers, talking about how she and colleagues went into the caves to observe these fish, and she says in this article quote, whenever you would touch the surface of the water with your finger, a swarm of cavefish would come right up to it. Not many fish would do that. These cavefish have zero predators, so they're not afraid.

Oh wow, that you know. That reminds me of other examples we've talked about in the show, like various birds of the Galapagos Islands, for example. It reminds me of some stuff I was just reading the other day about the dodo bird. You know, where you have these organisms that adapt over evolutionary time to an environment where there are no predators or there is just an entirely different predation situation going on, and yeah, they just lose their fear. There's no need to engage in that kind of protective behavior because those things don't exist for them until they show up on a bub Yeah.

Oh wow, that you know. That reminds me of other examples we've talked about in the show, like various birds of the Galapagos Islands, for example. It reminds me of some stuff I was just reading the other day about the dodo bird. You know, where you have these organisms that adapt over evolutionary time to an environment where there are no predators or there is just an entirely different predation situation going on, and yeah, they just lose their fear. There's no need to engage in that kind of protective behavior because those things don't exist for them until they show up on a bub Yeah.

Yeah, dutch. Okay, So that's lateral line sensations, and then the asymmetry of the skull, the kind of the circling behavior, all those differences. But there was one more thing I wanted to talk about. I mentioned in the previous episode another sensory enhancement found in some of these cavefish, and that sensory enhancement was taste. It appeared to be involved in a pliotropy. Remember that's where a single genetic change would result in multiple different changes in the phenotype in the body or the behavior. And in this case, the idea was that there was a single genetic change that would result in both regression of the eyes. So this process we talked about where the eyes are sort of absorbed and the adult fish doesn't have eyes, and then along with that development of a greater number of taste buds. Now, we speculated generally in the last episode that you know, having enhanced other senses in a cave would probably be useful in some way. Taste buds are generally useful. They are our body's chemistry set to know what we're putting in the digestive tract. But I was wondering if there was anything else we could know about that, like how do these extra taste buds work in these fish? What kind of benefit do they provide? So this is another thing where the answer is not fully known yet we know a few kind of interesting morsels. So I came across a very recent paper addressing this question. It was by Daniel Burning and Joshua B. Gross published in Frontiers and Ecology and Evolution twenty twenty three, called the Constructive Evolution of Taste in astianax Cavefish or Review. And one of the things I thought was interesting here, Rob, I've attached a I've attached a diagram for you to look at. It seems that mostly what we're talking about are what's called extra oral taste buds, taste buds that are not inside the mouth like hours, but outside the mouth and spread out over the jaws in the front of the face. So in this diagram, it shows blind cavefish from a couple of different populations compared to the surface variant with taste buds filled in as red dots on the illustrations. And while the surface variant looks like it is wearing lipstick, you know, the red dots, the taste buds are on the mouth, the cave fish are wearing clown makeup. The taste buds are all over the face.

Yeah, dutch. Okay, So that's lateral line sensations, and then the asymmetry of the skull, the kind of the circling behavior, all those differences. But there was one more thing I wanted to talk about. I mentioned in the previous episode another sensory enhancement found in some of these cavefish, and that sensory enhancement was taste. It appeared to be involved in a pliotropy. Remember that's where a single genetic change would result in multiple different changes in the phenotype in the body or the behavior. And in this case, the idea was that there was a single genetic change that would result in both regression of the eyes. So this process we talked about where the eyes are sort of absorbed and the adult fish doesn't have eyes, and then along with that development of a greater number of taste buds. Now, we speculated generally in the last episode that you know, having enhanced other senses in a cave would probably be useful in some way. Taste buds are generally useful. They are our body's chemistry set to know what we're putting in the digestive tract. But I was wondering if there was anything else we could know about that, like how do these extra taste buds work in these fish? What kind of benefit do they provide? So this is another thing where the answer is not fully known yet we know a few kind of interesting morsels. So I came across a very recent paper addressing this question. It was by Daniel Burning and Joshua B. Gross published in Frontiers and Ecology and Evolution twenty twenty three, called the Constructive Evolution of Taste in astianax Cavefish or Review. And one of the things I thought was interesting here, Rob, I've attached a I've attached a diagram for you to look at. It seems that mostly what we're talking about are what's called extra oral taste buds, taste buds that are not inside the mouth like hours, but outside the mouth and spread out over the jaws in the front of the face. So in this diagram, it shows blind cavefish from a couple of different populations compared to the surface variant with taste buds filled in as red dots on the illustrations. And while the surface variant looks like it is wearing lipstick, you know, the red dots, the taste buds are on the mouth, the cave fish are wearing clown makeup. The taste buds are all over the face.

Yeah, it's quite impressive, And again it makes sense for this kind of an environment, you know, you need to lean into a different sense situation. It reminds me a bit of our past discussions about catfish being super tasters, you know, and really when and again it come back to that situation where we have our human understanding of the senses, but we have a human level understanding of those senses. And so when you're talking about something like this that is enhanced, it's not taste as we know it, it's something different.

Yeah, it's quite impressive, And again it makes sense for this kind of an environment, you know, you need to lean into a different sense situation. It reminds me a bit of our past discussions about catfish being super tasters, you know, and really when and again it come back to that situation where we have our human understanding of the senses, but we have a human level understanding of those senses. And so when you're talking about something like this that is enhanced, it's not taste as we know it, it's something different.

Yeah, exactly. So I was wondering, like, what do we know about what kind of difference this makes? What difference does it make in the lives of these fish? So there were a few things mentioned in this review. One is that multiple studies have found what appears to be enhanced sensitivity to chemical repellence and taste sources in the water in the cavefish when compared to the surface fish. So just one example is a study by Humbach in nineteen sixty that found in the cave fish compared to the common minno, that the modality for bitter sensation was three hundred times more acute roughly, and then the salty slash acid slash sweet modality difference was about two thousand to four thousand times more acute in the cavefish, so much greater, much lower I guess threshold of sensitivity to these tastes also protus at all. In two thousand and eight found quote amino acids dissolved in system water were detected at a much lower concentration in Paschone cavefish. That's from one particular cave source paschone cavefish, compared to surface fish. And one possible explanation the authors discuss for this heightened sensitivity to amino acids could be what they call the savory taste receptor T one R one. This is the receptor that binds to glutamate and helps us taste savory umami flavors. So I wonder if you could really get these cavefish going bananas over something in the water, a piece of food or whatever is dispersed in the water if you hit it with a bit of the good old MSG.

Yeah, exactly. So I was wondering, like, what do we know about what kind of difference this makes? What difference does it make in the lives of these fish? So there were a few things mentioned in this review. One is that multiple studies have found what appears to be enhanced sensitivity to chemical repellence and taste sources in the water in the cavefish when compared to the surface fish. So just one example is a study by Humbach in nineteen sixty that found in the cave fish compared to the common minno, that the modality for bitter sensation was three hundred times more acute roughly, and then the salty slash acid slash sweet modality difference was about two thousand to four thousand times more acute in the cavefish, so much greater, much lower I guess threshold of sensitivity to these tastes also protus at all. In two thousand and eight found quote amino acids dissolved in system water were detected at a much lower concentration in Paschone cavefish. That's from one particular cave source paschone cavefish, compared to surface fish. And one possible explanation the authors discuss for this heightened sensitivity to amino acids could be what they call the savory taste receptor T one R one. This is the receptor that binds to glutamate and helps us taste savory umami flavors. So I wonder if you could really get these cavefish going bananas over something in the water, a piece of food or whatever is dispersed in the water if you hit it with a bit of the good old MSG.

I bet, or maybe one of those little fish shaped soy.

I bet, or maybe one of those little fish shaped soy.

Sauce. Yeah, we get soy sauce, some parmesan cheese, some tomatoes, some MSG, all the good savory things. However, the authors do say that several amino acids were used in the study that found this, so there could be other explanations, possibly also involving old faction rather than taste. But anyway, what difference would these these taste bud arrangements and heightened sensitivity to flavors make in terms of the behavior of the fish the author's right quote. One recent study argued that external taste buds are used for preliminary assessment of food items during random swimming or targeted searches for food. Extra oral taste buds thus carry in importance for determining whether to pursue or avoid a food item. So the way I understand that is it's heightening the fish's foraging efficiency basically by saying, before you even get something in the mouth, you're tasting the water around this thing with the front of your face, and it helps you zero in more quickly on something that is good to eat or is not good to eat. Like you're getting you're getting an idea about whether you're coming close to a good piece of food or not earlier. So that would make your foraging more efficient.

Sauce. Yeah, we get soy sauce, some parmesan cheese, some tomatoes, some MSG, all the good savory things. However, the authors do say that several amino acids were used in the study that found this, so there could be other explanations, possibly also involving old faction rather than taste. But anyway, what difference would these these taste bud arrangements and heightened sensitivity to flavors make in terms of the behavior of the fish the author's right quote. One recent study argued that external taste buds are used for preliminary assessment of food items during random swimming or targeted searches for food. Extra oral taste buds thus carry in importance for determining whether to pursue or avoid a food item. So the way I understand that is it's heightening the fish's foraging efficiency basically by saying, before you even get something in the mouth, you're tasting the water around this thing with the front of your face, and it helps you zero in more quickly on something that is good to eat or is not good to eat. Like you're getting you're getting an idea about whether you're coming close to a good piece of food or not earlier. So that would make your foraging more efficient.

Okay, that makes sense.

Okay, that makes sense.

In the end, however, they do say that that this is just an area that hasn't had enough research yet. They say that the quote precise function of cavefish extraoral taste buds remains unclear and largely unexplored, and then they also say that future studies need to do things like excluding the role of oldfaction or smell and isolating the variable of taste. And there are differences that even remain that they did examine in the paper that we just don't know how to explain yet, but could possibly be related to taste. One interesting idea they bring up is the feeding angle, so they you know, if you look at the cave variants of these fish versus the surface variants. One thing you will notice is that they both go along the bottom. Might there might be like a stony or sandy or pebbly bottom of the water source where they are, and they'll go along the bottom with their mouth down to the bottom, kind of searching for little bits of food to eat or you know, prey in the case of you know, carnivory, or just little bits of dead organic matter, whatever it is they're coming across to eat. They're scouring the bottom for it. For some reason, the surface fish have a steeper angle that they forage at with their body more it's almost more totally vertical, whereas the cave fish tend to forage at a more slanted angle that's closer. It's more like fifty five degrees from the bottom versus more like eighty degrees in the surface variant. They say this could be related to the changes in extraoral taste buds. Maybe it's you know, like they're tasting things differently, thus they have to orient their bodies differently. Don't know, but interesting question.

In the end, however, they do say that that this is just an area that hasn't had enough research yet. They say that the quote precise function of cavefish extraoral taste buds remains unclear and largely unexplored, and then they also say that future studies need to do things like excluding the role of oldfaction or smell and isolating the variable of taste. And there are differences that even remain that they did examine in the paper that we just don't know how to explain yet, but could possibly be related to taste. One interesting idea they bring up is the feeding angle, so they you know, if you look at the cave variants of these fish versus the surface variants. One thing you will notice is that they both go along the bottom. Might there might be like a stony or sandy or pebbly bottom of the water source where they are, and they'll go along the bottom with their mouth down to the bottom, kind of searching for little bits of food to eat or you know, prey in the case of you know, carnivory, or just little bits of dead organic matter, whatever it is they're coming across to eat. They're scouring the bottom for it. For some reason, the surface fish have a steeper angle that they forage at with their body more it's almost more totally vertical, whereas the cave fish tend to forage at a more slanted angle that's closer. It's more like fifty five degrees from the bottom versus more like eighty degrees in the surface variant. They say this could be related to the changes in extraoral taste buds. Maybe it's you know, like they're tasting things differently, thus they have to orient their bodies differently. Don't know, but interesting question.

Yeah, yeah, I mean this this is fascinating to think about, Like it makes one wonder if it has something to do with their being more predation opportunities for the surface fish, you know, like you've got to come in at that steeper angle because there's a greater risk of things, you know, on the floor of the of the sea or what have you, that might come after them while they're feeding. And maybe those are absent in these cave environments. Again, you know, we're talking about like a lack of just biodiversity in those environments. You know, there's many fewer predators, et cetera. But who knows. That's just me spitballing.

Yeah, yeah, I mean this this is fascinating to think about, Like it makes one wonder if it has something to do with their being more predation opportunities for the surface fish, you know, like you've got to come in at that steeper angle because there's a greater risk of things, you know, on the floor of the of the sea or what have you, that might come after them while they're feeding. And maybe those are absent in these cave environments. Again, you know, we're talking about like a lack of just biodiversity in those environments. You know, there's many fewer predators, et cetera. But who knows. That's just me spitballing.

I don't want to act like I'm just look at a diagram and a paper and answer the question. But just one thing I wonder about is looking at the looking again at the diagram of where these extraoral taste buds are in the surface fish. Remember they're all like right at the mouth, but in the in the cave variant, a lot of them tend to be spread out along the lower jaw. So I wonder if it can come in at this shallower angle because it's sort of like feeling and tasting more along the bottom without having to get the front of its mouth in contact with it. It can kind of taste with the slope of its lower jaw.

I don't want to act like I'm just look at a diagram and a paper and answer the question. But just one thing I wonder about is looking at the looking again at the diagram of where these extraoral taste buds are in the surface fish. Remember they're all like right at the mouth, but in the in the cave variant, a lot of them tend to be spread out along the lower jaw. So I wonder if it can come in at this shallower angle because it's sort of like feeling and tasting more along the bottom without having to get the front of its mouth in contact with it. It can kind of taste with the slope of its lower jaw.

Yeah, that would make a lot of sense.

Yeah, that would make a lot of sense.

But yeah, again don't know interesting questions about Usually when you when you think about fish and taste together, you're thinking about what a fish tastes like to you, not what it's like to taste as a fish.

But yeah, again don't know interesting questions about Usually when you when you think about fish and taste together, you're thinking about what a fish tastes like to you, not what it's like to taste as a fish.

Yeah, which again it can put you an entirely different sense realities, especially considering things like a catfish. But also you know, getting into taste and smell. When whenever I read information about, you know, the distances at which fish in the ocean can detect other things going on, say blood in the water or some sort of rotting shoe, I'm always just amazed because again it is an experience of the ocean that is just unlike anything we can experience when we venture into it. And the same holds true of the cave. Like when we enter into the cave, our experiences are rather different compared to the organisms that have evolved to thrive there. Now the place I'd like to turn to next. This gets into something that was probably one of the key reasons I decided this would be a good series for us to do, you know, to return to cave biology. This and the fact that I was also inspired by some environment related stuff at the Bishop Museum on a Wahuo recently when I returned there and got to take in their natural history section in addition to their cultural and historical sections. But yeah, this is the revelation that really pushed me over the edge that for many cave environments, batguano is sunlight. Ooh, batguano, that's bat poop if you will, if you're not familiar essentially in these environments, yes, this is the light of the sun. This plays a vital role in the food chain because remember light is the first step in the food chain of the Epigean world. Sunlight reaches the surface where photo autotrophic organisms create food via sunlight, carbon dioxide and water. These are autotrophs, and we call this the trophic level of the food chain.

Yeah, which again it can put you an entirely different sense realities, especially considering things like a catfish. But also you know, getting into taste and smell. When whenever I read information about, you know, the distances at which fish in the ocean can detect other things going on, say blood in the water or some sort of rotting shoe, I'm always just amazed because again it is an experience of the ocean that is just unlike anything we can experience when we venture into it. And the same holds true of the cave. Like when we enter into the cave, our experiences are rather different compared to the organisms that have evolved to thrive there. Now the place I'd like to turn to next. This gets into something that was probably one of the key reasons I decided this would be a good series for us to do, you know, to return to cave biology. This and the fact that I was also inspired by some environment related stuff at the Bishop Museum on a Wahuo recently when I returned there and got to take in their natural history section in addition to their cultural and historical sections. But yeah, this is the revelation that really pushed me over the edge that for many cave environments, batguano is sunlight. Ooh, batguano, that's bat poop if you will, if you're not familiar essentially in these environments, yes, this is the light of the sun. This plays a vital role in the food chain because remember light is the first step in the food chain of the Epigean world. Sunlight reaches the surface where photo autotrophic organisms create food via sunlight, carbon dioxide and water. These are autotrophs, and we call this the trophic level of the food chain.

Right, So yeah, this came up in the last episode that almost all of the food chain where we're really familiar with is happening where the base layer of the food chain is using energy from the sunlight to make its food and then we of course you know, other organisms eat those organisms and on and on it goes. But if you don't have the sunlight to power the food synthesis at the base layer of the food chain, what do you do.

Right, So yeah, this came up in the last episode that almost all of the food chain where we're really familiar with is happening where the base layer of the food chain is using energy from the sunlight to make its food and then we of course you know, other organisms eat those organisms and on and on it goes. But if you don't have the sunlight to power the food synthesis at the base layer of the food chain, what do you do.

That's right, yeah, yeah, most of it depends on sunlight. Plants are autotropes, as are seaweed phytal blanked in some kinds of bacteria, including bacteria that produce their own food vio chemosynthesis around volcanic vents. But most of the producers are producing their own food via the process of photosynthesis and therefore require the bounty of sunlight. The next trophic layer of the food chain is, of course the primary consumers who eat the producers, the herbivores being chief among them. And then the predators compose the third trophic layer, the secondary consumers, followed by the tertiary consumers and on up to the apex predators. And then you have you know, you also have the other roles in there, the you know, the scavengers, the decomposers, and so forth. Now, it's pointed out by sakoy at All in The Life Hidden Inside Caves, published twenty twenty in the International Journal of Ecology. Cave ecosystems are intrinsically devoid of primary productivity due to the absence of light. Again, light may enter the opening of a cave to different degrees, and other caves may feature open areas or areas with sort of like naturally occurring skylights. But past those pools of light there is only darkness, and that means again no photo autotrophic organisms.

That's right, yeah, yeah, most of it depends on sunlight. Plants are autotropes, as are seaweed phytal blanked in some kinds of bacteria, including bacteria that produce their own food vio chemosynthesis around volcanic vents. But most of the producers are producing their own food via the process of photosynthesis and therefore require the bounty of sunlight. The next trophic layer of the food chain is, of course the primary consumers who eat the producers, the herbivores being chief among them. And then the predators compose the third trophic layer, the secondary consumers, followed by the tertiary consumers and on up to the apex predators. And then you have you know, you also have the other roles in there, the you know, the scavengers, the decomposers, and so forth. Now, it's pointed out by sakoy at All in The Life Hidden Inside Caves, published twenty twenty in the International Journal of Ecology. Cave ecosystems are intrinsically devoid of primary productivity due to the absence of light. Again, light may enter the opening of a cave to different degrees, and other caves may feature open areas or areas with sort of like naturally occurring skylights. But past those pools of light there is only darkness, and that means again no photo autotrophic organisms.

Right, So this raises a question of how could there really be anything like an ecosystem inside a cave unless I don't know, it was just like unless things were coming and going from the outside to the inside constantly and eating each other in between. You know, how could there really be anything sustained within the cave purely in the dark.

Right, So this raises a question of how could there really be anything like an ecosystem inside a cave unless I don't know, it was just like unless things were coming and going from the outside to the inside constantly and eating each other in between. You know, how could there really be anything sustained within the cave purely in the dark.

And that's where bats enter the picture. We've of course talked about bats before. You have various species of bats that roost in cave and viral and do so in vast numbers. So batguano instead offers a major food source, a kind of alternate sunshine, brown sunshine if you will, that falls upon the floor of caverns where insectivore or frugivorous bats roost. So yeah, batsidiat insects bats that eat fruit. So we're talking about bat species that are generally nocturnal or crepuscular, that go out and feed and then return to the seclusion of their caves where they roost on the ceiling and when they poop, they poop on the floor below them, and that poop brings in quite a few nutrients.

And that's where bats enter the picture. We've of course talked about bats before. You have various species of bats that roost in cave and viral and do so in vast numbers. So batguano instead offers a major food source, a kind of alternate sunshine, brown sunshine if you will, that falls upon the floor of caverns where insectivore or frugivorous bats roost. So yeah, batsidiat insects bats that eat fruit. So we're talking about bat species that are generally nocturnal or crepuscular, that go out and feed and then return to the seclusion of their caves where they roost on the ceiling and when they poop, they poop on the floor below them, and that poop brings in quite a few nutrients.

So it's not like the base the photo autotroflayer outside, because in that case it is that would be organisms that are fundamentally synthesizing chemical food energy out of what was originally inorganic sunlight energy. In this case, they are bringing energy in already in the form of chemical food energy pooping it out on the floor, but it becomes like a new base layer of a food chain within the cave.

So it's not like the base the photo autotroflayer outside, because in that case it is that would be organisms that are fundamentally synthesizing chemical food energy out of what was originally inorganic sunlight energy. In this case, they are bringing energy in already in the form of chemical food energy pooping it out on the floor, but it becomes like a new base layer of a food chain within the cave.

Exactly. Yes, And I will also add it is like sunlight in that you can replace the word sun or sunlight with bat guano in any song lyric and it will work just as well. So please feel free to try that on your own time.

Exactly. Yes, And I will also add it is like sunlight in that you can replace the word sun or sunlight with bat guano in any song lyric and it will work just as well. So please feel free to try that on your own time.

I'm walking on guano.

I'm walking on guano.

Yeah, yeah, yeah, it works.

Yeah, yeah, yeah, it works.

It works perfectly, don't I feel good?

It works perfectly, don't I feel good?

So this guano often serves as the primary renewable organic resource of these caves, and a whole food chain extends from this, supporting various bacteria, fungi, uh protus, and small arthropods. Now, according to Sokoi, at all, the exact blend of nutrients is going to vary depending on broad category and specific species of bat. But the end result is that the fields of poop beneath the bats just become teeming with life, life enough to support an ecosystem of organisms, including those visiting from the outside, other creatures that spend part of their time in the caves, and also of course obligate cave dwellers that are there all the time. Also, this was interesting, the fermentation of the biomass, along with the presence of all those warm blooded bat colonies actually heats up the caves.

So this guano often serves as the primary renewable organic resource of these caves, and a whole food chain extends from this, supporting various bacteria, fungi, uh protus, and small arthropods. Now, according to Sokoi, at all, the exact blend of nutrients is going to vary depending on broad category and specific species of bat. But the end result is that the fields of poop beneath the bats just become teeming with life, life enough to support an ecosystem of organisms, including those visiting from the outside, other creatures that spend part of their time in the caves, and also of course obligate cave dwellers that are there all the time. Also, this was interesting, the fermentation of the biomass, along with the presence of all those warm blooded bat colonies actually heats up the caves.

Oh that's interesting. You know, that's a difference that is acknowledged in some of the literature I've looked at, but we haven't really talked about much. Which is a difference between cave environments and the surface is not only the lack of sunlight, but a much more constant temperature than you get on the surface. Though I guess this could be changed if yeah, you're bringing in a lot of biomass, and that's sort of like warming up the cavern.

Oh that's interesting. You know, that's a difference that is acknowledged in some of the literature I've looked at, but we haven't really talked about much. Which is a difference between cave environments and the surface is not only the lack of sunlight, but a much more constant temperature than you get on the surface. Though I guess this could be changed if yeah, you're bringing in a lot of biomass, and that's sort of like warming up the cavern.

Yeah, like at base level, it's like life in the wine cellar. But then if you get enough life in the wine cellar, well things they can have elevated temperatures, but still going to be pretty dependable. It sounds like, though, I guess you do have to factor in that there are sometimes fluctuations in these the occupation by bats and so forth.

Yeah, like at base level, it's like life in the wine cellar. But then if you get enough life in the wine cellar, well things they can have elevated temperatures, but still going to be pretty dependable. It sounds like, though, I guess you do have to factor in that there are sometimes fluctuations in these the occupation by bats and so forth.

I do have to apologize I'm only half following the conversation now because my brain is just running through song lyrics like I've been waiting so long to be where I'm going in the guano of your love of.

I do have to apologize I'm only half following the conversation now because my brain is just running through song lyrics like I've been waiting so long to be where I'm going in the guano of your love of.

Guano on my shoulder shoulders makes me happy. Yeah, yeah, I'm want to read a quote here from the sequoiad All paper that gets into some of the details here of the guano quote. For example, small metazoins such as mites, pseudoscorpions, beetles, thrips, mites, and flies inhabit the guano of insectivorous bats, whereas the guano of frugivorous vat bats is frequented by spiders, mites, isopods, millipedes, centipedes, waiters, bark lice, and insects. Salamander and cavefish populations and invertebrate communities also rely heavily on nutrients from the bat guano. They also point out that bat guano constitutes a niche of several varieties of micro organisms. Includeing fungi, protus, lichen viruses, and bacteria.

Guano on my shoulder shoulders makes me happy. Yeah, yeah, I'm want to read a quote here from the sequoiad All paper that gets into some of the details here of the guano quote. For example, small metazoins such as mites, pseudoscorpions, beetles, thrips, mites, and flies inhabit the guano of insectivorous bats, whereas the guano of frugivorous vat bats is frequented by spiders, mites, isopods, millipedes, centipedes, waiters, bark lice, and insects. Salamander and cavefish populations and invertebrate communities also rely heavily on nutrients from the bat guano. They also point out that bat guano constitutes a niche of several varieties of micro organisms. Includeing fungi, protus, lichen viruses, and bacteria.

I wonder if the bat guano is primarily sweet or savory.

I wonder if the bat guano is primarily sweet or savory.

I guess we'd have to ask those blind cavefish from earlier.

I guess we'd have to ask those blind cavefish from earlier.

Yeah, though, to be fair, in that quote, it just said that the cavefish populations rely on nutrients from bat guano. I don't know if that means they eat it directly or they eat other things that eat it, or what.

Yeah, though, to be fair, in that quote, it just said that the cavefish populations rely on nutrients from bat guano. I don't know if that means they eat it directly or they eat other things that eat it, or what.

True true that that is essential and I believe that something sakoy at All point out is that it's yeah, there aren't necessarily there are organisms that depend on the guano that are not directly eating the guano, but they are able to thrive on the things that do consume and thrive on the guano directly. Now, it's it's also worth noting that the presence of the bats themselves also produces feeding and opportunities for either scavengers or predators. I'm going to probably have more on this particular tidbit in the next episode. And yeah, there's another interesting thing that they point out is all of this can potentially change over time as well, you know, stable environments but not necessarily eternal. I was reading a CBC Radio story about a University of Ottawa study of bat guano in a specific Jamaican cave or cave system. I believe this cave is known as Home Away from Home cave. It's very remote and it has been a subject of some scientific study and they were looking at it and they were able to observe a shift over in the past from insect eating bats to fruit eating bats, though it was unclear as of twenty twenty one if this was a change in diet by a specific species or perhaps more likely the influx of a different bat species that had a different diet. They also found increased guano levels of cadmium, mercury, lead, and zinc present during the same time as the Industrial Revolution, so they were getting into like, you know, we can see this change, We can see this environmental change brought on by the Industrial Revolution in the of these bats in this remote Jamaican cave.

True true that that is essential and I believe that something sakoy at All point out is that it's yeah, there aren't necessarily there are organisms that depend on the guano that are not directly eating the guano, but they are able to thrive on the things that do consume and thrive on the guano directly. Now, it's it's also worth noting that the presence of the bats themselves also produces feeding and opportunities for either scavengers or predators. I'm going to probably have more on this particular tidbit in the next episode. And yeah, there's another interesting thing that they point out is all of this can potentially change over time as well, you know, stable environments but not necessarily eternal. I was reading a CBC Radio story about a University of Ottawa study of bat guano in a specific Jamaican cave or cave system. I believe this cave is known as Home Away from Home cave. It's very remote and it has been a subject of some scientific study and they were looking at it and they were able to observe a shift over in the past from insect eating bats to fruit eating bats, though it was unclear as of twenty twenty one if this was a change in diet by a specific species or perhaps more likely the influx of a different bat species that had a different diet. They also found increased guano levels of cadmium, mercury, lead, and zinc present during the same time as the Industrial Revolution, so they were getting into like, you know, we can see this change, We can see this environmental change brought on by the Industrial Revolution in the of these bats in this remote Jamaican cave.

Heavy metal guano.

Heavy metal guano.

Yeah.

Yeah.

Now, of course we have various other creatures besides the bat, but also from the era of bats to consider that are now extinct that would have entered into caves and and would have defecated. We have like the cave bear, that is extinct, the extinct cave hyena copy lights from both of these species. Fossilized fecal matter has been discovered in caves. Yeah, now another tidbit, and this is something you could definitely go in deeper on. We could come back to another episode in the future at some point. Sequoiat All point out that the other thing about bat guano is that human beings figured out that, hey, this stuff has value. So cave environments have also long been exploited by human beings due to its economic value as a fertilizer and also, for at least for a while there, it was harvested to produce gunpowder. And all of this can impact these cave environments. Here's another interesting thing. Bats, the bats that enter into these caves, these caves, they are not set in stone. They are changing. We just discuss how these caves form over geologic time in the first episode. But the bats by roosting in the caves physically change them roosting on the ceiling with their little claws, so that physically changes the cave. And then also there's chemical augmentation of the caves via their urination. Because yeah, they're going both number one and number two in that cave system and it does have an impact.

Now, of course we have various other creatures besides the bat, but also from the era of bats to consider that are now extinct that would have entered into caves and and would have defecated. We have like the cave bear, that is extinct, the extinct cave hyena copy lights from both of these species. Fossilized fecal matter has been discovered in caves. Yeah, now another tidbit, and this is something you could definitely go in deeper on. We could come back to another episode in the future at some point. Sequoiat All point out that the other thing about bat guano is that human beings figured out that, hey, this stuff has value. So cave environments have also long been exploited by human beings due to its economic value as a fertilizer and also, for at least for a while there, it was harvested to produce gunpowder. And all of this can impact these cave environments. Here's another interesting thing. Bats, the bats that enter into these caves, these caves, they are not set in stone. They are changing. We just discuss how these caves form over geologic time in the first episode. But the bats by roosting in the caves physically change them roosting on the ceiling with their little claws, so that physically changes the cave. And then also there's chemical augmentation of the caves via their urination. Because yeah, they're going both number one and number two in that cave system and it does have an impact.

Oh do you know if the urination does it primarily like build structures or dissolve parts of the cave.

Oh do you know if the urination does it primarily like build structures or dissolve parts of the cave.

I believe it is more dissolving. Yeah, okay, And again we're dealing often with limestone cave systems and so forth. So that's my understanding here, because I know what you're thinking. We end up with actual like.

I believe it is more dissolving. Yeah, okay, And again we're dealing often with limestone cave systems and so forth. So that's my understanding here, because I know what you're thinking. We end up with actual like.

Bat piece stalagmites.

Bat piece stalagmites.

Yeah, bat piece stalagmites. I do not have an answer to that, but I think it is more of a dissolving of the cave system that is in play here.

Yeah, bat piece stalagmites. I do not have an answer to that, but I think it is more of a dissolving of the cave system that is in play here.

Wait a minute, hold on, I just googled bat piece stalagmites with large numbers of bats, thick and hard stalactites and stalagmites of crystallized bat you'rein occasionally form.

Wait a minute, hold on, I just googled bat piece stalagmites with large numbers of bats, thick and hard stalactites and stalagmites of crystallized bat you'rein occasionally form.

Well, there you go. Okay, so that is also possible. It's just a wonderful world down there. It's a whole new world.

Well, there you go. Okay, so that is also possible. It's just a wonderful world down there. It's a whole new world.

Sorry, I should say, since I read that directly, that was from something called the Internet Center for Wildlife Damage Management. I don't know what that is, but that's what they claim.

Sorry, I should say, since I read that directly, that was from something called the Internet Center for Wildlife Damage Management. I don't know what that is, but that's what they claim.

Yeah, there was another art. I didn't get into this article a lot. Maybe I could come back more in the next episode. But there was a twenty twenty one article in The New York Times titled how bats and their poop erase ancient cave art, and that one got into this issue of it because again they're changing the caves, and sometimes that can change things that prehistaric humans did.

Yeah, there was another art. I didn't get into this article a lot. Maybe I could come back more in the next episode. But there was a twenty twenty one article in The New York Times titled how bats and their poop erase ancient cave art, and that one got into this issue of it because again they're changing the caves, and sometimes that can change things that prehistaric humans did.

Wow.

Wow.

They point out that large quantities of the urine and the guano it ferments, it can saturate the air with quote aerosolized particles of phosphoric acid. So it's a rich world down there. Goodbye horsetoodle. Now an interesting and largely unanswered question for me, they would get some answers on it. Pertains to the question what might cave environments have been like before the evolution of cave roosting bats, because again, bats are mammals, and mammals have not in their highly successful mammals, they've been around for a while, but they haven't always been around. So what would have potentially pooped up these caves and sustained these ecosystems before bats.

They point out that large quantities of the urine and the guano it ferments, it can saturate the air with quote aerosolized particles of phosphoric acid. So it's a rich world down there. Goodbye horsetoodle. Now an interesting and largely unanswered question for me, they would get some answers on it. Pertains to the question what might cave environments have been like before the evolution of cave roosting bats, because again, bats are mammals, and mammals have not in their highly successful mammals, they've been around for a while, but they haven't always been around. So what would have potentially pooped up these caves and sustained these ecosystems before bats.

That's a good point. So like the base layer of the food, the food web within the cave is emerging from back guano, and there were at a time, no back to bring the guano in. Could there be an ecosystem in the cave at all?

That's a good point. So like the base layer of the food, the food web within the cave is emerging from back guano, and there were at a time, no back to bring the guano in. Could there be an ecosystem in the cave at all?

Exactly? Yeah, And I think by and large the answer is yes, there would have been things that have done that. And we know that in part because even today bats are not the only trogs to poop in a cave. There are considerable factors, but crickets are often brought up as another major cave pooper that allows the sun to shine in these lightless places. So it would seem that prebat organisms would have taken advantage of the cave niche to do, you know, to whatever degree they could. One of the things about investigations into cave fossils is that fossils that you find in deep caves aren't necessarily telling you about subterranean life. Tracks in the floor or even ceilings of deep caves may actually be insightful about life along shorelines of the surface. You know. That's the degree of time that we're dealing with, and considering the likes of, for instance, a five hundred meter deep that's a third of a mile deep cavern in France. I was reading about this is and I may be butchering French here, likely am castle book cave. Here, for instance, you'll find dino footprints that were first etched in mud or sand on a beach one hundred million years ago, and they've just been gradually forced underground over time.

Exactly? Yeah, And I think by and large the answer is yes, there would have been things that have done that. And we know that in part because even today bats are not the only trogs to poop in a cave. There are considerable factors, but crickets are often brought up as another major cave pooper that allows the sun to shine in these lightless places. So it would seem that prebat organisms would have taken advantage of the cave niche to do, you know, to whatever degree they could. One of the things about investigations into cave fossils is that fossils that you find in deep caves aren't necessarily telling you about subterranean life. Tracks in the floor or even ceilings of deep caves may actually be insightful about life along shorelines of the surface. You know. That's the degree of time that we're dealing with, and considering the likes of, for instance, a five hundred meter deep that's a third of a mile deep cavern in France. I was reading about this is and I may be butchering French here, likely am castle book cave. Here, for instance, you'll find dino footprints that were first etched in mud or sand on a beach one hundred million years ago, and they've just been gradually forced underground over time.

So it's not like they were formed in the cave. These are rocks that were formed on the surface and then they later emerged in a cave.

So it's not like they were formed in the cave. These are rocks that were formed on the surface and then they later emerged in a cave.

Yeah, and kind of similar to like, oh, you can't find a trillobte in a mountain and be like these were the mountain trilobites. It's not really what's happening. But of course this doesn't mean we don't have evidence of dinosaur age cave dwellers. As reported by Nature in twenty twenty, cockroaches preserved in amber from ninety nine million years ago are likely the oldest evidence we have of organisms evolved for life in a cave environment.

Yeah, and kind of similar to like, oh, you can't find a trillobte in a mountain and be like these were the mountain trilobites. It's not really what's happening. But of course this doesn't mean we don't have evidence of dinosaur age cave dwellers. As reported by Nature in twenty twenty, cockroaches preserved in amber from ninety nine million years ago are likely the oldest evidence we have of organisms evolved for life in a cave environment.

Million year old cave cockroaches. What were they like?

Million year old cave cockroaches. What were they like?

Oh, they were they were kind of scary. I included an image here of one for you, Joe. This is one of the species that they were looking at, and you'll see that it has front appendages, these kind of like raptorial four legs, much like a praying mantis, which means they were likely a highly predatory species in their cave environments. MM. So that's that's one of the features that they found on these these amber preserved specimens. There's lost coloration, there's reduced wing and eye size, elongated antennae, and and reduced leg spines for passive defense. So two species were discovered in amber in this cave from me and mar, one of which apparently had these raptorial four legs, meaning it was it was likely primarily a predator. And according to a paper in Cosmos magazine by James Urckhart, one of the one of the interesting things about this find is that the specimens in question would seem to have mid Cretaceous origins, but all cave animals living today have a late Sinozoic origin. Now, why these older cave organisms died out is apparently a mystery, because it would seem like an ideal place to shelter and survive surface world extinction events, but obviously that's not the case. The article also stresses that it's not impossible that these cockroaches may have survived even into modern times in one form or another, because our understanding of living insects is of course incomplete, so it's not impossible even though we're gazing backwards through time with this particular specimen, its genetic legacy could still be alive today. The article here is quite good. It also stresses some of the larger challenges of understanding such ancient cave environments in figuring out what they consisted of. Other Mesozoic cave organisms, it certainly existed, but either we get into the same problems we encounter with the inherent incompleteness of a fossils in general on the fossil record, because either a cave system collapsed long ago or key to this example, didn't allow fossil preservation. This case, amber containing cave organisms is rather unique because a tree is not going to grow in said cave. They say this is kind of like a one in a million fine because it probably depended on resin from a tree growing directly in the mouth of a cave, like in exactly the right place, exactly the wrong right time, in order to capture this creature that otherwise would not be venturing out of the caves to climb around on trees.

Oh, they were they were kind of scary. I included an image here of one for you, Joe. This is one of the species that they were looking at, and you'll see that it has front appendages, these kind of like raptorial four legs, much like a praying mantis, which means they were likely a highly predatory species in their cave environments. MM. So that's that's one of the features that they found on these these amber preserved specimens. There's lost coloration, there's reduced wing and eye size, elongated antennae, and and reduced leg spines for passive defense. So two species were discovered in amber in this cave from me and mar, one of which apparently had these raptorial four legs, meaning it was it was likely primarily a predator. And according to a paper in Cosmos magazine by James Urckhart, one of the one of the interesting things about this find is that the specimens in question would seem to have mid Cretaceous origins, but all cave animals living today have a late Sinozoic origin. Now, why these older cave organisms died out is apparently a mystery, because it would seem like an ideal place to shelter and survive surface world extinction events, but obviously that's not the case. The article also stresses that it's not impossible that these cockroaches may have survived even into modern times in one form or another, because our understanding of living insects is of course incomplete, so it's not impossible even though we're gazing backwards through time with this particular specimen, its genetic legacy could still be alive today. The article here is quite good. It also stresses some of the larger challenges of understanding such ancient cave environments in figuring out what they consisted of. Other Mesozoic cave organisms, it certainly existed, but either we get into the same problems we encounter with the inherent incompleteness of a fossils in general on the fossil record, because either a cave system collapsed long ago or key to this example, didn't allow fossil preservation. This case, amber containing cave organisms is rather unique because a tree is not going to grow in said cave. They say this is kind of like a one in a million fine because it probably depended on resin from a tree growing directly in the mouth of a cave, like in exactly the right place, exactly the wrong right time, in order to capture this creature that otherwise would not be venturing out of the caves to climb around on trees.

Yeah, that's interesting, and I was wondering I was going to ask about exactly that like, how does a cave cockroach get trapped in amber? So I guess the answer is probably very rarely happened. We're incredibly lucky to have this unique find.

Yeah, that's interesting, and I was wondering I was going to ask about exactly that like, how does a cave cockroach get trapped in amber? So I guess the answer is probably very rarely happened. We're incredibly lucky to have this unique find.

Yeah, and it just raises the question, like what else would have been down there that we didn't crawl into the amber. You know, there's again just so many mysteries within within the fossil record, and back to the earlier point, so many mysteries remaining and just sort of the in the the existing organic world. You know, we're still making discoveries regarding insects, cave environments, of cave ecosystems. It's I mean, it's really exciting.

Yeah, and it just raises the question, like what else would have been down there that we didn't crawl into the amber. You know, there's again just so many mysteries within within the fossil record, and back to the earlier point, so many mysteries remaining and just sort of the in the the existing organic world. You know, we're still making discoveries regarding insects, cave environments, of cave ecosystems. It's I mean, it's really exciting.

No doubt, And you know what, I think we're going to have to end today's episode there, but we've got more cave stuff to talk about. So we're going to be back with part three definitely.

No doubt, And you know what, I think we're going to have to end today's episode there, but we've got more cave stuff to talk about. So we're going to be back with part three definitely.

That's right. We're gonna get into some cave creditors and who knows what else. All right, stuff to blow your mind. As you know. Core episodes are on Tuesdays and Thursday. We're primarily a science and culture podcast, and then on Mondays we do listener mail. On Wednesdays we do a short form episode, and then on Fridays we set us on most serious concerns to just talk about a weird film on Weird House Cinema. We bust out a rerun on the weekends.

That's right. We're gonna get into some cave creditors and who knows what else. All right, stuff to blow your mind. As you know. Core episodes are on Tuesdays and Thursday. We're primarily a science and culture podcast, and then on Mondays we do listener mail. On Wednesdays we do a short form episode, and then on Fridays we set us on most serious concerns to just talk about a weird film on Weird House Cinema. We bust out a rerun on the weekends.

Huge thanks as always to our excellent audio producer JJ Posway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello, you can email us at contact at stuff to Blow your Mind dot com.

Huge thanks as always to our excellent audio producer JJ Posway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello, you can email us at contact at stuff to Blow your Mind dot com.

Stuff to Blow Your Mind is production of iHeartRadio. For more podcasts from my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you're listening to your favorite shows.

Stuff to Blow Your Mind is production of iHeartRadio. For more podcasts from my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you're listening to your favorite shows.