Glow in the Dark: Bioluminescence Wonders of the Deep and Beyond

In this episode of Wildly Curious, hosts Katy Reiss and Laura Fawks Lapole dive into the mesmerizing world of bioluminescence, exploring how animals, plants, fungi, and even bacteria light up the natural world. From deep-sea fish with built-in flashlights to fungi glowing in forests, discover the surprising science and evolution behind nature’s glow. Why do creatures glow? Is it a defense mechanism, a hunting tactic, or a way to find love? Uncover the fascinating reasons bioluminescence has evolved and how these light-producing marvels use their radiance to survive. 

Perfect for anyone enchanted by the mysteries of nature or curious about what lights up our planet in the dark!

Transcript

Laura: Hello and welcome to wildly curious, a podcast that tells you everything you need to know about nature and probably more than you wanted to know. I'm Laura.

Katy: And I'm Katie, and today we're going to be talking about how animals, plants, and fungi, and even some bacteria have all developed ways to produce light on their own. A. bioluminescence.

Laura: I'm pretty excited about this one. We were, we were gonna, I mean, sorry guys, we were going to do this last week for Halloween. Um, but then I was away at a conference and we could not figure out how we were I could,

Katy: swear.

Laura: something

Katy: one thing. Yeah, we change, you change one thing in your, like, you get a good process down, and then you change one thing, and then boom. Yeah,

Laura: Yeah. It wouldn't let me record from where I was. So, oh well, you guys got caves. And now this week's Bioluminescence.

Katy: Oh no, you guys got caves! Goodness. Well, I do have, um, oh, I do want to say that we did miss a fantastic opportunity. [00:01:00] Did you know that October was Squirrel Awareness Month?

Laura: I did, my neighbor, who is a new podcast, very avid listener, shout out to Robin, she immediately texted me at the beginning of October going, did you know it's Squirrel Appreciation Month? Because her students were writing prompts about it and everything.

Katy: My boyfriend, he sent me a text because he has a thing with squirrels. Not a, I mean, so he did a project in undergrad with squirrels, um, where he was, um, Basically before they had ring cameras, he like made a camera and stuff. This is like back in the early 1800s because he's that old. No, I'm kidding. He's not that he's not.

He's not. He's older than me. So, uh, to squirrels for squirrel boxes. And so, um, but to watch their mating patterns and, uh, with the biology department. That's not how, I was gonna say, that's not how he described it though, it was squirrel porn. So now we all, it's, it's funny. But, um, so

Laura: we're gonna have to tag this episode as being explicit because of that word [00:02:00] choice. Gosh dang it, Katie! We didn't even get into the content!

Katy: boop. I'll bleep, I'll go back and bleep it out. Goodness. Um, But yeah, but we missed an opportunity there to either talk to him about his squirrel, boop, or just any, or splooting, to revisit the splooting, which is one of my favorite, favorite conversations.

Laura: laying down, I'm like, oh look, it's splooting.

Katy: Yeah, look at him splootin over there.

He's just splootin away, doing what squirrels do. Just lovin life and splootin

Laura: Um, well, mine, mine isn't really nature news, but I, um, have been listening to, like, uh, I'm, I'm done listening to an audiobook series I've been listening to for the past six months, so I'm like, now what do I do with my life? So now I'm listening to podcast episodes again. Um, and I just listened to, uh, it was recommended to me, it's called PBD Podcast, and I don't know about the rest of the podcast, I only listened to this one episode that was recommended to [00:03:00] me, but it's called We're Not Alone, Louis Elizondo, Real UFO Encounters, Government Secrets, and Underwater Aliens.

I mean, if that's not a, a, an intriguing title. I don't know what it is, but it was really good. Um, it's, uh, Luis Elizondo is a former U. S. military intelligence official who leads the AATIP program, or who did lead the AATIP program through the Pentagon, um, which is the Aerospace Threat Identification Program.

And he talks about, all about, like, UFOs and UAPs, which is, like, the newer term for it, and was exploding my mind, because I was like, As we, we are going to

Katy: like how they rebranded

Laura: every couple, yeah, but like, remember how like, I mean, we're going to bring up every few episodes, BTWs, there's aliens, BTWs, there's aliens, like between you and I, we're just going to keep bringing it up because it was said during COVID, there are aliens and everybody just let that one go.

But. This is like, it's a deep dive in, it's, it's a, [00:04:00] there's a lot of good content to it, but my favorite part that I've never thought about before was, you know, he was like, so like, aliens, and the guy was like, and Lou was like, okay, but let's stop right there and like, talk about this, because aliens I feel like everybody thinks about as being extraterrestrials, okay, but that's not necessarily What alien could be.

Aliens just mean not us, not, not human technology, like stuff. So, could be dwelling in the ocean, since we have less of the ocean's map than we do outer space.

Katy: Oh, yeah, we have no

Laura: another dimension. They could be interdimensional travelers. We have no idea, like that's how much we don't know. Doesn't have to just be like dudes from out On another planet, could

Katy: tiny green men. Yeah

Laura: which I've never thought about before and was like, like, what if they are from the oceans?

Or what if they are just from another dimension? What if they've been here all along and only now do we have [00:05:00] the technology to be able to see what's always been here?

Katy: well And that's what a lot of people are saying and if you look back through hit or there's a lot of people that will show Like evidence through you know aliens and UFOs and stuff like that throughout history And and that's what they say like they've always been around and yeah But I mean, I was a huge X Files junkie as a kid and I went through that whole phase in middle school I was like X Files everything.

So

Laura: I mean, it was just a men in black discussion. The whole

Katy: Yeah, essentially.

Laura: men in black is real, always has been guys.

Katy: Well, I have some nature news too, and I thought this was pretty cool. Um, this is not alien based. Uh, they kind of look like aliens, but we're gonna talk about bats for a second.

Laura: Okay. Cause it was bad appreciation month this last month too.

Katy: yep, I love bats. I absolutely love bats. Um, but researchers, they recently discovered that bats, through their poop, are providing scientists with surprisingly detailed history of regional fires.

So, So [00:06:00] bat guano previously to this, this is a new study that was published. Uh, researchers have analyzed bat guano to infer past climate and vegetation changes. Um, there was a huge study published in, uh, 21 recently that examined 4, 300 year old bat guano deposits in Jamaica to understand the history of dietary shifts and environmental conditions.

Through then, so this one is just then looking at bat guano to look at the history of wildfires. Uh, so bat guano, it can hold different clues to the past of wildfires. Thanks to tiny bits of charcoal that get stuck to their fur, they fly through the smoky areas and brush against charred plants. I mean, it makes sense.

Um, and when bats groom, Say again.

Laura: I was just gonna say, so when they groom, I

Katy: Yep. So yep. Yep. So when they they groom and do their business in caves, the charcoal particles settle into obviously the layers and layers of guano. A team [00:07:00] tested this theory by analyzing a two meter long guano core, which,

Laura: Didn't know it was a thing until right now. Yeah.

Katy: Alright, guano core, uh, from a Tennessee cave dating back to the 1950s, and they found that charcoal bits and bat poop lined up perfectly with records of local fires, making guano an unexpected but valuable tool for tracking historical blazes, which is pretty neat, I thought.

I

Laura: sounds like a new genre of music. Guanavacore. You're

Katy: was like, a new thing in music, what? Guano

Laura: I was, I was gonna say it faster, but then I would sneeze.

Katy: he snee he sneezed. He sneezed.

Laura: Of music.

Katy: Oh, goodness.

Laura: um, no, I should have let you go first because then there could have been the transition from the ocean to the bioluminescence. But now, alas, I [00:08:00] can't connect it to bats because bats don't bioluminesce, at least yet.

Katy: God, that would be amazing if they did, though. Could you freaking imagine?

Laura: Little guys flying through the air, just little beacons of light,

Katy: I I I could not love bats anymore until

Laura: they bioluminesce. Yeah.

Katy: I would love them even

Laura: a little bit more. Um, well, like Katie said earlier, we're talking about bioluminescence. So it's my job to tell you guys what that is and how does it work. And then, then Katie and I are both going to take a, a section of like, why do they bioluminesce.

Katy: different, like, sections. So I want to talk about offense, defense, and then, Laura, you're talking about communication, right?

Laura: Yes. All right. So first of all, what is bioluminescence? Well, according to the National Oceanic Administration, Who's, you know, the ocean people, and most bioluminescence happens there, so they're the experts. It's the production and emission of light by a living organism, okay? So it is not the same [00:09:00] as biofluorescence, which is when an organism absorbs light from an external source, and then re emits it at a lower wavelength.

So

Katy: Glow in the dark.

Laura: glow in the dark paint, right? You, you need light to make light. Bioluminescence is the organism makes its own light. So it seems to have evolved 40 different times over the millennia, like by itself. So it's not like one thing from one thing, from one thing. We're just talking like randomly.

It was like, you know, it'll be better if we glowed.

Katy: You know what I should do right now? Light up. I feel like I should light up. Yeah.

Laura: mostly 80 percent of things that do this are aquatic, but 20 percent are on the land. Um, these organisms can be found all over the world, it's not just a regional thing. And there are about 1, 500 species that do it. From fungi, to protists, to bacteria, to invertebrates, to fish. Nothing higher up. So [00:10:00] far, no reptiles, birds, amphibians, or mammals, which is a bummer.

Um, so we're not quite to avatar yet.

Katy: Wait, wait, wait. Say that again? Say that again?

Laura: so nothing higher than the order of fish.

Katy: Okay, okay, okay. I was like, hold up a second. It's like, because I have

Laura: Yeah, on the evolutionary tree, nothing higher than a fish. Um, or anything below that. But yeah, we're really missing out here on the mammal and the bird and, you know, like, I guess,

Katy: again, humans, we missed something

Laura: it'll make more sense later when Katie and I talk about the reasons for it. We're talking about a lot of stuff that can't talk or make sound do this.

But,

Katy: really

Laura: I feel like it'd be better if we could. It would be better! Yeah, it would be better!

Katy: haha

Laura: evolutionary goals? I want to talk and [00:11:00] glow. That is a great evolutionary goals. Um, okay, well, how does this work? Okay. So, I'm gonna go into the science without going too deep into the science. But, really, there's still a lot of unknowns. The exact ins and outs of myelominescence are not exactly known, because almost every species does it differently.

Or at least every group of animals does it differently. But, in general, it's a chemical reaction that happens inside the cells, or ejected by the cells. So when inside of a cell, the molecules that can be located are usually inside a special, what's called a photophore organ, or more generalized. So it could be like, sometimes it's in, okay, think of like a, like a, like a lantern fish with a little glow bulb.

That would be like a photophore organ. Or it could just be generally throughout the organism. And typically what [00:12:00] happens is that there is an, there is a molecule called luciferin, luciferin is called a substrate, so it's a molecule that produces the light in the reaction. Luciferase Is the catalyst.

And a catalyst, of course, is something that, um, speeds up a chemical reaction. Okay, so you need luciferase and luciferin, both together. So, luciferin plus oxygen, made to happen with a catalyst, luciferase, and that equals light. Okay, um, or it's luciferin, plus oxygen, plus a photoprotein, so a light protein, and then light, or like once you add in a specific

Katy: Yeah,

Laura: So a photoprotein is, um, it's another option, which, like, when, when a little protein that can do stuff [00:13:00] with light, is combined with luciferin and oxygen. It's a pre packaged thing. So it actually, it's like more efficient in an organism. So normally you've got this luciferin all over in their body, and then oxygen comes in, and then light.

Okay. But that requires a

Katy: that was a sound it made to

Laura: um, but that, that reaction sometimes takes a little bit because it needs some stuff to happen. Whereas if it's got A photoprotein, which is the luciferin, already mixed together with oxygen, they've taken out that part. Then all that needs to happen is some kind of element gets added, like calcium or something.

And then, boom, faster reaction and light. And if any of you are, are good with your Latin roots, um,

Katy: What y'all know I am

Laura: So, you might be like, Luciferine? Luciferase? Why are they similar names? It's because Luce, Lucifer, if you think about Lucifer from the Bible, his name was that because [00:14:00] his name meant lightbringer. Luce means light, or lux means light, um, in Latin.

So, um, When the molecules mix together with oxygen, the reaction produces light, and that light can be red, blue, green, yellow, or violet. Most of the time, we see blue green, um, emitting organisms because they're in the water, and the short wavelengths reach our eyes, or they're meant to communicate with animals that can only see in that light spectrum.

So if you're underwater, you're really only using blue and green, because honestly, it's the only thing you can see down there. With exceptions. Um, and then most terrestrial animals that are producing this light also do blue green, but also tend to lean more towards yellow, too, so think of, like, lightning bugs, which I'll talk more about later.

Different organisms have different types of luciferin molecules, so that's where things get different. Like, luciferin is just like a, like a catch all term for this, uh, [00:15:00] molecule that helps produce the light, but it might look different in different organisms. And other proteins can also be involved in this reaction, depending on the organism.

But what's cool about all of this is that, you know, normally when we think about like, light and, and reactions that make light, those reactions also make heat, right? Like the sun is bright and hot. Light bulbs, bright and hot. This reaction is considered a cold reaction, and they refer to it as a cold light because the only discharge from this chemical reaction is light, not heat.

So none of the little guys are getting overheated when this is happening. So in order, um, so that's the molecules involved. Now, whether or not they glow is typically dependent on the oxygen part, right? So if oxygen is what they have to add to make this reaction happen, then if they can control how much or [00:16:00] how little oxygen.

is allowed into the cell, that's whether they glow or not. So many can control when, and to what degree, and even what color the light is, um, based on how much oxygen is going in or out of the cell or what other proteins are involved. Some are even multicolored, but that's super rare for an organism to be able to do multiple different colors. Um, and where do these molecules come from that are even in their little bodies? So, um, Some make them, like, just on their own, like, especially if you're thinking, like, bacteria and things like that, because obviously that's lowest down on the food chain, but others get those molecules from eating the guys lower down on the food chain.

So, there's a really cool examples of, like, symbiotic relationships with fish or, um, like, siphonophores, which we've talked about in the podcast before, which are

Katy: Yeah, I don't remember what I was Yeah,

Laura: Um, There's a symbiotic relationship that they have with bioluminescent algae. So the algae are like, we need a safe [00:17:00] place to live.

And the organism is like, well, I want to glow. So let's team up here. So they, the, the bioluminescent algae live in their gut. But the organism itself is see through, so they glow because of the bacteria that are just healthily living inside of them. Um, which is kind of interesting and cool. So that's, that's bioluminescence, that's how it works.

Luciferin, oxygen, catalyst, light, for the most part.

Katy: yeah. Okay, perfect. All right. Well then as Laura said at the beginning here, then I'm gonna talk about Offense a bit and then Laura can talk about communication. I'll talk about defense. So I'm just gonna give some different examples of Why the animals would be using this and then specific examples of particular species Because that's really that's really the cool part Yeah, and that's the cool part.

Laura: Like, we're like, it's, it's interesting to know how it works, but [00:18:00] also like, why bother? Why bother

Katy: yeah, yeah. So when you think of light, you probably associate it with safety, guidance, and warmth, as most people would. Um, especially if it's in darkness. I mean, you would though, it would be like, oh, this is a safe place, this is something good,

Laura: exactly like in Finding Dor I we were just talking

Katy: Oh, that's going to be my example. Yeah. That's going to be my example here. And so that's my, that's my action. My first one is the anglerfish and it's for offense, the luring of the prey. So that is, I would say one of the most iconic examples I think of people, if you're thinking of like, okay, bioluminescence, like an animal that glows, it's going to lure in a boom anglerfish, um,

Laura: if you've ever seen Finding Nemo, perfect.

Katy: It's the one I see a light. And then that's what starts with, what do you see? I see a light. Um, so

Laura: And then things go south real quick.

Katy: real quick, right? So the anglerfish is, [00:19:00] uh, let's see, or bioluminescence strategy is, is a classic example of offense designed specifically to lure prey rather than ward off predators. Unlike defensive bioluminescence, which I'll talk about here in a bit, or which often serves to disorient or evade, the anglerfish's glowing lure acts as an irresistibly deceptive beacon in the dark depths, drawing prey right to the fish's jaws.

Laura: not even moths down there, but same, same thing.

Katy: Yeah, they just still

Laura: a light, something's gonna come for it.

Katy: This is amazing Uh, so living in pitch black environments of the mostly the atlantic and antarctic oceans Where food is very scarce the anglerfish relies on the small bioluminescence lure that dangles from a modified spine on its head Positioned strategically above its mouth and again, like we said if you've ever seen finding finding nemo That whole scene go watch it if you have if you haven't

Laura: Yeah, where have you been?

Katy: Yeah, where have you been?

Because it's so [00:20:00] good. So this appendage emits a faint, pulsating glow that mimics the appearance of a small, edible creature. In an environment where even the smallest glimmer is unusual and attention grabbing, this tiny glow becomes a beacon of basically somebody just being like, oh my gosh, I'm so excited, like either, this is, this is gonna be something, like I could eat this

Laura: It's so crazy that this works because you'd think that, you know, in a place that's pitch dark, I feel like the

Katy: It would be terrifying.

Laura: 50 it's either food or it's going to eat you.

Katy: yeah, or yeah, or it could be

Laura: dumb enough to not remember, like, oh yeah, sometimes the light can be dangerous.

Katy: Yeah. No, I have no clue. So the anglerfish has transformed the glow into a deadly trap, but as unsuspecting prey, prey swims closer, captivated by the rare sight, it's entirely unaware of the massive jaws lying in wait just behind the lure.

In an instant, the angler fish snaps forward [00:21:00] truly with incredible speed. Cause I mean, things down there generally move fairly slow, but not this thing. And it closes its jaws around the prey in a swift. Super fast strike. This offensive use of bioluminescence takes advantage of the deep sea environments, limited visibility using light, not to hide, but to weaponize in the darkness, transforming an unlikely beacon into a lethal snare.

So this tactic definitely highlights how the offensive bioluminescence can turn the ocean's darkness into a tool for ambush.

Laura: That's really metal sounding.

Katy: Right? It is pretty cool. More metal bands should use an anglerfish and

Laura: they should. I actually just, it's crazy that we bring up anglerfish. I mean, not that crazy because of bioluminescence. But crazy in that I just talked about an anglerfish with Allura Yesterday. No, wait, Wednesday. Because we saw a picture of one on a hat that was, [00:22:00] um, the logo of a brewery Um, and, and, and I was like, oh look that's anglerfish, like on Finding Nemo, and then she was like, oh, yeah And then yeah,

Katy: I had a thousand questions. Um, another form of offense is mimicry and deception. So, the anglerfish, they're not the only ones using light to their advantage. Some predators take bioluminescence a step further through mimicry and deception. Certain species of predatory worms, for example, use bioluminescence to mimic light signals of their prey, which is so mean.

Like,

Laura: that gives me the willies. I just got the shivers thinking about predatory worms I don't like that one bit.

Katy: No. So, this one's called the railroad worm, and their bioluminescence takes the concept of offense, uh, more into, like, It doesn't only just use light as an attractant, but a precise tool of like I said, mimicry and deception that it just, yeah. So, [00:23:00] so this is a, it's a predatory larva of beetles

Laura: Oh, I saw a picture of this. I'll look it up

Katy: in the genus.

It's filthorax, thrithorax, I don't know, was evolved, yeah, something Latin, evolved a unique form of bioluminescent mimicry that serves to lure prey directly into its grasp making it a master offensive bioluminescent tool. Tactics, which is similar to the anglerfish. So native to the human for, or the humid human humid forest of South and central America, the railroad worm resembles a miniature train, hence its name, uh, as it moves through the leaf litter with rows of bioluminescent green, green lights running down its side and bright red glowing at its head.

This striking display isn't just for camouflage or evasion, it's carefully crafted deception. The green light mimics the ambient glow that many nocturnal [00:24:00] insects associate with food or potential mates, effectively tricking them into approaching. They're which again so mean, so the rare ability to produce both green and red like Laura went into that.

It's very rare to do multiple, but it's two separate things. So it's not like it's like one. It's not like one area can go green or

Laura: Right, right. It's, it's sectional.

Katy: Yeah. So it's green on its sides and then red on a head allow, but this allows the railroad worm to differentiate its glow from other bioluminescent species in its habitat, making it signal distinct and more likely to.

Attract unsuspecting insects. This mimicry based offense is highly effective in low light environment, uh, where any glimmer is likely to draw attention. Insects approaching the glow, see what they perceive to be food source or a mate only to find themselves within striking distance of a hungry predator.

Which again, So, [00:25:00] yeah, so mean. Uh, another one that, another offensive tactic that can be used to confuse and dis, confuse and dis, bleh, let me start that over. There's another tactic that, uh, they can use for offense, and it can be used to confuse and disorient prey. So that's just like the group of confusion and disorientation, or distraction, sorry, distraction. In the dark depths of the ocean. So going back to the ocean, biosis, um, can turn from defensive smokescreen, which I'm gonna talk about into an offensive weapon, enabling creatures like the A to a tolli jellyfish to exploit light for confusion and deception, settling, setting the stage for an ambush, so known as an alarm jelly, quote, unquote, that's what its nickname is.

For its vivid pulsating display, the Atolla jellyfish uses its memorizing light to show, uh, not just to evade, but to capture prey. By creating [00:26:00] chaos in water, disorienting nearby creatures and setting them up as easy targets. Again, some of these ones are just so mean. So native to the Atlantic and Pacific deep water oceans, a total of jellyfish create, uh, basically a circular display of bright blue light along the edges of the bell, emitting pulsing rings that radiate to the darkness.

To unsuspecting fish or other small creatures, this rapid burst of light is confusing and distracting, distracting, capturing their attention, and momentarily blinding them in the otherwise pitch black environment, because it is pretty bright. Uh, the jellyfish, meanwhile, hovers nearby, ready to capture anything that becomes disoriented in the glowing frenzy that it

Laura: Just a flashbang under the ocean. And then it's just like, I'm the everything that's stunned.

Katy: right. A similar tactic is used offensively by the vampire squid, which I know we've [00:27:00] talked about vampire squids before. Uh, this releases a cloud of bioluminescent particles from the tips of its arms in the still dark waters. These particles basically are just like a glitter cloud. Uh, and it, uh,

Laura: Glitter bomb under, under the water.

Katy: Hehehehe I'm gonna light Hehehehe Hehehehe

Laura: spits out light everywhere.

Katy: I'm gonna make I'm gonna draw that one, a Vampire squid with a gl A glitter bomb.

Hehehe

Laura: everything within said glitter bomb.

Katy: Hehehe Hehehe I mean, it works. Um, but, it causes them to Again to stumble into the squid's range this glowing like quote unquote ink Is I guess it's like the easiest way to describe it serves more as just an escape mechanism For a well faced predator it becomes an at an attractive and active distraction making it difficult for prey to tell it from foe So [00:28:00] you think of like squids and inking?

Um again, there's a finding nemo in there where it's like, oh, sorry, you know, I inked um, and that's most squids it'll give off like that ink and then It They flee. Well, Vampire Squid, they use that bioluminescence and then they use it as attack. Let's see here, uh, one more, one more for offense here. Um, finally there are creatures that use bioluminescence as a form of camouflage, which I know sounds defensive, but just hang in here with me for a second.

Uh, blending it with the faint light of their surrounding. Surroundings to hide from prey the lantern fish, which I think laurie mentioned earlier Showcases how counter illumination can turn from simple camouflage into offensive hunting tactic So equipped with rows of photophores like laura was saying along their bellies lantern fish emit a faint blue green glow That perfectly matches the dim light filtering down from above So I know we've talked about in [00:29:00] other episodes the counter shading with uh, That's why like killer whales are black on top, white on bottom.

Cause anything that's from the bottom looking up, you're going to see white. And so the white belly of a killer whale blends in anything above it, looking down, isn't going to see it because it's, you know, the seafloor is black. Um, so. Let's see here. So, them emitting that blue green on their bellies, that mimicry of ambient light, essentially, is, like I said, known as counter illumination, unlike counter camouflage or counter shading.

It's a counter illumination. And it erases, basically erases their shadow. It makes them appear as though it's, Nothing like yeah, not just nothing's there which is pretty neat.

Laura: no shadow, but which is hilarious because it's the opposite of that. You know what I mean?

Katy: No, right? Yeah, like it has light So it's giving something but it doesn't give itself like an outline because then you can't see like what it is Like you see lines. Yeah, you see the glow, but you don't actually see what it is Um, so yeah, so that's offense [00:30:00] in a nutshell. Um, so you want to go over our communication then laura?

Laura: so communication is the earliest form of communication with on earth. Um, at least, or at least within the ocean, which is where life started. So definitely on earth. Um, so the earliest form of communication in the ocean was this bioluminescence and it was thought to arise about 540 million years ago. Um, And whether or not this was the OG reason for bioluminescence, I think it depends on the species because like I said, it's developed over 40 times.

Um, but communication is definitely probably one of the earlier ones. And then things like offense and defense have kind of come along because it's, it's all kinds of forms of communication, right? Because like offense, they're communicating something. But I wanted to do something that is besides [00:31:00] Communicating, come hither, and go, you know what I mean.

Um,

Katy: More, more true communication. Yeah.

Laura: So, I just have three different, three different things for communication. One, identification. So bioluminescence helps members of the same species to be able to identify each other. Um, two it can communicate to the same species if they found prey in the area. Um, I only found one example of this, but dragonfish, cool freaking name.

for another fish that's in the deep ocean, they use bioluminescence to create a red light in the deep sea, which allows them to see red colored prey and communicate with other dragonfish like, yo, there's prey over here. And this is really unique because If you remember when I was talking about the different colors that bioluminescence can create, red is like never one of them.

Um, very rarely. And that is because a lot, most animals, [00:32:00] especially the one in the ocean, like you were talking about the one, the railroad worm that lives, that's a terrestrial worm. This, or a terrestrial beetle. Larvae. Um, The dragonfish are deep ocean. Nothing can see red light down there, except for these dragonfish.

They have developed a way to see red light, which is very hard when those wavelengths are typically blocked under the water. Um, so others can't see this red light that they produce, so nobody runs away. Meanwhile, the dragonfish are all like, Wee wee,

Katy: Yeah, right.

Laura: like, Prey party over here.

Katy: Yeah,

Laura: Um, and then the most exciting form of communication is, of course, mating.

Um, and a lot of the organisms use the, use, uh, the spiluminescence for mating.

Katy: I mean, I can't blame him. That'd be

Laura: If you glow, you've definitely taken it up a notch. Yes.

Katy: ha ha ha

Laura: Hence, glow sticks at a rave, right?

Katy: [00:33:00] ha.

Laura: more glow bracelets, the better. Not that I've ever been to a rave, but I would definitely be more attracted to someone who was wearing lots more glow bracelets.

Katy: Justin, take notes. Right.

Laura: Uh, so recent research has showed that fish that use bioluminescence for communication diversified into more different species than those that didn't. Okay, so let's break that down. A lot of deep ocean fish are using this by luminescence.

Some are just using it for camouflage, which I'm sure you're going to talk about more with defense. Um, but the fish that use it for defense They have not turned into that many different species of fish, right? Like, they have found their niche and they have went with it. Meanwhile, certain fish that are using [00:34:00] bioluminescence to attract a mate, they're diversifying into many more species.

And why is that significant? Because in the deep ocean, space is the biggest barrier to diversify like, to finding a mate, right? Like, there's you're not divided by the scenery, right? By rivers, by mountains, nothing. The only thing that is preventing you from meeting your dream boat is the darkness and vastness of the ocean.

Which is significant. And how do you overcome that? Light. So if you get

Katy: feel like there's some like bit like, I don't know, deep, meaningful quote that just came out of that.

Laura: How do you find your dream boat?

Katy: yeah,

Laura: light. Um, so yeah, so those that are finding, it, basically, this equates to, you produce light, easier to find a mate, you diversify into more different kinds of fish. [00:35:00] You've, you've beaten it. Um, so, definitely, it is proven, it is proven, that bioluminescence helps find mates in the ocean.

because that's the biggest barrier. Um, but when we think about like bioluminescent animals that try and find mates, if you're not thinking about anglerfish with bioluminescence, chances are the thing you're thinking about is fireflies. Because we're on land, so we see mostly things that glow on land, and that's fireflies.

That's the big one. Um, so preface this though with saying that not all fireflies flash. Um, they're just called that because the majority of them do. Those that do are the more recently evolved. Of the species of the different varieties. So what are the, what are the fireflies doing to make this so successful so they can control when the chemical reaction within their bodies stops and starts?

So remember I said this whole key to all of that was oxygen. So they, [00:36:00] they have tea, tiny muscles in their little firefly abdomens that can let in oxygen when they relax or contract one of the two. And they're letting oxygen in, so starts it, and then stops it, and then starts it, and then stops it. But their, their tiny little muscles just aren't that super fast because they're very, very small.

So to make them be able to flash faster and more often, they rely on nitric oxide gas, which, hilarious, I only included this because it is the same gas that is produced when taking Viagra.

Katy: Interesting

Laura: So I don't know who, I mean, I'm, I hope that whoever invented Viagra was like, the Fireflies, let's do what they're doing.

Probably not, could just be a coincidence, I don't know, but the results are similar, mating, right?

Katy: right.

Laura: um, [00:37:00] Their muscles, It helps theirs not to be hard longer, theirs is to be able to contract faster or

Katy: Yeah,

Laura: so that they can flash faster. Okay, so once, now that they've got the flashing part down, now they're using their unique flash patterns that show, it shows who they are to each other. And they're, like, it is, it shows the species and it shows the sex of the firefly.

So most males fly around and are the ones blinking. Um, while females just sit and wait and watch the sky. So, the ladies are all down in the grass, looking up. Trying to figure out who's who up there, flashing around, and what they're trying to say. And fireflies are very, very particular in how they go about all of this, to be able to identify who's who.

So if you want to be [00:38:00] like, Okay, wait, there's lots of flashing going on. What's my kind of firefly? I am looking at, are the males flying at the right height? Are they in the right habitat? And is it the right time of day? If I can figure out that, then I know what kind of species is flying around. Um, so usually it is a male trying to do his little thing exactly right to attract the same species of lady.

And then once, once they do, Well, if the lady likes what she sees, she signals and guides him down with her flashing display. So she's like, ooh, you know, I like that. Come on down. So she's using her own glow bracelet tactics. Um, however, some chicks out there, some of these female fireflies are tricky. And if they're like, you know what?

I don't like anything I see from my own men. Let's choose somebody different. They will mimic a [00:39:00] different species to bring a dude down. If it's like, well, if I can't, if none of my own are doing it for me, I'll just choose somebody else. So she will interbreed with a completely different species if she likes what she sees.

That they're doing better, um, which is pretty

Katy: then there are cross breeds out there?

Laura: guess so. Or, or maybe, maybe they do it but it doesn't result in anything. But, but she's thirsty and she's willing to catfish.

Katy: right?

Laura: Um, And so, um, I read a really, I, I couldn't figure out how to like summarize this without just reading it. So I'm just gonna read this.

this quote from the scientist, which I thought was fascinating. So according to Clyde Sorensen, a professor of entomology at North Carolina State University, a good example of like these very specific interactions is done by a backyard species of firefly called the Big Dipper. So a male, which is also a cute name for a species, the [00:40:00] Big Dipper fireflies, um, a male flies around at dusk, about three feet off the ground.

And every five seconds or so he makes one. second flash. So he's gonna flash, flash, flash, and then every five seconds he does flash, flash, and he makes, as he flies in a J shape, okay? So he is coming out three feet off the ground at dusk, flashing in a specific pattern, flying in little Js. And then the female, she's in the vegetation, if she sees what she likes, she waits two seconds before making a half a second flash of her own.

on the third second. So like, this is like very much like they, they can't talk. This is all down to little flashing lights and they mean very specific things, kind of like Morse code or like semaphore, you know, like they're just using their little butts. Um, and most, most species do flash independently. Like [00:41:00] of each other, so they're all competing against each other. But there are two southern species where the males will synchronize their lights together. This is you, this is, there's like a species in the Smoky Mountains of Tennessee that people like travel all over to

Katy: Oh, yeah. Yeah.

Laura: is just pulsing, glowing light, because they're all doing it at the same time.

I would love to see it. And that's how they're using, those guys are using bioluminescence for communication.

Katy: That's cool. Lighting bugs. We don't have as many down here in Texas is what

Laura: mean, we don't have as many up here anymore either, which is a real shame, but

Katy: going away,

Laura: all those lawn chemicals.

Katy: Right. Geez Louise. Killing one of the coolest things out there. All right. So then last thing we're going to talk about then real quick is the defense. Um, and

Laura: love that you looked this for last. We're like, you know, lame. Defense. Lame.

Katy: but offense is so much cooler.

Like

Laura: This tells you so much about Katie's personality.

Katy: Listen,

Laura: gonna [00:42:00] glow, I'm going on

Katy: I'm gonna kill, yeah,

Laura: And I'm like, let's communicate here. And then finally we're like, okay, and if

Katy: okay, defense, yeah,

Laura: it.

Katy: alrighty. Um, so again, like I said, it's not always about standing out, in some cases, you need to just blend in so that you can virtually disappear. Um, so we're going to talk about a few, let me see here, one, yeah, a few different examples here real quick. Uh, so we already briefly talked about counter illumination, and so we're going to talk about that again, but this time this one is more on the defense, not the offense of the, the other ones.

Laura: just trying to hide.

Katy: They're just trying to hide. So we're gonna talk real quick about, uh, the, a deep, there's a deep sea shrimp actually that use this. Uh, and it is a certain species of deep sea shrimp. It's, again, so many things don't have actual names. Sur Guesties Simis.

Laura: All [00:43:00] right.

Katy: My, my closest guests, uh, they employ counter elimination, not for offense, like we already talked about, but as a highly effective defense mechanism.

So, uh, this adaptation allows the shrimp to remain concealed from predators lurking below, creating a stealthy advantage that enhances their chances of survival in a harsh environment where exposure can be deadly. Counter elimination, like we kind of already talked about works as a form of camouflage.

By using bioluminescent organs, like we already said, photophores using the shrimps under bellies. The they emit a soft blue green glow, which we've talked about, that matches the faint light filtering down above, just like what was it? The the lantern fish? Yeah, I talked about,

Laura: Yeah, yeah,

Katy: um, so for a predator gazing upwards, that ambient light merges seamlessly with the shrimp's emitted light, rendering the shrimp pretty much invisible from from the[00:44:00] 

Laura: like, oh, it's just starlight filtering down through or like bioluminescent bacteria.

Katy: Yeah, yeah, and they have no idea. Um,

Laura: it's just shrimp running around. They're all, you know, this is kind of sad. Like it's all the predators at the bottom. They're just thinking they're seeing shooting stars all the time and they're making so

Katy: so beautiful. Yeah,

Laura: just wish I could eat.

Katy: it's just

Laura: And really it's food the whole time.

Katy: Yeah, yeah. I just wish I had, I just, I just wish I had a next meal to provide for my family, and it's right there in front of our face. It's right there. All their wishes could come true if they would just go

Laura: can tell that Katie and I are both are fans of predators more than prey. More families.

Katy: Oh, goodness. So, again, the light shrimp, it perfectly matches the natural light, uh, cloaking its outline and making it blend seamlessly. [00:45:00] By diffusing their glow to mirror the ocean's light, the shrimp essentially vanish into their environment. This basic Good?

Laura: I was just gonna, sorry, I, I'm just thinking to myself, okay, there are some animals out there where I can see why there would be no common name. Because nobody would know and not that many people would care. But we are talking about bioluminescent shrimp and I think that any animal that has put forth the effort to glow should have a common name, especially because it could be so cool.

So today, right now, these are called twinkler shrimp. Like for sure, twinkler shrimp.

Katy: Okay,

Laura: it not be called that? I don't know,

Katy: Twinkler Shrimp, yeah. I'm gonna I don't know how we get that, um, Officially recognized.

Laura: of our listeners, we're going to talk about them to each other and to everyone we know as twinkler

Katy: Twinkler Shrimp. Twinkler Shrimp.

Laura: It's not the perfect name for any kind of shrimp in general.

Katy: It is. Twinkler. Just a little twinkler shrimp. Um, so yeah, so counter [00:46:00] illumination is just one of the many ways organisms use bioluminescence for defense. Uh, consider there's another one known as the green bomber worm, which, which its scientific name

Laura: offense, but it's defense.

Katy: is defense. This is kind of, okay, so this, this scientific name is swimmer, swimmer bomb of Veritas, which Yeah, but swimma.

I'm like, of course. S W I M A. Um, swimma. Swimma. Uh,

Laura: talking about him. Fascinating.

Katy: Uh, native to deep, deep waters, this worm has developed a remarkable defensive mechanism. When disturbed, it releases small glowing sacs that emit bright green light. These glowing quote unquote bombs startle predators to which are momentarily distracted by the sudden flash Giving the worm time to escape.

So we talked about other examples

Laura: another flashbang, but this

Katy: Yeah

Laura: away.

Katy: Yeah. Yeah. The other [00:47:00] flashbang was flashbang. I'm gonna come eat you. This is flashbang now i'm running

Laura: This is, it is crazy. Can you imagine also, so we're talking about all these flashbangs, right? You got predators flashbanging prey and prey flashbanging predators. Meanwhile, you just have the Innocent bystanders of the deep ocean who are just minding their own business and constantly being blinded.

Katy: it's not like, a little, the

Laura: when you're in your bedroom at night and like traffic comes by and just pshhh

Katy: aw, someone got eaten again,

Laura: the neighbors are getting flash banged again or like you live in a bad neighborhood and there's constantly raids. Just. Damn, another flash bang. Somebody got eaten or somebody, somebody's dead.

I don't know who.[00:48:00] 

Katy: Such

Laura: about that? Like, six anemones over. Flashbang again! Like, just,

Katy: a

Laura: the bad side of the reef. Ha ha ha. Ha ha ha. Ha ha ha.

Katy: Sex anemones over.

Laura: I'm glad, glad I could be here for ya. Uhhh. Ha

Katy: My sides hurt. Oh, goodness. Oh,

Laura: I guess I just like the word flashbang, and like, I don't play Call of Duty that much, but whenever we would, we would just be chucking flashbangs everywhere. It wouldn't matter if they were effective or not, you'd just go, flashbang!

And yell it and throw. And so I'm just imagining, like, if I had that capability to just

Katy: In real life.

Laura: flashbang, flashbang! Like, [00:49:00] I'd just throw them around everywhere. And then yeah, all these little just bystander fish just like, Gah! Everyone's in a while. But it would be dead silent. Just dead

Katy: No, right?

Laura: too, right?

Just explosions happening around you, but in dead silence.

Katy: Yeah, because it's not like, okay, so you think of like, okay, if that were to happen on land, you would hear like leaves ruffle, you know, rustling away, there's, yeah, but there's just nothing,

Laura: Or right, or right. Like you think about like when a flashbang happens, it's also like a concussion sound. And you hear that like, you know, like in video games, it's like the sound, like the sound. Meanwhile, no, just in the crushing void. There is blasts of light happening, death all around,

Katy: the only fear is like but and so it's all in your head like all the panic is in your brain I

Laura: Just silence.

Katy: if

Laura: [00:50:00] The deep sea just got even more terrifying for me. I already didn't want to go down there, but this sounds a thousand times worse.

Katy: you were a tiny predator like a tiny prey fish, oh

Laura: shrimp are so much braver than I thought.

Katy: Yeah. Oh, goodness. So, uh, No, I can't, I can't, uh, Not that I'm, I was always like, I can't ever think of a green bomber worm in the same way. I've never thought about a

Laura: But they had a name at the very least.

Katy: Right? Oh, goodness. Uh, so there's anoth another organism. Um, it's a type of sea cucumber, which again, scientific name because it doesn't really have just a common name.

Uh, any finastus exum ex examia? Close, close enough. They use bioluminescence [00:51:00] as a warning signal. So when threatened, the sea cucumber emits a bright glow, uh, serving as an advertisement of basically saying like, I'm toxic. Um,

Laura: because everything else that I've seen so far glows to like, I'm food, right? Like this is a very backfiring glow, I think,

Katy: Back

Laura: right? Like, what makes their glow any different than the anglerfish who's like, please eat this glow? And this is like, don't.

Katy: Backfiring Oh Eheheheh That's what I was gonna

Laura: great band name, Backfiring

Katy: amazing Eheheheh Yeah, right Eheheheh

Laura: if anybody's ever seen a cute sea cucumber, you know, this thing already is like the most phallic shaped you could possibly imagine. And then it's just a pulsing glow, because it doesn't want to be eaten? Like,

Katy: Yeah Opposite effect, my man.

Laura: yeah. Oh, a delicious ocean pickle. And then it glows. If it were me, I'd be [00:52:00] like, no, I'm definitely

Katy: Oh, hey!

Laura: Glowing pickle? I can't think of anything more

Katy: Hehehehe

Laura: I'm gonna pee my pants.

Katy: I have actual tears! A glowing pickle! I can't think of anything that would be more fun! Hehehehe Hehehehe My eyes hurt so bad! Hehehehe

Laura: thousand times funnier too, knowing that you're the Vlasic white girl. So like, that literally would be our reaction. Would be

Katy: Which I have!

Laura: pickle? Just like, totally freaking

Katy: picture, the picture that Laura sent me, like, what was it, two years ago now, [00:53:00] whatever that episode was,

Laura: Yeah, or

Katy: uh,

Laura: three.

Katy: yeah, gosh, classic white girl, uh, which I, I have converted. I am a full, um, best made pickle girl now, where I'm, uh,

Laura: Pickle Girl.

Katy: that's our local pickle company.

Laura: gobble a glowing pickle.

Katy: Oh my god, yeah, yes. We have way more fun in the dark.

I mean it would be

Laura: Taking notes. He's taking notes. It's

Katy: Oh goodness.

My side hurts so bad. I'm laughing so hard. Oh, man. Well, it does have a 4th of a morning coloration. Um, similar to bright, the bright colors of toxic animals on land. So I think that's where it thinks it's going, anyway. If it's like,

Laura: like, I'll mimic toxic land animals. Am I on the [00:54:00] land? Nope, but it

Katy: No, I'm in the, I'm in the sea. Let's, let's figure out if this works. I mean, I guess evolution has to start somewhere.

Laura: it must

Katy: what I mean? And, and this is like where, where I see cucumbers going is like, I, I don't know what else to do. Let's give this a try. Everything else keeps eating me. Like, let's just, let's just go with this, right?

Oh, goodness. Um, let's see here. Uh, there's other fish, brown snout spook fish. They take bioluminescence defense a step further by employing false eyes. Uh, and, and this happens like throughout. Other species that you could actually see. But again, this is a deep sea, uh, fish that has bioluminescent spots near its rear tail that resembles eyes tricking predators into aiming basically for the wrong end.

And again, this happens with like butterflies and all kinds of things. Yeah, and so this just has to be false eyes that glow because it's under, you know, in deep ocean. You can't [00:55:00] see

Laura: Yeah, it doesn't know where the eyes are normally.

Katy: No, right? Yeah, right. Yeah, true. Yeah, I can't see anyway. Um, another remarkable example comes from the Stalartheus serenteus, which is a deep sea octopus with bioluminescent suckers on its arms.

Laura: that, that looks cool.

Katy: Yeah, so when faced with a threat, it flashes these glowing suckers, creating a blinding display that disorients the predators, again, with a flashbang. Just long enough for the octopus to make a hasty escape. Um, which, again, it's sort of like a flash dazzle, like

Laura: That's what I was just thinking. It's definitely more of like a razzle dazzle situation. Where it's just putting it's tentacles out and it's like, Ahhhh!

Katy: one I gotta draw.

Laura: Yeah. A little razzle dazzle to get away. Ha ha ha.

Katy: imagine it does that and it like scoots out of the picture, like out of the, out of frame.

Laura: has to be like a [00:56:00] side scooch. As it's, yeah, it's like, the predator comes over and it's like, Uh, uh, a little song and dance. De de de de de. Like, just to get out of the way. The predator's like, Alright, fair enough, that was pretty good. I'll

Katy: was pretty good. Yeah, A performance here. Just go ahead and shimmy away now. Um, lastly, another squid. The Hawaiian Bobtail Squid. Demonstrates,

Laura: And this is, our, uh, squid biologist studied

Katy: yep. Yep, yep. Um, so they demonstrate, and that was uh, What was it called?

Laura: Sarah McNulty.

Katy: episode something squiddy.

Laura: Oh yeah, yeah, yeah, something squiddy.

Katy: Anyway, yeah, if you go and you search squiddy and are wildly curious, it'll, yeah, it'll come, it'll come up.

Um, but they demonstrate a fascinating form of bioluminescence camouflage, um, Because it forms a symbiotic relationship with biolucent bacteria [00:57:00] that produce light to match basically the moonlit water above, and by eliminating the subtle glow, the squid again erases its silhouette, hiding from the predators below.

Um, so yeah, so that's all I have for, for, uh, I say that's all I had for defense, but man did that, that turned out, that took a, that took a different,

Laura: enough.

Katy: Yeah, that's a good term we weren't expecting. Oh, goodness. Well, everyone, please support us on Patreon, so we can keep bringing you pickle con glowing pickle content.

And, uh, and other and other magical content. Um, are we out of caves? Episodes,

Laura: So are we taking, are we taking a short break?

Katy: no we'll do a wrap up.

Laura: Okay, okay.

Katy: Hold on pause. Yeah, we'll talk about it But yeah, because we were supposed to do that one with with ally which all that stuff's good

Laura: That's right. That's right. We

Katy: Yeah, but she's good. She's good now. Um, which i'll take all this [00:58:00] out. She's good. Yeah, so that was a relief Um, so I can always reach out to her too and see if she wants to if she wants to do that one Because I just didn't want to bug her where all that stuff was going on Um, but yeah, if not, then we should probably do a wrap up for this season, too Maybe we can just hop on and do something dumb So anyway, so yeah, so go check us out on Patreon and support us there.

It really does help Laura and I to keep doing this, um, because there are fees and stuff with all this. And, um, so far, even though Laura and I are bringing in money for advertising, our whole

Laura: cents,

Katy: yeah, right? Yeah, yeah. Laura and I split in a 50 50. We both made 0. 88 so far, um, which is fantastic. I mean, it's better than nothing,

Laura: man. Yeah. We're living the dream, making money on what we're doing.

Katy: yeah, right? So anyway, so yeah, support us on Patreon, it's a huge help. And then you guys will hear from us next week with another episode.

Laura: Your, your guess is as good as ours.

Katy: Which makes it exciting! Which makes it exciting.

Laura: We live on the edge.

Katy: Alright, till next time guys. [00:59:00] Bye.