27: Sentry Dragonfly & Leafy Sea Dragon

Ellen: Hey. You.

Christian: Me?

Ellen: You're finally awake. This is Ellen Weatherford.

Christian: And Christian Weatherford.

Ellen: And this is Just the Zoo of Us, your favorite animal review podcast in which we take your favorite species of animals and we review them and rate them out of 10, and this week we're bringing you: dragons. Christian and I are not zoological experts, but we do a lot of research to get ready for the show and make sure that we are presenting you information from trustworthy resources. Really, really quick before we get started in the show, I don't normally put announcements at the top, but this is a big one: If you are listening to this and you live in Jacksonville, Florida, and you would like to hear us do this at your face in real life, in person, you can come see us do a live show at Cultivate on Saturday, November 30th. Tickets are available online, so come check us out.

Christian: Yes, it will be very good. I promise I don't have a radio face.

Ellen: Oh, so you are saying like, I promise I'm very attractive and handsome.

Christian: Of course! No, I wouldn't go that far, but...

Ellen: I promise I'm very pleasant to look at that. Anyway, so that was my little announcement section, so on to the dragons.

Christian: Alright babe, who's up first this week?

Ellen: Me. It's my turn.

Christian: Okay.

Ellen: This week I have the absolute pleasure of reviewing the sentry dragonfly, also known as the Australian Emerald dragonfly.

Christian: It sounds pretty.

Ellen: The scientific name is Hemicordulia australiae.

Christian: Excellent name.

Ellen: Yes. So this species was submitted to us by our new friend Benjamin Lancer. A while back, I praised Alyssa Años for submitting like, the best species request ever where it was just an email where like. The body of the email was just the word "quokka" and that was it, and I was like, that's the best request ever. This request was the best request ever and it was the exact polar opposite of that. So Benjamin reached out because Benjamin researches these dragonflies specifically, in a laboratory setting. Earlier I mentioned that we're not experts on these animals, but Benjamin is.

Christian: Yay!

Ellen: So all of the details that I'll be getting into are all from our buddy Benjamin.

Christian: Nice.

Ellen: Yes. So Benjamin Lancer is at the University of Adelaide's Visual Physiology and Neurobotics Laboratory, so I'm mostly going to be paraphrasing the treasure trove of information he sent- he was so kind to send to me. To introduce you to this dragonfly, this is going to be kind of an introduction not only to this dragonfly, but to dragonflies in general if you're not very familiar with them. This dragonfly is about five centimeters, or two inches long and has a wingspan of about seven centimeters, or just under three inches.

Christian: Okay.

Ellen: It's big for an insect, right? Bigger than most insects you find.

Christian: Sure, but probably about what one thinks of when you think of a dragonfly.

Ellen: Yeah. If you've never seen a dragonfly, what they look like is most of their length is made up of their very, very long, skinny body and that is all abdomen baby. Like it's all like, kind of what you would think of as their tail, and they have two pairs of wings. One of them is in front of the other and the one closest to the head is slightly larger. And when they are at rest, they hold those wings out horizontally. This is as opposed to the damselfly, which holds the wings vertically at rest. So this is one of the ways you can tell a dragonfly from a damselfly, is whether they hold their wings out to the side or upways. Now, this dragonfly in particular is located, as the name would imply, in Australia. It can also be found in the surrounding islands and New Zealand.

Christian: Okay, cool.

Ellen: So you're not going to find them where we live. We have dragonflies, but we don't have this dragonfly.

Christian: Okay.

Ellen: Dragonflies makeup the infraorder Anisoptera, of which there are about 3,000 recorded species. There's so many dragonflies.

Christian: Makes sense.

Ellen: There's a lot. So we have some in our backyard, but they are definitely not this one. In their genus there are about at least 13 known species, but the one I'm specifically talking about, their common names include the sentry dragonfly and the Australian emerald dragonfly. Let's get into their ratings. If this is your first time joining us, we divide our ratings into three categories, the first of which being effectiveness, which we define as the physical attributes of the animal that give it a sort of competitive edge over other animals that make it really good at doing the things that it's trying to do and accomplishing what it's going for. So just because they're called "dragonflies," dragon is in their name, does that necessarily mean that they are these legendary killing machines, menacing the skies and striking terror into the hearts of their utterly defenseless prey? Yes, it absolutely does. 10 out of 10. Dragonflies are believed to be some of the world's most successful predators, securing 95 to 97% of their attempted prey captures.

Christian: Oh okay.

Ellen: To put this into context, the highest vertebrate predator's success rate is 85% by African wild dogs.

Christian: Huh.

Ellen: Now, African lions, between 20 and 30%. Absolute garbage.

Christian: Yeah, I remember hearing about those.

Ellen: But so the dragonfly almost always catches what it's trying to catch. Almost every time. Very, very close to 100%, like pretty much as good as it gets as far as predators.

Christian: Can I take a stab at why?

Ellen: Best of luck.

Christian: Is it their aerial acrobatics?

Ellen: Sort of.

Christian: Okay.

Ellen: Sort of. Related to their aerial acrobatics, they are very powerful fliers. So as I mentioned a minute ago, they have four really powerful wings, but something that is unique about dragonflies and their wings is that they have the ability to control each wing individually, separately from each other.

Christian: So, not even like, the separate pairs but each one individually?

Ellen: Each individual of the four wings, they can move separately from the others.

Christian: Wow.

Ellen: So there's this sort of concept of what's called a stroke plane, which is the axis along which the wings are aligned. Dragonflies, like other insects, can rotate their wings to flap in different directions. But the dragonfly is able to change the angle of each of its four wings. So this is what allows it to pull off some of those really crazy aerodynamic moves. So they can hover, where they're just flying completely still in the air, they're just hanging there like they're frozen in the air, they can make sudden sharp turns and even 180 degree turns just on a dime.

Christian: Wow.

Ellen: Yeah. It's really crazy to see them do this, but it's because of how much control they have over their wings. So as a really cool little added perk of those wings, dragonfly wings are completely covered in microscopic spikes. They're called nanopillars, and the nanopillars shred bacteria to bits, preventing it from being able to survive on the surface of the wing.

Christian: Oh, okay. Oh, so it's like really, really small.

Ellen: Yes. It's really just for preventing bacteria from growing on the wings.

Christian: That's one way to do it.

Ellen: Isn't that cool?

Christian: Huh.

Ellen: Yeah. So as amazing as their wings are, the wings do have one weakness: Water.

Christian: Huh.

Ellen: So when the wings are wet, they are too heavy to flap and the dragonfly cannot take off. So this is not really ideal for a species that lays eggs in water, and therefore it needs to be hanging around water quite a bit. Yeah. So that was just, that's just their one sort of weakness, I suppose.

Christian: What parts of Australia are these things in? Is it like the whole continent or...

Ellen: It's more like near the coasts, like along riverbanks and stuff like that.

Christian: Oh yeah, I guess that makes sense, cause they need that to breed. Okay.

Ellen: So the next thing I want to talk about is their eyes. So dragonflies, when you look at them, most of their face is the eyes, right? The eyes are kind of like two hemispheres on the front of the head. So dragonflies have compound eyes that are very large. So relative to their body size, they're among the biggest eyes of all of the animals. Which, if you remember last week, I also said that about the vampire squid. So I don't know, I don't have access to the numbers needed to make those calculations. But if anybody does, if anybody out there can run the math to see which has bigger proportional eyes, the dragonfly or the vampire squid, please figure that out and hit me up. Please do the math for me. Thank you. So we've talked about compound eyes on the show before, way, way, way back when we talked about the praying mantis. But let's go over them one more time because that's been a really long time and our audio quality wasn't very good back then, so let's do it again.

Christian: Alright.

Ellen: So the compound eye is made up of very, very many little teeny tiny miniature... Kind of like eyes, and those little teeny tiny eyes are called ommatidia.

Christian: One more time.

Ellen: Ommatidia. O-M-M-A-T-I-D-I-A, and that is the plural of the word ommatidium.

Christian: Okay.

Ellen: So one of them is an ommatidium, many of them are ommatidia. And they all function together to make the visual image that the dragonfly is seeing. So a lot of people kind of assume that a compound eye made up of many, many eyes means that the insect can see very, very well. It's not necessarily true. So the ommatidia don't actually produce very detailed images. So the metaphor that Benjamin provided when talking about the compound eye is that of an image on a computer screen, where each ommatidium gives the dragonfly one pixel that together form a whole image, but it's in pretty bad resolution. It's like a pixelated, not very clear image. You're not going to get a lot of detail out of it. So the strength of the compound eye is in field of view rather than detail. So the dragonfly can see in nearly 360 degrees, eliminating their blind spot and making them very, very hard to sneak up on. So they can't see itty bitty details, but they can see everything. But with that being said, the real strength in the dragonfly's visual system is in its processing power, in the way that its visuals are connected to its brain and the way its brain processes that information. Which brings me to our next category: ingenuity, which we define as clever behavioral adaptations that an animal has that make it good at kinda outsmarting the obstacles in its way every day. For the Australian Emerald dragonfly. I'm giving it a 10 out of 10 for ingenuity.

Christian: Okay! That's surprising for an insect.

Ellen: Yes. It's very surprising for an insect. This is our friend Benjamin's area of expertise, and kind of the whole reason for requesting this dragonfly. This dragonfly has, at sort of a cursory glance, a very simple brain. It only has about a million neurons, which sounds like a lot, but to put it in perspective, a human has 86 billion neurons, so a human has 86,000 times more neurons than this dragonfly.

Christian: Alright.

Ellen: It seems like a very simple little brain, seems like not a lot going on. However, there's one neuron in particular that Benjamin studies in the dragonfly called the Centrifical Small Target Motion Detector 1, or CSTMD1, which he does by placing electrodes inside the brains on the individual neurons of the dragonfly.

Christian: Wow.

Ellen: I got stressed out just thinking about that game of Operation. And then after putting electrodes on the brain of the dragonfly, presenting the dragonfly with stimuli and then measuring the response of the dragonfly's brain to the stimuli. This neuron, CSTMD1, has the job of keeping track of moving targets by predicting where the target is going and focusing its visual processing attention there at the spot where the target is going.

Christian: Okay.

Ellen: The dragonfly doesn't chase their prey in the sense that other predators do by following behind the prey, catching up to it based on speed, and that's kinda it. Right? So instead, the dragonfly predicts where its prey is going, and flies there instead, and intercepts the prey as it travels along a path.

Christian: Does this imply their prey are usually also flying?

Ellen: Yes. They hunt other small insects like mosquitoes, flies, basically any- they could even hunt like smaller dragonflies. Basically any flying insect that's small enough for them to eat.

Christian: So that predictive capability is... Even for computing, is pretty complicated.

Ellen: It's extremely complicated and it's very surprising that they do that with such a small brain. But so yeah, they intercept the prey as it travels along a path. I mean, this is so complicated that this is something that even like, I can't do. Which you know, having played video games with me that require firing slow-moving projectiles at moving targets.

Christian: Which is why you play hitscan.

Ellen: I can't! But you know, if you've ever like, tried to throw a ball at a moving target or something, it's very, very hard to factor both your target's trajectory in your own and accurately hit something with a 97% accuracy rate! That's insane!

Christian: Well, what's also impressive, you know, when you're talking about a ball or something, you know, the target might be moving along a linear path at a set speed. So it's somewhat easier to predict, but with something like trying to chase down a mosquito, that mosquito could go in any direction at varying speeds. So that's just more, more impressive in my mind.

Ellen: Yeah, it's insanely cool. So now, whenever- I feel like whenever I see dragonflies, like zipping around in our backyard, I'm imagining the little floating math equations around their heads. Simple geometry. When we talk about focusing on a target, what the dragonfly is doing when it's focusing on a target, is it is amplifying visual responses from the target and suppressing responses from anything that is not the target. Does that make sense so far?

Christian: Yeah.

Ellen: So instead of amplifying everything, they're only amplifying what they're interested in. So you're not amplifying all of the sort of noise around it, ignoring the entire world outside of that target and pretending everything else in the world does not exist. This is called giving it absolute attention. Anything other than that mosquito that they're after might as well not exist. So this means that even if some unexpected stimulus, like say like something falls out of a tree or something moves in the water below them, something like that, they resist the distraction and stay perfectly on trajectory.

Christian: Nice.

Ellen: Even if that stimulus is more noticeable than their target of interest. Right? So say they're flying after a mosquito and then like, a fish jumps out of the water or something, that's way more noticeable than a mosquito flying around, but they're on target so they don't get distracted. So this is different from attention in, for example, vertebrates, which rather than absolute attention, is something called "weighted attention," which responds to stimulation from multiple sources by averaging out the intensity of the responses. In the case of weighted attention, even just the existence of other stimuli, regardless of their importance, impacts the amount of attention given to the task at hand. So imagine that there's like, a lot of people talking, you're in a crowded room, but you're trying to have a conversation with somebody in particular. Even though you're paying attention to that person and you're giving them, to the best of your ability, all of your attention, you can still kinda hear the people around you, right? It's still a little bit more difficult for you to focus on them cause there's just a lot going on, right?

Christian: Right.

Ellen: You're going to get distracted, there's just- even though you're focusing on them, the other things going on around you are factoring into the amount of attention you can pay to the conversation you're trying to have. The dragonfly is not like that at all. The dragonfly can just pretend the rest of the world doesn't exist.

Christian: Cool.

Ellen: So the ability of the dragonfly to entirely filter out all distractions allows them to focus completely on their prey and pull off all the crazy trajectory calculations that they need to do while they're zipping around in the air. So this is particularly useful for two reasons, the first of all being that dragonflies are most likely to be active and hunting in these very visually noisy areas. So there's lots of foliage, lots of vegetation, other wildlife around. So hunting insects in these kinds of settings is a little bit like playing where's Waldo, except everything is moving and Waldo is less than half an inch long, and also your vision is in 144p. It's very, very difficult to do. So having that ability to sort of laser focus is very important in this setting. So the second reason is that dragonflies largely hunt prey that groups together in swarms. So when there are hundreds of possible targets buzzing around, it's really easy to get confused and lose track of them, which is why the mosquito swarm in the first place. They do this on purpose. This is a tactic to confuse predators. But dragonflies are immune to the confusion response.

Christian: Wow.

Ellen: They cannot be confused. So what that means is that when the mosquitoes are swarming and there's a whole bunch of them in a small area, that makes it more difficult for them to evade because they're densely crowded, right? So since the sentry dragonfly doesn't get confused by those large numbers, what they're essentially doing is they're turning that swarming tactic against the mosquitoes and turning it into a weakness instead of a strength. Because now, instead of having the benefit of flying around and confusing your predators, now you've just crowded yourselves and made it more difficult for you to get away.

Christian: So it picks out a target. Does it just keep following that target or does it reassess like, "oh, wait a minute, there's an easier target in the swarm"?

Ellen: I don't think it really needs to do that. Like I don't think it needs to factor in easier targets, because once it's kind of locked on, it's probably going to get what it's after.

Christian: I guess if it's chasing a mosquito and it runs into another mosquito, you know that kind of thing.

Ellen: I'm sure it wouldn't turn it down. Free meal I guess.

Christian: Just like, "No, not this one. I want that one."

Ellen: I don't know. But that's a pretty funny idea, that like one literally flies directly into its mouth and it just spits it out on the ground. Like, that's not the one I wanted. So what you are probably thinking is that, well, what if the dragonfly is hyperfocused on a mosquito, it's chasing down a mosquito and what it doesn't notice is a bird swooping down to catch it, right? Like what if it's ignoring threats because of its sort of tunnel vision?

Christian: Right.

Ellen: Fret not for our dragonfly friend. The dragonfly is able to prioritize targets to focus on and switch between them, thanks to our new favorite neuron, CSTMD1. This essentially gives them kind of the best of both attention styles, providing them the distraction-free hyperfocus of absolute attention and the responsive flexibility of weighted attention. So yes, they can switch the things that they're focused on.

Christian: Okay.

Ellen: But the things that they are focused on, they are 100% focused on. Nothing else exists to them.

Christian: Yeah, I wouldn't describe it like that then, cause it- they are aware of everything else around it.

Ellen: So that's kind of the mystery of this neuron. That's why they're studying it.

Christian: Okay.

Ellen: Because nothing else that has this type of completely focused attention, nothing else is able to switch targets like a dragonfly. They don't know why. They don't know why it can do that. So that's why they're studying it, to figure out why it's able to switch targets like that. It's kind of a mystery.

Christian: I have a theory.

Ellen: Okay, let me hear it.

Christian: Two brains. One body.

Ellen: Okay...

Christian: That's it.

Ellen: Great job Christian.

Christian: I guess in my mind I'm imagining some sort of like, two creatures fused into one, one is concentrating on like a particular thing and then the other one's concentrating on everything else. It's like my... Two headed dragon! There it is.

Ellen: Perfect. Alright. Headcanon accepted. So Benjamin actually said that kind of the hope for their lab's research is to figure out how the dragonfly's very simple brain is able to pull off such insanely complicated and adaptive processes, and what they want to do is they want to apply those concepts to artificial intelligence.

Christian: Ah, okay.

Ellen: To do things like making self-driving cars safer, make them better at, you know, like sensing targets and making changes to their behavior based on what they're focused on.

Christian: Hmm. That's interesting.

Ellen: Yeah, I thought that was pretty cool. I thought you would like that.

Christian: Yeah. That's awesome.

Ellen: So all this is really cool, right? They can hyperfocus on things, they can switch what they're hyper focused on, it's all really awesome. But wait! There's more. There's even more cool stuff the dragonfly does. They have this really awesome hunting strategy. Besides the interception strategy, another really cool thing that they do is that they approach their prey from below, so they're staying within their prey' blind spot until they're close enough. So they know where their prey can't see them, and they come from that angle.

Christian: Okay.

Ellen: That's pretty smart, right? Because you have to understand your prey well enough to know where it cannot see you.

Christian: I wonder if dragonflies also have a weakness in that angle.

Ellen: They don't really have a blind spot, but they have another way that they sneak up on each other.

Christian: Ah, okay.

Ellen: So when male dragonflies fight each other, they can fight each other over territory or mates or something like that, and when that happens, you end up in a real predator vs. predator situation, right? Like you have like two unstoppable, perfect killing machines in a dog fight to the death, right?

Christian: Yeah.

Ellen: It's kind of two champions enter, one champion leaves. Usually they will actually end up not fighting. They will size each other up, dance around each other a little bit, do some cool moves in the air, kind of show off a little bit and be like, look, I'm so much stronger than you. And then one of them will chicken out and leave. So they will usually opt not to actually physically fight.

Christian: Okay.

Ellen: However, if neither of them back down and it comes down to it, they will escalate to violence and they will use their own weaknesses against each other. So, not having a blind spot, they sneak up on each other by using an illusion. It's called motion camouflage. What it means is that they fly on a path to intercept the target in such a way that from the target's perspective, their position doesn't change. It stays in the same spot over the target's retina. Does this make sense?

Christian: Oh, yeah... Yes.

Ellen: So it's not moving from like, left to right, or up or down...

Christian: Relative to its prey.

Ellen: Relative to its target that it's hunting down. It's not changing position.

Christian: Okay.

Ellen: So they don't appear to be moving to their target. So the target doesn't notice them, and ignores them until they're too close to escape.

Christian: Interesting.

Ellen: Yes. Is that not crazy? It's like they know, I'm hunting down another dragonfly. It has bad depth perception because I also have bad depth perception.

Christian: So the thing with that, not moving relative to each other, that would be observed from both of them, though. But I guess the one initiating the attack is already focused on the dragonfly and understands that's what's going on.

Ellen: Yes.

Christian: Okay.

Ellen: It's like, I'm attacking that dragonfly. I'm going for it.

Christian: To me, I know it doesn't look like it's moving, but I know what's going on cause I'm the one initiating this. The one initiating the attack is focused on it and the other one just doesn't know yet.

Ellen: Yeah. Hasn't noticed it.

Christian: Okay.

Ellen: So yeah, I thought that was just really, really cool.

Christian: Yeah.

Ellen: It knows the pitfalls of its own visual system, so it knows how to... It knows how to use that to its own advantage. So once the dragonfly has caught his rival, their combat strategy against each other is to grab the opponent's tail and just yeet him down into the water below. Cause they're usually fighting over water.

Christian: Yeah...

Ellen: So they just pile drive them down into the water below, which as I mentioned earlier, that can be a death sentence.

Christian: Sure.

Ellen: It can kill the other dragonfly because if they get down on the water, their wings get too wet and they can't take off. And if they're not able to like, climb out of the water or something so that their wings can dry off, then that's just it.

Christian: Something will probably eat them.

Ellen: A frog, a lizard, a fish, something like that will probably get them before they can get out of the water. The last thing that I wanted to talk about about their mating and their ingenuity in their mating is my favorite thing ever, that if a male dragonfly is attempting to court a female who is not interested, the female will suddenly drop to the ground, falling out of the sky, faking her own death...

Christian: Womp womp...

Ellen: To get out of a bad date. We've all been there, girlfriend. This is a relatable dragonfly who has just faked her own death to get out of date.

Christian: Yikes...

Ellen: Yup. So those are all the absolutely mind-blowingly cool stuff about dragonflies that I learned from our buddy Benjamin Lancer.

Christian: That's awesome.

Ellen: Yeah. It's just so surprisingly complex, all of the insane things that are going on in a dragonfly's brain, and he said that their brains are the size of a grain of rice, and they can pull off all of these insane like- motion prediction, they've got trajectory calculations, they've got stealth, they've got illusion, they just have so much. And they're even thinking about like, I know what kills me. I'm going to use it to kill the other one of me. Just, I can't, I can't, I can't. It blows my mind if I think about dragonflies too much. This brings me to my last category for the Australian emerald dragonfly: aesthetics. I give it an 8 out of 10. This is a pretty dragonfly. It has this long, black-and-yellow segmented abdomen. I think it looks like bamboo, maybe like aged bamboo, how it's got like a black and yellow coloration to it. So in maturity, their eyes turn from brown to bright green, which is where they get that name, Australian emerald. Like all dragonflies, the shape of their body and those four wings- and the wings look like glass, right? They're completely transparent. They have those veins all throughout them that make them look kind of like... I say stained glass, but they're just clear. They're not colorful or anything.

Christian: Yeah.

Ellen: I think it makes them look like a really cool futuristic spaceship.

Christian: Sure.

Ellen: And sometimes, when you see them flying, their wings are arranged in such a way that they kind of look like an X-wing.

Christian: Ha, yeah. I can see that.

Ellen: So yeah, that's my 8 out of 10 for their aesthetics.

Christian: Nice.

Ellen: I'm gonna wrap up with some miscellaneous information. Their conservation status is of least concern. They're fine. Benjamin really wants people to know that dragonflies cannot sting you or hurt you in literally anyway.

Christian: Oh good.

Ellen: There's nothing they can do to you. He says that they can bite, but it does not hurt, and it is very rare. They can bite you, but I mean, there's nothing to it. He said that he works with them every single day and has been bitten like once or twice. So it's really not a thing that they do. It's not something that they use for self-defense. So they have these two appendages at the end of their abdomen, they look like a pincer, so they look like something that would be able to pinch you or something, but it's actually just a little grabby bits and all they use it for is to hold on to each other when they mate. So it's not anything that they could use against you in any way. They're totally fine. Leave them alone. Like they're not going to hurt you in any way at all.

Christian: Cool.

Ellen: You actually want dragonflies around. Like they're awesome to have around. I love having them, because they eat all the mosquitoes in our backyard.

Christian: Yay!

Ellen: We have blue dashers, we don't have this type of dragonfly. So another thing that Benjamin wanted to kind of reiterate is that this neuron that he studies has only been recorded in this species of dragonfly and another one that's closely related to it that's in the same genus, but it's likely that they exist in many other types of dragonflies, they just haven't been recorded yet.

Christian: Nice.

Ellen: Yeah. So that's why I wanted to specify that that was the species I was talking about in this episode, because this information is particularly- I can only like confirm that it's this species has this, others probably do, this is just the information that is available to me at this time.

Christian: Cool.

Ellen: Yeah. So in summary, they are the perfect hunter and it is by nothing short of the merciful hand of mother nature that made them too small to eat humans that we survive to this day. Because if they were big enough to eat us, they would, and we probably never would have made it past like an early primate stage.

Christian: Well, you can thank the oxygen content of our atmosphere is that is the main limiting factor in the size of bugs and insects.

Ellen: I did see that there was this ancient prehistoric species of dragonfly that had a two foot wingspan.

Christian: Yikes.

Ellen: It's pretty big. It's still not big enough to eat a human, so I think we would still be okay.

Christian: I mean, I still- you probably would want to avoid the bite of that even more so.

Christian: Yeah... Although I don't know. I don't know if they would have had like, anything that they could bite us with. Well anyway, I'm glad they don't exist!

Christian: Yeah.

Ellen: So that's all the, that's all the information I had on the Australian Emerald dragonfly.

Christian: Very good. Thank you.

Ellen: I have one thing before we move on.

Christian: Okay.

Ellen: It's a special treat. Do you remember last week when you wrote a poem about the botfly?

Christian: Yeah.

Ellen: So you did that, and it got a bunch of people riled up who rioted in the streets and demanded that I write a poem. I wrote a poem about the Australian emerald dragonfly.

Christian: Oh boy. Let's hear it.

Ellen: So here's my poem:

For their name to glorify,
Without a doubt they qualify.
Midges and mosquitos try
Escaping peril in the sky,
But though they flee and try to hide,
Their swarming tactics won’t divide
The focus of the steely-eyed
Australian emerald dragonfly.

Christian: Oh, that's so nice. I like it.

Ellen: That's my poem!

Christian: Well done honey.

Ellen: Thank you. What you got now, Christian? Step up your game.

Christian: Well, I'll put this out there now: I did not prepare a poem.

Ellen: Before we move on to Christian's animal, I would like to thank our patrons for this week: Briana Feinberg, Krystina Sanders, the Jungle Gym Queen, and Jacob Jones.

Christian: Oh, thanks y'all.

Ellen: Thank you guys.

Ellen: Now what you got Christian?

Christian: The species that I'm bringing to this episode is the leafy sea dragon.

Ellen: We did the sky dragon. This is the sea dragon.

Christian: Yes. Scientific name: Phycodurus eques. I'm assuming that's how that's pronounced, based on the word equestrian.

Ellen: You got it.

Christian: And this species was submitted by Dalton Weeks.

Ellen: Thanks Dalton!

Christian: And I'll be getting my information from Marinebio.org, Monterey- I typed in Monterey May Aquarium, but I know it to be MontereyBayAquarium.org, and nationalgeographic.com I have a fourth source, but I will mention that when I get to its content-specific piece.

Ellen: A secret surprise?

Christian: Yes.

Ellen: It's a surprise tool that'll help us later.

Christian: So first of all, these things have a nickname. They are called leafies.

Ellen: Oh! A leafy!

Christian: Yes.

Ellen: I love them.

Christian: And they get to be about 35 centimeters long, or 14 inches, thereabouts. And you can find these off the Southern coastline of Australia.

Ellen: This is a sub theme.

Christian: Yeah. So a-

Ellen: Primary theme theme, dragons, secondary theme, Australia.

Christian: So you mentioned Adelaide, I believe that is located in the Southern part of Australia, so it's even more themed. They belong to the taxonomic family Syngnathidae.

Ellen: Nailed it.

Christian: And the notable evolutionary relatives there are pipefish and sea horses.

Ellen: And the weedy sea dragon, right?

Christian: Yes. A lot of people will probably note they do look somewhat similar to sea horses, so that is their relation, but they are not the same thing. And to describe what these guys look like, so they are called the leafy sea dragon because they have appendages that look almost exactly like seaweed, and the color kind of ranges around the browns, yellows, olive-colored. That brings me to my first point of effectiveness, on which I'm giving an 8 out of 10.

Ellen: That's pretty good!

Christian: Yes. And the main thing there is camouflage.

Ellen: Yeah, that'll do it. That'll keep you alive.

Christian: Yep. That's its main thing. It's meant to blend in with the seaweed. Very well, I might add. So you'll see these things, the best way I can describe them is imagine a sea horse, but with leafy appendages.

Ellen: So the sea horse is like the day time, going to work office attire, and then at night when the seahorse goes out to the club, then you get the leafy sea dragon.

Christian: Sure.

Ellen: Leafy sea dragons are just drag sea horses. There, I said it.

Christian: Oh, that's what you're getting at. Okay, thank you. And real quick, what they eat: so they have these pipe-like snouts, and they use those to suck up small animals like plankton, mysids, and other small crustaceans. But that's, that's another trait that they share with seahorses is that little pipe snout.

Ellen: It's like a little straw that they're sucking stuff through?

Christian: Yep.

Ellen: Oh, okay. I guess they're not chewing things, then. Right?

Christian: I think they're just swallowing them whole.

Ellen: Aww, it's a little sea Roomba.

Christian: And I also wanted to mention that those little leafy appendages, they are not used for locomotion at all. They're just there for looks, for camouflage. And they also have little spots in them like, like the kind of spots you would actually see in seaweed. I just think that's really neat how closely they resemble it.

Ellen: That is cool.

Christian: Yeah.

Ellen: That's like when you talked about the Gaboon viper, and you mentioned how their head has a marking that is supposed to mimic the vein in a leaf.

Christian: Yeah.

Ellen: It's really cool when you look into animals that mimic foliage, it's insane how spot on they can get.

Christian: For sure. Also I should mention, the seadragon is a fish

Ellen: I guess... Okay. So logically I understand that, yes, that makes sense, but I guess I never thought of them or... Are seahorses fish? I don't know why this is surprising to me. It shouldn't be, right?

Christian: Well, it's peculiar because of their skeletal structure.

Ellen: Their shape. They're not shaped like fish.

Christian: Right. They're very unique.

Ellen: Yeah. It's really weird because now that I think of it, they're not shaped like fish, but they're not quite shaped like anything else.

Christian: Yeah. Yeah. So one thing that might help you better associate them with fish is how they do get around, or what their method of locomotion is. They have two small fins, one is along its back and the other one is further down its tail, and they undulate. Maybe like an eel.

Ellen: Okay. Okay. So it ripples sort of?

Christian: Yes. And these are small, these are small little fins. And they're almost transparent, so you have to look really close to see them. That's primarily what they use for locomotion.

Ellen: Wow. I never knew that they had a little fin I didn't know about!

Christian: Yep.

Ellen: They've got a secret fin that they didn't tell me they had.

Christian: Now because of this, they cannot move particularly quickly and they're very prone to being moved by strong currents.

Ellen: Oh no, bye!

Christian: Think I have a propensity to be washed up on the shore with storms.

Ellen: Oh my gosh.

Christian: Yes.

Ellen: I've never heard of that.

Christian: And my next one is their reproduction. So I think a lot of people have heard how with sea horses, the male carries the young.

Ellen: Best dad. Yep.

Christian: Yes. So one of- this is where one of the big differences are between seahorses and sea dragons. So seahorses, when the eggs are transferred to the male, they're in an internal pouch on the male, in their abdomen. Right?

Ellen: Sure. Yeah.

Christian: And then when they give birth, they just kind of come out of that pouch.

Ellen: Yeah.

Christian: With sea dragons, they do not have that pouch. They instead have what's called a brood patch.

Ellen: Brood patch?

Christian: Yes.

Ellen: Okay. I've heard of a brood pouch, but I haven't heard of a brood patch.

Christian: So it's an interesting thing. It's a little spot on the underside of the males' tails that, when when they're ready to reproduce, this area starts to look wrinkled. And so what happens is when they reproduce, the female will release the eggs and then those eggs will fit into little pockets on that brood pouch.

Ellen: Okay.

Christian: And then they get stuck there. The eggs are basically sitting on the outside of the male's body. And in this little brood pouch are blood vessels that supply oxygen to the eggs.

Ellen: Wow.

Christian: Yeah.

Ellen: Huh. That's crazy.

Christian: Yep.

Ellen: And does he like, carry them around until they hatch or?

Christian: Yes. So in this transfer from the female to male, this is also where the eggs are being fertilized. So the eggs are fertilized, they're attached to the underside of the male, and then four to six weeks later, they hatch.

Ellen: Do all of the members of this family have that sort of mechanic where the female transfers the eggs to the male and the male kind of takes it from there? Cause I know the seahorses do this, I did not know that the sea dragons did it as well.

Christian: Yeah. So I know the leafy sea dragon does this as well as the weedy sea dragon.

Ellen: Okay. That's really interesting cause I think I knew that they were related, but I didn't know that they also had a similar- but that's crazy that they have a similar behavior but it's different mechanically in the way that it works.

Christian: Right.

Ellen: That's really... Crazy, that it's similar but also so different.

Christian: And also I should mention when they do these eggs, the females transfer about 100 to 250 eggs.

Ellen: That's so many.

Christian: And they're pink!

Ellen: Ohh! I thought they couldn't get cuter!

Christian: Yeah. So four to six weeks later, the eggs hatch and the babies are on their own. For the first two or three days, they are supplied nutrients from yolk sacs that they got from the egg, similar to how other animals that are hatched. So eventually those nutrients run out and they have to start basically hunting for very, very small things that can get in their teeny-tiny pipe snoots.

Ellen: So like the, the adult sea dragon is swimming around with essentially like a smoothie straw, right? Big, big thick noodle that they're sucking stuff up through. And then here comes a little baby sea dragon with a little coffee stirrer straw. Just barely sucking up nothing. But you know what? That is a lot like the vampire squid that we talked about last week, how it just kind of sets the little eggs off and then it's like, well best of luck and it's got to live off of its egg yolk until it can survive.

Christian: Yeah. So that being said, not very many survive, but that's kind of the purpose of having that many eggs to try and beat the numbers game. Next point where I consider a deduction for their effectiveness is I'm going to say- I'm going to title it, "No Plan B."

Ellen: Okay.

Christian: Meaning if the camouflage fails, they don't really have anything else. They don't have a defense mechanism or a good way to escape outside of trying to hide again.

Ellen: They literally don't even have teeth.

Christian: No, nothing.

Ellen: Aw, poor babies.

Christian: We don't know of any particular species that like to eat these, but, I mean we know things can eat them.

Ellen: With how skinny and ornamental they are, they don't seem like they would be nutritionally dense. They don't seem like they would be a great meal.

Christian: Yeah. I think I read somewhere that even anemones are known to eat these.

Ellen: Really?

Christian: Yeah.

Ellen: How do they do that? How do they catch them?

Christian: I didn't look into it. I just saw them mentioned.

Ellen: Is it the case that like, not a lot of things eat the leafy sea dragons?

Christian: Well it's just, it's not known that like they're a preferred thing for any particular species.

Ellen: Okay. You know what is funny to me? The idea that like, even fish hate salads. Even fish look at a floating bundle of lettuce and they're like, "Mmm. I think not."

Christian: And then my final point is they're pretty fragile. So in addition to only having camouflage and then not being very mobile, they're pretty fragile in terms of could be damaged fairly easily. Divers are actually told not to try to handle them when you're in the same spaces as them.

Ellen: That kind of goes for any animal that you encounter while you're diving. Right? You're not supposed to touch 'em.

Christian: Yeah, but especially with these, because it could...

Ellen: They'll die.

Christian: It could hurt them. So yeah, that's my 8 out of 10 for effectiveness. That camouflage is really the biggest point there because once you see these things, you could see how even for a person you would have a hard time spotting these in the kelp environments and that kind of thing.

Ellen: Yeah. Very, very, very well specialized for that.

Christian: Yep. Ingenuity, I'm gonna do a 6 out of 10. I only had one point for ingenuity, and that's the fact that not only do they look like seaweed, but they also mimic the movement of the seaweed around them.

Ellen: Oh really?

Christian: Yes. So they try to match the swaying of the seaweed around them.

Ellen: Oh my gosh!

Christian: Yes.

Ellen: A third sub theme: motion camouflage.

Christian: Yup.

Ellen: Look at all of these common threads between the dragons!

Christian: And then final one, aesthetics. I'm giving a full 10 out of 10. I'm very impressed with the way they look.

Ellen: They're beautiful.

Christian: Yeah, they're very exotic and elegant and cute and they have very cool colors. I saw a little tidbit, I don't know how verifiable this is, but they seem to enjoy having their picture taken.

Ellen: I can vouch for this, because I have some really good pictures of the leafy sea dragons at the Florida Aquarium.

Christian: Yes!

Ellen: And they are like, posed perfectly. They're like, they're like, aligning perfectly with the background. So you get like a solid background. They have like, tilted and angled themselves in just the perfect way or it makes it very nicely framed picture. So I can personally confirm that, yes. This goes back to, this is a drag sea horse. This is a drag sea horse. It is a model and it is here for the look.

Christian: Excellent. So, time to get into some little miscellaneous information: conservation status is near threatened.

Ellen: Oh no!

Christian: So, a lot of that has to do with their popularity in the private pet trade.

Ellen: Bad.

Christian: So much so that their numbers were so badly affected in the 90s that Australia, uh, Southern Australia have put laws on the books to protect them. So they're very strict. You have to go through a lot of hoops to legally catch them out of the wild. And it's usually a solid, no.

Ellen: Probably not. Probably leave them alone.

Christian: And then, yeah, it's very regulated and usually they're only caught for educational and research purposes. The Monterey Bay Aquarium is one that has them as well as the Florida Aquarium, as you mentioned.

Ellen: Yeah, we love them.

Christian: Yeah. They've also been threatened by pollution, like fertilizer runoff and habitat loss, of course. So that's kind of a recurring theme.

Ellen: Yeah. That's something we get into with pretty much every ocean-dwelling animal.

Christian: Yeah. I want to talk a little bit more about what else distinguishes them from seahorses. So we've already talked about how their reproduction is a little bit different, and the other thing is sea horses can curl their tails and use them to grab onto things. Sea dragons cannot.

Ellen: Yeah, their whole body isn't really made for a whole lot of flexibility.

Christian: Right.

Ellen: Yeah. They're very highly ornamented, and that doesn't really give them a lot of wiggle room to be very flexible.

Christian: Yeah. They went in all in on the camouflage bit.

Ellen: They specked highly into stealth and little into dex. They min-maxed.

Christian: Yeah. And then last little final piece I want to talk about is, I got some information from a 2006 animated short that was created to educate school children and it was made on behalf of several South Australian organizations and it is titled "The Amazing Adventures of Gavin, a Leafy Sea Dragon.

Ellen: Gavin! I love you, Gavin!

Christian: It's this cute little cartoon, it's like 10, 15 minutes long. We follow Gavin, a leafy sea dragon on his journey along the Southern coast of Australia, and he meets other animals like a great white shark, a sea lion, nudibranchs.

Ellen: Oh, I love you Gavin! I love this. We'll have to drop a link to this video on our social media

Christian: Yes, you can find it on YouTube. The leafy sea dragon is the official marine emblem of the state of South Australia.

Ellen: Wow!

Christian: Yes.

Ellen: Excellent choice. So I have this really cool picture of one of the leafy sea dragons in the Florida Aquarium, and I was going through my pictures recently and I came across this picture again. I was like, yes. Awesome. And then I noticed something really weird that I hadn't noticed when I took the picture, that the sea dragon had these two little... Looked like plastic rings around its body. And I was like, "that's weird. What is that?" And so I did a little Googling and I found that these leafy sea dragons had some sort of injury that made them not float so good and they couldn't stay upright and they couldn't like swim correctly. They kept falling over to the sides. So the very, very nice people at the Florida Aquarium made them prosthetic floaties, made them little floaties that they put on the sea dragons to keep them upright and let them keep swimming around.

Christian: How cute.

Ellen: I didn't know that that was what it was, and I took a picture and it's so cute, and they're just good boys that just want to float around! And now they have floaties, Christian, they have floaties! It's so good!

Christian: How nice.

Ellen: Yeah. Top, top notch animal.

Christian: So that's the leafy sea dragon.

Ellen: Excellent. Nicely done.

Christian: Thank you.

Ellen: This was a couple of very good dragons.

Christian: Yes.

Ellen: That brings us to a close. Thank you so much to everybody who has spent this time with us. It means a lot to us that you checked us out, and thank you for recommending us to everybody that you know and annoying everybody with telling them to check out this really cool animal review podcast that you listen to. So thank you for doing that. If you want to hang out with us in the virtual space, you can connect with us on Twitter, Instagram, and Facebook. Just search the title of the show. You'll get there, I promise. We have a really cool group, so get in there. Oh, we did a giveaway, uh, that was going on over the course of the last week and the winner was Abigail Cornett!

Christian: Awesome!

Ellen: Thank you, Abigail. If you have an animal species you want to hear us review, you could submit those to us either on social media or at my email address, which is ellen@justthezooofus.com. A transcript of this episode and all of the rest of them is on www.justthezooofus.com, wrapping up, thank you, Louie Zong for the use of your song "Adventuring" off of your album Bee Sides.

Christian: Yes. Thank you so much.

Ellen: Maybe they should call it Dragon Sides.

Christian: Instead of bees?

Ellen: Yes.

Christian: Ah.

Ellen: I don't- It sounded good in my head. I don't know. Once it came out of my mouth, I knew it didn't. This kills the joke.

Christian: Thanks everyone!

Ellen: Bye!