Embedded - 530: A Living Highlighter

Episode Date: July 25, 2026

Marine biologist Dr. Steven Haddock joins the show to share the alien, glowing, and transparent wonders of the deep ocean. We discuss his beautiful new book, The Radiant Sea, and explore the complex engineering and high-sensitivity optics required to capture living deep-sea creatures. Steve walks us through the evolutionary logic of biological light, how vantablack organisms trap photons in the dark, the horizontal sun-compass navigation of jellyfish blooms, and what it's like to play games underwater with giant Pacific octopuses and jumbo squids. Dr. Steven Haddock is a Senior Scientist at the Monterey Bay Aquarium Research Institute (MBARI) and an adjunct professor at UC Santa Cruz. Some related MBARI Videos Bioluminescence in the deep sea: How and why do animals create their own light? Steven Haddock explains the diverse and striking functions of light emission in the ocean's twilight zone. (So many pretty pictures!)  Mysteries of the Deep with Dr. Steve Haddock — Bioluminescence! Long-form lecture on the physics and evolutionary biology of bioluminescence. Live Blackwater Diving Q&A with MBARI and Aquarium Scientists! | Into The Deep Q&A with scientists about diving in the middle of the ocean at night. Rarely Encountered Seven-Arm Octopus in Monterey Bay: Footage captured by Steve Haddock and MBARI's Biooptics team shows an octopus with a jelly snack. Discussion Resources & Links Steve's Books: The Radiant Sea: Color and Light in the Underwater World  by Steven Haddock and Sönke Johnsen Practical Computing for Biologists by Steven Haddock and Casey Dunn Scientific & Marine Mentions: Steven Haddock's Wikipedia Page Steven's MBARI home page. His lab is the Biodiversity and Biooptics Lab Electric Disco Clams Exist—Watch Them Light Up This Coral Reef | National Geographic  Why is she like this? Disco Snails (Official Video) - Music More neat creature videos Jelly-like Siphonophores Astound with Breathtaking Beauty: A close-up collection of the incredibly complex, colonial siphonophores that Steve mentioned, showing off their bizarre structures and flowing shapes in the pitch black. How the Disco Clam Uses Light to Fight Super-Strong Predators: See the "electric" flashing effects inside the disco clam's mantle up close, alongside an explanation of how their silica spheres scatter ambient light to startle predators. Absurd Creatures: Comb Jellies Are Ready to Rave – A fun, fast-paced video exploring the "Skittles" rainbow iridescence caused by the moving rows of cilia on ctenophores under white submersible lights. Transcript

Welcome to Embedded. I am Elysio White alongside Christopher White. Well, let's see. I have finally achieved my dream of conning a jellyfish scientist to come onto the show and talk to me about the innovations and technology needed to study jellyfish. But you know we're just going to talk about jellyfish. And eel pout. Do you know eel pout are a thing? Disco clamps. It's going to be so exciting. We're going to talk to Steve. Welcome, Steve. I don't know that you know what you've gotten yourself into. I know. I didn't agree to this. What's going on here? Could you tell us about yourself as if we met at the lunch table at Embari? I am, I guess, in short, a marine biologist, and I really like gelatinous organisms. So actually, the other things that are not technically jellyfish, but other things like comb jellies. ziphonophores, and all the kind of alien-looking creatures of the deep ocean, especially, and the open ocean. So I study their genetics and how they make biluminescence. And you recently wrote a book? Yes, we recently, with my co-author Sanka Johnson, we created a like a coffee table book that is called The Radiant Sea,

which it's basically trying to trick people into learning some science by showing them pretty pictures and then having captions next to them that describe what's going on in the picture. It is so effective. I read half the captions to Christopher. That's funny. I wonder which ones. We want to do lightning round, so we get to know you a little bit better. Okay.

And this means we'll ask you pretty. fast questions and want short answers. This lightning round is going to be focused on which of these things is the best. Are you ready? Ready. Disco snails

or disco clams? Disco clams. Or fish or mola mola. Oh no. Don't make me choose. I'm going to have to go mola mola. West Dorm or Case Dorm?

Case dorm. photosynthesis in giant clams or in jellyfish? Oh, boy. Jellyfish. It's a hard question, isn't it? Yes, these are all. Excuse me, I have not read this one. Nitrogen fixing organelles in marine bioloi.

Bigelowy. Right, right. Sorry, I tried to read that as biology. Nitrogen fixing organelles in marine bigelowy are using the GFP as a visual marker of medical gene therapy. GFP, 100%. reading neat factoids from a book to your spouse or being the spouse who receives the facts. I'm afraid I'm the one who's reading them, but I would enjoy being the one who receives them. Me too. Me too.

That sounded like some sort of accusation. Take a note, Chris. Octopus or whale? Octopus. Eopout or giraffe? Eopout. Bioluminescence or transparency or chromatophores in animals. Bioluminescence.

All right. Favorite fictional robot. Favorite fictional robot. I'm a Star Wars guy, so, I mean, B-B-8, I think, is pretty amazing. But K2SO from Rogue 1, I think, is probably the funniest. And IG-88 is pretty amazing. But, yeah, I guess if I have to choose one, BBA, it is kind of a classic for its uniqueness. All right.

Do you have a tip everyone should know? Oh, I have a lot of tips. Use floating time zones in your calendar when you make an appointment so you don't show up to the airport 12 hours early. Learn. Yes, there is a story behind that. Learn how do you tie a slippery sheet bend or slippery bowlin as opposed to a regular bowline? It's pronounced bolin, not bolein? Bolin, yeah.

It's very maritime, bosun, bowlin. In a terminal window, if you open and then a period, it'll pop open that window in your Mac GUI. To look at previous commands? No, no, no. Just open a window in your GUI, in your browser that corresponds to the terminal window that you're in. You'll open the folder that you're working in. Anyway.

And also waffles with making waffles with soda water. Make some really fluffy and crispy. Like tempura. These are all good tips. I feel like we could just do a tip show. I love tips. Okay, let's talk about your book because I have been very excited about it. And because this is audio only, I'm going to need to describe all the photos in the book.

Okay. A word is worth a thousand pictures. I mean, I guess, are you going to ask another question? I'm going to answer that one now. Describe all the photos in the book. I mean, one thing about the photos in the book is that there are no CGI. They're all living animals, so they're in good shape. And that alone, I think, makes them unique in kind of the domain of books about the deep sea.

Because if you've ever seen a live deep sea organism, you immediately recognize that most of the pictures in the books are dead specimens. Their eyes have turned milky white, their jaws torn halfway off. Their skin is peeled away. They look basically like roadkill. And I always think of it like if you had a book about like the wildlife of Africa and it was a zebra that had been hit by a land rover and, you know, like tire tracks across its back. That's what a lot of the depictions of deep sea animals are like. And so this book is kind of an antidote to that. I mean, because jellyfish are kind of hard to get to the surface intact.

Absolutely, yeah. They don't really come up in the nets so well? Net, that's all very true. And so most of the people that I know, practically all the people I know who study jellyfish are also photographers because you don't have the luxury of just like throwing it in a jar and I'll look at it. it later when I get back to the museum. They're basically live. If you get them up with a submarine, which is what we do, or for the scuba diving,

they're alive for a short window of time, unfortunately. And so you document them and what they look like and what their internal structures are by taking photographs of them. And your book has many jellyfish photographs, but it's also got larval eels. and octopus and all kinds of, yeah, the squid. Yeah, the squid. And unlike my other jellyfish books and octopus books, yes, those are all plural folks, this one is organized differently.

It's not organized by animal or, you know, these are the jellyfish, these are the comb jellies, and they're not really the same animal. it's organized around their function? Kind of around how they play with light. We divided it because both of us study light. Sanka works a lot on structural colors, like black pigmentation, transparency, and I work a lot on biluminoussense and fluorescence.

But so we organized the book around optical properties of animals and kind of optical, the way they hack their optical environment, essentially. So we have transparency, we have pigmentation, we have iridescence, which is structural colors, and then we have bioluminescence and fluorescence. And what's kind of funny is that some animals appear in like practically every chapter. They have examples of interesting transparency, and parts of them are pigmented, and they're also bioluminescence. So there's a few featured creatures that show up in each section.

What started your interest in bioluminescence? I mean, I think kind of everybody who experiences it is somewhat fascinated by it to some extent. And I was just lucky. So I went to Harvey Mudd. I feel like we should do our secret handshake. M-I-C-E-Y. No, it's not M-I-C-Y, that's Mickey. Oh, wait, no.

Right, H-A-R-V-E-Y. Do you hear the sound of secret handshake taking place? Being messed up. But I had a biology professor there who was a really influential person, and he basically recognized that I was the annoying student who was always asking questions in class. So he encouraged me to go to grad school. with some of his former colleagues at UC Santa Barbara. And the team there, I worked with a professor case who studied bioluminescence,

another guy studied deep sea, another woman Alice Aldridge studied open ocean ecosystems through scuba diving. So I just got really immersed in it from the get-go. And, you know, there's so many unanswered questions about bioluminescence. that is just a really fruitful field to be able to explore. Like, why can't we make lights more like jellyfish and squid do? Why do we have to be so inefficient with our electricity? Yeah. Well, actually, LEDs, like people often email me.

They're like, oh, yeah, we want to make a bioluminescent street light or lamps around the house that are organisms. and it is actually way, way more efficient to use an LED because if you use an organism, you basically have to keep it alive and happy and growing and well-fed and in a controlled environment. And so just the energy to do that, I think is more than the energy of the light that you would get out. But having said that, for the animals themselves,

it's incredibly efficient. So, you know, imagine something, a millimeter long communicating to something that is maybe, I don't know, 2,000 times larger than it, and at a distance of like a kilometer, proportionally to its body size, it's really light is the only way that you can send a signal like that if you're something small living in the dark ocean. So it's a really efficient process.

Wouldn't, I mean, sound transmits so much better in the ocean? Sound transmits further. It's not directional. It's not traceable to a discrete point. And it's also really hard to generate sound. So the things that do it, if you're a squishy jellyfish, you don't really have a structure that is going to allow you to make sound. So you need either a gas-filled float or hard surfaces like snapping shrimp.

It actually caused cavitation with the claws, but, you know, rubbing your legs together like a grasshopper or something like that or a whale. So most invertebrates don't have anything that can produce those sound waves. And so they chose light. Yeah. Or light shows them and many, many times through evolution, at least probably a hundred times. It's so improbable. And light also requires eyes, which also, even Darwin said, well, that's kind of the weakness in my theory here. Eyes are just so improbable.

Yeah. The better question is, why don't we produce light? Yeah, I know. We think we're so special and that these are primitive organisms like jellyfish. And yet, you know, birds and all of these glorious creatures of the land cannot do something so simple that, a jellyfish and thousands of other ocean creatures can do it. But yeah, and I've kind of shifted my thoughts about the evolution because, like you said, the eyes have to come first for it to really function well.

And people think, well, jellyfish are biluminescent, therefore it must be this primitive thing. But actually, it must have evolved after all the visual predators evolved and all these visual interactions happened in the ocean. So it's really interesting to think about how potentially recent and widespread the evolution is, at least in the ocean. You've been doing this for a couple of decades. Yeah. More than two, less than ten. Correct.

Thank you for your discretion. How has the technology to study jellyfish changed over that time? And we have ROVs now and they just wander around. People watch them for amusement value. Yeah, no, it's changed immensely in that time. I think between even when I started and now, you know, let alone a century ago when people were studying bioluminescence in the early days. But probably the two biggest revolutions are the imaging,

which is just driven by, you know, the thirst for consumer electronics. But when I started, we had these intensified cameras that they were 640 by 480. They had like the photons would hit a phosphor and cause an electron cascade. So they were incredibly noisy. So you would get these grainy black and white images, low-res images of bioluminescence. And that was the only way we could document it. And now we have cameras that we actually take down in our cell. on our ROVs, and they have 4K full-color low-light capability that is not quite as good as the human eye,

but it's getting there. And it allows you to capture things that previously you could only see with your naked eye. So that's the one. And the other is really the genomics revolution. With the cameras and the bioluminescence, you said low light, but are you still showing? want to flash to them or how are you actually seeing the creatures? So when we take our low light camera down there, we crank up the ISO. We crank up the sensitivity to like 80,000, maybe 60,000 ISO.

We turn. 80,000, 60,000 ISO? Yeah, like you're... Like, I can buy 400 ISO film at like fast. I mean, DSLRs go quite high now too. Okay. Yeah, yeah. So DSL probably go to like 12,000 and start to get noisy and maybe 25.

But these 4K cameras can, and it can't even have one that I think goes to 500,000, but it's only HD. So there's a Sony camera that goes 4K, and we shoot at about 80,000. We turn all the lights off on the ROV, except we have some dimable LEDs, red LEDs, and we put that on the lowest set. and so we can drive around with just like the very barest amount of red light shining out and find the animals. And then we actually, we have different ways to stimulate them.

I still want to make, and maybe one of your listeners can help me with this, but I still want to make like an underwater horn that I can honk to like a buzzer to start all the animals to make their flash of light. Have we got the past guest to hook you? up with. Oh, really? I seriously want to follow. The people from the African animal studies who who play back animals at the other, at the animals in different sounds of animals to see if they scare them. So I need that that can work underwater to 4,000 meters depth. But what we do now is we have a paintbrush in our robotic arm that we stick out next to the camera and we like brush the animal

with this paintbrush so that it doesn't, it doesn't really damage it, but it stimulates it. to cause its biluminescent flashes. Or we just hover there with the ROV. You know, this ROV, the size of a sport utility vehicle, looking at an organism that is maybe like two centimeters long. And the pilots are really incredible. So we just hover there next to it until it kind of gets spooked and swims away and makes a flash.

So some of the pictures in the book are actually frame grabs from the videos that we've gotten with the sub. That disparity never occurred to me that the ROVs are so big and you're studying a lot of times animals that are so tiny. Yeah. It must be just a really difficult job to follow or find and then hold position and stuff. Oh, wow. They love it when I come out because it's like they're used to just going on the seafloor and picking up things that they can see. And when I come out, it's like, I want that invisible thing that, you know, is smaller than a P.

And can you please put that in the sampler for me? You said red light, which these animals probably cannot see because they're deep underwater and red light doesn't go down there. Wouldn't you use blue or white light like anglerfish do? Well, we're not trying to attract them or lure them. We're just trying to see where they are. So by using red light, it gives us the ability to have the animal in the frame and still see the blue bioluminescent light. in front of it. And we can actually choose either to drop that red channel out of the video and just see the bioluminescence or leave it in to give you some context. But we're using it like

night vision, you know, to find the animals. And actually, you know, there's some classic stories of deep sea fish that have their own red lights that only they can see. And they swim around hunting prey using this special invisible, yeah, flashlight right under their eye. Deep sea animals are really weird, right? I say that is a very biased, prejudiced, bigoted land animal. I mean, in some ways, I feel like the aliens of Hollywood are so much less creative than actual life because they're bilaterally symmetrical. They have kind of a head thing. They have eye-looking things and arm-like appendages.

And then in the deep sea, all the rules are just thrown out and things don't have to. have any kind of familiarity in their body. So they are alien, but on the other hand, they have been in the ocean for millions of years, and they probably outnumber us. So they could be thought to be the norm, and we're really the exception. Oh, look at those cute little humans. They only have two arms and two legs. How do they get by like that?

And they all look the same. They don't glow. It's just that. Yeah. Look, I'm not squishy there. I don't know. I mean, the other aspect of that is that we think, wow, they're living in this incredible extreme environment,

but to them, our environment, you know, like think about the temperature fluctuations that we experience in a day, and in the deep sea, it's like 1.9 degrees. You know, tomorrow's forecast, 1.9 degrees. Still dark. Still dark. Never mind, it's much less humid here. Yeah.

The humidity is what gets you. Does the constant and low temperature help with the camera noise? Maybe a little bit. It's still, I think it's hot inside the housing, but we do have a little bit of heat sink ability. They're in these titanium cylinders. And so there would be some heat transfer going to the outside, but I don't think the sensor itself is cooled.

I started to ask you about your describing the book, but do you have a couple of favorite photographs? Yeah. I mean, the one, one of them is a frame grab. It's a picture of this arrowworm that has just done like an escape response where it swims in a circle and each time it pulses its fins to swim. It creates a vortex ring of illuminated particles. So you see this kind of like a ring of little, kind of like smoke rings of light. And that one is special to me just, I mean, partly because it looks cool, but also that's like my first big discovery as a grad

student when I saw that out the back of a submarine with my eye. And then I spent years literally trying to figure out what I had seen. And to be able to film that and show it to other people is really special. Even a lot of the iridescent jellies that are just so, like, it's not something that ever is seen in their environment because it's these rainbow patterns that are across the bell of the jelly that are only caused because I have a white strobe light shining on it to interact with it. And that would never happen in its environment.

but some of those are just, I think the colors are just so vivid and so beautiful. So I feel like the function of those is to just get people to appreciate these jellies more. And I had a lot of fun taking pictures of soap bubbles on our kitchen table, basically. I created this setup. I went to our maker space and I cut some acrylic white acrylic to use as a diffusing dome across the top of it. And then I had our sun blowing soap bubbles basically in a little chamber. And I shot literally probably 2,000 pictures of soap bubbles, of which we used one in the book. But those just look like planets.

You know, they look like Jupiter or something. I don't know. Some of the squid shots are really pretty special to me. One of the squid sections really caught my attention because they can, we think about squid being able to ink things. Yeah. And, but they can choose, I don't know if it's by species or they can choose, choose, to output, shoot, ink, black or bioluminescent. Mm-hmm. And the bioluminescent would convince someone that they were still there, and the black would convince someone that they weren't there?

How does that all work? Yeah. Well, some of the animals we see have, they have two different escape reactions or two different phenomena that one seems to be meant to work in the daylight and one to be meant to work in the darkness. So like you mentioned, you know, things like a, they call them. a pseudomorph, a false body. So if an octopus or squid shoots out an ink cloud, often it's like a skinny ink cloud for a skinny squid and a puffy cloud for a puffy round squid. Oh, interesting. But so they'll shoot out ink. It may have some noxious chemicals in it as well, but really its function is they're going to swim away and leave you looking at this cloud

and thinking that that is the organism still there. The bioluminescent, that, that, that kind of display with bioluminescence. Actually is super common. There's worms that do it. There's jellies that do it. There's shrimp that do it, squid, fish even. They'll shoot out a big cloud of ink and then they'll just skiddle away so that the predator, the potential predator, is totally distracted by this glowing target.

So this would be like me glitter bombing a mugger. Yeah. Same exact thing. I haven't finished the bioluminescent and fluorescent sections. Okay. But I did read all of the transparency, including seeing the picture where you have one that is in a black background and you can see the creature. But then there's another one that's in a blue water area of the same eel. And it's just not there.

I mean, it's barely there. How do we know these things exist and aren't just made up? Well, yeah, we, I mean, when we collect things with blue water scuba diving, that is when we go out in the open ocean, it's just like blue in every direction that you look. And you're surrounded by creatures, but you don't see them. And I take a lot of people on there, like their first blue water dive because it's kind of an obscure method. But often they're like, oh, there's nothing down here. But then you start focusing on your hand in front of your face and you see, wow, wait, I'm surrounded by transparent creatures.

So what we do is sometimes if you're on a blue-water die with me, I'll just be staring at you kind of with a vacuous look on my face. And it's because I'm using you as a black background to highlight the animal. So you're basically a black backdrop for me. And then we also look back up at the sun so that sun coming through the transparent animals can give them away. But oftentimes you'll see something with the sun up there. You'll reach down to get your jar to collect it. You'll look back up and it's like gone. You just cannot find it again.

So things are really amazing. They put a lot of attention to detail on making themselves completely clear. especially in the shallow surface waters. I liked the idea that if I was transparent and I didn't want someone to eat me because I had eaten something that glowed, I needed to have my stomach be basically mirrored so that people couldn't, didn't eat me

so that they could eat my lunch, which would be bad. Yeah. Yeah, so things try to be totally transparent, but for example, you can't make your eyes transparent, right your eyes functioned by absorbing light so they they automatically have to pull light out from you know the path and so things will do all kinds of crazy things with putting silvery surfaces around their eyes they'll put bioluminescent light shining out below their eye to um reproduce like mask out the silhouette it's called counter illumination and um there's some really fun squid

that they rotate their eye so that their light organ is always pointing down. So we see them swimming upward in the water. Their eyes pointing horizontal. It's like a plumbob or something. And then they rotate their body swimming down. Their eyes completely horizontal still, like in that same orientation. So the eye and the stomach are two things where organisms will compromise their transparency because it's just too risky to be totally clear in your stomach.

especially if you're eating the little light-emitting copepods. Yeah. How much of what you've studied over your career has an application in human technology? I mean, we mentioned GFP for medical. Yeah. If it's a granting agency that I'm talking to, then all of it pretty much has. No. Yeah, so we do have the advantage in this field that both the bioluminescent and the fluorescent molecules and the genes associated with them that organisms have come up with end up being incredibly useful for biotechnology, biomedical, because you basically have a living highlighter.

You have a system that, you know, I want the nervous system to light up or I want the nervous system because, fluorescent in this organism that I am studying, well, put a gene from a jellyfish in there and you can achieve it. Or, you know, the example that we always give, but it's true is that studying cancer, if you want to study the treatment and see if a tumor is growing or shrinking, you don't necessarily have to sacrifice a little experimental mouse and cut it open and look side of it to measure the tumor. If you make that tumor glow, you can actually visualize it in the live organism. And so the same properties that make it kind of a magical thing for the organisms in their life also make it a very powerful magical tool for technology.

Bioluminescence is when I create light and fluorescence is when I take light and reflorescence is when I take light and reflect it later or reflect it into a different color? Yeah. It's not quite a reflection, but it's like an absorbing and reemitting that happens pretty much instantaneously. Oh, it's not like storing it later like radium does for watch dials? No. Well, radium is radioactivity.

Yeah. It's just emitting. The later fake radio. Oh, glow in the dark paint? glow in the dark. Okay. Thank you. You could have fluorescent phosphors that are excited by radioactivity.

Actually, I have a little demo box of fluorescent minerals and rocks and stuff. And one of the things in there is this uranium glass that they used to make China. You know, like, look at this pretty china that's kind of got a greenish tint to it, but it's saturated with uranium. That stuff is also fluorescent. So there are close associations between all kinds of electromagnetic interactions that happen. Fluorescence, basically, it's like a pigment that converts light to a different color instead of just absorbing light out of the environment. And so the power of fluorescence is that it lets organisms be brightly colored in a blue monochromatic environment.

if that makes sense. Because if you only use pigments, you can just absorb light. You can just be different shades of blue down there. If you have fluorescence, suddenly you have this whole palette of colors that you can exhibit. The one thing about fluorescence, though, is that you can't turn it off and on. It's basically built in, right? You could maybe shutter it, but I don't know of any examples of things that shudder their fluorescence. By aluminum essence, you can kind of store it up and release that light energy when you need it,

and you can control how bright it is and make it glow. But yeah, fluorescence is just going to have a brightly pigmented flag on your body if the lighting conditions are right. But aren't chromatophores basically pigments you can open and close? Why wouldn't there be fluorescent chromatophores? I mean, there could be, but Nobody's thought of it yet, as far as I know. Does anything take advantage of birefringence, the kinds of thin film or thin diffraction kind of things?

Yeah, so those are the, that's all the iridescence chapter is where we lump all the structural type phenomena in there. And so the disco clam that you mentioned at the beginning, that's a structural color. A good example is the blue ring octopus. So it has these bright blue rings on its body that warns you that it's a venomous species. And the blue rings are an iridescent structural color. Do not pet the blue ring. Do not pet. Yes. It will go badly for you. Even though it's tiny, it can take you down. I know. If you look on some social media, there's all the pictures of people like holding them in their hand. Like, look what I found.

Wow, that's really going to hurt if you survive. Should you go pick up a cone show instead. Sorry, sorry for the distraction. Well, actually, let me ask you about the disco clamps. Let me ask you about the disco clamps. It was all going to come down to this. They provide a white color that is very startlingly white. And it is reflective.

It's not bioluminescent. They don't generate any light to get with it. They only react to light surrounding them. Right. And they live pretty shallowly or they wouldn't be able to get to all the light, the whole light spectrum. And they have little glass,

silicon beads that help them do this retro-reflective display. Why? I hope you're not going to ask me of the function. I mean, they really do look like they have little lightning storms in their mouths. Yeah. And their mouths are surrounded by small red tentacles. So it's creepy.

Yeah. No, it's really cool. It looks like a little electric sparks going across. I mean, I'm going to say we use this out a lot in the book, is that we still don't know. Scientists still don't know, you know, why this does that. I'm going to use that out for this and you can do a what's the call a friend thing

and ask Sanka if he has any ideas about it but I basically I don't know about why those guys do it some clams have really cool lures that they inject their larvae into fishes mouths and they lure them over and then they inject their larvae

and they like kind of temporarily They parasitize them. I don't think anything like that is happening. Nothing in science fiction that the deep sea animals haven't done. And it's all horrible. Like you were saying they're so different. The word that comes to mind sometimes is Lovecraftian. Yeah.

I mean, it just, yeah, okay. Oh, yeah, I could tell you about the ones that hollow out the other organisms and lay their eggs around this. I guess there's land animals that do that sort of thing. I mean, wasps. Yeah. Yeah. Yeah. So there are some pictures in the book of the,

this big amphipod that basically does that. And you can see the little babies like crawling around inside the barrel of its host. As you just said, the book notes that science doesn't know how some things are done. And it's like you're setting up open problems in biochemistry. Has anyone taken you up on that? Has anybody said, oh, I saw this in the book. And will you be my PhD advisor? I mean, I have gotten grad student inquiries.

I basically was really lucky. I just hired a biochemistry technician who is full-time kind of going through the list of mysteries and trying to solve the hows of like some of these bioluminousine creatures that we found or we just don't even know the first thing about the chemistry of their light emission. I think the two big areas of questions. One is the how, so the chemistry, but the other is the why, which you alluded to before. And we do have some experiments that have shown some of the whys, but a lot of those are just, you know, stories that we make up. This seems plausible.

You know, it looks like this might be functioning in this way. But as you might imagine, it's pretty hard to do experiments to demonstrate natural behavior. in the deep sea. Let me ask a slightly different question that you also may divert from. All these strange to us things like transparency, bioluminescence, fluorescence, they must come at some cost to the creature, right? Nothing is free. I mean, like, why isn't it a transparent creature that can flash things and do a,

why doesn't have all the functions? There must be some costs. So what's the thinking on, okay, well, if I become a transparent creature, am I giving up or what becomes difficult? Yeah. I mean, I think surprisingly, like, you might think I think that fluorescence or bioluminescence would be the most costly in the sense that you're talking about. But I think transparency actually is one of them that requires the most commitment in a way.

Because, like, if you look in Finding Nemo, they have the big anglerfish character in there. and its eyes are milky white. And the reason they're milky white is because it's a dead fish. It's the proteins in its lenses have become denatured and turned, you know, basically just like a hard-boiled egg goes from clear to white. That's pretty much happened to their eyes. So it takes energy and organization at the cellular level and the sub-cellular level to keep things transparent.

So, I mean, probably what, one of the things that you're giving up is musculature. You know, you just can't be like a bee slab a tuna and be transparent at the same time. But there is also a lot of energy invested, I think, in the chemicals that produce bioluminescent light. And so for some things, it's pretty much like the emergency flare last resort thing, it seems like. I've seen jellies, like little comb jellies, and the poor thing was like biluminescing, and it was exuding out its biluminescent material in a cloud, and its whole body was just like shrinking at the same time. It was like giving its all literally to make this biluminescent display. They have good regeneration capabilities, but I think this little guy was just

not going to recover from that because it had invested so much energy just in the that emergency. Oh, interesting. Okay. So there are ones where they can store it up and then use it, but then either it's damaging to them to do it too much or they have to wait a long time before they can try to escape. Yeah, they hold it in reserve and they're usually kind of careful about when they flash. And that's why they're not just like, well, partly why they're not flashing all the time because they're saving it for the right occasions. It seems like iridescence. And the using molecular or very small structure to augment or produce colors is probably the least investment evolutionarily.

Do you agree with that? I think energetically maybe, but as far as like subtlety and organization and precision, It's probably the most because those plates in the iridescent structures on a squid, they have to be aligned to within the nanometer, really, to function in the way that they're supposed to. And so I think, yeah, once you have it built, you're probably getting like a free ride, but up to that point, it can easily go wrong. There's a couple, I think I had both pictures in the book, but there's a couple. a picture of like a shiny, silvery-looking deep-sea fish. And when I was shooting that guy, like it would go from brown, just like drab brown to shiny, bluish, silver, you know, between shots, basically. Because of the angle of the strove and the angle of the camera,

that iridescence had to be, it had to be such a precise relationship in order for that to even show up. And you mentioned that comb jellies, which have the rain, around them that we see at aquariums and whatnot, don't actually have anything under the water because that's all about reflecting light. Yeah, it's, that's so, I mean, it's like a soap bubble, sort of, or like, I don't know if people are probably old enough to remember compact disc and DVDs,

but basically like the fine grooves in a diffraction grading, that when Tina Force basically have a whole series of those plates along their body, and it makes these incredible rainbows that flicker and flutter along the side of their body. But none of that really happens in their environment. Like they never are in that pure white light to really have that show up. But they are also biluminescent in those same places, like under those comb rows. are canals that have biluminescent proteins, photoproteins, and so they can produce bright flashes of blue light.

And when you get to the bioluminescence chapter, you'll see some examples of tinafore biluminescence where it's like these radial mesh patterns and really, really cool displays. One of the things that surprised me that was in the aerodecent chapter was the Vanta Black. and that it is an iridescent sort of feature. It's a structural, molecular way of shining the light inside you so it doesn't come out.

It was sort of how I described it. Is that right? Or how would you describe blacker than black? And blacker than black. How much more black could it be? Yeah. So when we take pictures of some of these black fish, like the dragon fish and the angler fish, they just suck in the light of your strobe. And it's really hard to get good illumination, which is kind of my excuse for some of those pictures in the book where it's like, yeah, you can see the face, but the rest of the body just fades off into the distance.

And what Sanka studied, like how they achieve that. And I think in short, instead of just having a sheet of pigment like a piece of black paper or something, where it has one, chance to absorb light, but otherwise it can potentially bounce off. In those fish, their pigment is in like a gumball machine or, or, you know, a bag of marbles or something. So light goes in there and it bounces off one of those pigment, has a chance to be absorbed. And instead of coming right back out and being seen, it goes and hits another gumball and hits another gumball. And so it has multiple chances. It kind of gets trapped in this pocket of pigment. so that there's many more opportunities for it to be absorbed.

And so, yeah, they, it's actually, Vantablack doesn't work underwater, unfortunately, because it's these nanotubes. And so it's pretty much a water repellent surface. But if we could make a Vanta Black version that uses the same deep sea fish technology, so to speak, then I think it'd be really neat. It would be a really useful product. But this super black actually did have an interesting why. And it was a very, oh, yeah, okay, that makes sense. Like anglerfish need to be super black, blacker than black, because of their lower. And they can't reflect upon themselves or,

it gives the whole game of it. Right. They would just be lighting themselves up. It's like the guy looking for his keys under the streetlight. It's like, why are you looking for, you know, could you drop him here? He's like, no, I dropped him over there, but the lighting's better over here. So, yeah, with the fish, it's the same kind of thing where they have to have that light out to attract prey, but they don't want to just be shining that light on their face.

They want to come looming out of the darkness and surprise their prey. You've mentioned that some of these images are from ROV video captures. How many of them are from a human in the water with the camera? So there's, I would say, three types of photos. So some of them are from the ROV video. Some of them are from scuba diving, you know, person in the water with the camera. The majority of them actually are animals that we've collected from the deep sea, but then brought up to the ship to photograph.

And so a lot of them are things that are like captive specimens still alive, but not in their actual environment. I have a couple of listener questions. The first one from Nick, which probably should have been a lightning run question. Have you ever played games with an octopus? I have played games with octopus. and squid. I mean, I did up at Friday Harbor, Washington in the Puget Sound, I just, I did a scuba dive, and there was a giant Pacific octopus that was under a rock, and so I took my

glove off, even though the water is, like, freezing cold, and, yeah, I just couldn't resist, like, wiggling my finger next to it, and it put its giant suckers on top of my hands. And then also in Mexico on a night dive, we were studying creatures down there. And there was this whole wall of these jumbo squid they're called, the Cicius, the Diablo Rojo. They're like as big as a human adult. They're like five or six feet long. Their tentacles, their suckers are lined with teeth. So like it's a disc.

It looks like a normal sucker, but it has a stucer. serrated edge to it. So if you just lay it on your arm, well, kind of, yeah. They leave a little bloody, you know, waltz along your arm. But anyway, we saw all these, and we would have, like,

if we turn off your flashlight, they would come towards you and investigate. And then if you turn your light on, they would swim away. And one time I turned my light on too late, so it, like, shot out its tentacles towards my hand, and then swam away. But, yeah,

There's a lot of really cool deep sea squid that they're fun to interact with. So you've said a night dive and you've talked about blue water diving, which is out in the middle of nowhere, no islands, no continental shelf nearby. Do you do nighttime and blue water diving? That seems like a good way to get lost in the middle of the ocean. Yeah, I mean, we have tethered. when we're doing this, but that's basically called blackwater diving. And there's a whole tourism industry, especially in Hawaii, the Philippines, Florida. People go out and they pay money to be dropped in the ocean in the darkness.

And some of the really great photography that you'll see is blackwater photography. Because things were vertically migrate. Yeah. Yeah. There's a lot of migration. So a lot of the larval fish pictures in the book were taken by my friend Jeff Mlaison, who is a blackwater guide. And so I think there's like two or three pages in a row that are just all Jeff's photos of these amazing larval fish that he took during blackwater dives. The squid on the cover is one that I saw on a blackwater dive.

It's got really cool transparency, but all those are these pigment spots that would kind of, contract and dilate as its mantle pulsed. From Simon, are there any, or what are the best, cooperative behaviors or emergent effects of jellyfish blooms? Interesting. Do jellyfish work together? They don't work together, per se, but they're often found together. part of that is attributable to their life cycle where they'll have a face in their life that pops off a bunch of baby jellies and then those guys all drift around and kind of grow up together.

And so you get blooms in the bay. I don't know that there's any coordinated. Probably the closest thing is that Bill Hamner was an open ocean ecologist who sort of started blue water diving. And he found that they did like sun compass navigation. So in this bays, they would all swim the same direction at a certain time and swim the same direction in the other way at a certain time. But that's not vertical migration. That's east-west?

That was horizontal. Yeah, there are ones that vertically migrate, but this was like an east-west thing. It was different from what most people had seen. Was that related to photosynthesis or just weird? No, these were, it was not a species that had symbionts. There are some in the lakes in Palau that are swimming up and down to like, the thought is that they swim down to get nutrients or basically fertilize their algae and then they swim up to photosynthesized and swim. You know, they have this vertical migration that's not to avoid predators, which is the usual rationale, but it's to actually nurture and babysit their symbionts, their algal associates.

So are these jellyfish with algae that they're farming, or is this algae with jellyfish as their chariots? It's mostly the farming. There's one, the upside down jellyfish that's in the Caribbean and Florida and stuff. I guess it's throughout the tropics, but it lays on its back on the bottom pointing up and it looks just like a plant or a piece of seaweed or something. and it basically just spends the whole day sitting there letting its algae photosynthesize for it. Okay, so why can't I glow? Why can't I photosynthesize?

Why can't you farm algae? I mean, that's photosynthesize, basically. And why can't I live in the deep sea where all the other interesting creatures are? I think that's the last one. Yeah. Let's see, Simon also asked, Are there any intriguing biomimetic engineering efforts to adopt the jellyfish's way of addressing a problem?

There are people who make like soft robotics that use jellyfish-like motions for swimming. I think somebody might have even done. So comb jellies are these, it's this other group of organisms that's actually not. related to jellyfish were more closely related to jellyfish than these things are. But they use these cilia that cause the iridescence for locomotion. And I think that could be kind of a cool way to make a very maneuverable vehicle more so than a jellyfish that pulses. Their rotational ability is somewhat limited. Their ability to back up is somewhat limited.

but tina force can go forward, backwards, spin, you know, and I think it would be potentially an interesting avenue for some kind of biometric robot. But it'd have to be water-based. You can't do that in the air. It'd be too heavy. Yeah, maybe if it was helium-filled, you could have little thrusters and basically like a drone. A little sylium thrusters. Yeah.

I guess they're kind of feathery. Yeah. All right. All right. I can see it. Oh, I have so many more questions. You wrote a book about scientific blue water diving. Yeah.

And you wrote a book called Practical Computing for Biologists. Yeah. Were those books significantly different to write than the Radiancy? Oh, yeah. A thousand percent. I mean, the Radiant Sea was. it was definitely a project that we had been talking about for like at least 10 years and really laying the groundwork for it for probably 30 years each. Accumulating photographs and just knowledge of what the organisms were doing.

Practical computing was written with my friend Casey Dunn and it was kind of inspired. Like, you know, our education at Harvey Mead College is very eclectic and, um, You have to study a lot of different disciplines. But then I become a marine biologist afterwards, but I still was kind of standing on the shoulders of that education. And so my friend Casey and I both had a computing background, and we saw how understanding just kind of relatively simple things. We always say that it's like the 10% of the knowledge that will get you 90% of the way. way. And so we wanted to create this book to, like, lower the barrier of entry for people who

are biologists and just empower them to use computing more efficiently. So it's definitely not, like, a purist's guide to Python's programming or syntax or shell operations, but it's a very practical approach of, like, this, you know, this will get you partway there and it will teach you enough that you can learn the rest of the way yourself. So yeah, that was, and the reaction, the most common reaction to people saying that they have that book is that I wish I had known about this, you know, last year before I did this super tedious project that I could have programmed my way out of it. So, yeah, it was very different. It was actually, honestly, a lot harder to write because we had to, like, create screenshots of all the, you know, interface and write all the programs and, you know, double-check them and do the syntax highlighting.

And that was a multi-year project. And the Radiant Sea book came together relatively quickly, I would say, because we had already gathered, like, the information over the time. I've been talking to another author commiserating about the difficulty of finishing technical books. Yeah, well, you wrote to at least technical books, right? Well, that was, yeah, it was his first, and he's almost done, and he hates everything about it, which is a normal stage in the book writing process. Yeah.

But the Radiant Sea didn't feel like that. It felt like you or Sakha was just, had a fun, joyful feeling of sharing the wondrous discoveries and saying, hey, look at this. Isn't this cool? Was it like that? Or did you just successfully write amazingly well? Well, thank you. But I think it was really like that. It was just like a fun thing. And Sanka is, you know, Sanka is funny. We both are like kind of irreverent in different ways. he's, I don't know, maybe more like Monty Python or kind of over the top. And I'm more just like deadpan of like, I'm going to say this and I hope that you don't notice that it's like not serious until a little bit later.

But yeah, it was just fun. It was very interactive. We, you know, we would pass the captions and the chapters back and forth and just like have free reign to like critique. but it was a lot less pressure to be like technically correct. You know, everything we made sure it was factually accurate, but we could just say, oh, you know, check this thing out. This is really wild. This is something that we saw.

This is something that we experienced. Or this picture, you know, look at how amazing this organism looks. And it was just much more of a kind of like a conversational thing, write than like an authoritative textbook. I have one more question for you. When you do these dives and explorations, how often have you been surprised by something and how often have you been actually shocked by something?

Not shocked electrically, but like, oh my gosh, what is that? Stung by something many times. Right. I mean, we, so on one sense, we go out a lot like we go out pretty much every month to the deep sea and so in a way it's like going to your local park and you see the scrub jays and the banana slugs or whatever it is you see the animals that are in your area so some of them are new to science they've never been described but they're still somewhat familiar and then there's the stuff where it's like what in the world like this you know we just this syphonophore, which is a kind of jelly, and it was just exuding out these plumes of green fluorescent fluid from its, from like, not its tentacles,

but they're called palpons. Anyway, it was just like creating these green plumes. We've seen this one comb jelly that's also a new species, but we saw it's like feeding response of like how it actually grabs prey with its lobes, which was unlike any other comb jelly. And so there have been times when everybody just like kind of exclaims in the control room. And those are always really super fun. We've seen a jellyfish.

We just saw an octopus where we had, we've only seen it like four times in 30 years. And we found that it eats jellyfish. But then we just came upon another one and we opened up its arms. and it also had a different species of jellyfish in its arms. So we were all like really kind of surprised and delighted to have that confirmed. So yeah, there's, I would say it's pretty regular that we just say, like everybody's just kind of going, wow, you know, in the control room. Were you at Embari when Davidson Mount,

was discovered to have an octopus guard? Yeah, I was not on that cruise. That's Jim Berry's work and the Marine Sanctuary's work. But yeah, that overlapped with the time that I was there. So, yeah. I mean, that was accidental and weird. Yeah, yeah. I mean, accidental and weird, we found,

haven't actually still published this yet, but there's been a New York Times article about it, but we found the tusk of a woolly mammoth. on the top of a sea mount 3,000 meters deep. So that was probably the most surprising thing I've seen. But yeah, you just never know what you're going to come across. The thing that gets me about a lot of the deep sea creatures and things is that there's so many people obsessed with cryptids like, oh, the Nessi, oh, it might be a lost pleasiosa. Right.

And Sasquatch, look, it's a giant man ape thing. And the reality of the creatures we keep finding is so much weirder. I know. And more interesting than any of those things. Weird. Yeah. How is this giant VW-sized creature that's a turtle without a hard shell survive on jellyfish, which are basically water? Tick-TACs.

Yeah. Well, I mean, all the giants, the ocean giants, like Mola Mola, you know, leatherback turtles. this octopus that I just mentioned is it's called the giant seven-arm octopus. So it's also one of the larger octopus species. And they subsist on jellyfish, basically. So it is one strategy is to be slow-moving and have this very sedate life cycle,

but persist at it. And so you can grow it a big size overtime. I mean, it's the jellyfish version of iceberg lettuce. Yeah. Well, you don't talk about that now. It's a bad time. Oh, yeah. Yeah.

I mean, it gets back to that question of if there's coordinated activity in the jellyfish. Some of the predators depend on that coordination. You know, they depend on there being a giant aggregation of jellyfish to be found or else they wouldn't be able to find enough prey to feed on. So it's part of the circle of life. Do you have a favorite animal? I do. Probably my son. A favorite marine animal?

It's really hard to choose, but probably some kind of a comb jelly. Yeah, they're just... I think comb jelly is probably... So pretty. And just, like, most people don't get to see, them so I just really feel lucky you know every time we come across I just gave a talk to some six to ten year olds and I had a live tina for that I brought with me from a jar that that we had

collected and it was just so fun to like shine the flashlight on them and let them see the flickering rainbows and have them all gathered around the table and you know kind of these too cool for school boys that were just like what what check this out um So, yeah, it's really fun to share them. Steve, do you have any thoughts you'd like to leave us with? I would say there's a whole wonderful world down in the deep ocean. It's not lifeless and it's not grotesque and scary. It's actually worth understanding, studying, and preserving.

Our guest has been Steve Heddock, author of The Radiant Sea, color and light in the underwater world. You can find his book wherever you usually find books. It's beautiful. I recommend it. Dr. Hedek is also a senior scientist at the Monterey Bay Aquarium Research Institute and an adjunct professor at the Ecology and Evolutionary Biology Department at the University of California, Seneca Cruz.

Thanks, Steve. Thank you, guys. That was fun. Thank you to Christopher for producing and hosting. Thank you to Scott for the introduction and our Patreon listener Slack group for their questions. And of course, thank you for listening. You can always contact us at a show at embedded.fm or hit the contact link on Embedded FM, the website where you can find the show notes and the transcript.

And now a quote to leave you with. This is actually going to be from Steve's book, The Radiant Sea. It's in the afterward. there's perhaps an unintentional poem about what visual communication says in the voices of the ocean. I am here. I want to find you. I'm someone else. I think I'm in love.