The Manta Ray, Part 1
46:39 Share

This is an iHeart Podcast. This July 4th, celebrate freedom from spills, stains, and overpriced furniture with Anabay, the only machine washable sofa inside and out where designer quality meets budget-friendly pricing. Sofas start at just $699, making it the perfect time to upgrade your space. Anabay's

pet friendly stain resistant and interchangeable slip covers are made with high performance fabric that's built for real life you'll love the cloud like comfort of hypoallergenic high resilience foam that never needs fluffing and a durable steel frame that stands the test of time with modular pieces you can rearrange anytime it's a so

Offers are subject to change and certain restrictions may apply.

Let's talk photos, not just storing them, showcasing them. You've got images that matter. Whether you're a photographer, a business updating your followers, or just someone who wants to share life's moments the right way. So why hand them over to Big Tech's one-size-fits-all cloud? Big Tech companies are the fast food of photo sharing. Quick, easy, but not exactly gourmet. And what about your data integrity? Jalbum.net is the photo sharing solution that puts you in control.

Want to host images on your own server? You can. Want a layout that actually reflects your brand or style? JAlbum's customizability is unmatched. And if you're a business sharing regular photo updates with your audience, this tool was built with you in mind. But don't just take our word for it.

Over 230 million webpages have been created with JAlbum, and it's got stellar reviews on Trustpilot to prove it. So head to jalbum.net to download your free software and try it out. When you're ready to upgrade, use the code podcast for 20% off. Your photos, your layout, your rules. Jalbum.net.

I'm Bob Crawford, host of American History Hotline, a different type of podcast. You, the listener, ask the questions. Did George Washington really cut down a church tree? Were JFK and Marilyn Monroe having an affair? And I find the answers. I'm so glad you asked me this question. This is such a ridiculous story. You can listen to American History Hotline on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

Are there any pictures of you online? Then you could already be in a massive police database without even knowing it. Clearview scrapes together images from Facebook, from LinkedIn, from Venmo accounts. I'm Dexter Thomas, host of Killswitch, a podcast about how living in the future is affecting us right now. Police, they are trusting the software with this magical ability to lead them to the right suspect. In this episode, we dive into how cops are using AI and facial recognition and sometimes getting it wrong and

putting innocent people behind bars. So if your accuser is this algorithm, but you're not even being told that it was used, let alone given any of the details about how it works. Listen to Kill Switch on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb. And I am Joe McCormick.

In this episode, we're going to begin our look at the manta ray, because I very recently had the privilege to travel with my family to Raja Ampat in Indonesia for a week of snorkeling. And during that snorkeling, I got to observe manta rays while in the water snorkeling. And it was

Just a mind-blowing experience. It was just magical. I can't quite put it into words exactly, but it was one of these situations where as I was snorkeling out with the other snorkelers towards this manta ray cleaning station, I found myself like mouthing, oh my God, oh my God, through my breathing apparatus. Now the cleaning station, is that, do I understand right, that's a place where they come to sort of be, be,

Swarmed by fish that will help get parasites or other kind of contaminants off of their bodies. Correct. This is pretty remarkable in its own right. And I think we'll get into that more in the second episode of this series. But yes, that's what we were observing. These were some reef manta rays that had come out to the cleaning station so that these various fish could eat their parasites and

And yeah, it was just magical to watch these creatures move through the water like some sort of animate black and white cape, you know, some sort of an angel or demon, just something almost beyond our ability to comprehend.

It's a Bach coming in on the organ as they swish around. Yeah, yeah. They're very, very dramatic. But also, as we'll be discussing, relatively drama-free, at least as far as what they're doing and what they're bringing to the table. There's a lot of manta ray drama, but it's almost entirely on us, the humans. Yeah. So I want to mention up here at the top that we did this snorkeling at the Missoula Marine Reserve, this event.

This is also where you find the Missoula Resort. The resort is just one leg of the overall conservation mission here, which actually started before the tourism part of the operation. Like the tourism part apparently was then built up afterwards to fund the conservation mission.

And I can't say enough good things about this place. Founded on the site of a former shark finning camp and in an area that had been previously targeted by illegal lumber operations and dynamite fishing. And now through the Missoula Foundation, they manage about 300,000 acres or 12,200 square kilometers of marine reserve with two distinct no-take zones.

They engage in various conservation efforts, such as the Missoula Manta Program, a ReShark Program. And this includes a program to reintroduce Indo-Pacific leopard sharks. And they partner with various organizations, various aquariums around the world who have the right eggs, egg sacs to reintroduce. And their partners include Atlanta's own Georgia Aquarium.

They're also involved in coral reef restoration, sustainability efforts, and various community outreach and education programs.

So you said you were doing a lot of snorkeling here. I know y'all are a snorkeling family, right? I have no experience with this. Yeah, my wife got us into it, and we'll go on snorkeling excursions here and there. And I have to say, yeah, this is the best snorkeling of my life thus far. This part of the world is in what's known as the Coral Triangle. This is an incredibly rich and diverse marine environment that happens to include

According to the NOAA, quote, over 600 reef-building coral species, 75% of all species known to science, 3,000 species of reef fish, 40% of the world's coral reef species, and six of the world's seven marine turtle species. Also, three-quarters of known mollusks. So it's happening. Yeah, it's just a very, very rich place. And, you know, I'll no doubt come back to...

other things I observed there in future episodes. But one of the many highlights, again, was getting to observe these reef manta rays in the wild.

So we'll get back to the details of the two main different manta species. But this is the second largest of the rays and one of only two, possibly three, extant manta ray species. They can weigh up to 1,500 pounds or 700 kilograms. And that's with a maximum disk width of 15 feet or 450 centimeters. I guess you could sort of...

Frame that as their wingspan, if you want. But you said, so these are the reef mantas and the largest of the manta rays would be the giant oceanic mantas? Correct. Yeah. And we'll come back to the stats on them in a minute. But yeah, in both cases, great bat-like black and white creatures that seem to glide and soar through the depths.

And I think I had observed some in the water while standing on a sandbar elsewhere in the world previously. But this was my first and only time getting to see them while in the water. And again, it was just astounding. So I have no experience with snorkeling, but in reading up for this episode, I just kept coming across firsthand descriptions again and again of snorkels.

how strange and amazing it was to be in the water with manta rays. A common thing these divers and researchers talk about is a feeling of kind of intelligent or almost emotional connection with the animal that they have not experienced with any other animal.

Because to be clear, the manta is not like a mammal like dolphins or whales might be that you might be more, you know, dispose. You might have more experience hearing about these kind of connections people have with marine mammals. But these are fish. You know, we think of them as these very kind of cold animals.

creatures of limited intelligence kind of like sharks that seem to be mainly just kind of machines acting on impulse they don't have that feeling of emotion and intelligence you might get from a mammal but in this case this is a fish that lots of people say does it does have that feeling it's like it's there and it's alive and it's thinking and

Yeah, this is a great point. And I think we'll probably get into the brain, the intelligence of the manta ray, especially in the next episode. But you do see this observation a lot. There seems to be a curiosity on the part of the manta. And in many ways, this kind of curiosity reminds us of our interactions with mammalian marine species like dolphins and whales. Yeah.

Now, in the case of our own experiences, I want to stress that we observed them while snorkeling rather than say that we swam with them. I guess you could technically say we swam them with them. We were in the same body of water with them. But we did keep our distance. We did not chase the manta rays, and we certainly did not attempt to touch these gentle giants of the sea. I assume that's discouraged. It is discouraged, yes. And in discussing this, like the human desire

desire to touch the manta ray. I wanted to get into a preliminary discussion here about the human attitudes toward the manta ray, because this is important, because ultimately human attitudes towards the manta rays also plays into their endangered status in the world, certainly with the oceanic manta.

So manta rays enjoy a pretty wide range. They're found in warm, temperate, subtropical and tropical waters around the world. As such, humans and coastal areas within their range have known about them for a very long time.

Hawaiian, Micronesian, Southeast Asian, and South American traditions have viewed the manta in varying supernatural lights as reincarnations of human souls, as avatars of a creator deity, as divine protectors, as divine messengers. And as such, they've even enjoyed traditional protected status among certain groups, at least at different times.

But there's also a darker side to human attitudes toward manta rays. Over the past couple of decades, the demand for manta ray gill plates in traditional medicine, particularly traditional Chinese medicine, has proven devastating for manta ray populations. Based on the unproven and, to be clear, pseudoscientific idea, the consumption of these gills in some sort of like powdered, dried and or powdered form can boost the human immune system, among other supposed benefits. Yeah.

And the story about this is really interesting in its own right. I was reading about this in a paper by O'Malley et al. titled, "Characterization of the Trade in Manta and Devil Ray Gill Plates in China and Southeast Asia Through Trader Surveys." This was published in 2016 in Aquatic Conservation Marine and Freshwater Ecosystems.

And they point out that mention of manta gill plates didn't pop up in traditional Chinese medicine publications until around 1976. This, to be clear, despite the fact that traditional Chinese medicine itself is very, very old, going back like 5,000 years, widespread and popular form of alternative medicine. But

This the consumption of these gill plates is not some sort of deep seated tradition in this alternative medicine practice. This would not be the only case that something is presented as a traditional or ancient cure from some culture or other when it is not. It is a fairly recent thing people have started doing.

Yeah. One of my key sources for these episodes is 2018's Guide to the Manta and Devil Rays of the World by Stevens, Fernando, Dando, and Descaria. And in this book, which I'll keep coming back to, they say that this was all likely a, quote, clever marketing of a readily available and cheap bycatch product. So in other words, various unsustainable fishing practices would be pulling mantas in anyway,

And then they're like, well, let's market the parts of this creature and sell it. And then as popularity builds, it translates into direct targeting of mantas by what they describe as boom and bust fisheries. So for reasons we'll discuss in these episodes, these are vulnerable species that do not easily endure this sort of targeted fishing. So these operations inherently produce very short-lived paydays while doing long-term damage to the populations. Mm-hmm.

They also note that the rise in popularity may also tie in with the rise in human respiratory illnesses due in part to pollution. And again, these pseudoscientific claims basically were dealing with the idea that, OK, these are filters for the fish. And therefore, on some level, if I consume them, it's going to help filter me out as well. It's going to protect me from the things that would harm me in the environment.

So again, gill plates would seem to be a relatively recent addition to traditional Chinese medicine and one that has had a marked impact.

on populations of these vulnerable fish species. The reef manta is currently flagged as vulnerable while the giant oceanic manta is endangered. And I would imagine that we can come back to this because I'm sure there's more nuance, but I would imagine that they are especially vulnerable to heavy fishing and harvesting because they're larger species that have a slower reproductive schedule. Exactly. ♪

This July 4th, celebrate freedom from spills, stains, and overpriced furniture with Anabay, the only machine washable sofa inside and out where designer quality meets budget-friendly pricing. Sofas start at just $699, making it the perfect time to upgrade your space. Anabay's

Pet-friendly, stain-resistant, and interchangeable slipcovers are made with high-performance fabric that's built for real life. You'll love the cloud-like comfort of hypoallergenic, high-resilience foam that never needs fluffing and a durable steel frame that stands the test of time.

With modular pieces, you can rearrange any time. It's a sofa that adapts to your life. Now through July 4th, get up to 60% off site-wide at washablesofas.com. Every order comes with a 30-day satisfaction guarantee. If you're not in love, send it back for a full refund. No return shipping, no restocking fees, every penny back. Declare independence from dirty, outdated furniture. Shop now at washablesofas.com. Offers are subject to change and certain restrictions may apply.

American history is full of wise people. What women said something like, you know, 99.99% of war is diarrhea and 1% is gory. Those founding fathers were gossipy AF and they love to cut each other down. I'm Bob Crawford, host of American History Hotline, the show where you send us your questions about American history.

And I find the answers, including the nuggets of wisdom our history has to offer. Hamilton pauses and then he says, the greatest man that ever lived was Julius Caesar. And

And Jefferson writes in his diary, this proves that Hamilton is for a dictator based on corruption. My favorite line was what Neil Armstrong said. It would have been harder to fake it than to do it. Listen to American History Hotline on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

Are there any pictures of you online? I'm not just talking about Google. I'm talking anywhere. Clearview scrapes together images from Facebook, from LinkedIn, from Venmo accounts. That database is now being used by police departments all across the country to match criminal suspect photos. And sometimes it makes mistakes.

So in this one case, two of the search results that I think were in the top 10 of the search results were Michael Jordan. It's a picture of Michael Jordan. But cops are still using it to make arrests. Police, they are trusting this software to lead them to the right suspect. But you're not even being told that it was used, let alone given any of the details about how it works. This is not Minority Report.

This is happening right now. People are getting arrested and doing actual time in jail after being picked out by a computer. I'm Dexter Thomas, host of Kill Switch, where every Wednesday we explain the right now of living in the future. You can turn off the computer, but do not let the computer turn you off. Listen to Kill Switch in the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. OpenAI is a financial abomination.

a thing that should not be, an aberration, a symbol of rot at the heart of Silicon Valley. And I'm going to tell you why on my show, Better Offline, the rudest show in the tech industry, where we're breaking down why open AI, along with other AI companies, are dead set on lying to your boss that they can take your job. I'm also going to be talking with the greatest minds in the industry about all the other ways the rich and powerful are ruining the computer. Listen to Better Offline on the iHeartRadio app, Apple Podcasts, wherever you happen to get your podcasts.

And then historically, on top of all of this, there are Western European misconceptions and myths about manta rays and devil rays rooted apparently in the observations of sailors, but managing to survive well into the early 20th century and manifesting in written fiction, as well as in at least a couple of early horror films.

Yes. So, Robert, your suggestion, I looked these up. You sort of gave me an assignment here and I checked these movies out. Strangely, both of these made in the 1930s.

You know, I think of the 70s through the 90s as kind of the heyday of, oh, I don't know, killer monster in the ocean movies. Of course, following Jaws. Jaws is the big one. And then you get all the Jaws copycats, you know, Orca and everything like that. And then even further down the chain into like the real kind of Z grade copycats, you know, in the 90s and 2000s, there were just 10 billion direct to video shark movies made.

Yeah, that is a great observation, especially since, what is it, 50 years of JAWS now celebrating a major...

a major birthday. But yeah, we... I mean, you can't deny the power of Jaws. As much as I hate to contribute to the demonizing of ocean creatures, Jaws is just a banger. It's a great movie. It is. It's a great film. It changed movies forever. You can't talk about blockbusters without talking about Jaws. You can't talk about monster movies, really, without talking about Jaws. But it is interesting, pointing out that films like Jaws arise in the 1970s.

And then various other creatures are drawn into the mix. But the 70s seemed to be the time period during which Europeans in the West woke up to the idea that, oh yeah, manta rays are fine. They're absolutely not threatening anybody. Not only are they not threatening, not actually threatening, it's hard to conceive of them being threatening. Like we can't even...

Think about making a monster movie about something so tame. We'll make one about the killer rabbits first. I feel like the stuff you would get later, like in the 80s, is movies that had friendly aliens that were basically manta ray shaped. I can't even remember what movie I'm thinking of, but I can picture it in my mind like a gentle sort of illuminated bioluminescent forest.

floating manta ray with intelligence that's like communicating with a child or something. Does that ring any bells for you? That one, not specifically, but I was doing some additional reading and there are various examples of creatures in sci-fi that say live in the atmosphere of Jupiter. They're at least partially...

based on the manta ray. It just has a pleasing, ethereal form. Again, it's like to the point where it's almost hard for us to put ourselves in the mindset of someone who sees a manta ray and thinks about it as a relentless killer.

Oh, the Jupiter one you mentioned rang a bell because we just talked about the story in our series on the Great Storm, the big red spot of Jupiter. Yeah. Because that was in A Meeting with Medusa by Arthur C. Clarke. One of the aliens they meet there is like a giant manta ray in the atmosphere of Jupiter. But anyway, we got it. OK, so we got to talk about these manta horror movies from the 1930s, neither of which exactly lives up to that.

promise, but they're both kind of marketed that way. So one of these movies is called The Seabat, S-E-A, not

C the letter C bat, um, C bat, uh, from 1930. This is a pre-code American romantic melodrama directed by Wesley Ruggles. Apparently in early production, uh, Todd Browning was somehow attached to this and it was maybe supposed to be a vehicle featuring, uh, Lon Chaney, but that never worked out. Uh, so this was directed by Wesley Ruggles shot in Mexico, starring Charles Bickford, Raquel Torres, and Nils Astor.

And it even has Boris Karloff in a small role. This came out a year before Karloff's big break in Frankenstein. That was 31. So this is set on an island in the Caribbean, and the story follows a character named Nina, played by Mexican actress Raquel Torres, who is either in love with or is the sister of, depending on which synopsis you read. I was not able to watch this movie before recording today.

is either in love with or is the sister of a sponge diver named Carl. Sadly, Carl is killed when his diving party is attacked by a dreaded local creature known as the sea bat.

And this is described in some sources as a giant manta ray in other sources as a stingray, which as, uh, we'll discuss more throughout the series that those are not the same thing. Uh, though some publications describing the movie seem not to recognize that there is a difference. I think they just think like manta rays are stingrays, same thing. Yeah. Um,

In some effects shots, you can see it really doesn't look like either one. Rob, I put one screenshot in here for you. There are shots of it underwater where it, I don't know, it's shaped kind of like an airplane or like a spaceship of some kind. And then there are some shots where you see it at the waterline and it looks just more like a giant shark or tuna type creature.

Anyway, after the tragic loss of Carl in this CBAT related incident, the character Nina starts getting into voodoo and then declares that she will marry any man who can kill the dreaded CBAT.

Several men try and fail. And then eventually a traveling preacher named Reverend Sims comes to town. This is Charles Bickford. And he somehow both converts Nina to Christianity. He like leads her out of her pact with voodoo and falls in love with her. And it's a, it's a tragic romance, I guess, or I don't know how tragic. I think they do end up happily together at the end.

But there is a twist because it turns out Reverend Sims is actually an escaped convict pretending to be a minister. And then some of Nina's other jealous suitors try to capture him and turn him in for the bounty. But on the way there, they're like on a boat and the boat gets attacked by the sea bat. So they get sea batted. But Reverend Sims survives and he goes back to Nina and I guess they live happily ever after.

Uh, that's what I could piece together reading various synopses online, uh, from the American film Institute catalogs, historical entry on the movie. I just wanted to read a couple of production notes because, uh, they, they, they factor into the stingray or manta ray discussion, uh, quote, according to the telegraph news, the movie with its crew of 62 personnel was quote, believed to be the largest motion picture expedition to leave Hollywood for another American country. Uh,

The production required three Pullmans and two baggage cars with 200 tons of equipment and an inventory of articles taken into Mexico under customs bond covered by more than 1,000 pages and showed a total value of $80,000. The article also claimed that the titular subject of the film, the giant stingray, was filmed for the first time in the sea bat. Yeah.

The giant stingray. Now, I'm not sure what that would be that there is a giant freshwater stingray. But I think this is a creature you find in touch tanks. This is not in captivity. I don't think this is something that is going to be that threatening. And once again, like I said, I couldn't watch the whole movie. But in the clips I saw, there were two different ways the sea bat looked and neither of them looked like a real animal. Hmm.

Anyway, not clear if anybody involved here knew the difference between a stingray and a manta ray, which is Rob. See if you follow me here. I think that's somewhat comparable to the difference between like a great white shark and a whale shark, like pretty different organisms. One's a filter feeder. The other is a predator. Yeah.

Right, right. And even then with the stingray, depending on what type of stingray, you have different forms of feeding that are taking place. But yeah, essentially. Many reviewers of CBAT also say not enough CBAT. CBAT sequences are limited there.

Um, and, uh, yeah. So in the, in the scene I did see of it chasing the boat, it's like attacking the boat as they're out on the water. It's basically jaws. The creature looks like a cross between kind of like a stingray, but also like a shark and kind of a giant silver tuna type thing. The other thing.

killer Manta movie, uh, that you flagged for me is the devil monster, which, uh, was released in several different years. There was a 1936 version, 1946 version, also known as the sea fiend. Uh, this is yet another production, at least somewhat marketed as Ray horror, but it actually features relatively little onscreen Ray action, uh,

So it was first made in 1936, re-edited and re-released multiple times, including in 1946 when it was beefed up with a bunch of exploitation content, which included footage of what appears to be sadly genuine animal cruelty, like forcing live animals to fight each other.

And then also stock documentary footage of native Pacific Islanders just going about their daily life included, no doubt, because this was a way around Hays Code prohibitions on nudity at the time. This was directed by S. Edwin Graham. The basic plot of the 1946 version is about a mission to find a missing sailor whose ship was wrecked on the Galapagos coast.

Uh, though apparently huge stretches of the movie take a break from the main narrative to just show octopus fights or top topless women processing grain. Um, and the climax has several characters forced to battle a giant manta ray that is said to be a threat to the local tuna fishermen. Um,

Um, so once again, you got a, you got a monster manta ray, the monster. So I looked at this part where they're battling the ray and it does look much more clearly like a ray. Unfortunately, I think in this case, that's because it is a real manta ray and the film's action climax is just an unsimulated harpooning of a real animal. Oh, well, that's, that's quite unfortunate.

So from a distance, I'm going to give a preemptive thumbs down to both of these movies. Yeah, I don't think either of these are contenders for weird house cinema treatment. Yeah. But it does raise this question, like, because it's framing them as framing rays as this monster that attacks humans and threatens boats and all this.

Was it common before the modern era to view manta rays as a kind of monster or at least a potentially dangerous animal like its cousins, the predatory sharks?

And yes, I did find evidence that this was just kind of common sailors lore that rays would, you know, could be dangerous, could attack you. They might attack boats. They might attack divers. One article I came across that was recounting some of this folklore was from 1910 by the American biologist Theodore Gill. It's called The Story of the Devil Fish.

That name can be a little confusing because the term devil fish or devil ray is still used today to refer to a number of species within the genus Mobula. And that is the genus to which the manta rays belong. Basically, manta rays are the largest couple of species within the genus Mobula. And then some of the other species within the genus Mobula are often called like devil rays or devil fish.

But the term I think also is still sometimes used to refer to just the rays in this genome more generally. So I know that's confusing. I think the lore Gil is talking about in this article probably does not observe distinctions between devil rays and manta rays as we would sort them today. It's probably just.

sailors are looking at this thing is basically manta ray shaped these things probably look mostly the same to sailors that's got you know it's got the wings and it's got something that looks like horns in the front and it's big so that's one of these devil fish or devil rays and

Gil, in the beginning of this article, attests to common associations made between what he calls the Great Ray and devils, vampires and bats. And he mentions that common names include the sea bat, like in the movie.

And then concerning these associations with bats, he's quoting another author named Holder. And he writes, quote, Holder thought that, quote, no more diabolical creature could be imagined. They resembled enormous bats. And in following one another around the circle, raised the outer tip of the long wing like fin high out of the water in a graceful curve, the other being deeply submerged. But then Gil goes on to say, quote,

Another name for the monster ray has been borrowed from the Spanish. Among the fishermen, and especially the pearl divers of Central America and Western Mexico, it is known as the manta. This is a Spanish term, meaning originally blanket, and was given by the fishermen in parts of Spain and the island of Mallorca to a species of the Mediterranean and extended thence to similar fishes of other regions.

It has been explained that the name was given by the Spaniards of America to the devil fish because it was alleged to hover over and cover a fisherman at the bottom as a blanket preparatory to killing him for good. The belief indeed that the devil fish may so attack a man is not only widely spread, but of an ancient origin.

Such an idea, however, is contrary to our knowledge of the fish. Like several other of the gigantic salations, its diet is an almost inverse ratio to its size.

So already in 1910, Theodore Gill is not going for the Lord that the, that the rays fold down like a death blanket over the divers to cover them on the bottom and prepare them for death. But I did want to say he, I think he is sort of onto something when commenting about the, the idea of the diet being an almost inverse ratio to its size. This is not like a hard and fast rule. And there are very big active predators that prey on large animals. But again,

Yet many of the largest animals in the ocean and the largest species within different marine lineages are filter feeders feeding entirely on tiny organisms and small bits of organic matter. And this is true, of course, of the giant oceanic manta ray. Now, why would that be? If you have a big filter feeding surface and basically like a big kind of bowl shaped mouth that functions like a sieve.

and a big body that can store a lot of energy for time in between feeding booms, it can be an awesomely efficient way to live. And with a large body yourself, you don't need to worry a whole lot about predators. From what I've been reading, the

The only real predators of the giant oceanic manta rays are humans, of course, and maybe some toothed whales like orcas. And I think sharks may sometimes bite them as well, but I understand sharks are not major predators for giant mantas. Yeah, we'll come back to this, but basically that's the case. But with some...

variations depending on exactly where in the world you are, like what, like what, what the actual, what the surrounding, uh, environment is consisting of and, you know, where the mantis are living. Yeah. So in general, there are a lot of upsides to being a big filter feeding organism. If you're big, you don't have to worry much about predators. You don't have to be all that like fast or dangerous or anything. You just kind of have to like cruise around with a

Big filter feeding surface, scoop in a lot of stuff, just take it all in and get huge amounts of biomass going straight into your metabolism and then store a lot of it for later. That's another thing that people often don't think about, about the advantages of having a big body biologically. You know, you think, well, it's good to be bigger if you're in a fight. I mean, sometimes that's true, yes, but it's also just like you've got a big freezer, basically. You can store a lot of energy in that body.

But of course, a big part of this is in doing this as an organism, you become a specialist. Right. So if you're a giant manta ray and you come across some divers in the water, I mean, those divers might be delicious and full of nutrition, but you just there's nothing much you can do with them. Like you don't even have the tools really to eat that diver if you wanted to. Yeah, that ship sailed long ago. Well, one can only imagine that this is based perhaps on the fact that, of course, they're big.

And it's natural for a human being in the water outside of their element to be a little spooked by large fish. I mean, that's common. You encounter that snorkeling. I feel unless I know for certain what I'm looking at, I would be a little nervous around a large fish in the water. And then on top of that, we have this. We've already talked about how their observations of manta rays being curious.

concerning humans. Manta rays more than devil rays, I'm to understand. But that would, of course, add to it. If you're already a little nervous around a big animal and it is even halfway curious about you, that might also lead to this kind of conclusion. Right. And while manta rays are...

very well known for not being aggressive towards humans. I mean, it would still be totally possible for one to just like injure you by accident if you're getting too close. I mean, they're big animals, you know, roll over. So like you just, you know, keep your distance. Yeah. And it's my understanding that as far as any kind of like recording recorded accounts of even minor injuries concerning manta rays and injuries to human beings, uh,

It's involved people getting too close to them, trying to ride them and so forth, which you are not supposed to do. So despite their reputation as diabolical, you know, vampire bats of the sea or some kind of underwater death blanket, no...

giant manta rays or manta rays, generally devil rays as well, are generally not to be thought of as a threat to humans, generally not very aggressive and not anything to be all that concerned about. But there is one other thing I came across in Gil's article that really

Yeah.

Um, so Gil writes quote, uh, it is the great leaps out of the water that are most striking, especially during the stillness of the night holder on such an occasion on the outer Florida reef first encountered the fish. And then quoting holder, he says, quote, there came out of the darkness near at hand, a rushing swishing noise, then a clap as of thunder, which seemed to go roaring and reverberating away over the reef, like the discharge of a cannon.

Not hard to imagine how that could engender a sense of fear about this animal. Absolutely. Yeah. The authors of The Guide to Manta and Devil Rays of the World, Stevens et al., they mentioned that if you're in the water when this happens, you definitely feel it. Yeah.

So, yeah, mantas and devil rays all engage in leaping behavior like this, sometimes several meters out of the water. And it's unknown exactly why they do it, which I guess is similar to other fish, which we've talked about on the show in the past. But the predominant theories involve either the dislodging of parasites. And as we'll discuss in, I think, the next episode we do on mantas, they carry a pretty large parasite load. The other possibility is communication.

Now, the authors note that this would mean there's much more to their social interaction than is often thought. But the basic hypothesis here is that these different mobilid species, especially the manta, they slap back down on the surface of the water. And in doing so, they create a pressure wave, this thunderclap that you referenced, that could then be detected by humans.

other rays of the same species miles away. Given that they're often observed leaping before feeding, they could be alerting other mantas to a feeding opportunity. Oh, interesting. Okay. And why would they do that? Because that's another, why would you want to tell the other rays about all this great food you just found? Well, the authors point out because food is plentiful, but the opportunity itself for it to feed is fleeting.

subject to the tides and so forth. So the signal might be to bring in as many fellow rays as possible to engage in group feeding strategies, which we'll get into in a bit here, that also increase individual food halls. So, you know, let's all do it while the getting's good. Let's all feed together and we'll all feast.

Ah, interesting. Okay. And then on top of that, some devil rays might engage in breaching as a fitness signal for mating. But again, that's again, that's a hypothesis based on just how it seems to time with other things that they're doing in the water.

At any rate, as we get back to human sentiments about manta rays and the idea that they're vampiric death blankets and so forth, Western sentiments seem to turn in a major way during the 1970s, despite the Jaws movies, with exposure to the reality that manta rays are anything but the devil fish of a sailor's legend. Yeah.

You know, they are the epitome of a gentle giant, indifferent or even curious considering humans in the water and not aggressive at all. Again, I think the rare cases you'll find of people being injured at all by a manta are because they were intentionally trying to get way too close to them.

And as far as the harvesting of their gills goes, manta tourism has apparently been a major factor thus far in the fight against this practice. People around the world continue to spend a lot of money to observe manta rays in the wild.

In that 2018 Guide to the Manta and Devil Raises the World book, the authors share that at the time of its publication, the global estimate for direct revenue generated by Manta tourism was something like $73 million annually, with associated tourism revenue pushing that up to like $140 million annually.

So all of that basically translates to the realization that if manta tourism is in the mix, a live manta ray is worth far more than a dead one. And so manta tourism, like a lot of marine tourism, plays an important role in manta conservation. At the same time, of course, there's a careful balance there, right?

Because you want people to be excited about the mantas. You want people to come out and see the mantas, spend money on the mantas and thus helping to protect them. But also you want to avoid detrimental side effects, you know, that can occur in a number of forms. You don't want divers and snorkelers getting way too close to the animals.

You also don't want unsustainable practices at resorts and on liveaboards and so forth. You know, the ships are going to take divers and snorkelers out to see these creatures. You know, you have to walk that line. And I think my understanding is that everyone involved continues to figure out exactly where that line falls. ♪

This July 4th, celebrate freedom from spills, stains, and overpriced furniture with Anabay, the only machine washable sofa inside and out where designer quality meets budget-friendly pricing. Sofas start at just $699, making it the perfect time to upgrade your space. Anabay's

pet friendly stain resistant and interchangeable slip covers are made with high performance fabric that's built for real life you'll love the cloud like comfort of hypoallergenic high resilience foam that never needs fluffing and a durable steel frame that stands the test of time with modular pieces you can rearrange anytime it's a

sofa that adapts to your life. Now through July 4th, get up to 60% off site-wide at washablesofas.com. Every order comes with a 30-day satisfaction guarantee. If you're not in love, send it back for a full refund. No return shipping, no restocking fees, every penny back. Declare independence from dirty, outdated furniture. Shop now at washablesofas.com. Offers are subject to change and certain restrictions may apply.

American history is full of wise people. What women said something like, you know, 99.99% of war is diarrhea and 1% is gory. Those founding fathers were gossipy AF and they love to cut each other down. I'm Bob Crawford, host of American History Hotline, the show where you send us your questions about American history.

And I find the answers, including the nuggets of wisdom our history has to offer. Hamilton pauses and then he says, the greatest man that ever lived was Julius Caesar. And

And Jefferson writes in his diary, this proves that Hamilton is for a dictator based on corruption. My favorite line was what Neil Armstrong said. It would have been harder to fake it than to do it. Listen to American History Hotline on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

Are there any pictures of you online? I'm not just talking about Google. I'm talking anywhere. Clearview scrapes together images from Facebook, from LinkedIn, from Venmo accounts. That database is now being used by police departments all across the country to match criminal suspect photos. And sometimes it makes mistakes.

So in this one case, two of the search results that I think were in the top 10 of the search results were Michael Jordan. It's a picture of Michael Jordan. But cops are still using it to make arrests. Police, they are trusting this software to lead them to the right suspect. But you're not even being told that it was used, let alone given any of the details about how it works. This is not Minority Report.

This is happening right now. People are getting arrested and doing actual time in jail after being picked out by a computer. I'm Dexter Thomas, host of Kill Switch, where every Wednesday we explain the right now of living in the future. You can turn off the computer, but do not let the computer turn you off. Listen to Kill Switch in the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. OpenAI is a financial abomination.

a thing that should not be, an aberration, a symbol of rot at the heart of Silicon Valley. And I'm going to tell you why on my show, Better Offline, the rudest show in the tech industry, where we're breaking down why open AI, along with other AI companies, are dead set on lying to your boss that they can take your job. I'm also going to be talking with the greatest minds in the industry about all the other ways the rich and powerful are ruining the computer. Listen to Better Offline on the iHeartRadio app, Apple Podcasts, wherever you happen to get your podcasts.

So at this point, I thought we'd run through some basics about manta rays and some associated devil rays to finish out this episode. So mantas and devil rays belong to a group collectively known as the Mobulids of the family Mobulidae.

Zooming out, they're rays of the order Myelobatiformes, which contains 12 families, 370 species of rays, including stingrays of various species. Mobolids are most closely related to eagle rays and clown nose rays of this order, which are bottom feeders. They sift for mollusks and crustaceans on the seabed.

Mobulids, however, have adapted to pelagic filter feeding in the open water, similar to the evolutionary path we see with like baleen whales and whale sharks, as we've been discussing, like specialize in feeding on all the little things in the water.

Eat the cloud, if you will. Yes. So they use their mouths and modified gill plates in their filter feeding. The devil ray that we've been discussing, these are much smaller. There are a few different varieties with the largest, I believe, being the Chilean devil ray or sicklefin devil ray. It has a maximum disc width of 11.2 feet or 340 centimeters, and it can weigh up to 882 pounds or 400 kilograms.

The spine-tailed devil ray is also rather big. I mention it because its scientific name is Mobula mobular, which is always fun. And again, the reef manta ray, Mobula alfredi, which sounds delicious, but it's not on the menu, comes in at a maximum disc width of 15 feet or 450 centimeters and a weight of 1,500 pounds or 700 kilograms.

But then again, the oceanic manta is the biggest. That's Mobula birostris, and it can reach a disk width of 23 feet or 700 centimeters and a weight of up to 4,400 pounds or 2,000 kilograms. They are the largest of all rays. And actually, I'm to understand the fifth largest fish period.

There's also some argument to be made for a possible third species of extant manta, a Caribbean manta, closely related to the oceanic manta, only smaller.

Now, in addition to those gill plates, the other defining characteristics of the mobolids are their devil horns. That certainly seems to lend to this idea that there's some sort of evil vampiric creature. They're like bats, and then they have devil horns. These are not horns, of course. These are modified cephalic fins.

So the rays use these special fins to funnel plankton into their mouths during feeding. So the gill plates that we were describing, these are supported by five pairs of gill arches. You can see these when you see some like wide mouth photographs of these various organisms.

And each species boasts slightly different gill plate structures to capture particular target prey. We were talking about the ratio between the size of the organism and the size of the prey. Manta rays, the biggest, have gill plates evolved to capture much smaller plectonic prey compared to various devil ray species, for example. They're going after the real small stuff.

Their feeding is really interesting, though, on top of this, because their bodies are, you know, we think of them as being largely flat. You know, they're kind of flattened out. But as Stevens and co-authors point out, during feeding, quote, their once flattened body and mouth becomes a giant black hole with the pectoral fins serving as wings that power the ray through the water. And then the gill plates do the rest. So, yeah, they expand out. They become this like giant gaping maw.

to just consume all the plankton they can get. And so that's the basic strategy. Open your mouth really wide, use your cephalic fins to help guide the food into the mouth, and then go in a straight line. Just go straight through the food. You know, eat the cloud. But that's just one of eight and possibly nine different observed feeding strategies that you see in rays, with only half of those being used, at least observed, in devil rays.

So I'm going to roll through these because they're pretty interesting. Some are only slight variations based on the other ones. So first of all, you have straight feeding. So this is usually horizontal, but sometimes it's vertical. And the distance depends on prey frequency. So you have a cloud of plankton, a big school of plankton or something. Well, you just move straight through it. Eat it, eat it up, swallow it up. And then you do a 180 degree turn at the end and repeat as needed.

Number two, this is mantas only, apparently, and it's surface feeding. So this is basically straight feeding except right at the surface of the water. All right. All right. Now it starts getting interesting. Chain feeding. So up to several dozen individuals proceeding in a line feeding.

Oh, it's funny that that would actually work. I would imagine the further back you are in the line, maybe you're not getting anything. But I wonder if going through a head kind of creates a vortex maybe that sucks some more things in. I think that that might be what's happening. And also, we just have to remember that we're dealing with an abundance of food here. And this ties in. This is exactly, this is an example of the social feeding technique, group feeding technique that they might hypothetically create.

be calling other mantas to engage in. Hmm. Okay.

Up next, piggyback feeding. So this is mantas only, and it's actually only been observed in reef mantas. So you'll have a smaller manta, usually a male, and it finds a larger, usually female, matches her pace, and is like stacked on top of her and feeds as she's feeding in a straight line. And sometimes you'll get additional mantas stacked on top of that until the bottom most manta swims off and displaces the whole stack.

All right, here's where it gets a little fancy, somersault feeding. So this is where they're going in a straight line and then they'll do a 360 degree loop in the water while feeding. Usually just one or two loops out of straight feeding, but they might do several dozen continuous somersaults, depending, I guess, on how it's going for them with the plankton.

This next one, though, this is where it gets, this one gets crazy. Cyclone feeding. What? Yeah. So this is apparently reef mantas only, at least as far as observations go. And it begins as just a line of chain feeding straight feeders. But then, you know, something, something changes. You know, maybe it's in just how much plankton they're encountering, but the chain loops back on itself to form a circle.

And now we have a circle of mantas feeding. And then more mantas begin to form, to join in and become part of the formation. And so we end up with a counterclockwise cyclone that might ultimately entail 150 individuals, and it might even last up to an hour. And again, the idea here seems to be that these mantas

These group feeding scenarios, when they're able to pull them together, it actually results in a bounty for everyone involved. On top of this, we have sideways feeding. This is maybe not that fancy. It's just the manta ray doing chain feeding or straight feeding, but on their sides. Then we have bottom feeding, which I guess you can think of as a return to form, feeding along the bottom like some of the other rays that they're more distantly related to.

And then a ninth possible feeding technique that the authors here observe in devil rays is what they call lunge feeding. And that's rapid feeding acceleration into dense schools of prey. Again, this would, I think, only be devil rays, which are going to be, you know, the smaller of the species involved here. Mm-hmm.

So mongolids first pop up in the fossil record some 28 million years ago during the Middle Oligocene Epoch. So according to Stevens et al., they're among the most recently evolved of the Elasmobronx. This includes all sharks and batomorphs. So, you know, sharks, rays and so forth, the various cartilage fish swimmers of the oceans.

They've evolved to, of course, become exceptional open water swimmers with sufficient speed bursts of up to, I believe, 20 miles per hour or 33 kilometers per hour. And this was interesting. And I have trouble exactly understanding how this works, but I totally believe it. They say that their flattened shapes apparently make it more difficult for predators to bite onto them, hold onto them, or certainly to target vital areas that way.

Okay. Yeah, I wonder how that would work. Because I would imagine, you know, if you're kind of cookie-shaped, if you're flat, it might not be that hard to take a bite of you. But I wonder if doing that, you're maybe able to keep your most vital parts kind of central. So if something does bite you, it gets a less vital part of you. Yeah, like maybe you're more...

It's more possible that you get a bite of a fin or wing, if you will. Yeah. This is something they get into in the book. They do rapidly heal from serious injuries. The book displays a few different rather dramatic examples via photographs of rays with clear bites taken out of their fins, out of their wings. And then a subsequent photo showing how those massive rays

bites have mostly, but you know, imperfectly healed at a later observation date. And I mentioned this already, but predation rates also seem to depend on particular communities and environments. So for example, the authors of this book point out that mantas in Mozambique display far more evidence of shark attacks compared to those in the Maldives, where less than 15% of mantas show evidence of bites.

Yeah, I think I was specifically reading about off the coast of Mozambique where there was common evidence that mantas had been bitten by sharks but had survived the encounter because they grew up and the wounds healed. Yeah. And the healing of those wounds also involves some of the cleaning fish, which we'll get back to in the next episode we do on mantas. Cool.

All right. Well, we're going to go and close this episode of Stuff to Blow Your Mind, but we're going to be back. I don't think it's going to be this week. I think it's going to be next week based on the way the schedule is coming together. But we'll be back with at least one more episode on the manta ray, if not a couple. We'll just see how it comes together.

Just a reminder for everyone out there, the stuff to blow your mind is a science and culture podcast with core episodes on Tuesdays and Thursdays. On Fridays, however, we set aside most serious concerns to just talk about a weird film on Weird House Cinema.

wherever you get the podcast, we just ask that you rate and review us. Give us a few stars. That helps us out. And if you want to follow us on social media, let's see, we're STBYM Podcast on Instagram. That's our more recent Instagram account that we're still trying to build back up. Let's see, if you want to follow Weird House Cinema, we're on Letterboxd.com.

We are Weird House on that platform. And yeah, you can otherwise just get the podcast wherever you get your episodes of podcasts. Huge thanks, as always, to our excellent audio producer, JJ Posway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello, you can email us at contact at stufftoblowyourmind.com.

Stuff to Blow Your Mind is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app. Apple Podcasts are wherever you listen to your favorite shows. ♪♪♪

This July 4th, celebrate freedom from spills, stains, and overpriced furniture with Anabay, the only machine washable sofa inside and out where designer quality meets budget-friendly pricing. Sofas start at just $699, making it the perfect time to upgrade your space. Anabay's pet-friendly, stain-resistant, and interchangeable slipcovers are made with high-performance fabric that's built for real life. You'll love the cloud-like comfort of hyper

We'll be right back.

Today's episode is brought to you by USPS. I know, I know you've got your shipping game on lock, but did you know with USPS Ground Advantage service, it's like your shipment has a direct line to you.

You're in the loop the whole time. It leaves the dock, you know about it. It's on the road, boom, you know. And when it reaches your customer, you guessed it, you're in the know again. Here's the real game changer. It's one journey, one partner, total peace of mind. Check out USPS Ground Advantage service at usps.com slash in the know. Because if you know, you know.

I'm Bob Crawford, host of American History Hotline, a different type of podcast. You, the listener, ask the questions. Did George Washington really cut down a church tree? Were JFK and Marilyn Monroe having an affair? And I find the answers. I'm so glad you asked me this question. This is such a ridiculous story. You can listen to American History Hotline on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

Are there any pictures of you online? Then you could already be in a massive police database without even knowing it. Clearview scrapes together images from Facebook, from LinkedIn, from Venmo accounts. I'm Dexter Thomas, host of Killswitch, a podcast about how living in the future is affecting us right now. Police, they are trusting the software with this magical ability to lead them to the right suspect. In this episode, we dive into how cops are using AI and facial recognition and sometimes getting it wrong and

This is an iHeart Podcast.