The Manta Ray, Part 1

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.

fish could eat their parasites. 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.

where you find the Missoul 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 side 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 Missoul Foundation, they manage about three hundred thousand acres or twelve two hundred square kilometers of marine

reserve with two distinct no take zones. They engage in various conservation efforts, such as the Missoul Manta Program, a reshark program, and this includes a program to reintroduce Indo Pacific leopard sharks, and they partner with various organizations of various like aquariums around the world old who have the right eggs egg secs to reintroduce and their partners include

Atlanta's own Georgia Aquarium. They're also involved in coral reef restoration, sustainability efforts in various community outreach and education programs.

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 six hundred reef building coral species, seventy five percent of all species known to science, three thousand species of reef fish, forty percent of the world's coral reef species, and six of the world's seven marine turtle species. Also three quarters of known molluscs.

They can weigh up to fifteen hundred pounds or seven hundred kilograms, and that's with a maximum disc width of fifteen feet or four hundred and fifty centimeters if you were. I guess you could sort of frame that as their wingspan if you want.

the animal that they have not experienced with any other fish. Because, to be clear, the manta is not like a mammal like dolphins or whales might be that you might be more you know, disposed, 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 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.

that we swam with them. I guess you could technically say we swam them with them. We're in the same button body of water with them, but we did keep our distance. We did not chase the manta rays, and we certainly did not attempt attempt to touch these gentle giants of the sea.

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 life, 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 amongst 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 of pseudoscientific idea, the consumption of these gills in some sort of like powdered driver and or powdered form can boost the human immune system, among other supposed benefits, and the story of how this is

really interesting in its own right. I was reading about this in a paper by O'Malley at All titled characterization of the Trade in Manta and Devil ray gill plates in China and Southeast Asia through Trader Surveys, published in twenty sixteen 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 nineteen

seventy six. This to be clear, despite the fact that traditional Chinese medicine itself is very very old, going back like five thousand years, a widespread and popular form of alternative medicine. But the consumption of these gill plates is not some sort of deep seated tradition in this alternative medicine practice.

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. They also note that the rise in popularity may also tie in with the rise in human respiratory illnesses do in part to pollution, and again these pseudoscientific claims. Basically, we're dealing with the idea that, Okay, the 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 the populations of these vulnerable fish species. The reef manta is currently flagged as vulnerable, while the giant oceanic manta is endangered.

like the real kind of Z grade copycats. You know, in the nineties and two thousands there were just ten billion direct to video shark movies made.

manta rays are fine. They're like 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.

kind of marketed that way. So one of these movies is called The Sea Bat Sea, not c the letter Sea Bat Sea Bat From nineteen thirty This is a pre code American romantic melodrama directed by Wesley Ruggles. Apparently, in early production, Todd Browning was somehow attached to this, and it was maybe supposed to be a vehicle featuring

Lon Cheney, but that never worked out. So this was directed by Wesley Ruggles, shot in Mexico, starring Charles Bickford, Raquel Torres, and Nil's 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 thirty one.

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 sting ray, which, as we'll discuss more throughout the series, that those are not the same thing, though some publications describing the movie seem not to recognize that there is a difference. I think they just think, like

mantray's our stingrays same thing. 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 water line and it looks

just more like a giant shark or tuna type creature. Anyway, After the tragic loss of Carl in this sea bat related incident, the character Nina starts getting into voodoo and then declares that she will marry any man who can kill the dreaded sea bat. 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 leads her out of her

pact with Voodoo and falls in love with her. And 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 they I guess they live happily ever after. That's what I could piece together reading various nazis online from the American Film Institute Catalog's historical entry on the movie. I just wanted to read a couple of production notes because they factor into the Stingray or Manta Ray discussion quote. According to

the Telegraph News. The movie, with its crew of sixty two personnel, was quote believed to be the largest motion picture expedition to leave Hollywood for another American country. The production required three pullmans and two baggage cars with two hundred tons of equipment, and an inventory of articles taken into Mexico under customs bond covered by more than one thousand pages and showed a total value of eighty thousand dollars.

The article also claimed that the titular subject of the film, the Giant Stingray, was filmed for the first time in the sea bat.

released in several different years. There was a nineteen thirty six version, nineteen forty six version, also known as The Sea Fiend. This is yet another production at least somewhat marketed as ray horror, but it actually features relatively little

on screen ray action. So it was first made in nineteen thirty six re edited and re released multiple times, including in nineteen forty six 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 Hayes Code prohibitions on nudity at the time. This

was directed by s Edwin Graham. The basic plot of the nineteen forty six version is about a mission to find a missing sailor whose ship was wrecked on the Galapagos, 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, 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.

So once again you got a monster manter 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.

like its cousins, the predatory sharks. And yes, I did find evidence that this was just kind of common sailor's 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 nineteen ten by the American biologist

Theodore Gill. It's called the Story of the Devilfish. That name can be a little confusing because the term devilfish 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 mobular are often called like devil rays or devilfish.

But the term, I think also is still sometimes used to refer to just the rays in this geno 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's 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 devilfish or devil rays. 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 winglike 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 devilfish because it was alleged to hover over and cover a fisherman at the bottom as a blanket preparatory to killing him for good. Indeed, that the devilfish 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 selations, its diet is in almost inverse ratio to its size.

So already in nineteen ten, Theodore Gill is not going for the lore 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 I think he is sort of onto something when commenting about the idea of the diet being in 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 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 manterray. 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 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.

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.

a large fish in the water. And then on top of that, we have this we've already talked about how there are 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.

because of the sonic atmosphere it creates. And this is Gil describing the experience of what it's like to be around one of these giant rays jumping out of the water, which they often do. So Gil writes, quote, it is the great leaps out of the water that are most striking,

especially during the stillness of the night. Holder, on such an a case 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.

But the predominant theories involve either the dislodging of parasites, and as we'll discuss and I think the next episode we do on mantas, they geary a pretty large parasite load. The other possibility is communication. 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 reference that could then be detected by 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.

the getting's good. Let's all feed together and we'll all feast. Ah.

in the water. At any rate, as we giving 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 nineteen seventies despite the Jaws movies, with exposure to the reality that manta rays are anything but the devilfish of a sailor's legend. 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 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 twenty eighteen Guide to the Man and Devil Rays of the World book, the authors share that at the time of its publication, the global estimate for direct revenue generated by manta tourism with something like seventy three million annually, with associated tourism revenue pushing that up to like one hundred and forty 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 manti 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 manta, 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 liver boards 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 in my understanding is that everyone involved continues to

figure out exactly where that line falls. 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 mantis and devil rays belong to a group collectively known as the Mobulids of the family mobili day zooming out there rays of the order milio Batiforms, which contains twelve families, three hundred and seventy species of rays, including

sting rays of various species. Moboloids 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. Moboloids, 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, you know, 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 sickle fin devil ray. It has a maximum disc width of eleven point two feet or three hundred and forty centimeters, and it can weigh up to eight hundred and eighty two or four hundred kilograms.

The spinetail 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 fifteen feet or four hundred and fifty centimeters and a weight of fifteen hundred pounds or seven hundred kilograms. But then again, the

oceanic manta is the biggest. That's Mobula birostras, and it can reach a disc width of twenty three feet or seven hundred centimeters and a weight of up to forty four hundred pounds or two thousand 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 extent 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 mamboloids are their devil horns. That certainly seems to lend to this idea that there's some sort of evil, vampiric creature there. 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 both 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 they're feeding. Is really interesting though, on top of this, because their bodies are you know, 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 you know, 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 they're pretty interesting. Some some are only slight variations based on the other ones. But 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 plankedin or something. Well, you just move straight through it, eat it, eat it up, swallow it up, and then you do a one hundred and eighty degree turn at the end and repeat as needed. Number two this is manta's 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.

in reef mantas. So you'll have a smaller manta, usually a male, and it finds a larger usually female, matches her pace, and it's 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.

Summer salt feeding. So this is where they're going in a straight line, and then they'll do a three hundred and sixty degree loop in the water while feeding, usually just one or two loops out of straight feeding, but they might do several dozen continuous summer salts, depending I guess on how it's going for them and with the plankton. This next one, though, this is where it gets. This one gets crazy cyclone feeding. What Yeah, so this is a parent 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 the how much planked in their 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 one hundred and fifty individuals and it might even last up to an hour.

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 the smaller of the species involved here. So mangoloods first pop up in the fossil records some twenty eight million years ago during the Middle Oligocene epoch, so according to Stevens at All, they're among the most recently evolved of the elasmo Bronx. This includes all sharks and battomorphs, 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 up to a belief twenty miles per hour or thirty three kilometers per hour. And this was interesting, And I have trouble exactly understanding this how this works, but I totally believe it. They say that they're flattened shapes apparently make it more difficult for predators to bite onto them, hold onto them, or certainly to target vital areas that way.

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 mantis and Mozambique display far more evidence of shark attacks compared to those in the Maldives, where less than fifteen percent of mantis show evidence of bites.

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 the 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

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