SciShow Tangents - Predators with Jaida Elcock!

Episode Date: August 20, 2024

Here in the remote vistas of the Tangents jungle, observe a group of mighty science communicators expertly stalking their primary prey: knowledge. Ever so tantalizing to behold, knowledge lounges in the shade of a fern, oblivious to the danger sneaking up behind it, ready to strike at a moment's notice! Truly, these must be the most fearsome of all predators!SciShow Tangents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! Head to www.patreon.com/SciShowTangents to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter! A big thank you to Patreon subscriber Garth Riley for helping to make the show possible!And go to https://store.dftba.com/collections/scishow-tangents to buy some great Tangents merch!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen[This, That, or the Other: Munch Squad]Barnacle and crab-eating animal in North American oceansBird-eating ungulate in captivity Small mammal that ate raptor’s meat meal instead of being eatenhttps://new.aquaticmammalsjournal.org/wp-content/uploads/2010/10/29-01_Courbis.pdfhttps://www.researchgate.net/publication/340941147_Do_lowland_tapirs_Tapirus_terrestris_eat_meat_Evidence_of_carnivory_in_a_large_South_American_herbivorehttps://link.springer.com/article/10.1007/s10344-015-0980-yhttps://bioone.org/journals/annals-of-the-entomological-society-of-america/volume-105/issue-1/AN11057/Opportunistic-Carnivory-by-Romalea-microptera-Orthoptera-Acrididae/10.1603/AN11057.short[Fact Off]Late-stage bamboo shark embryos have electroreception within their egg case Collaborative hunting gestures in coral reef residents (e.g. groupers or coral trout and moray eels)https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040431https://www.nature.com/articles/ncomms2781https://www.cell.com/current-biology/fulltext/S0960-9822(14)00885-9https://www.nationalgeographic.com/science/phenomena/2013/04/24/groupers-use-gestures-to-recruit-morays-for-hunting-team-ups/[Ask the Science Couch]Bioaccumulation and biomagnification of pollutants in the food web (including humans)https://www.fisheries.noaa.gov/feature-story/toxic-killer-whaleshttps://www.sciencedirect.com/science/article/abs/pii/S0048969722022549  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10212926/https://www.sciencedirect.com/science/article/pii/S0160412021002671https://link.springer.com/article/10.1007/s11356-013-1722-xhttps://www.acs.org/pressroom/tiny-matters/plastic-micro-plastic-everywhere-what-does-it-do-and-why-should-we-care.htmlPatreon bonus: Sharks have cartilaginous skeletons https://www.ncbi.nlm.nih.gov/books/NBK557576/https://www.sciencedirect.com/science/article/abs/pii/S0944200606000080?via%3Dihubhttps://magazine.scienceconnected.org/2015/12/preserving-soft-skeleton-backs-without-bones/https://onlinelibrary.wiley.com/doi/full/10.1111/jfb.14444https://journals.biologists.com/jeb/article/221/24/jeb188318/20570/Mechanical-behavior-of-shark-vertebral-centra-at[Butt One More Thing]Coprolites show that Smok wawelski (an archosaur from the Late Triassic) was eating boneshttps://www.nature.com/articles/s41598-018-37540-4https://www.eurekalert.org/news-releases/838032

You're listening to a Complexly Podcast. Hello and welcome to SciShow Tagin, such a delightly competitive science knowledge showcase. I'm your host, Hank Green, and joining me this week,ents, which is the lightly competitive science knowledge showcase. I'm your host Hank Green and joining me this week as always is science expert and Forbes 30 under 30 education luminary, Sari Riley! Hello! And of course also our resident everyman, the one and only Sam Schultz. Hello! And also also we have a special guest today, another science expert. For the past four months she's been our SciShow resident, which is a real thing that we recently created She is a shark scientist finishing up her PhD with research focused on the movement ecology of basking sharks It's marine biologist, Jada Elcock

Howdy! How's it going? How are the sharks? The sharks are great. It's summertime. So they're out and about they're hanging out I'm excited because in August, I'm gonna go jump in the water and put some tags on some sharks and learn more about what the heck they're doing out here. So I'm super excited. If you were gonna get, let's say, Hank, you have to put a tag on a shark, I would choose a basking shark. Yes, yeah, yeah, yeah.

Well, so the basking sharks are the ones that are really hard to find. This summer has been like an anomaly. They're like kinda everywhere. So I had to pivot some of my research to whale sharks instead. But also whale sharks, you know, similar vibe. I actually if you if you'd ask me, I would have said that whale sharks are harder to find. I have no idea why I feel that way.

They seem elusive. But once you know where to find them, they're there in some pretty decent numbers. They're just out there all the time. Like every minute of your day, there's a whale shark. Like there's just a bunch of whale sharks doing their own day. I think about that a lot. I'm just like, animals just exist outside.

There's no inside for them to go to. And that's their normal. I'm like, wow, that's kind of wild. Yes, they're inside, but they're inside the water. They have no idea what's going on up here. Which God bless them, if only. They'd be really disappointed if they found out what was going on up here too, I think. They would be so disappointed.

They're like, why are you, what are you guys doing? Then they can't exist in 3D space the way that like they do in the water. We're stuck to ground all of the time. Yeah, I wish, this is what I wish either I had gills so I could swim and like exist in the water or that I had wings and I could fly. Just I wanna exist in 3D space. It really, it's a real ridiculous notion. And in fact, kind of unusual on earth

to be stuck to surfaces the way that we are. Yeah, I don't like it. It's restrictive. Most animals are not stuck to surfaces, though they do have certain amounts of areas that they can traverse without problems starting to happen in the water. Unless you're a sessile animal and then you're quite literally stuck to surfaces. I guess there's a lot of wet animals that are stuck to surfaces. Is that like a barnacle or something?

Yeah, like a barnacle or an anemone. Anemones can kind of pop off and swim, which is weird, but like, you know, the ones that are stuck. How are the, I shouldn't ask that because it might be sad, but how are the sharks? Yeah, I mean, well, if you're looking at white shark populations on Cape Cod, they're doing great. They're recovering. They're bouncing back after they like disappeared because we like hunted all the seals and now the seals are recovering. So the white sharks are coming back. Some people aren't thrilled about that but the scientists are. When you say white shark do you mean the the biggest scariest of them? The big great white shark? The great white shark yeah. I feel like great white shark implies the existence of a lesser

white shark and there is not one so it's just the white shark. So you just call it a white shark? I like this branding change because I do have a certain idea of a great white shark. It does say, I will eat your whole leg in one bite, but also is not changing their faces. Yeah. They're gonna still gonna have that face that says I will put your whole leg in my mouth. I think their faces are so cute though.

And I know that I'm in the minority here, but I just, I don't know. I've seen, there's like a picture, maybe it's not a white shark, but a shark that's like biting like a book propeller and it just looks so like puppy, adorable. And I'm just like, hello, friend. I will not pet you, but hello from a distance.

So cute. I think we need to reclaim the word great and just put it in front of all sharks, like the great whale shark or the great basking shark. Like all sharks are great. That's why the word is that's why the adjective is there. I fully support this. I never thought about the fact that there wasn't just like a white shark

in addition to there being a great white shark. You know, we don't need to bring down the great white shark in order to uplift the other sharks. So just great in front of all of them. And it's wonderful. Yes. Either you take the great off of and they're just white sharks or you add great to every single shark So that they don't feel bad common names are made up. Anyway, I'm just gonna start doing that

And if you do it then you're a scientist, so we'll all start doing it I mean we have the power like we run sideshow we can call things whatever we want Yeah, we're saying words for the first time ever constantly Yeah, we're saying words for the first time ever constantly. We're like, constantly in the studio, look up the pronunciation of words and it will play a SciShow video. And we're like, oh, I guess that's the one. I love that. Yeah.

All right. Well, every week here on SciShow Tangents, we get together to try to win a maze and delight each other with science facts while also trying to stay on topic. Our panelists are playing for glory, but also for Hank bucks, which I will be awarding as we play and at the end of the episode one of these people will be crowned the winner. But first, as always, we will introduce this week's topic with the traditional science poem this week. Thank you from Jada. Think of a leopard way up in a tree eating a carcass with much joy and glee or maybe some wolves running around with their packs just howling at moons and sniffing their cracks. How about an otter eating urchin's galore? Good thing because

without them, kelp forests would be no more. What do these creatures all happen to share? They're predators, duh. They eat meat, not eclairs. There are so many types in water, air, and land, and they matter to ecosystems, so give them a hand. I wonder which predator leaves you in awe, because sharks are the coolest predators I ever saw. The topic for the week is predators! But before we dive in, we will take a short break and then be back to define what the heck that is. I'm a predator.

Am I a predator? Do I have to do the killing myself? Question mark. Feels like I do. I think you might have to. Otherwise, you're a scavenger. Oh, my God. Are we all scavengers except for the ones who work at the factories where the meat

goes? And I guess you could you could debate, are we social predators in that? Yeah. Like, are we are we technically a pack hunter where somebody else is killing the food for us and bringing it to bring it to me? Yeah. The farmer who harvests the corn, who brings it to me, is just my friend. And that's Tak, being a social predator. Yeah, except it's not corn. We're not talking about corn. Well, this is the other thing.

Predation is if you eat anything else alive and you totally kill it. Uh... So, we think predators are meat eaters like carnivores, but if you are a plant eater, if you're a herbivore and you eat the whole plant, you kill it. You have to kill it. You're a predator. Yeah. How often is that actually happening though?

That a deer is eating an entire bush. You know what I mean? Yeah. I feel like that's why maybe they're not predators. Well, but that that certainly like there are lots of like phytoplankton that get eaten in their entirety. So so I guess a copepod, I guess a copepod is a predator. Just eating the whole algae cells. And this is where I think it gets a little bit.

But like egg predation. So snakes can go eat bird eggs or whatnot. And so what happens when you eat the egg equivalent of a plant? So seed predation is a type of being a predator, is where mammals, birds and insects eat seeds from a plant. You eat all the seeds and you're not just making this up. This is really how this is real. This is like Hoping that that Sarah was just

Doing a bunch of weird He was waiting for the LOL JK. Yeah, just kidding. No, this is No, this is really what predators are predators are anything that kills something to eat it, regardless of whether that something has bones and blood and stuff. OK, so the word predator is completely devoid of any meaning. The concept of is just nothing. It's just eating something. It means very specific thing. I feel like this is of things.

To kill and eat. You kill something that was alive and you totally kill it and you eat it. Including seeds, which may or may not be alive. Yeah, that's like the fuzzy. If you if you think of seeds as eggs, of plant eggs, then like fertilized plant eggs, then yes. But for most cases, it's pretty straightforward. You watch an animal kill another animal and you're like, that animal is dead. It's eating it. That's a predator.

I can't wait for me and Sarah to write a book about what life is so that we can make it clear to everyone why it's totally chill for a seed to not be alive. We can just make the rules. We can make the rules. Sarah, do we know where the word comes from? We do. It comes from classical Latin, and it's been the same word for a while.

It's been predator. But it specifically meant a, like a plunderer or pillager. It feels like piracy to me. If you're a predator, you're robbing things. And if you're a predator, you live on the things that you've plundered. We think the first record of predator becoming a biological term was when it was used to describe a group of beetles that ate other insects. And so they saw beetles that ate other insects and they were like, those guys, they're predators. They're looters. They live on booty and plunder and the booty is other insects. And then in 1862-ish, then we think it was applied more broadly to animals that prey on one another.

I'm so confused as to what we were using to describe predators before that. Or we just like, hey, it's that thing that ate another thing. Yeah. Yeah. I'd be real. I'd actually be really interested to get it, because there was all there's there's been over the course of humans a lot of times where we assign, you know, a kind of morality to animals. And I know that for a long time, any animal that ate other animals was seen to be in some way immoral, unless it was a human, in which case it was fine. But I'd wonder if, like, maybe it was just sort of classified as in some more subjective, bad guy kind of way.

My brain went in a totally different direction where it's just like, they were being like really specific and they were like, wolves are deer, vores, and then everything is so specific. And then it's like, there are too many words, predator, just encompass it all. I also liked that the word prey actually comes from predator, which I just looked up.

So that it's from the same root. And so we had this word of predator and then we had to create the word for the thing that got robbed of its life. Robbed of its life was such an aggressive like. Yeah, it's like that original Latin word meant like to rob, like to steal and the thing that is being stolen got transferred from like people living off of the thing that is being stolen got transferred

from people living off of the stuff that they stole from other people to animals living off of the life they stole from other animals. Wow. I mean, that's basically, that's the thing is when you look at animals too, they're not so clean cut.

If you think, oh, deer, they're chomping on little bushes. Deer just walk around being like, I could eat that. I will eat anything. Baby bird, I could eat that. Egg on the ground, I could eat that. I will be bird. I could eat that. Yeah. Egg on the ground. I could eat that. I don't know. So that's all animals.

Almost any predator would happily eat a chocolate eclair. Yeah. Yeah. Exactly. Would a shark eat an eclair? How would a shark feel about an eclair? I feel like it would, especially if it's a tiger shark, it would eat it because tiger sharks

eat literally anything and everything. I was doing field work and they like to vomit up their stomachs, tiger sharks. Do they come out of their mouth? Yes, and then they like swim with their mouths open and it like shoves it back in place. But one of them like vomited up like rotting sea turtle and it smelled so bad that everyone on the boat was just like sympathy puke just

It was so bad. Yeah, it's rough. It's rough tiger sharks are so much fun because they're really interesting, but they're they're literally so gross Well that like worse we're learning so much here on SciShow All right, I feel like I know what a predator is which means means it's time to move on to the quiz portion of our show. We were just talking about how we learn to put animals in these neat little boxes. Carnivores, we eat meat, and herbivores eat plants. But as we all learn with horror when we see a video of a horse eating a chick, nature tends to resist simple categorizations. Many animals thought to be obligate herbivores, that is, exclusively plant eaters, have been observed going for a meat snack

when they think no one is looking. It's called opportunistic carnivory, and the reason for it is simple. Why pass up a free chance for protein and minerals? So for this game, which we're calling Munch Squad, I'm going to tell you where the animal lives and what it ate, and you're gonna tell me what herbivore is playing predator for a day. Okay. Question number one, this animal is found in the waters of North America.

In 2001, researchers observed some of them, quote, loudly gnawing barnacles, crabs, and other marine invertebrates off of the lip of a dock and a nearby rope. Well, while these animals are thought to graze for algae in this fashion, researchers were quite sure it was the crabs and barnacles that were intentionally being eaten. Was it the green sea turtle, the Florida manatee,

or the slender parrotfish? I would think this would be the manatee because that would be distressing to see. They're supposed to be nice. Wait, where was this again, you said? The only clue I'm giving you is the waters of North America. Oh, wow. I thought that it was that broad.

That's not helpful, but it is maybe a little. Okay. I feel like parrotfish already eat coral. Sure, which is definitely a correlation. Which is not very far off from nine. I would not be surprised to see it eating a barnacle because it's just like, oh, you got confused by another hard, crunchy.

It might as well be the same thing. Yeah. What about crab though? Would it be weird to see one eat a crab? I wouldn't think it would be surprising though. A manatee would be surprising. I'd be like, what are you doing? You're gentle.

Sure. Yeah. Oh, I think that I'm going to go with manatee mostly because sea turtles like have that hard beak. And I feel like it's much more shocking to see an animal with like big fleshy lips. Oh, yeah. Like gnawing on like hard stuff like that. So I'm going with manatee. Yes, I'm going to go with manatee as well, because I feel like turtles, their freaky eating is all swallowing related.

Like they they swallow a jellyfish or something like that. All right. We got three winners for our first. What is the Florida manatee? They lack speed and mouth parts and also really anything much that could assist in capturing prey. Fortunately, barnacles are even slower than manatees. And given that the individuals were chewing, the researchers repeated repeatedly emphasized the noise.

It seemed clear that these animals were eating, not simply playing with their prey. When I turned like like 12 suddenly potato chips, you got the option of having like extra hard ones. It was Lays and Ruffles, but then these Kettle chips came along. Oh, Kettle. Which are just like, oh my God. That must be how the manatees feel

when they're having the Barnaby snack. Yeah, they're like, this is the amount of crunch I've been craving for years. Yeah. It's like a bag of Timbs. I have these two big teeth and I've never craving for years. It's like a bag of Timbs. I have these two big teeth and I've never really used them. See what these bad boys can do. Yeah. All right. Question number two, like the horse in the video

I was referencing, this animal was observed eating birds. Also like the horse, it's a type of ungulate. But unlike the horse, it's native to South America. Several captive individuals were seen eating pigeons and herons in their enclosure on multiple occasions. Was it the lowland taper, the white lipped peccary, or the alpaca? Sorry, herons are not small, correct?

I know. They're small. There are some like on the smaller end. There's a lot of different kinds of herons. But I certainly don't think they're eating like a great blue. But they're big. And there is both a great blue heron and a little blue heron. Oh, cute.

OK, that's great. We love that. I feel like maybe I just don't know what a tapir is They are the ones with the little things they got the little trouble knows it but they have a full mouth underneath the little trunk Yeah, they can put a mouth that could eat a heron. That's the that's what I'm struggling with I was a pretty thin neck. You could just I don't bite No matter how strong If you can just take a bite and you don't need to eat it whole. That's predators don't eat their food whole.

You need to bite its head off, which is probably one of the easiest heads to bite off of any head in the animal kingdom. I could do it. I think I could do it too. I think it would be easy. Uh-huh. Okay. Okay.

I wouldn't put it past any of these guys, but I'm going to lean towards it being the shock factor maybe of seeing a llama do it because they're so like, they have a bad attitude, sure. They would do anything. I wouldn't be surprised that a llama did anything, but I think seeing a llama eat, he'd be like, I think I know, I thought I knew what llamas eat. This is challenging that llama.

Are llamas the same as alpacas? Or alpaca, whatever. I was gonna say that, but I was okay. It's fine. They just small. Say everything applies to alpaca as well. I'm torn between alpaca and tapir because peccaries, I know that they're not pigs, but like similar enough to where I'm like, that would not shock me at all.

I'm going to go with tap, just because tapirs are dope and they deserve more attention. I am also gonna go with tapirs because of our conversation. I could see them going for the neck now. I think they can do it. I think they're vicious. I think I'd be more surprised

if they could eat these birds than an alpaca. Well, indeed tapirs or however It's pronounced everybody's saying it slightly differently from each other is making me so conscious Are not very well equipped to capture prey their trunks are meant for browsing plants very specifically they have like well I like tiny little elephant trunks the researchers suggest however that they are perfectly happy to hoover up dead or that they are perfectly happy to hoover up dead or incapacitated birds that they happen upon. So they're not hunting these them down, but if they get hurt some way, they're happy to devour them. They also think that the captive animals, they also don't think that these animals were stressed or lacking protein. They had, they had, they were fed by people. They just liked snacking

on the birds that found their way into the enclosure. I feel like this answer doesn't shock me too much because tapirs are so big. I feel like those are one of the animals where you're like, how big is it really though? And then you see a picture of it next to a person and you're like, oh no, that's a really large animal. So eating a heron, I guess, when you're that big,

I don't know, that's my logic. All right, question number three. This small mammal is native to Europe. It was housed in a wildlife rehabilitation exhibit with a bunch of raptors, including kites and buzzards, as a way to teach visitors what the raptors wouldn't eat. Instead, the researchers learned something themselves. When these individuals finished up their vegetarian lunches, they would begin to eat the raptors' meals of dead mice and birds. Was it a Eurasian beaver, a Eurasian red squirrel, or the domestic rabbit? Rabbits are obscene.

Rabbits have surprises. Yeah. There's just something about them that I don't quite trust, so I don't know. I don't trust any of these guys. I don't want to think a beaver would do this, Sari. I don't quite trust. So I don't know. I don't trust any of these guys. I don't want to think a beaver would do this, Sari. I don't want to think that. I think a beaver.

Yeah, just walk up with his big old teeth and go, no, yeah, for sure. Squirrel would do the same. Squirrel also, they're bad. Menaces. Yeah. I think that I'm going to go with rabbit because I feel like if you are gonna be like we're gonna toss

This Raptor some food it would be a rabbit, but then you're supposed to be like, whoa It's actually not eating the rabbit. That's crazy Oh, I for that reason I'm thinking rabbit But I thought the thing was it was sharing a pin with an animal wouldn't eat was that the case correct? Yeah, that's what I mean. It wouldn't I think oh, I guess there's not a raptor out there that I don't believe would eat a rabbit A beaver though. Maybe it is a beaver because I'm maybe a raptor wouldn't eat a beaver too stinky or something I mean also a full-grown beaver is like the size of a man I'm gonna get squirrel. guess, just to split it up. And cause I don't know, maybe they don't want all that tail fluff.

Or like. That's why they got such fluffy tails. Yeah, they're like actually yucco. Yeah. Well, you guys, Monty Python tried to warn us. In their paper, which is delightfully called Carcass Consumption by Domestic Rabbits, the researchers expressed concern

that the So, yeah. Well, you guys, Monty Python tried to warn us. In their paper, which was delightfully called, Carkus Consumption by Domestic Rabbits, the researchers expressed considerable skepticism about the dogma that rabbits can't eat meat ever because they lack the dentition and digestion for it. And because of how they watched it happen, the bunnies would chase the raptors away from their meals and follow the caretaker bringing food with enthusiasm.

The enthusiasm of a pet dog at dinnertime. Carnivory, the researchers propose, is all about opportunity. Why are these raptors afraid of the rabbits, is my question. Like they're actively being chased away? Yeah, I think that they probably just aren't big enough to take down a rabbit. There's lots of different, they're actively being chased away. Yeah, I think that they probably just aren't big enough to take down a rabbit.

There's lots of different probably they're probably littler ones. That's really funny. Absolutely like any like a Golden Eagle boot athlete. Have that as like a pre lunch snack. Yeah, just popping in. Oh, yes. Yeah, it was like an appetizer. Yeah. To be chased away by a rabbit is not that's embarrassing. That's embarrassing.

Yeah. I mean, I probably, like if a rabbit wanted to chase me away from something, I bet they could. I think that's like one of the few animals that if it rushed at me, I would be like, okay. That's fine. I think the first time that like literally jumped up and kicked me, I'd be like, oh, okay, I'll go.

I don't know. I think I'd go, whoa, whoa, hoo, hee hee. Do it again. Yeah, I feel like if I was, if it like came out of my cabinet, there it is. I'd definitely run away. If a mouse came out of my cabinet, yeah, I'd go, ugh. I think if a rabbit popped out, I would still go, whoopee.

I love you. I cannot think of a situation in which a rabbit would ever, ever scare me unless it was like a giant. It would have to be like, and it would actually have to be like as big as a house before it scared me. Yeah, I think that might be why the Monty Python joke was made. All right, JD, you got all three of them correct. That means you lead. Sari has two, Sam has one.

Next up, we're going to take a short break. Ben, it'll be time for the fact-off. Welcome back, everybody. Now, get ready for the fact-off. Our panelists have all brought science facts to present in an attempt to blow my mind. And after they have presented their facts, I will judge them and award Hank Bucks anyway I see fit. But to decide who goes first, I thought about it very hard.

And I just think that Jada should go first. Yay. Thanks. Okay, so there's sort of two different elements to combine to create one really cool fact for this one. So let's look at each of these different elements and then we'll talk about them together. First is shark sensory biology. So sharks have technically seven senses, sight, hearing, smelling, touch, taste, their lateral line system and their electroreception. The ampullae of Loren, their lateral line system and their electroreception. The ampullae of Lorenzini is that organ for the electroreception.

But electroreception specifically is used by sharks to potentially navigate, but also to detect prey and potentially to detect predators so that they can escape. So that's one element. What was the sixth sense? Lateral line. That's like, they kind of have these like, I guess, pores sort of with these little hair like structures on the inside, like down the side of their body. This is something that all fish have, and it basically can detect like water movement. Okay. Disturbances in the water.

I guess I kind of describe it like if you're in the water and someone like pushes the water at you, and you can kind of feel it on your leg. They can feel that, but like a lot higher of a level if that makes sense. That makes sense, yeah. Yeah, so electroreception is number one. Number two is shark reproduction. So as a group, sharks use three different modes of reproduction.

There's viviparity, which is where like the pup gets nutrients from mom via placenta and is born live. There's ovoviviparity, I'm probably saying that incorrectly, but it's fine, where the eggs hatch inside the mother and then the young are born live. There's ovoviviparity, I'm probably saying that incorrectly, but it's fine, where the eggs hatch inside the mother and then the young are born live. And then there's oviparity, which is where the mother lays eggs and then the young develop completely outside of the mother and then they hatch later from their egg cases. And those sharks are among those oviparous sharks. So they lay eggs, they spend like five months in an egg case just sitting there

vulnerable and whatnot. And as the embryo is developing the egg case like cracks open on one end allowing for good water flow in and out of the egg case and the baby shark can like beat its tail to try and like increase that that water flow to make sure they're getting enough oxygen and stuff. Now the problem is when they're doing that it can make predators aware of them so now there's baby shark smell in the water and if the predators are close enough they can sense that movement of the water when the baby shark is beating its tail. But it's not all lost for this tiny shark. While they're developing their sense of electroreception starts to become functional towards the end of their stay in their little egg cases. So a 2013 study supplied electrical current stimuli to a tank housing egg cases with shark

pups in them to try and figure out like what would happen, just to see how the pups would react. And they found out that the pups would just freeze, their tail would wrap around themselves. And not only that, but they would stop breathing to try and limit any electro electro sensory output that they're putting out there in hopes that any nearby predators just like won't sense them. And so these later stage embryos can detect weaker electrical stimulus more so than

the early stages. And so basically it's just these baby bamboo sharks are using their newly developed electro-section to sense predators and then avoid predation while still inside the egg case. And I think that that is wicked cool. That's wild. So while they are little babies, like while they're in the egg case, and then they just like pretend to be dead. Because the signals of the nervous system and all the like pumping of ions and stuff

that the muscles are using actually creates enough of a signal that a predator could sense it. Yeah, that's how sharks can like detect their prey is basically like sensing the like electric field of your own like functioning, like just your heart beating. Like they can sense that. So these baby sharks are like, I'm just gonna freeze and make as little output as possible

so that you don't try to see me and eat me. Is there, I mean, this is very unrelated, but is there a reason why we can't do that on land? Like is the electrical signal like transferred faster in water or something? Or is that I know sound moves faster in water. So maybe well water is also a conductor. Yeah, I is is air I guess. No, like I don't know. Good conductor of electric. So maybe then that's why. That's a good point. That's why.

No, like, I don't know. Air is not a good conductor of electrons. So maybe then that's why. That's a good point. Maybe that's why. Maybe because it's impossible, Hank. Maybe because air is traditionally considered to be a pretty good insulator. Okay. Cool, cool, weird.

And these little eggs just float around? They sit on the bottom. They're like, if you've ever seen, like, they call them mermaid's purses, little shark eggs. Those are also egg cases of skates, not just sharks. Like the shark ones usually don't look as Percy. You know what I mean? They don't look quite as purse-ish as like the shark ones, but yeah.

Yeah, those ones I've seen are the skate ones. Okay, that's fascinating. And I love it. Dari, do you go first? Do you go next? I'm just picking. Zari, you go first, second. You go first, second.

I'll go first, I'll go first now. Humans are okay predators, I guess, because our species somehow made it this far. But honestly, where would we be without our trusty companions? The ever loyal, the brave hunting dogs. I'm talking beagles or dachshunds or pointers or spaniels or any of these sweet beans. But this fact off is not about land animals. It's about

a different predator duo and what I'm declaring to be the hunting dog of the ocean, the moray eel. That's right, because multiple species of fish in the same genus, including the spotted coral grouper and the leopard coral grouper, also called the coral trout, which is very confusing because it's a grouper, not a trout, will recruit and collaborate with giant moray eels to help them hunt. This partnership was first described in a 2006 paper thanks to around 187 hours of footage taken by these researchers, and it's unique as far as we know among fish. And the grouper and the moray eel each play a different role in the hunt. So, groupers are good at bursts of speed in open water

and chasing their smaller fish prey during the daytime, while moray eels sneak in crevices in coral reefs and corner their prey in these holes mostly at night time. But when the groupers are extra hungry, they find a snoozing moray eel and signal with a distinctive gesture, a fast head shake, it's like around three to six shakes per second, and there are videos of this out there. And this gesture means, follow me, let's go catch a fish.

And usually the moray gets woken up, swims out of its hole to like follow the grouper and find the prey. And if the moray gets woken up, swims out of its hole to follow the grouper and find the prey. What? And if the moray stops and gives up halfway through the hunt and re-hides, the grouper will shimmy again to egg it along and say, like, come on, let's go. Like you do with your lazy beagle that's taking a nap. And if a grouper has unsuccessfully chased down a prey fish and the prey fish like hit

in a rock somewhere and the grouper knows exactly where it's hiding. It will go near that hole and do a different gesture. It'll make a sort of like headstand move. It'll face vertically downward and then shimmy and say as a gesture that means like, look in this hole, go get them, go get them. At which point the mores swim in the holes to inspect. And this rarer gesture was described in detail in a 2013 study based on that same 187 hours of footage. And sometimes the prey gets flushed out and the grouper gets to chomp the fish hole, while other

times the moray swallows it first. So scientists think that this partnership evolved somehow because it's mutually beneficial. And particularly during all this footage, they didn't observe any signs of aggression between the groupers and the morays. It just seems like the grouper does a little signal, the moray follows along and it's like, okay, I trust you, there's going to be prey around. How does the grouper get any of the food? Do they share it at the end? They don't share it.

I think sometimes the moray like chases it out of the reef. And so then the grouper gets another chance to bite it. And sometimes the moray catches it and then it just gets the food. I mean, it almost seems at this point that the grouper is like, I don't need to eat this fish, but I do need it to die. I just hate this guy. It's my enemy.

Wow, there's such an iconic bully duo too. Yeah. Looking at them. Yeah, totally. Like a big hulking giant. Yeah, and then just a little sneaky guy. And then just like a little sneaky guy. Yeah.

It's so funny because I love that you guys are seeing this as like a bully situation or like a dog with like a team in but like this whole head shake situation just instantly made me think of like a toddler Going into mom's room at like midnight and be like mom. I'm thirsty You helped me and mom's like, oh my god fine. I'll come out of my hole and get you some water I guess Yeah, I don't know. I guess you're a fish Yeah, definitely the moray is like I'm sick of this that means he needs it way less than the other than the Gruper does.

So like, which one is, I don't know, which one's the boss? Gruper seems like the boss to me. I guess so. Gruper's saying come here. Yeah, the Gruper's the one communicating. The Moray's just sleeping. Yeah. Hmm.

I'm just, I'm surprised that it evolved. Like, it's very behavioral and I don't think of either Grouper or Moray Eels as like super intelligent but maybe I need to rewrite my thoughts about fish. Think differently. Fish are always smarter than you think they are. There's the thing about being a mammal and looking into the eyes of an animal where the eyes stay fixed and I'm like, you're a dummy. Like I just think you're...

I mean, that's fair. I need your eyes to do stuff in order for me to think you're intelligent, which is. Well that's when you're going to see a group of shimmy in in front of you and then all of a sudden it's more a buddy is going to bite your arm and go. Thanks for having it be my arm, Sari. Yep. I was close to your butt and then I was like, I don't want to... And the eel never takes a bite out of the grouper because grouper looks like good eating. I got to tell you. No, the eel doesn't take a bite out of the grouper.

I feel like that would be a mistake. Yeah. That's like not only is it biting the hand that feeds you because they're basically finding the food for you, but it's also like, let me attack the thing that is a hundred times my size and could swallow me in one bite. I feel like that's not smart. Look pretty nasty though. And this is not, this is like the best example, I think they have the most videos, but they've

also observed groupers collaborating with rasses, Napoleon rasses, which are other big fish, but they have these jaws that can stick into the holes of coral reef and octopuses. So they just need anyone to get into the holes of the reef for them. They'll collaborate and say, like, I need help. Makes perfect sense to me that an octopus would learn from a Moray eel a little bit. Yeah, octopus is also punch fish, which I think is very fun. Why?

For what reason? I know, it's never even occurred to me to punch a fish. No. And Sam, you don't have a fact. So you 100% just lose. Yeah, yeah, I already lost. You had no dog in this hunt. Maybe if I had three points from the first game,

I'd have some kind of chance. Yeah, if everybody had really messed up and you, but you didn't. No. That's not what happened. All right. Well, I find these facts pretty equally fascinating. I learned a lot about sharks and senses, but I also love an interspecies duo, but Jada came in in the lead.

So Jada is the winner of our episode. The most expert science expert. I always feel weird having that title when there's someone who actually knows more. I gotta say, we didn't, I guess we learned a little about predators that aren't underwater, but it was really weighted towards being underwater. Seems like a bit of an unfair advantage, huh? That's because underwater is just so much better. Underwater is good. Again, I want gills, just send me down there.

Are you saying it's better down where it's wetter? Is that what I'm hearing? Correct. Take it from me. And now it's time to ask the science catch where we ask a question from our listeners to our couch of finely honed scientific minds. The Space Say on Discord asks,

I know y'all have talked before about bioaccumulation of pollutants in the food chain. And I've had a question in the back of my head. Do vegans and vegetarians theoretically eat less pollutants than our meat-inclined friends? Well, I'd say they definitely eat less methylmercury, but there's other sources of pollutants. our meat inclined friends. Well, I'd say they definitely eat less methyl mercury, but there's other sources of pollutants. There's a lot of acids in water, right? And that's what plants got inside of them.

Yeah, I mean, we've all got water inside of us. Yeah, oh, yeah, I guess it's true. But yeah, I think it is a little messy. We know that mercury is very bad and mercury bioaccumulates as it moves up the food chain. So the higher up the food chain you're eating the worse it is for the amount of mercury and specifically aquatic I think is a bigger concern because that's where the mercury gets is that wine? I don't know but there's lots of different

toxins so it's kind of hard for me to say what do you think, Sarah? It is hard to say. This is a complicated question, but it'll get us both on in the water and on land. To break down what they're asking a little bit. So this idea of bioaccumulation is the idea of toxins. So things that are in large amounts are bad for us or bad for life in general, entering the food web and building up in an organism. And you can enter the food web in so many different ways. It can be taken up into a plant from soil or floating in water and then absorbed into a plankton

and then eaten. It can be taken in by things that eat those other things. It can be inhaled through the air if it's flying around or whatever. Yeah, and it can just be like sitting, it can be like a dust, you know? If you've got a crop that's by a road, you might end up with some heavy metals from car ware

settling down on the strawberries or something. So there's bioaccumulation, which is just like getting into the stuff. And then there's biomagnification, which is just like getting into the stuff. And then there's bio magnification, which is like bigger things eat smaller things. And then as you eat a bunch of small things, then you build up more and more and more toxins in you. And you have to eat like way more than your weight

in the small things to make your body. But with methylmercury specifically, it's very sticky. It sticks to tissues. It sticks to fats, I think. So like every bit with methylmercury specifically, it's very sticky, it sticks to tissues, it sticks to fats, I think. So like every bit of methylmercury you consume stays in your body. So if you eat like 10 times your body weight in plankton, all that plankton's gonna just kind of pass

through your digestive system, but every bit of methylmercury that was in those plankton's gonna end up sticking around in your body. And the things that we're talking about when we talk about toxins generally are these chemicals that seem to stick around biologically for some reason, whether it's because they bind to fat molecules or they bind to proteins

or they stick around in our bloodstreams or whatnot. And sometimes we know what they do, sometimes we don't know what they do, and you're gonna see a lot of different acronyms. This is where with long chemical names, scientists love their acronyms and they are sprinkled all over the papers, the, I don't know, pop science articles related to this. And the ones that you're going to see probably are POPs,

which are persistent organic pollutions. That is like the umbrella term. It's usually used to refer to the stuff that you find in the oceans, like complex organic molecules that were in industry like flame retardants or PCBs, like PCB chemicals, which were used everywhere, like electric appliances sprayed on dirt roads to keep the dust down, whatnot. DDT, dichlorodiphenyltrichloroethane, which was used as an insecticide, falls under this category of POP, of persistent organic pollutant. And then the hot term in recent days is PFAS, so per- and polyfluoroalkyl

substances. So there are a bunch of these synthetic organic chemicals that are used in a lot of like nonstick coatings. They repel oil stains or grease or water. They're in like nonstick pans. If a fabric is water repellent or stain repellent, like PFAS chemicals are part of it. And these are like thousands of different molecules that all fall under this umbrella. And they're all like long chain molecules

that exist in the environment. We're trying to measure how they get taken up by organisms in the water and in soil and what they do to our bodies. Yeah, exactly. What do they do? Because the original idea we thought like, oh, well, these are like extremely non-reactive. Like part of the reason why they're forever chemicals

is because they never break down. So if they're unreactive, what harm could they do? It's just like nitrogen or a noble gas. But it turns out that they can sort of, even if they're not reacting, they can take up a space in the body that would normally be being taken up by a different molecule and and

Thus interfering with the body's systems in some ways and then like separately from those there are PHE's or potentially harmful elements where if you just look at one thing, so those are like mercury or Lead or arsenic as opposed to like iron. PHE's potentially harmful elements. Yeah. So the umbrella term like a different umbrella term for like arsenic. Yeah. Yeah. You know, the bad stuff.

And as far as like what you eat and how these things build up, I don't think it matters like meat versus plant. It depends on kind of like where we have studied, it seems like. So like the hot headline is orca whales are one of the most toxic animals because they are an apex predator and they eat a lot of salmon especially and there is a lot of very clear bioaccumulation of mercury compounds as well as some of these other pops, these other organic chemicals in their bodies. We've studied soil plant systems less well, and like we think that there is just by volume, kind of like what we're talking about, where like water

is all around you, and you can move in 3D space in the water. And then on land, you can walk across the ground. And so there's just like more space and you are living and breathing the water and absorbing stuff that is around you. Whereas on land, you have to get it from the soil or from the air around you. And so there are fewer ways for like a cow to get and ingest chemicals in it it or like plants to take up

that chemical from the soil or the air than there is for plankton to take up a chemical floating in the water. And there's also like, it's a magnification problem where like a cow is gonna eat a corn. And that's the, that's so a corn has this, like it's taking up from the soil and then the cow eats the corn and then we eat the cow

with, you know, with salmon, it's gonna be plankton eats a plankton eats a plankton And then a small fish eats that and then a bigger fish eats that and then an even bigger fish eats that and then The salmon eats that and then the killer whale eats that salmon It's just like you have if you have a 10x at every predation event the the magnification Hits hard in the last two steps, not in the first two steps, because if it's multiplying by 10 each time, which it's probably maybe more than that. Yeah, this is one of many reasons why people are like,

maybe don't eat sharks. And if you do, be very strategic about it. Yeah, exactly. We only eat fish predators. We only eat aquatic predators. We don't eat land predators. Yeah, Very strategic about it. Yeah, exactly. We only eat fish predators. We only eat aquatic predators. We don't like, we don't eat land predators. Yeah, I've never heard of someone being like, yeah, you want a mountain lion steak? Be like, I don't think that I do.

Thank you. Weird guys who are trying to like do a thing at a party once, you know, are going to have some polar bear. But the, you know, but we eat a lot. Like most of the fish we eat are predators. And so it depends. And also if you're growing plants on top of a Superfund site where there was once a spill of toxic lead compounds, then the plants, the tomatoes that you grow will probably take that up and they're probably not good to eat.

So it depends on where your food is coming from, always. And wash your fruits and vegetables, everybody. Bugs walk on those things. Man, bugs is definitely the last concern. And now for our listeners on Patreon, we're answering a bonus science couch question. Sam, what is it? A man, duh, at 728 on Twitter asks, this shark week someone said that they don't have bones and they could theoretically fold in half.

Is this true? If you wanna hear the answer to that question, as well as where we went with that, which did include a fair amount of penis talk, as well as enjoy other episodes totally ad free, you can head on over to our Patreon. That's patreon.com slash SciShow Tangents. At our $8 a month tier, you get new ad-free

and extended shenanigans as we answer bonus SciScout questions every episode. Also, you will get a link to our private Discord server and maybe some other goodies in the future and also access to some previous goodies that we've made along the way. Our patrons are the best, and we are so grateful for their support of the show.

If you wanna ask us your science catch question, you can follow us on Twitter at SciShowTangents or check out our YouTube community tab where we send out topics for upcoming episodes every week, or you can join the SciShow Tangents Patreon and ask us on our Discord. Thank you to at Sonny AJ8 on YouTube, LaToranis on Discord,

and everybody else who asked us your questions for this episode. Jada, thank you. Where can we find what you are up to? Yeah, so I am on so many platforms. I am on Twitter and Blue Sky, if that's a thing that you use, and TikTok as Sophistication,

and Instagram as Sophistication underscore, because Sophistication was not free. I'm still very sad about it. And then you should keep an eye on the SciShow channel for some things that will be happening with me coming up soon as your SciShow resident for the last four months. It's something I've been very excited about.

So I also have a nonprofit organization that I co-founded with three other black ladies involved with shark science called Minorities in Shark Sciences. If this is something that you are interested in or just want to support, you should check on our website, which is misselasmo.org, and we are Miss Underscore Elasmo

on all these different social media platforms. We're dedicated to supporting gender minorities of color in the field of shark science, so we can get more info on sharks and more diverse people in the science field. So you should check us out. Amazing. And there's merch. Yeah. Well, oh yeah.

We did shark madness, which is like, instead of March Madness, we do like a bracket of sharks every year. This was my brainchild. I'm so excited about it. And we had our members make stickers for like, which team are you rooting for? It's so cute. So check out our red bubble.

We've got stuff there. So yeah, all the fun things. Sweet. Well, Jada, thank you so much for joining us. If you like the show and you want to help us out, it's very easy to do that. First, you can go to our Patreon at patreon.com slash SciShow Tangents

and become a patron and get access to all the stuff that we already talked about. Shout out to Patreon, Les Aker for their support. Second, you can leave us a review wherever you listen, so we know what you like about the show and other people can find us and decide whether they want to try us out. And finally, if you want to show your love for SciShow Tangents, just tell people about us.

Thank you for joining us. I've been Hank Green. I've been Sari Riley. I've been Sam Schultz. And I've been Jada Elcock. SciShow Tangents is created by all of us and produced by Just Stempert. Our associate producer is Eve Schmidt. Our editor is Seth Glicksman.

Our social media organizer is Julia Buzbazayo. Our editorial assistants are Deboki Chakravarti and Alex Billo. Our sound design is by Joseph Tuna-Medish. Our executive producers are Nicole Sweeney and me, Hank Green. And of course, we could not make any of this without our patrons on Patreon. Thank you, and remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. In the Late Triassic, around 210 million years ago. One of the largest reptilian predators was smock Well, well ski well

Smock well well ski we think these fearsome five to six meter long predators weren't just eating meat They were also crunching on bones to get marrow and salts nice a 2019 paper studied 10 coprolites aka fossilized poop and found that they contained lots of bone fragments from prey animals and some of their own broken teeth that they Accidentally swallowed and this was a pretty exciting discovery because the main other bone crunching reptiles that we know of were the Tyrannosaurids like T-Rex, which didn't evolve until around 140 million years later. Smok beat him to it. Smok, he definitely sounds like the guy from Monster's Inc.

Mike Wazowski. Smok Wawelski. Yeah, it's like what your dad would call Mike Wazowski. That guy's smock. Well, well, with the one eye. Yeah, OK.