Stuff You Should Know - Short Stuff: Horseshoe Crab Blood

Episode Date: August 21, 2019

Perhaps the most expensive liquid on the planet is the blue blood that comes from horseshoe crabs. Researchers realized that horseshoe crab blood could indicate the presence of pathogens and the massive, ongoing horseshoe crab harvest began.  Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

On the podcast, Hey Dude, the 90s called, David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're gonna use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s.

We lived it, and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, and welcome to Short Stuff. I'm Josh, and there's Chuck, and there's Jerry over there. And this is short stuff, so we should probably

get talking about this right away. What are we talking about right now, Chuck? We're talking about an ancient, primitive animal, a beast that was around before dinosaurs that survived ice ages. And that has been virtually unchanged since they made their way onto the scene as little horseshoe crabs.

Little horseshoe crabs, still around, still kicking, still virtually unchanged after, I think I saw about 450 million years. Yeah, and still when you have a child or when you were a child, when you go to the beach and you see one for the first time, the question, what in the world is that to your parents? Yeah, and they say, stop asking questions.

They're crazy looking. They really are crazy looking. It looks like, how do you describe a horseshoe crab? You think of what I thought about this? Looks like you flipped over a wooden bowl and gave it a tail. Okay, great, we'll go with that. But it also has like a, it's a really tough exoskeleton.

It's got six legs. If it's a male, the front two legs are hooks because it uses those for mating. Yeah, and the legs look like, you know, little crab claws. Yeah, and so it looks like a freaky scary little thing, even though it's called a horseshoe crab, it's actually much more closely related to spiders and scorpions.

And once you realize that, number one, what it looks like makes sense. Number two, it becomes maybe the most terrifying thing you've ever seen in your life, in person. They're not gonna hurt you though, they're friendly. They are, they're fine. They don't want anything to do with you. They're two, they're old souls.

They've been around too long to mess with you. But we humans like to mess with them. And there's a reason why. And the reason is, is because they have a very peculiar kind of blood. It's copper based actually, so it's blue. And back in the fifties, a guy named Fred Bang, Frederick Bang, figured out that you can use horseshoe crab

blood to identify whether there is harmful bacteria is present in say like a biological sample, a medical device, a vaccine, a new drug. And with that, I think 20 years later, we got FDA approval to use it for that use. It just began a horseshoe crab harvesting bonanza. All right, so we'll explain how that all works here in a sec. But let's talk a little bit more

about the body of these guys and gals. Like we said, they have a big head, it's called a prosoma. And in that head is the brain and the heart, which is super cool. You already mentioned the six little claw legs. And in the males, the very first pair are like hooks. And they used to clamp onto the female during mating. And this is how that happens.

The ladies dig a hole in the sand. They had several thousand eggs. And the male hooks in, clings to her back, and fertilizes these eggs. And the coolest thing about all this is there are other males sort of in the area kind of hanging around. And they're like, hey, if you've done your thing,

maybe give me a shot. Right, that guy, he was a real jerk, wasn't he? I'm a nice guy. They're called satellite males. Yeah, but the females can do this a few times per night for several nights in a row. And all in all, a breeding female can lay about 100,000 eggs a season.

Which is great too, like great. We're in the horseshoe crabs. The world is saved, fantastic. But they also are a delicacy for shorebirds who fly up and down the eastern coast of North America of the Iraq. And they eat tons of these eggs. So even though a female might have like 10,000 of these,

and there might be a million mating pairs of horseshoe crabs in a single place, a lot of them get eaten by birds. Yeah, I mean, if you've ever been to Delaware Bay, or seen pictures of just type in Delaware Bay horseshoe crabs, it's like a beach made of horseshoe crabs during mating. It's a great season. Right, so the horseshoe crabs can deal with the shorebirds.

It's fine, they've been around for a very long time, and shorebirds have too. So they've learned to just kind of live with it. The problem is, is we humans have a big impact on horseshoe crabs as well. We like to catch them and use them for bait. And we also develop in the areas where they mate and reproduce, and so we eat up their habitat.

So when you put those together with shorebirds eating thousands and thousands and thousands of eggs that could have been little tiny new horseshoe crabs, their population has, it's under strain. And that's just the population of the United States. It's actually far worse in Asia. Yeah, and you know what, let's take a break. We'll talk a little bit about how they benefit the humans

and what's going on in America with this research and in Asia, right after this. And I'll see you in the next one. Bye. Bye. Bye. Bye. Bye.

Bye. Bye. Bye. Bye. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. Do you remember going to Blockbuster? Do you remember Nintendo 64?

Do you remember getting frosted tips? Was that a cereal? No, it was hair. Do you remember AOL Instant Messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper, because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge

from your Game Boy, blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude, the 90s, called on the iHeart radio app, for example, podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. The hardest thing can be knowing who to turn to when questions arise or times get tough, or you're at the end of the road.

Ah, OK, I see what you're doing. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place, because I'm here to help. This I promise you. Oh, God. Seriously, I swear. And you won't have to send an SOS because I'll be there for you.

Oh, man. And so my husband, Michael. Um, hey, that's me. Yep, we know that Michael and a different hot, sexy teen crush boy band are each week to guide you through life step by step. Oh, not another one. Uh-huh. Kids, relationships, life in general can get messy.

You may be thinking, this is the story of my life. Just stop now. If so, tell everybody, yeah, everybody about my new podcast and make sure to listen so we'll never, ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the I Heart Radio app, Apple Podcasts, or wherever you listen to podcasts. OK, Chuck, we're back. So I think I mentioned that you can actually use horseshoe crab blood

in the biomedical industry. It's virtually priceless, although there is a price for it. It's just really expensive. Yeah, it's $15,000 a quart, making it one of the most valuable fluids on earth. And this is specifically the clotting agent that's that expensive. It's called LAL, limelus or limelus amoebocyte lysate. And it is in their blue blood, and it is a supreme clotting agent,

as it turns out. Yeah, and the reason why it's a great clotting agent is because that's how horseshoe crabs fend off infection on their own. In your body, you have white blood cells, and you have all sorts of veins that your body can kind of close off and surround a foreign invader, a pathogen in, right? Well, blood just flows freely all throughout the horseshoe crab. Yeah, they got no blood vessels.

They don't. They kind of move through their tissues and their organs and everything. It just sloshes around everywhere in there. Pick one up and shake it. You'll hear it just plain as day. Don't do that. No, don't do that. But the fact that the blood can just move around very easily means

that they have to have a very specialized type of blood cell that can do everything. So I guess it's a generalized type of blood cell if you think about it. And that's what they have. And these blood cells, when they encounter a pathogen, they clot like crazy around that thing because that is their immune response. They basically sequester it in a big gob of goo, a gob of goo. Right. So we figured out that we could use this LAL.

And the way that we originally started harvesting this was from rabbits because I guess rabbits have, I don't think, as much, right? Well, they don't have specifically the same thing. We didn't harvest it from them. We would just inject them with a drug that we were testing and see if they got an infection. And then whether they did or not, we'd just kill them when we were done with them anyway. Gotcha. So the fact that we are able to use horseshoe crabs has saved rabbit lives.

Yes. So we can feel good about that on one hand. Right. But here's the deal. Horseshoe crabs can survive about four days out of the water. So if you want to harvest this crab blood or this spider scorpion blood, you pick one of these horseshoe crabs up. They like females because they're much bigger.

I don't think we said they can be much, much larger than the males. Yeah, like by half, I think. Yeah, 50% larger. And so they bring them out. They bring them to the lab. They chill them for an hour, put them on ice, then they mount them to a wreck. And keep in mind, they're alive this whole time. And they insert a needle around the heart into that tissue and they drain about 30% of

the blood from these horseshoe crabs and try and get them back in time to survive. It looks like, like I said, four days out they can survive. I imagine probably less in a traumatic situation like this. But they like to get about a, what, 70% survival rate in America? Yeah. I mean, they want even higher than that. But what it washes out to is that they have about a third, about 30% of the horseshoe crabs that they harvest and put back end up dying.

And they think that it's not the bloodletting process. They've got the bleeding process down pretty well, down to a science, basically. That's how they're caught, transported, and handled during this process that can kill them, that they think that that's usually what kills them. So if you're talking about like 600,000 horseshoe crabs being harvested every year in the United States alone, 30% of that, that's a lot of dead horseshoe crabs that would otherwise still be alive. That, and this is the point, I mean, aside from the fact that we're killing horseshoe

crabs for our own purposes, if those things survived, they regenerate their blood and we can bleed them again. It's not like a once in a lifetime thing. And they tag them so that they don't over bleed them too much. But 30% of them dying, that's a big problem because that's just a big loss of that blood market down the line. Yeah. That's about 180,000 a year in the US that are not surviving.

And we mentioned before the break that it's worse in Asia, and that's because in places like Singapore, they do the same thing, except when they bleed them out, they then sell them as food. So they don't return them to the ocean at all. At all. They eat them. There was an expert on this who said that at this rate in a decade, the other three, so North America has one species of horseshoe crab.

The other three on earth all live in Asia, and those species may be extinct within a decade because of those practices. Yeah. And this is interesting. I don't know anything about these kind of processes, but they are making synthetic LAL. They've been doing it for about 15 years. But there's only one company and one facility that was doing this.

And I never knew that that was a big deal, but it makes sense now. If you're a biomed company, and there's only one facility producing this, you can't just say, all right, we're scrapping all of the harvesting because we're going to use synthetic LAL only. What if something happens to that company, you're back to square one? Exactly. Well, you're worse. You need at least two.

Exactly, for sure. And I think that's wise because from what I understand, if LAL, the supply of LAL ran out, the biomedical industry would just stop because they have to test this stuff. You can't put like a pacemaker inside a human being with it potentially covered or infected with some sort of bacteria that could kill the person who received the pacemaker. So you have to test some of this stuff in the way that they tested by exposing it to this LAL. So if you don't have the LAL, people don't get their pacemakers and the whole industry

is grinds to a halt. So it would definitely make sense because if you have one factory producing this stuff and the thing gets hit by a hurricane or a tornado or something like that, that's it. But more and more people are starting to make the synthetic LAL, so it looks like within just a few years, the horseshoe crabs might start to be left alone, which is good for them. That'd be great. I think so too.

Let's push for it, Chuck. We'll make it a SYSK initiative. Let's create a hashtag. Okay. Save the horseshoe crab. That's a long hashtag, but okay. But you too can save a horseshoe crab. If you're ever walking along the beach, they have something called a telson.

That's their little spiky tail that they use to flip themselves over if they have flipped over the wrong way, which would be legs up. If you happen to see a horseshoe crab alive though and their little arms are wiggling and their telson's not flipping them over, do so yourself. Don't grab them by the telson. That should be the stuff you should know, T-shirt. Grab them on the sides. Pick them up on the sides, flip them over, maybe in the water, and they will be eternally

grateful. I could imagine they would be. They'd be like, thank you so much. Then they swim about five feet and someone grabs them and takes them to the horror show for the blood landing. Well, maybe. At least you did your part. Yeah.

That's good advice, Chuck. Since we don't have anything else to say about horseshoe crabs, then this short stuff is out. Adios. Stuff you should know is a production of iHeartRadio's How Stuff Works. For more podcasts from iHeartRadio, visit the iHeartRadio app. All podcasts are wherever you listen to your favorite shows.