Short Stuff: Horseshoe Crab Blood

It's a little horseshoe crabs. Little horseshoe crabs still around, still kicking, still virtually unchanged after I think I saw about four hundred and fifty million years. Yeah, and still when you're 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, um, how do you

how do you describe a horseshoe crab? Do you think it looks over a wooden bowl and gave it a tail? Okay, great, we'll go with that. But it also has like a it's really tough exoskeleton. It's got six legs. If it's a male. The front two legs or hooks, because it uses those for mating, 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 the 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. There too, they're 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. The reason 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 at you can use horseshoe crab blood to identify whether there's harmful bacteria is present, and say like a biological sample, a medical device, UM, a vaccine, a new drug, and UM. With that I think twenty years later it

got FDA approval to use it for that use. It just began a horseshoe crab harvesting bananza. All right, so we'll explain how that all works here in a sec. But um, 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 in the heart, which is

super cool. You already mentioned the six little claw legs. Uh. And in the males, the very first pair are like hooks, and they used to clamp onto the female during mating. And uh, this is how that happens. The ladies dig a hole in the sand lay had several thousand eggs, and the ale 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 know, if you've done, if you've done your thing, maybe give me a shot. Right that guy he was he was a real jerk, wasn't he. I'm a nice guy. They're

called satellite males. Yeah, but this you know, 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 out about a hundred thousand eggs a season, which is great to be like, great, we're in the horseshoe crabs the world, is say, fantastic, But they also um are a delicacy for shore birds who fly up and down the the eastern coast to the of North America of the Iraq, and they eat tons of these eggs.

So even though a female might might um have like ten thousands of these and there might be a million mating pairs of horseshoe crabs in a single place, a lot of the 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 season, right, so remarkable. So the horseshoe crabs can deal with the

shore birds. It's fine. They've they've been around for a very long time um and shorebirds have to 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 shore birds eating thousands and thousands and thousands of of eggs that could have been a little tiny new horseshoe crabs, their population has um. 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 m m okay choke, we're back. So I think I mentioned that you can actually use horseshoe crab blood to um in the biomedical industry. It's it's virtually priceless, although there is a price for it. It's just really expensive. It's dollars a court, making it one of the most valuable fluids on Earth. And this is specifically the clotting agent that's that expensive. It's called l A l uh limitless or lime less amba site LI sate and it is in their blue blood, and

it is a preme clouding agent, as it turns out. Yeah, And the reason why it's a great clouding agent is because that's how horseshoe crabs fend off infection on their own um and 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 or pathogen in right, Well, blood just flows freely all throughout the horseshoe crab. The blood vessels, they don't. It's just kind of moves through their tissues and their organs

and everything. It's just it just slashes around everywhere and they're pick one up and shake it. You'll hear it just plain Now. I don't do that. But the 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 clock like crazy around

that thing because that is their immune response. They basically sequester it in a big gob of goog a gobba goom. Right, So we figured out that we could use this l a l. And the way that we originally um 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, and we didn't harvest it from him.

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 just kill them when we were done with them anyway, gotchas. So the fact that we are able to use horseshoe crabs has saved rabbit lives. Yes, we can feel good about that on one hand, Um, but here's the deal. Horshoe 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 UM much much larger than the males, like by half I think, yeah, 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 Iraq 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 thirty of the blood from these horseshoe crabs and try and get them back in time to survive. Um, 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 survival rate,

I mean, they want even higher than that. But what it washes out too, is that they have about about a third, about thirty of the horseshoe crabs that they harvest and put back end up dying. And they think that it's not the blood lighting process. They've got the blood the bleeding process down pretty well down to a science. Basically, it's how how they're caught, transported and handled during this process that can kill them. That they think that that's

usually what kills them. UM. So, if you're if you're talking about like six hundred thousand horseshoe crabs being harvested every year in the United States alone, 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. Um, if we 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 bled them too much. But um, the you know, thirty percent of them dying, that's a that's a big problem because that's just a big loss of that blood market down the line. Yeah, that's about a hundred and eighty thousand a year in

the US that are not surviving. Uh. 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. Um. There was an expert on this who said that at this rate, in a decade, the other three. That's 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 um, they are making synthetic L A L. They've been doing it for about fifteen 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 if you're a biomedic 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 gonna use some synthetic L A L. Only what if something happens to that company, you're back to square one

exactly well exactly for sure. And I think that's that's wise because from what I understand, if if L A L just the supply of L A L right now, like 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 L A L. So if you don't have the L A L, people don't get their pacemakers, and the whole industry is grinds to a hall. So it would definitely make sense because if you have one factory producing this stuff and the thing gets hit by a hurricane or tornado or something like that, that's it.

But more and more people are starting to make the synthetic L A L. So it looks like within just a few years the horseshoe crabs might start to be left alone. Yeah, which is good for them. That'd be great, I think so too. Let's push for it, Chuck, we'll make it an s Y s K initiative. Let's create a hashtago save the horseshoe crab. That's a long hashtag. Okay, but you two can save a horseshoe crab. If you're ever walking along the beach. They have something called a tellson.

That's our 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 there Tellson's not flipping them over. Do so yourself. Don't grab him by the telson that should be a stuffs in that t shirt. Grab him on the sides. Just pick them up on the sides, flip them over. Uh maybe in the water, and they will be eternally grateful.

I couldn't imagine they would be. They'd be like, thank you so much. And then they swim about five ft and someone grabs them and takes them to the horror show for the blood lighting. Well, maybe at least you did your part. Yeah, that's good advice, Chuck. And 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 iHeart Radio's How Stuff Works.

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