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Speaker 1: My Welcome to Stuff to Blow Your Mind, a production

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Speaker 1: of I Heart Radios How Stuff Works. Hey, you welcome

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Speaker 1: to Stuff to Blow your Mind. My name is Robert

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Speaker 1: Lamb and I'm Joe McCormick. And today we're gonna be

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Speaker 1: talking about an underappreciated evolutionary marvel, the horseshoe crab. Robert,

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Speaker 1: this this episode was your idea, and I'm so glad

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Speaker 1: you you thought of this. Yeah, And I'll bring up

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Speaker 1: a little later in the episode what what reminded me

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Speaker 1: that the horseshoe crab should be a topic of discussion.

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Speaker 1: But but really, this is a creature I feel like

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Speaker 1: that I've been admiring my whole life. It's frequently brought up.

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Speaker 1: It's frequently pointed out to me. I remember as a

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Speaker 1: kid being if not shown an actual horseshoe crab, I

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Speaker 1: mean maybe I was shown like the remnants of one

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Speaker 1: that had washed up, or picture of one, and it

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Speaker 1: was explained to me that like, this is a unique

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Speaker 1: organism that you don't find many things that I really

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Speaker 1: like it on this earth, on the earth today, and

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Speaker 1: if you went back far enough in time time you

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Speaker 1: would find them in in ages of of strange biological

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Speaker 1: diversity that what otherwise seem alien, but the horseshoe crab

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Speaker 1: has remained largely constant. It is an olive colored lump

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Speaker 1: from the Jurassic period and beyond. So one of the

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Speaker 1: great things about it is it's sort of perfect fodder

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Speaker 1: for our show, I think, because it's something that, uh,

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Speaker 1: if you don't go deep on it, it might be

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Speaker 1: uh you might think of it as a kind of

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Speaker 1: like lowly and uninteresting, just sort of lump in the

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Speaker 1: mud with with some scuttling claws, and you know that

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Speaker 1: there's not really much to it. There's a lot to it.

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Speaker 1: This creature is marvelous. And to start us off, I

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Speaker 1: want to inspire some wonder by by reading a passage

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Speaker 1: with a few abridgements from a really excellent book I've

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Speaker 1: been reading this week by the British paleontologist Richard Forty,

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Speaker 1: called Horseshoe Crabs and Velvet Worms, The Story of Animals

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Speaker 1: and Plants that Time Has Left behind. It was published

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Speaker 1: into the two thousand twelve. Now velvet Worms by the

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Speaker 1: way we spoke about them recently, it was potentially buried

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Speaker 1: if you skip our movie episodes, and you shouldn't, uh,

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Speaker 1: we did an episode on the Tingler, that old Vincent

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Speaker 1: Price horror movie, and the title character in or the

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Speaker 1: title monster in that film. The Tingler very closely resembles

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Speaker 1: a velvet worm, so we discussed its unique biology, so

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Speaker 1: to be mentioned in the same sentence as the velvet worm,

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Speaker 1: that should I'll let you know that the horseshoe crab

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Speaker 1: is no joke, totally. So. Richard Forty, the author of

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Speaker 1: this book, is a former president of the Geological Society

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Speaker 1: of London. He spent much of his career as a

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Speaker 1: staff paleontologist at the British Natural History Museum, where his

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Speaker 1: research included a special focus on our old friends, the

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Speaker 1: trialo bites Uh. And he's also done a lot of

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Speaker 1: public natural history communication, appearing on BBC documentaries and stuff

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Speaker 1: like that. So in the opening chapter of this book,

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Speaker 1: Forty is describing a massive gathering of horseshoe crabs that

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Speaker 1: he witnessed one night on a beach in Delaware. So

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Speaker 1: I'll begin reading here deep in the night along the

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Speaker 1: shore of Delaware Bay, the horseshoe crabs are stirring. The

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Speaker 1: tide is now high, and there is no moon. Darkness

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Speaker 1: rules But even in the feeble starlight, the overwhelming flatness

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Speaker 1: of the countryside can be made out, except along the

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Speaker 1: rim of the bay, where old sand dunes have built

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Speaker 1: up a levee heave with gentle movements. First I noticed

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Speaker 1: some very odd sounds. There is a general hollow clattering,

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Speaker 1: a tapping and grinding sound somewhat like that made by

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Speaker 1: knocking coconut shells together, once used on the radio to

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Speaker 1: imitate horses hoofs, but altogether less rhythmic and with a

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Speaker 1: kind of underlying push. Then, as my eyes get used

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Speaker 1: to the darkness low shelly mounds, the size of inverted

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Speaker 1: colanders can be seen slowly pushing and jostling all along

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Speaker 1: the shore, and perhaps six meters up into the sands.

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Speaker 1: They're bumping and clambering together. Is the source of those tap, tapping,

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Speaker 1: percussive sounds. The flash of an infrared horch reveals more details.

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Speaker 1: The head shield of the horseshoe crab is domed upwards

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Speaker 1: and carries a few weak spines at its back end.

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Speaker 1: To hinge marks a jointed boundary with a second large

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Speaker 1: plate spiny at the edge, which can flap downwards, and

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Speaker 1: beyond that again projects a stout triangular spike as long

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Speaker 1: as the head, which can waggle up and down. Here

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Speaker 1: at Kit's shomach. More crabs are gathered on the mud

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Speaker 1: flat seaward of the sands, waiting their turn. Strange green, black,

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Speaker 1: slowly animated lumps. Further offshore again in the shallow seawater,

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Speaker 1: tail spikes project briefly above the gentle waves like raised

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Speaker 1: radio antenna, and are gone, showing where still more horseshoe

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Speaker 1: crabs vie with one another to get their place on

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Speaker 1: the sand. So if that doesn't attempt you to buy

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Speaker 1: the book, I will say that the whole thing I

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Speaker 1: think is great like that forty is uh he's a

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Speaker 1: great scientist but also a really great writer. In this

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Speaker 1: book is just a fabulous read. Yeah. I like the

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Speaker 1: details he gives to describing it. Like one thing that

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Speaker 1: I think stands out for me is the horseshoe crab

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Speaker 1: always looked like an element from a suit of armor.

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Speaker 1: You know, it has a it looks it looks like

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Speaker 1: a little tank moving along the shoreline. Well, yeah, exactly,

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Speaker 1: and there's a good reason it looks like that. I mean,

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Speaker 1: that is quite literally what it is. This is a

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Speaker 1: creature that is mostly a suit of armor, especially if

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Speaker 1: you're looking down from above right, it is quite literally

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Speaker 1: biological armor. Now, Forty goes on to explain the marvels

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Speaker 1: of the scene. He says, there are thousands of these

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Speaker 1: creatures gathered on the beach and coming onto the beach

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Speaker 1: from the waves. Uh. He at one point finds one

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Speaker 1: horseshoe crab upturned on its back in the sand, desperately

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Speaker 1: bending its tail spike up and down in an attempt

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Speaker 1: to flip itself back over, which is a strategy that

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Speaker 1: I believe would probably work in the water, but not

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Speaker 1: so much on the land. Um And despite his status

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Speaker 1: as a scientific observer, Forty admits that he's unable to

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Speaker 1: resist the urge to right the animal, and he does,

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Speaker 1: grasping it by its head shield, and he flips it.

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Speaker 1: But once upright, of course, it doesn't say any thanks.

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Speaker 1: It just kind of trundles away and gets back to business.

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Speaker 1: But what is this business? It is mating. This is

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Speaker 1: a giant convention of horseshoe crabs, essentially for the purpose

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Speaker 1: of an invertebrate orgy. And that's not Forty Forty himself

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Speaker 1: uses the word orgy. I think that is the correct

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Speaker 1: term for this. So he notes that the largest animals

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Speaker 1: on the beach are digging down in the sand, so

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Speaker 1: while their dorsal shields hide most of what's going on,

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Speaker 1: their jointed limbs underneath are industriously removing sand. And then

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Speaker 1: some of the larger crabs end up digging themselves so

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Speaker 1: far down that they're almost completely buried. And these larger creatures,

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Speaker 1: the ones doing the digging, or the females, they will

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Speaker 1: ultimately be burying their freshly laid eggs in the sand

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Speaker 1: here on the beach. Meanwhile, smaller crabs are fighting to

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Speaker 1: climb on top of the buried females. These smaller ones

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Speaker 1: are the males, and the reason they're fighting for positioning

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Speaker 1: is that they're competing for a chance to fertilize the

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Speaker 1: female's eggs with their sperm cells, which are called milt.

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Speaker 1: And uh forty realizes that much of the tapping he's

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Speaker 1: talking about in that passage, I read that clacking noise

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Speaker 1: that he heard in the dark comes from what he

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Speaker 1: calls tussles for dominance. Male horseshoe crabs knocking one another

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Speaker 1: about by the exo skeletons as they fight for a

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Speaker 1: chance to be the first in line to reproduce, and

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Speaker 1: this can get really violent. Forty notes that finally, uh,

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Speaker 1: many of them don't survive this night of mass invertebrate

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Speaker 1: sex on the beach. In the morning, the shore is

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Speaker 1: just littered with assorted chunks of horseshoe crab carcasses. It's

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Speaker 1: an amazing scene and I wish I could be present

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Speaker 1: to see this. Something I would go to Delaware for that.

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Speaker 1: That would get me into Delaware. Yeah, they should put

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Speaker 1: it on the license plate, right yeah. Uh. This does

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Speaker 1: remind me of of a story that I've heard before.

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Speaker 1: My wife's grandmother had an amusing tale of horseshoe crabs.

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Speaker 1: I believe this is a tale from the Great Outer

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Speaker 1: Banks of the United States. Uh, though she also lived

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Speaker 1: in Australia for a time when she was younger, so

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Speaker 1: it might be a tail from Australia, but I'm pretty

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Speaker 1: sure it's out of banks anyway. The story goes that

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Speaker 1: she happened upon a bunch of horseshoe crabs on the

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Speaker 1: beach and thought they were in danger. So um, my

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Speaker 1: wife's grandmother then devoted an hour or so to collecting

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Speaker 1: them and hurling them back into the sea, only to

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Speaker 1: learn later that they had come ashore to make so

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Speaker 1: she thought that they were like beached whales essentially. Yeah,

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Speaker 1: you know, they're usually not there here they are in mass.

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Speaker 1: Maybe something is wrong. They need help, you know, throwing

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Speaker 1: back in before the birds get them, that sort of thing.

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Speaker 1: So she meant, well, but it turns out she was

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Speaker 1: interfering in their natural process. I bet those were some

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Speaker 1: frustrated invertebrates. Uh. Now, these mass meetings on the beach

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Speaker 1: bear a and actually pretty great ecological significance. Forty describes

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Speaker 1: the eggs they lay as tiny and green, and he

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Speaker 1: writes that they're they're laid together in these golf ball

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Speaker 1: sized clumps of about four thousand to six thousand eggs apiece. Uh.

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Speaker 1: He says up to fifteen or so males will have

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Speaker 1: the opportunity to fertilize the eggs of a single female,

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Speaker 1: and during a reproductive cycle, a single female horseshoe crab

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Speaker 1: might lay about eighty two a hundred thousand eggs total.

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Speaker 1: And yet Forty notes that on average, it's estimated that

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Speaker 1: only about thirty three out of every million eggs survive

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Speaker 1: into adulthood. So again this comes back to kind of

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Speaker 1: in the invertebrate numbers game, much like we talked about

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Speaker 1: in our Christmas Island Crabs episode. Uh, you know, there's

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Speaker 1: a lot of larva and only a tiny fraction of

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Speaker 1: them actually ever become adult crabs. Uh, but this massive

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Speaker 1: eggs and juveniles that don't survive. They're ecologically very important

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Speaker 1: because like the Christmas Island crabs, they are an important

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Speaker 1: food source for lots of animals living in and passing

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Speaker 1: through the region. Longerhead turtles prey on the crabs even

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Speaker 1: into adulthood. Uh. The that is kind of weird imagining

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Speaker 1: eating a horseshoe crab because if you look at one,

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Speaker 1: it just really does not look like it would have

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Speaker 1: much good meat. It looks like an animal made entirely

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Speaker 1: out of shell and bone. So I was looking around

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Speaker 1: on this and uh. In some parts of the world

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Speaker 1: that they are sometimes harvested for food, but only the

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Speaker 1: eggs or row are edible. According to Malaysia Best dot Net,

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Speaker 1: which is a blog post about this and some photos,

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Speaker 1: you'll find them on the menu and some restaurants either

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Speaker 1: grilled and flipped over for row consumption, or some places

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Speaker 1: you can get the row already scooped out and served

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Speaker 1: to you. And I read that the eggs basically have

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Speaker 1: a rubbery texture and a salty taste, so nothing really

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Speaker 1: all that exotic in terms of you know eating uh,

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Speaker 1: you know, the the the eggs of marine creatures like this.

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Speaker 1: But again the end of they are favorites among birds

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Speaker 1: and other creatures, and the horseshoe crab is a keystone

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Speaker 1: species for this reason. Like it's we're gonna spend a

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Speaker 1: lot of time on this show talking about, you know,

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Speaker 1: how ancient they are in their ancient origins. It's easy

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Speaker 1: to maybe fall into this notion that they are an outcast,

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Speaker 1: that they're not really important, they're just a throwback. But no,

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Speaker 1: they have a very important role in a number of species. Again,

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Speaker 1: like migratory seabirds depend upon them. Yeah, you're exactly right

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Speaker 1: about that. And Forty talks about this at length that

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Speaker 1: you know, the birds will peck around in the sand

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Speaker 1: to find the hidden caches of buried eggs. Um. So

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Speaker 1: this scene that Forty describes so vividly is not just

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Speaker 1: an amazing spectacle of nature. We sort of alluded to

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Speaker 1: this earlier, but it's also a window into the deep

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Speaker 1: history of planet Earth and a way to think about

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Speaker 1: the wonders of evolution across geologic time. So maybe we

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Speaker 1: should take a closer look at the horseshoe crab and

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Speaker 1: its anatomy and its body before we kind of zoom

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Speaker 1: out to the evolutionary picture. Yes, absolutely, and uh and

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Speaker 1: we do encourage you look up some footage or some

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Speaker 1: images of the creature if you have a chance to

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Speaker 1: while while we're discussing it here um, because that'll be helpful. Though.

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Speaker 1: I think a lot of you, if not most of you,

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Speaker 1: have seen a horseshoe crab before and have at least

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Speaker 1: a basic idea in your mind what it looks like.

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Speaker 1: I guess maybe let's start from looking from above, right

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Speaker 1: the way you would normally see one if you're looking

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Speaker 1: down at it on the beach. So from above, the

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Speaker 1: horseshoe crab is this closed dome of armor that has

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Speaker 1: three obvious body segments. The first segment is the headshield,

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Speaker 1: technically known as the pro soma, which is a solid, rounded,

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Speaker 1: vaguely horsehoof shaped plate of protective kitanous material, which forty

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Speaker 1: says is similar to the material you'd find making up

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Speaker 1: the wings of a beetle. And then it's got on

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Speaker 1: top of that headshield two obvious compound eyes poking up

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Speaker 1: on on either side, and those compound eyes are used

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Speaker 1: for locating mates. One thing I was reading about them

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Speaker 1: that was very interesting is that they they have drastically

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Speaker 1: different levels of light sensitivity between the night and day cycle.

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Speaker 1: Uh So, during the daytime, the receptors in those compound

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Speaker 1: eyes are tuned way down, I guess, to make them,

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Speaker 1: you know, less likely to get blinded by the light

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Speaker 1: coming in from above. But in the nighttime they get

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Speaker 1: tuned way up up, and that's I think primarily used

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Speaker 1: for seeing a mate somewhere on the beach and navigating

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Speaker 1: toward it in the dark, because again this a lot

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Speaker 1: of the spawning happens at night. I think the eyes

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Speaker 1: are are kind of really key to the human experience

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Speaker 1: of the horseshoe crab, because you know, we like things

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Speaker 1: with eyes that it helps us sort of connect with

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Speaker 1: them and sort of even think of a personality for them.

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Speaker 1: The horseshoe crabs eyes, certainly at first glance anyway, they

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Speaker 1: seem to have a certain seriousness to them, or even

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Speaker 1: kind of a determination or a even a sinister quality,

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Speaker 1: and so they're just all business. Yeah, they look they

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Speaker 1: look very serious. They don't have like goofy eyes. You know,

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Speaker 1: we've discussed animals on the show before that from the

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Speaker 1: human perspective may even have googly eyes. But like Glanaria,

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Speaker 1: these however, they look very serious and so we kind

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Speaker 1: of consider them seriously. I think sometimes, well, it turns

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Speaker 1: out there even more serious than you think, because they've

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Speaker 1: got those two big compound eyes that are that have

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Speaker 1: that alternating sensitivity good for locating mates. But the horseshoe

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Speaker 1: crab actually has something like ten eyes total. Uh. These

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Speaker 1: are you know, less easily identifiable as eyes just by

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Speaker 1: looking at them, but they've got basically ten photosensitive spots

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Speaker 1: or organs that in some way help the creature detect

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Speaker 1: light and detect movement. Okay, so that's the big first

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Speaker 1: part of it, the domed part of the head shield.

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Speaker 1: Then you've got if you're going from front to back,

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Speaker 1: you've got the next segment which connects behind the head shield,

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Speaker 1: and this is the abdomen, also known as the opus

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Speaker 1: the soma. Uh. This is a more flattened plate attached

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Speaker 1: to the head shield by a Hinge As forty wrote,

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Speaker 1: and uh and it's got these backward facing spines along

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Speaker 1: its lateral edges. And then finally, the horseshoe crab terminates

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Speaker 1: in this long, straight, rigid tail known as a telson. Uh.

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Speaker 1: And if you've ever seen one of these animals moving

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Speaker 1: or being handled, especially if you've seen, you know, like

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Speaker 1: a demonstration where somebody holds a horseshoe crab upright for

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Speaker 1: you to see it's underside, you know, the tail can

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Speaker 1: kind of whip up and down dramatically. Now, other arthur

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Speaker 1: pods have Tellson's as well, such as the shrimp, And

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Speaker 1: I think the shrimp is a great example because a

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Speaker 1: lot of you have probably at least some you probably

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Speaker 1: have some experience with shrimp tails via consuming shrimp tails.

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Speaker 1: So in shrimp, lobster's, krill, and crayfish, uh. The the

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Speaker 1: telson is important for what is known as the the

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Speaker 1: karadid escape reaction, in which a downtail tail flip allows

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Speaker 1: a startled individual to dart backwards through the water. Which, again,

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Speaker 1: that kind of comes back to what you said earlier

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Speaker 1: about how the thrashing of the tail would be more

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Speaker 1: useful to to write oneself or to escape a stressful

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Speaker 1: situation in the water as opposed to on land. Yes,

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Speaker 1: and that's a really interesting thing to look at too,

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Speaker 1: because when you look at a display like the tail

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Speaker 1: wagging up and down this, you know, the the rigid

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Speaker 1: pointed stick there. Basically, especially when the animal is handled,

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Speaker 1: you might guess it's a defensive weapon. Right. You'd think, like, okay,

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Speaker 1: stinger of a scorpion, And a lot of people do

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Speaker 1: assume that about the horseshoe crab that has got a

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Speaker 1: stinger on its tails on, and that guess would be

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Speaker 1: half right and half wrong. The correct part is that

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Speaker 1: there probably is an evolutionary relationship at play in this

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Speaker 1: similarity with the scorpions tail. Will come back to that

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Speaker 1: in a bit. But the wrong part would be to

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Speaker 1: assume that it is a stinger weapon. It is not,

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Speaker 1: as we were talking about. Primarily, it's used to help

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Speaker 1: the horseshoe crab navigate aquatic environment, so it can help

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Speaker 1: the animal steer its body while it's swimming. But it

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Speaker 1: can also help the animal, like we said, right itself

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Speaker 1: once it becomes flipped on its back, and you can

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Speaker 1: imagine in its natural habitat this could happen quite a bit.

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Speaker 1: Because this is a creature that's going to be dealing

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Speaker 1: with the physical tumult of the title zone. You know,

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Speaker 1: you can imagine it might get rolled upside down in

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Speaker 1: the surf, where might get rolled over while it's clambering

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Speaker 1: around on something in the mud flats, and this popping

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Speaker 1: up and down motion of the tail can help flip

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Speaker 1: it back over like one of those spring flipping wind

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Speaker 1: up toys. H Now, I just mentioned swimming. One other

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Speaker 1: very strange aspect of the horseshoe Crab is that when

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Speaker 1: it's time to swim, the horseshoe Crab usually swims upside down,

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Speaker 1: doing a kind of invertebrate backstroke with its head shield

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Speaker 1: angled down towards the bottom and it's jointed legs paddling

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Speaker 1: towards the sky. If you can find video of this this,

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Speaker 1: it will will probably recommend you go look at video

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Speaker 1: of several things in this episode because a lot of

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Speaker 1: a lot of this animals, movements and behaviors are are

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Speaker 1: fascinating to see. But yeah, if you can find video

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Speaker 1: of its swimming with its legs inverted up towards the sky,

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Speaker 1: it looks very strange, very cool, and it well, yeah,

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Speaker 1: it's basically just a backstroke. Well, as long as the

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Speaker 1: animals flipped over here, let's discuss what's going on underneath

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Speaker 1: the armor. I think that's a great idea. So yeah,

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Speaker 1: well you're flipping it over looking at its belly, and

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Speaker 1: on this side it is bug city. You've got five

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Speaker 1: pairs of jointed walking legs that look kind of like

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Speaker 1: crab legs or spider legs, and these are known as pedipalps.

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Speaker 1: The first four pairs of legs all end in a

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Speaker 1: a pincer claw shaped tips, so imagine kind of a

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Speaker 1: regular crab with claws on all of its walking feet.

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Speaker 1: But then the final pair of legs ends in what

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Speaker 1: looks like a kind of strange flower shape, which is

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Speaker 1: apparently used mostly for digging, and then towards the front

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Speaker 1: of the head. In in front of the walking legs,

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Speaker 1: there's another smaller pair of appendages that are known as

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Speaker 1: the chillissary, and we'll come back to their significance in

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Speaker 1: a moment, but they're primarily used for guiding food toward

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Speaker 1: the mouth. So here's maybe one of my this might

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Speaker 1: be my favorite part. Where's the mouth? You might expect,

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Speaker 1: in line with other crabs and invertebrates that the mouth

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Speaker 1: is in the front facing part of the head, but nope,

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Speaker 1: in horseshoe crabs, the mouth is in the middle of

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Speaker 1: the underside between all of the animals jointed spidery legs,

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Speaker 1: so as the legs move, any food caught underneath them

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Speaker 1: is sort of show fold inward toward a crevice running

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Speaker 1: between the leg pairs, aided by these gripping spines that

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Speaker 1: run along the inside of the appendages, so as the

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Speaker 1: legs scuttle, the food is also partially chewed up by

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Speaker 1: those legs and prepared for digestion. There's this grinding scraping

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Speaker 1: action of the exoskeleton parts of the legs and the joints. So,

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Speaker 1: in perhaps illicit anthropomorphic terms, the horseshoe crab has crotch, mouth,

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Speaker 1: and leg teeth. Yes, But on the other hand, I

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Speaker 1: feel like if you really break down how any animal,

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Speaker 1: including not especially humans, eat, it's it's all pretty gross.

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Speaker 1: So oh no, I'm sure they think the way we

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Speaker 1: eat is great, especially when we're eating their eggs. But

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Speaker 1: but I do. I do agree that the footage is

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Speaker 1: very interesting and once should check it out. Amazing, Yeah,

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Speaker 1: look at that. There are videos of this online as well. Yeah,

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Speaker 1: It also reminds me that a a fictional creature that

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Speaker 1: the horseshoe crab is very typically compared through these days is,

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Speaker 1: of course, the the xeno morph alien face hugger. UM

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Speaker 1: Like even that that Malaysian blog post about eating them

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Speaker 1: reading their their eggs at restaurant UH invoked the face

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Speaker 1: hugger comparison. It's kind of inevitable at this point, though,

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Speaker 1: I'm not sure the face hugger eat um No, I'm well, okay,

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Speaker 1: I mean, that's a whole another description to start talking

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Speaker 1: about the face hugger and how it matches up with

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Speaker 1: UH with with actual biology. I'll have to save that

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Speaker 1: for another episode. But but the face hugger does have

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Speaker 1: the what is kind of like a mouth that had

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Speaker 1: it definitely has a tubular orifice that emerges from the

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Speaker 1: underside and pretty much the same place one would find

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Speaker 1: the mouth of the horseshoe crab. But just in general,

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Speaker 1: the horseshoe crab and the and the face hugger have

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Speaker 1: kind of a similar body layouts, even though they're they're

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Speaker 1: rather you know, textually different. I can agree with that, though,

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Speaker 1: I maybe another similarity if the face hugger doesn't actually

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Speaker 1: eat and it's just like a you know, no no

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Speaker 1: digestive system, reproductive organism. Well I would I think you

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Speaker 1: could even class sated. The face hugger in alien is

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Speaker 1: a mobile sexual organ yes. But but to bring it

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Speaker 1: back to the horseshoe crabs, forty rights that mature adults

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Speaker 1: can sometimes go for months at a time without eating,

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Speaker 1: So these things are tough. Uh. And then also to

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Speaker 1: continue our exploration of the underside, behind the legs and

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Speaker 1: the mouth crack on the animals underside, you will see

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Speaker 1: a series of overlapping leaf like flaps, and these are

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Speaker 1: the animals gills, which allow it to breathe by absorbing

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Speaker 1: dissolved oxygen from the water. And the horseshoe crab can

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Speaker 1: survive out of water for a time if it can

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Speaker 1: keep its gills wet. These organs are a specific type

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Speaker 1: of underwater breathing apparatus. Unlike many other animals gills, these

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Speaker 1: are these are known as book gills. Now you might

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Speaker 1: have heard us talk before about other arthropods with book lungs,

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Speaker 1: animals such as the spider. And with that teasing detail,

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Speaker 1: maybe we should take a break and then come back.

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Speaker 1: All right, we'll be right back. Thank alright, we're back.

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Speaker 1: So we were talking about the horseshoe crab. We were talking,

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Speaker 1: and we talked. We mentioned a little bit about spider.

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Speaker 1: So let's let's get down to it. Let's get down

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Speaker 1: to that that basic factoid that that I imagine most

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Speaker 1: of you have heard plenty of times, and that is

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Speaker 1: that the horseshoe crab is not a crab, despite the

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Speaker 1: fact that we will refer to it often on as

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Speaker 1: a crab, and you'll find plenty of, uh, plenty of

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Speaker 1: studies where scientists will off handedly just refer to them

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Speaker 1: as crabs. Everybody keeps calling them crabs, but they're not crabs. True.

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Speaker 1: Decapod crabs and horseshoe crabs both belong, of course, to

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Speaker 1: the file of Arthropoda. They are both are arthropods, meaning

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Speaker 1: they both have hard exoskeletons, they've got segmented bodies, and

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Speaker 1: they've got multiple pairs of jointed legs, and the sharing

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Speaker 1: of jointed legs is where the word arthropod comes from.

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Speaker 1: Arthur pod means jointed leg or jointed foot. But after this,

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Speaker 1: evolutionary histories of crabs and horseshoe crabs really diverge. Crabs,

426
00:23:04,720 --> 00:23:07,880
Speaker 1: along with shrimp, lobsters, would lice, and and many other

427
00:23:07,880 --> 00:23:11,600
Speaker 1: creatures belong to the subphylum of Crustacea. We would call

428
00:23:11,640 --> 00:23:15,840
Speaker 1: them crustaceans. And Forty points out that crustaceans have antennae,

429
00:23:16,000 --> 00:23:19,400
Speaker 1: or feelers on the head used for sensing the environment

430
00:23:19,440 --> 00:23:22,840
Speaker 1: by touch and by smell, and horseshoe crabs don't have these,

431
00:23:23,240 --> 00:23:27,960
Speaker 1: so what do they have? Instead? They have chillissary. Horseshoe

432
00:23:27,960 --> 00:23:32,920
Speaker 1: crabs are not crustaceans their chill serata in evolutionary history,

433
00:23:33,040 --> 00:23:38,680
Speaker 1: they are more closely related to arachnids like spiders, ticks,

434
00:23:38,720 --> 00:23:42,240
Speaker 1: and scorpions, which if you look at the mouth parts

435
00:23:42,280 --> 00:23:44,720
Speaker 1: of these creatures, like spiders and scorpions, you will find

436
00:23:44,760 --> 00:23:48,080
Speaker 1: these similar little mouth parts that that guide food into

437
00:23:48,119 --> 00:23:52,720
Speaker 1: the orifice. The chillis sary. Uh. They're also Horseshoe crabs

438
00:23:52,720 --> 00:23:55,800
Speaker 1: are also more closely related to an extinct branch of

439
00:23:56,040 --> 00:24:00,920
Speaker 1: chill Serata known as the euryptorids also known as sea scorpions.

440
00:24:01,359 --> 00:24:05,640
Speaker 1: Now again in misleading names see scorpions. Is somewhat misleading

441
00:24:05,640 --> 00:24:09,000
Speaker 1: here because euryptorids were not actually scorpions and they didn't

442
00:24:09,000 --> 00:24:11,960
Speaker 1: all live in the sea. But they are truly awesome

443
00:24:12,080 --> 00:24:14,840
Speaker 1: that this is one of the great lines of extinct creatures.

444
00:24:15,359 --> 00:24:17,800
Speaker 1: We we talked about in the past episode, didn't we.

445
00:24:17,840 --> 00:24:20,320
Speaker 1: I think they've come up before. Yeah, So the Europtorids

446
00:24:20,359 --> 00:24:24,560
Speaker 1: were briefly a diverse order of predatory animals, including the

447
00:24:24,600 --> 00:24:30,360
Speaker 1: genus of the largest arthropod ever known to exist on Earth, Jclopterus,

448
00:24:30,400 --> 00:24:33,800
Speaker 1: which based on some fossil remains found in Germany, is

449
00:24:33,920 --> 00:24:36,160
Speaker 1: estimated to have grown up to about two point five

450
00:24:36,240 --> 00:24:40,040
Speaker 1: meters or over eight feet in length. So that's definitely

451
00:24:40,080 --> 00:24:42,880
Speaker 1: big enough to start its own harmon. Yeah, just try

452
00:24:42,960 --> 00:24:45,959
Speaker 1: to imagine it. So you got an eight foot arthropod,

453
00:24:46,280 --> 00:24:50,359
Speaker 1: a sort of scorpion lobster like creature bigger than your

454
00:24:50,400 --> 00:24:55,359
Speaker 1: whole body, with a plated exoskeleton and claws, scuttling around

455
00:24:55,400 --> 00:24:57,480
Speaker 1: at the water's edge, or just hanging out in the

456
00:24:57,520 --> 00:25:01,840
Speaker 1: shallows and ambush mode. Uh I have before. I sometimes

457
00:25:01,920 --> 00:25:05,520
Speaker 1: like to imagine these types of creatures surviving into modern

458
00:25:05,560 --> 00:25:08,919
Speaker 1: geologic periods and living alongside humans. And I wondered if

459
00:25:08,960 --> 00:25:12,080
Speaker 1: the ancient Egyptians would have had a euryptorid headed god

460
00:25:12,160 --> 00:25:15,680
Speaker 1: in place of the crocodile deity so back. That would

461
00:25:15,680 --> 00:25:18,639
Speaker 1: be quite a quite a god to behold. You know,

462
00:25:19,359 --> 00:25:21,040
Speaker 1: I mentioned that it is something like this would deserve

463
00:25:21,040 --> 00:25:24,160
Speaker 1: its own horror movie. But now I'm remembering the creature

464
00:25:24,320 --> 00:25:28,400
Speaker 1: in Deep Star six, the underwater horror movie from the

465
00:25:28,480 --> 00:25:32,679
Speaker 1: director of the original Friday thirteen. Oh, I believe the

466
00:25:32,720 --> 00:25:35,399
Speaker 1: monster in that is a euryptorid uh it is a

467
00:25:35,440 --> 00:25:39,000
Speaker 1: straight up sea scorpion. I remember Miguel for Air exploding

468
00:25:39,080 --> 00:25:40,840
Speaker 1: in the movie, but I do not remember what the

469
00:25:40,840 --> 00:25:43,480
Speaker 1: creature looked like. Yeah he did. I guess he did explode.

470
00:25:43,600 --> 00:25:45,760
Speaker 1: Um he he. There's a scene where they're like, don't

471
00:25:45,800 --> 00:25:48,640
Speaker 1: get in the escape pod, you'll go through explosive decompression,

472
00:25:48,680 --> 00:25:51,359
Speaker 1: and he's like, no, I'm scared, and then he blows up.

473
00:25:51,560 --> 00:25:54,359
Speaker 1: I just remember, I'm the most recent time I watched it,

474
00:25:54,440 --> 00:25:57,879
Speaker 1: I was on an airplane on medication, and I remember

475
00:25:58,000 --> 00:26:03,040
Speaker 1: just thinking it was a wonderful film. We'll see how

476
00:26:03,040 --> 00:26:05,840
Speaker 1: that would hold up over time. But yeah, uh, well,

477
00:26:05,880 --> 00:26:10,080
Speaker 1: I mean all those underwater horror movies are worth a watch,

478
00:26:10,440 --> 00:26:12,480
Speaker 1: but certainly I think it was a case where they're like, Okay,

479
00:26:12,480 --> 00:26:14,720
Speaker 1: we need it underwater monster. Let's look at some real

480
00:26:14,800 --> 00:26:17,240
Speaker 1: underwater monsters from the past, and they found one and

481
00:26:17,280 --> 00:26:19,920
Speaker 1: they said, heck, let's not try and recreate the wheel here,

482
00:26:20,160 --> 00:26:23,040
Speaker 1: let's do that guy. And so that's what they did. Okay.

483
00:26:23,040 --> 00:26:26,080
Speaker 1: So these would be the ancient closer relatives to the

484
00:26:26,119 --> 00:26:29,119
Speaker 1: horseshoe crabs, the the you know, the arachnids, the scorpions,

485
00:26:29,119 --> 00:26:32,600
Speaker 1: even the euptorids. There are a few extant species of

486
00:26:32,600 --> 00:26:36,320
Speaker 1: horseshoe crab like animals, including a few species found in Asia,

487
00:26:36,440 --> 00:26:40,440
Speaker 1: but the most common by far is the Atlantic horseshoe crab,

488
00:26:40,520 --> 00:26:44,560
Speaker 1: which has the scientific name of Limulus polyphemus. So it's

489
00:26:44,560 --> 00:26:47,520
Speaker 1: got the same name as the the cyclopid monster in

490
00:26:47,920 --> 00:26:52,280
Speaker 1: the Odyssey uh and and Limulus polyphemus. The the Atlantic

491
00:26:52,280 --> 00:26:55,040
Speaker 1: horseshoe crab can be found primarily along the East coast

492
00:26:55,080 --> 00:26:58,479
Speaker 1: of North America, roughly from Mexico to Maine. So your

493
00:26:58,480 --> 00:27:02,240
Speaker 1: wife's grandmother's story, I think probably more likely happened in

494
00:27:02,240 --> 00:27:06,560
Speaker 1: in the outer banks on these tcent. Sure it was,

495
00:27:06,600 --> 00:27:11,000
Speaker 1: it was outer banks, but yeah. So another thing that's

496
00:27:11,040 --> 00:27:13,879
Speaker 1: interesting about the horseshoe crabs is something that's more common

497
00:27:13,920 --> 00:27:17,480
Speaker 1: to arthur pods generally, but like other arthropods, the development

498
00:27:17,520 --> 00:27:20,880
Speaker 1: of their bodies as they mature happens through a fascinating

499
00:27:20,920 --> 00:27:24,320
Speaker 1: process called molting. So, since these animals have a hard,

500
00:27:24,480 --> 00:27:27,680
Speaker 1: rigid exoskeleton, you might wonder, how would they ever grow?

501
00:27:27,760 --> 00:27:30,040
Speaker 1: How do they get bigger? Right? You know, if you've

502
00:27:30,040 --> 00:27:33,080
Speaker 1: got you've got your bones on the outside, and molting

503
00:27:33,160 --> 00:27:36,320
Speaker 1: is the answer. Periodically during its life cycle, the horseshoe

504
00:27:36,320 --> 00:27:39,920
Speaker 1: crab will bust out of its own exoskeleton and emerge

505
00:27:39,960 --> 00:27:42,679
Speaker 1: as a softer critter from within, only to quickly have

506
00:27:42,760 --> 00:27:47,000
Speaker 1: its soft, new larger outline harden again pretty rapidly in

507
00:27:47,119 --> 00:27:50,159
Speaker 1: defense against the perils of the sea. Now, a normal

508
00:27:50,240 --> 00:27:53,920
Speaker 1: horseshoe crab takes about ten years of growing and molting

509
00:27:54,240 --> 00:27:57,679
Speaker 1: before it reaches sexual maturity, which seems like a very

510
00:27:57,720 --> 00:28:00,800
Speaker 1: long time for an animal of this kind. And uh,

511
00:28:00,840 --> 00:28:03,000
Speaker 1: you know, imagine it has to grow for ten years

512
00:28:03,040 --> 00:28:06,360
Speaker 1: before it's ready to mate in that orgy on the beach. Yeah,

513
00:28:06,400 --> 00:28:08,400
Speaker 1: I mean, certainly when we compared to something like say

514
00:28:08,400 --> 00:28:10,560
Speaker 1: a cat or a dog or you know, a rat

515
00:28:10,680 --> 00:28:14,640
Speaker 1: something like that, where the pretty short turnaround. But this

516
00:28:14,720 --> 00:28:17,680
Speaker 1: is this is ten years. But especially many other invertebrates,

517
00:28:17,720 --> 00:28:21,800
Speaker 1: we should think reach sexual maturity very fast. But after

518
00:28:21,800 --> 00:28:25,040
Speaker 1: reaching sexual maturity, it never molts again, and instead it

519
00:28:25,080 --> 00:28:28,040
Speaker 1: heads to the beach for mating, to leave fertilized eggs

520
00:28:28,040 --> 00:28:30,919
Speaker 1: in the wet sand and start the life cycle over again.

521
00:28:31,359 --> 00:28:33,960
Speaker 1: And so this this life cycle has worked pretty well

522
00:28:34,000 --> 00:28:35,919
Speaker 1: for the horseshoe crab, and it's worked that way for

523
00:28:36,160 --> 00:28:40,080
Speaker 1: quite a long time. Yes, the earliest fossil evidence for

524
00:28:40,120 --> 00:28:45,800
Speaker 1: horseshoe crabs is incredibly ancient. The oldest fossil remnants resembling

525
00:28:45,880 --> 00:28:48,920
Speaker 1: these modern animals, the modern horseshoe crabs, go all the

526
00:28:48,920 --> 00:28:53,680
Speaker 1: way back to the Ortivician period. This is so long ago,

527
00:28:53,960 --> 00:28:57,680
Speaker 1: it's unbelievable. Yeah, we're talking about four hundred and fifty

528
00:28:57,840 --> 00:29:02,280
Speaker 1: million years ago. Um. I mean just consider that the

529
00:29:02,400 --> 00:29:05,360
Speaker 1: for instance, the goblin shark is also something that is

530
00:29:05,400 --> 00:29:08,200
Speaker 1: sometimes referred to as a living fossil. And we'll get

531
00:29:08,200 --> 00:29:11,080
Speaker 1: back to that terminology in a second. But the goblin

532
00:29:11,120 --> 00:29:14,920
Speaker 1: shark only dates back a hundred twenty five million years

533
00:29:15,520 --> 00:29:19,960
Speaker 1: is an extremely long time. Yeah, um, still incredible. Crocodilia

534
00:29:20,160 --> 00:29:23,880
Speaker 1: goes back some nine million years. Hagfish or virtually the

535
00:29:23,920 --> 00:29:26,560
Speaker 1: same as they were three hundred million years ago. Lamp

536
00:29:26,640 --> 00:29:30,280
Speaker 1: raise go back roughly three hundred sixty million years. Not

537
00:29:30,440 --> 00:29:33,880
Speaker 1: Alloyd's have evolved very little since roughly five hundred million

538
00:29:33,960 --> 00:29:36,320
Speaker 1: years ago. Although that's an example of a creature to

539
00:29:36,400 --> 00:29:39,000
Speaker 1: where they were, there were certainly more varied two hundred

540
00:29:39,000 --> 00:29:42,200
Speaker 1: million years ago. Yeah. About this idea of of a

541
00:29:42,240 --> 00:29:45,640
Speaker 1: living fossil, Richard forty, Actually he kind of warns about

542
00:29:45,640 --> 00:29:47,920
Speaker 1: this phrase. He calls it quote a paradox and an

543
00:29:47,920 --> 00:29:50,840
Speaker 1: oxymoron rolled into one. Well, yeah, because I mean, on

544
00:29:50,840 --> 00:29:54,440
Speaker 1: one level, it is not a fossil. I think that

545
00:29:54,520 --> 00:29:57,120
Speaker 1: much is probably obvious to most people. It is not

546
00:29:57,200 --> 00:29:59,880
Speaker 1: a fossil. A fossil cannot be alive. A fossil is

547
00:30:00,000 --> 00:30:05,920
Speaker 1: inherently the the the mineralized remains of something that once lived,

548
00:30:06,000 --> 00:30:08,920
Speaker 1: though he also sort of uses the word cautiously. His

549
00:30:09,040 --> 00:30:11,920
Speaker 1: point is mainly that we shouldn't be lulled into the

550
00:30:12,000 --> 00:30:15,000
Speaker 1: mistaken assumption that a species can exist for millions of

551
00:30:15,080 --> 00:30:20,040
Speaker 1: years with no changes, For example, without significant genetic change.

552
00:30:20,120 --> 00:30:24,000
Speaker 1: Genetic changes are always accumulating. They just build up over time,

553
00:30:24,320 --> 00:30:28,560
Speaker 1: even if the overall form of the animal stays very similar. Uh.

554
00:30:28,560 --> 00:30:31,960
Speaker 1: And also the ecological surroundings of these organisms change over time.

555
00:30:32,000 --> 00:30:36,080
Speaker 1: He talks about how even if the the the horseshoe

556
00:30:36,120 --> 00:30:39,600
Speaker 1: crabs of today look extremely similar to the horseshoe crabs

557
00:30:39,640 --> 00:30:42,880
Speaker 1: of the Jurassic Period, the animals all around them would

558
00:30:42,880 --> 00:30:46,160
Speaker 1: have been completely different, and thus they there they were

559
00:30:46,200 --> 00:30:48,560
Speaker 1: probably you know, they had a different ecological niche, They

560
00:30:48,560 --> 00:30:51,960
Speaker 1: were dealing with different relationships and different energy dynamics in

561
00:30:51,960 --> 00:30:55,960
Speaker 1: the in the environment. Yeah, eating different things, potitially being

562
00:30:55,960 --> 00:30:59,800
Speaker 1: preyed upon by different things. But it is truly remarkable

563
00:31:00,200 --> 00:31:03,200
Speaker 1: to see a type of animal that has survived. I

564
00:31:03,640 --> 00:31:08,040
Speaker 1: think the horseshoe cribs have survived five different mass extinction events,

565
00:31:08,080 --> 00:31:12,560
Speaker 1: definitely four, I think five, and they still exist today

566
00:31:12,720 --> 00:31:16,200
Speaker 1: in in a body plan that is pretty close to

567
00:31:16,280 --> 00:31:18,720
Speaker 1: the same animal you would have found four hundred and

568
00:31:18,760 --> 00:31:21,560
Speaker 1: fifty million years ago. And so, as alternatives to the

569
00:31:21,560 --> 00:31:25,480
Speaker 1: phrase living fossil, some paleontologists have proposed calling these types

570
00:31:25,520 --> 00:31:29,320
Speaker 1: of organisms stabil a morphs. You know that that morph

571
00:31:29,400 --> 00:31:34,120
Speaker 1: meaning like body basically and stabilo meaning stable, meaning that

572
00:31:34,200 --> 00:31:38,080
Speaker 1: at some point long ago, there was a body plan

573
00:31:38,160 --> 00:31:40,440
Speaker 1: that was reached and it just has not needed to

574
00:31:40,520 --> 00:31:44,520
Speaker 1: undergo change much since then. Yeah, this is interesting and

575
00:31:44,520 --> 00:31:46,920
Speaker 1: and definitely touches on something we've discussed in the past

576
00:31:47,000 --> 00:31:50,480
Speaker 1: in terms of of body forms that work, and sometimes

577
00:31:50,520 --> 00:31:53,880
Speaker 1: you see those basic body form that works to the

578
00:31:53,960 --> 00:31:59,960
Speaker 1: degree that it is acquired by by rather distantly related relative,

579
00:32:00,640 --> 00:32:05,040
Speaker 1: such as such as the basic dolphin or the basic

580
00:32:05,120 --> 00:32:07,760
Speaker 1: dolphin form, and it's you can compare that to h

581
00:32:08,000 --> 00:32:10,920
Speaker 1: to various other fish forms, and then also to the

582
00:32:11,000 --> 00:32:16,720
Speaker 1: reptilian creatures that preceded them um uh ichtheosaurus for example.

583
00:32:16,840 --> 00:32:19,520
Speaker 1: I was just looking at a paper a while ago.

584
00:32:20,120 --> 00:32:21,960
Speaker 1: I don't remember where it was, but there was something

585
00:32:22,000 --> 00:32:25,959
Speaker 1: about how nature repeatedly has tried to build crabs like

586
00:32:26,080 --> 00:32:30,280
Speaker 1: crustacean crabs, the actual crabs, that it's like a form

587
00:32:30,360 --> 00:32:32,760
Speaker 1: that just kind of nature keeps coming back to from

588
00:32:32,840 --> 00:32:36,080
Speaker 1: different evolutionary pathways and ending up in the same place. Yeah,

589
00:32:36,120 --> 00:32:40,280
Speaker 1: it's like the most logical engineering solution to a given

590
00:32:40,400 --> 00:32:43,280
Speaker 1: environment and a given set of challenges. But of course,

591
00:32:43,960 --> 00:32:47,720
Speaker 1: with the the saus of course went extinct for for

592
00:32:48,120 --> 00:32:50,600
Speaker 1: some some essential reasons that I think we've touched on

593
00:32:50,840 --> 00:32:53,480
Speaker 1: the past show on the show in the past, But

594
00:32:53,600 --> 00:32:55,840
Speaker 1: with the horseshoe crab, it's rather different. It's like they

595
00:32:55,880 --> 00:32:58,840
Speaker 1: acquired this form and that form has remained relatively stable

596
00:32:59,080 --> 00:33:01,680
Speaker 1: for the duration. Yeah. I mean those are two. So

597
00:33:01,800 --> 00:33:04,600
Speaker 1: you can talk in one sense about forms that are stable,

598
00:33:04,640 --> 00:33:08,320
Speaker 1: and you see that they're they're advantageous because of conversion evolution,

599
00:33:08,400 --> 00:33:11,120
Speaker 1: different evolutionary pathways sort of arrived in the same place.

600
00:33:11,480 --> 00:33:14,560
Speaker 1: But we're talking about animal forms that were achieved at

601
00:33:14,600 --> 00:33:17,400
Speaker 1: some point in the past and then they just kept

602
00:33:17,480 --> 00:33:21,240
Speaker 1: working over time and they didn't undergo significant changes in

603
00:33:21,240 --> 00:33:24,320
Speaker 1: their lineages. Uh, you know, little changes here and there,

604
00:33:24,320 --> 00:33:27,000
Speaker 1: but not major changes in the body form and they

605
00:33:27,040 --> 00:33:30,120
Speaker 1: never went extinct. Yeah, I mean, really, to invoke some

606
00:33:30,160 --> 00:33:34,720
Speaker 1: more alien terminology, this is a perfect organism. It it

607
00:33:34,960 --> 00:33:41,000
Speaker 1: perfectly survives in the environment for which it has evolved,

608
00:33:41,160 --> 00:33:44,920
Speaker 1: and it has remained stable ever since. Then again surviving

609
00:33:45,320 --> 00:33:49,680
Speaker 1: mass extinction events for four hundred and fifty million years. Crazy. Yeah,

610
00:33:49,720 --> 00:33:52,640
Speaker 1: there's another alternative name for what to call these types

611
00:33:52,680 --> 00:33:55,480
Speaker 1: of creatures that was actually proposed by Darwin's bulldog, Thomas

612
00:33:55,520 --> 00:33:59,680
Speaker 1: Henry Huxley, who just called them persistent types. I think

613
00:33:59,720 --> 00:34:02,960
Speaker 1: that's pretty straightforward. Yeah, but it makes you wonder how

614
00:34:03,040 --> 00:34:06,240
Speaker 1: on Earth is something like this possible? Like what makes

615
00:34:06,400 --> 00:34:09,520
Speaker 1: animals like the horseshoe crab special? How does this type

616
00:34:09,520 --> 00:34:15,600
Speaker 1: of creature persist for so long without huge morphological changes. Uh,

617
00:34:15,640 --> 00:34:18,640
Speaker 1: and you know, surviving all these extinction events, never you know,

618
00:34:18,719 --> 00:34:22,279
Speaker 1: becoming all that different of an animal fundamentally. Yeah, because

619
00:34:22,320 --> 00:34:24,200
Speaker 1: I can't help but think of think of it in

620
00:34:24,239 --> 00:34:27,920
Speaker 1: comparison to say the business environment. You know, like like

621
00:34:28,000 --> 00:34:31,440
Speaker 1: what are the persistent forms in the business world, Like

622
00:34:31,480 --> 00:34:36,680
Speaker 1: what what brands or franchises or product types just survive

623
00:34:37,080 --> 00:34:41,560
Speaker 1: for the duration through multiple like economic extinction events and

624
00:34:41,640 --> 00:34:44,719
Speaker 1: also surviving all the things changing around them, you know,

625
00:34:44,840 --> 00:34:48,279
Speaker 1: predators and prey changing the way they behave and the

626
00:34:48,320 --> 00:34:50,680
Speaker 1: way they eat. You know, things in the in the

627
00:34:50,800 --> 00:34:53,720
Speaker 1: natural world that are ever trying to find that new

628
00:34:54,000 --> 00:34:58,600
Speaker 1: niche that will allow them to to to themselves survive

629
00:34:58,920 --> 00:35:02,080
Speaker 1: since the early devo ony in nature has pivoted to

630
00:35:02,200 --> 00:35:08,719
Speaker 1: video exactly. Um, So it's you know when we say

631
00:35:08,719 --> 00:35:10,840
Speaker 1: that you know they're true survivors, that it's like you

632
00:35:10,840 --> 00:35:15,080
Speaker 1: know perfection. I mean, really you you're tempted to go

633
00:35:15,200 --> 00:35:17,480
Speaker 1: that far and say like something here is just really

634
00:35:17,520 --> 00:35:21,799
Speaker 1: working that they have not been um surplanted by some

635
00:35:21,880 --> 00:35:25,520
Speaker 1: of their creature along the way. So many terrific seeming

636
00:35:25,600 --> 00:35:30,640
Speaker 1: organisms have certainly proven to have a very tenuous role

637
00:35:30,880 --> 00:35:33,560
Speaker 1: in the environment, but the horseshoe crab remains. Yeah, I mean,

638
00:35:33,600 --> 00:35:36,520
Speaker 1: we got no room to talk, puny, Homo sapiens. What

639
00:35:36,560 --> 00:35:38,359
Speaker 1: have we been around, you know, less than a few

640
00:35:38,400 --> 00:35:42,239
Speaker 1: million years. Yeah, And and we're continuing to work hard

641
00:35:42,280 --> 00:35:47,120
Speaker 1: and making sure that doesn't go too long. Um okay.

642
00:35:47,160 --> 00:35:49,680
Speaker 1: So actually, so we don't know the answer for sure

643
00:35:50,160 --> 00:35:53,080
Speaker 1: why the horseshoe crab in particular, and animals and other

644
00:35:53,160 --> 00:35:56,760
Speaker 1: organisms like it has persisted so long in its basic

645
00:35:56,800 --> 00:36:00,200
Speaker 1: body type. But Forty has some general thoughts of out

646
00:36:00,200 --> 00:36:03,640
Speaker 1: the question of of what causes this sort of thing.

647
00:36:03,760 --> 00:36:06,160
Speaker 1: He's got some arguments, and one that I thought was

648
00:36:06,239 --> 00:36:09,880
Speaker 1: really interesting was that he talks about how survival is

649
00:36:09,920 --> 00:36:12,439
Speaker 1: not just about the endurance of the animal, but it's

650
00:36:12,480 --> 00:36:17,120
Speaker 1: also about the endurance of habitat. So often the ability

651
00:36:17,239 --> 00:36:20,000
Speaker 1: of an animal type to survive through the eons largely

652
00:36:20,080 --> 00:36:23,359
Speaker 1: unmodified is a feature of the animal's habitat more than

653
00:36:23,400 --> 00:36:27,160
Speaker 1: the animal itself. Some habitats are just better equipped to

654
00:36:27,280 --> 00:36:33,239
Speaker 1: sustain their adapted inhabitants through ecological catastrophe than others. And

655
00:36:33,360 --> 00:36:36,000
Speaker 1: so what would be an example of this, Well, Forty

656
00:36:36,040 --> 00:36:40,600
Speaker 1: mentions inter title zones of the ocean and goes into

657
00:36:40,680 --> 00:36:46,279
Speaker 1: quote shallow subtitle habitats on muddy sandy shorelines. Now, why

658
00:36:46,280 --> 00:36:50,759
Speaker 1: would this be a favorite habitat for survival through mass extinctions? Well,

659
00:36:50,880 --> 00:36:54,840
Speaker 1: a big killer for ocean dwelling organisms during environment environmental

660
00:36:54,880 --> 00:36:59,120
Speaker 1: catastrophe appears to be antoxic seas where due to several

661
00:36:59,160 --> 00:37:02,680
Speaker 1: cascading fact ers, you know, and there's a big environmental catastrophe,

662
00:37:02,960 --> 00:37:06,080
Speaker 1: oxygen is often removed from a lot of the ocean water,

663
00:37:06,360 --> 00:37:08,680
Speaker 1: and the animals in the water can no longer breathe

664
00:37:08,680 --> 00:37:12,520
Speaker 1: and they die. Even in these conditions, forty suggests that

665
00:37:12,560 --> 00:37:16,960
Speaker 1: these shallow, muddy ocean edge habitats could still be pretty

666
00:37:17,000 --> 00:37:20,640
Speaker 1: well oxygenated quote. After all, the wind still ruffled the

667
00:37:20,640 --> 00:37:24,080
Speaker 1: waves on shore, and so many of the organisms adapted

668
00:37:24,120 --> 00:37:27,080
Speaker 1: to this environment can make it do with very little

669
00:37:27,080 --> 00:37:30,080
Speaker 1: food to begin with, and they tend to bury themselves

670
00:37:30,120 --> 00:37:33,279
Speaker 1: in sediment at low tide and sort of feed on

671
00:37:33,400 --> 00:37:36,319
Speaker 1: particles of food that wash in with the surf, And

672
00:37:36,360 --> 00:37:39,480
Speaker 1: their access to the surface would keep them in oxygen,

673
00:37:39,600 --> 00:37:42,600
Speaker 1: and their access to the tide would keep them supplied

674
00:37:42,640 --> 00:37:46,880
Speaker 1: with particles of biomaterial for food. Uh to quote forty again,

675
00:37:47,520 --> 00:37:50,880
Speaker 1: I am tempted to return to the military metaphor, maybe

676
00:37:50,880 --> 00:37:54,000
Speaker 1: this habitat was like a tunnel that simply went under

677
00:37:54,120 --> 00:37:57,120
Speaker 1: the front line. The luck came in if you happen

678
00:37:57,200 --> 00:38:00,680
Speaker 1: to belong to that special battalion with access to the tunnel.

679
00:38:01,320 --> 00:38:04,640
Speaker 1: And for this reason, he points out mud flats as

680
00:38:04,680 --> 00:38:08,239
Speaker 1: a special sort of extinction event survivor zone. Now, of course,

681
00:38:08,280 --> 00:38:12,160
Speaker 1: we know that you would often find horseshoe crabs scuttling

682
00:38:12,200 --> 00:38:16,279
Speaker 1: around in mud flats and tidal areas. Um. Now, now,

683
00:38:16,280 --> 00:38:19,600
Speaker 1: why don't ancient animal forms in zones like this get

684
00:38:19,600 --> 00:38:23,600
Speaker 1: out competed and displaced by new arrivals? Uh to read

685
00:38:23,640 --> 00:38:27,560
Speaker 1: from forty quote. Populations in many habitats are critically limited

686
00:38:27,560 --> 00:38:30,759
Speaker 1: by the quantity of food available. However, in places such

687
00:38:30,800 --> 00:38:33,840
Speaker 1: as mud flats, food may not be the limiting factor

688
00:38:34,200 --> 00:38:37,480
Speaker 1: for filter feeding. Animals are rich food store is carried

689
00:38:37,520 --> 00:38:40,480
Speaker 1: into the area with every high tide, or is brought

690
00:38:40,520 --> 00:38:44,080
Speaker 1: from nearby land during storms. The crucial things to find

691
00:38:44,280 --> 00:38:48,160
Speaker 1: living space. The problem is not the food in the trough,

692
00:38:48,600 --> 00:38:51,279
Speaker 1: but making a place at the stall. So if it

693
00:38:51,320 --> 00:38:54,960
Speaker 1: can establish itself in its borrow lingula, a creature he's

694
00:38:55,000 --> 00:38:57,760
Speaker 1: talking about is able to compete for food on equal

695
00:38:57,920 --> 00:39:01,560
Speaker 1: terms with a later arrival glow Agically speaking like a shrimp,

696
00:39:02,000 --> 00:39:04,239
Speaker 1: this habitat does seem like a good place to be

697
00:39:04,719 --> 00:39:09,160
Speaker 1: for an organism with conservative tendencies. And so he's sort

698
00:39:09,200 --> 00:39:11,880
Speaker 1: of talking again about many of the creatures that survive

699
00:39:12,000 --> 00:39:14,560
Speaker 1: these mass extinctions and go on for long periods of

700
00:39:14,560 --> 00:39:22,080
Speaker 1: geologic time having kind of behaviorally or ecologically conservative behaviors. Uh.

701
00:39:22,120 --> 00:39:24,759
Speaker 1: To quote him again, in one way, it is survival

702
00:39:24,760 --> 00:39:28,000
Speaker 1: of the fittest, but of the fittest habitat with the

703
00:39:28,080 --> 00:39:32,319
Speaker 1: right design specifications to offer long term security stick in

704
00:39:32,400 --> 00:39:35,840
Speaker 1: the MUD's last longest. Now, he also points out a

705
00:39:35,840 --> 00:39:39,080
Speaker 1: few other things, a few other cases of evolutionary survival

706
00:39:39,160 --> 00:39:42,320
Speaker 1: of an organism type over geological time, Like if there

707
00:39:42,440 --> 00:39:45,960
Speaker 1: is an animal that's a specialist and a specialist niche,

708
00:39:46,160 --> 00:39:49,400
Speaker 1: and then their particular niche, by luck, persists over time.

709
00:39:49,400 --> 00:39:52,640
Speaker 1: He gives the example of like lampreys and hagfish that

710
00:39:52,760 --> 00:39:56,920
Speaker 1: survive as parasites on bony fish um and then uh,

711
00:39:56,960 --> 00:40:00,759
Speaker 1: and he calls these areas that tend to a humulate

712
00:40:01,120 --> 00:40:07,799
Speaker 1: long term evolutionary survivors together time havens. Yeah, I like that, uh.

713
00:40:07,840 --> 00:40:10,640
Speaker 1: And finally he points out also an interesting fact that

714
00:40:10,800 --> 00:40:15,120
Speaker 1: longevity seems to be a common feature in long surviving animals,

715
00:40:15,120 --> 00:40:18,760
Speaker 1: but it alone, of course, won't preserve You remember again

716
00:40:18,800 --> 00:40:21,520
Speaker 1: that that it takes horseshoe crabs ten years to reach

717
00:40:21,560 --> 00:40:24,919
Speaker 1: sexual maturity, which is an unusually long period of time

718
00:40:24,920 --> 00:40:27,160
Speaker 1: for an arthropod. Alright, on that note, we're going to

719
00:40:27,200 --> 00:40:29,200
Speaker 1: take a quick break, but when we come back, we

720
00:40:29,280 --> 00:40:37,440
Speaker 1: will venture into the blood. Thank alright, we're back. All right,

721
00:40:37,800 --> 00:40:40,759
Speaker 1: let's talk about blood. So one of the most astonishing

722
00:40:40,800 --> 00:40:44,720
Speaker 1: things about the horseshoe crab is their amazing blue blood.

723
00:40:46,239 --> 00:40:49,759
Speaker 1: It's literally blue. Now why would this be Humans and

724
00:40:49,800 --> 00:40:53,000
Speaker 1: other mammals have red blood because of the presence of hemoglobin,

725
00:40:53,080 --> 00:40:56,399
Speaker 1: which is an iron based compound that carries oxygen away

726
00:40:56,440 --> 00:40:58,200
Speaker 1: from the lungs to the rest of the body and

727
00:40:58,200 --> 00:41:02,360
Speaker 1: then transports carbon dioxide back the other way. Horseshoe crabs

728
00:41:02,440 --> 00:41:05,600
Speaker 1: do not have hemoglobin. Instead, they have a protein called

729
00:41:05,840 --> 00:41:09,920
Speaker 1: hemo cyanin, which is based on copper instead of iron,

730
00:41:10,280 --> 00:41:14,120
Speaker 1: and the copper content makes the horseshoe crabs blood blue.

731
00:41:14,680 --> 00:41:17,400
Speaker 1: I can't help but think of the I core of talos,

732
00:41:17,440 --> 00:41:20,800
Speaker 1: the bronze automaton from Greek myth. But more specifically, I

733
00:41:20,880 --> 00:41:22,800
Speaker 1: guess that you have blue blood that shows up in

734
00:41:22,840 --> 00:41:26,280
Speaker 1: science fiction like the alien opera singer in the Fifth

735
00:41:26,280 --> 00:41:29,759
Speaker 1: Element we find out as blue blood. Oh yeah, like

736
00:41:29,840 --> 00:41:33,920
Speaker 1: everyone else, I mainly remember multi pass um. So this

737
00:41:34,120 --> 00:41:37,640
Speaker 1: hemocyanin based blood has has some really amazing properties. So

738
00:41:37,719 --> 00:41:40,480
Speaker 1: Richard Forty writes of how on this beach in Delaware,

739
00:41:40,480 --> 00:41:42,840
Speaker 1: when he's walking around looking at all these animals, he

740
00:41:42,880 --> 00:41:46,880
Speaker 1: comes across many horseshoe crabs crawling around with signs of

741
00:41:46,960 --> 00:41:50,240
Speaker 1: old wounds that look really like they should have been fatal,

742
00:41:50,360 --> 00:41:53,480
Speaker 1: like a large hole punched in the middle of the head,

743
00:41:54,000 --> 00:41:56,360
Speaker 1: or just part of the thorax missing, or you know,

744
00:41:56,440 --> 00:41:59,960
Speaker 1: broken off tail, whatever, And the survival of such wound

745
00:42:00,200 --> 00:42:03,600
Speaker 1: may in part be due to the amazing clotting power

746
00:42:03,719 --> 00:42:07,640
Speaker 1: of horseshoe crab blood. Another anatomy fact that we didn't

747
00:42:07,640 --> 00:42:10,439
Speaker 1: get into earlier was about the circulation of the horseshoe crab.

748
00:42:10,520 --> 00:42:13,560
Speaker 1: Like many other arthropods, the horseshoe crab has an open

749
00:42:13,640 --> 00:42:17,200
Speaker 1: circulatory system, and this is very different from our mammalian system,

750
00:42:17,680 --> 00:42:21,000
Speaker 1: known of course conversely as the closed system, where blood

751
00:42:21,080 --> 00:42:24,120
Speaker 1: is entirely contained within vessels. Right. If you cut a

752
00:42:24,120 --> 00:42:27,839
Speaker 1: person open, they've got veins, arteries, capillaries. You have to

753
00:42:27,840 --> 00:42:30,959
Speaker 1: to rupture these containers for the blood to spill out.

754
00:42:31,360 --> 00:42:34,440
Speaker 1: The horseshoe crab is is something closer to kind of

755
00:42:34,480 --> 00:42:37,120
Speaker 1: like a box of free range blood. It has a

756
00:42:37,200 --> 00:42:41,960
Speaker 1: heart type pump that circulates blood oxygenated blood from the gills,

757
00:42:42,239 --> 00:42:45,120
Speaker 1: but then the blood sort of sluices around and bathes

758
00:42:45,239 --> 00:42:50,120
Speaker 1: the creatures organs without being contained entirely within vessels. So

759
00:42:50,160 --> 00:42:53,640
Speaker 1: how do horseshoe crabs survive the carnage of these mass

760
00:42:53,680 --> 00:42:56,239
Speaker 1: mating battles, even having like chunks ripped out of the

761
00:42:56,280 --> 00:42:59,800
Speaker 1: thorax or holes punched in the head. Forty Rights quote

762
00:43:00,040 --> 00:43:03,960
Speaker 1: such endurance as possible because the blood of Limulus polyphemus

763
00:43:04,000 --> 00:43:07,560
Speaker 1: has exceptional clotting powers. The animal does not bleed to

764
00:43:07,600 --> 00:43:11,880
Speaker 1: death because it's blood coagulates and walls off damaged areas.

765
00:43:12,239 --> 00:43:15,800
Speaker 1: So this blood is unique, but it has also proven

766
00:43:15,880 --> 00:43:20,080
Speaker 1: quite useful to humans. Uh specifically, it's been become very

767
00:43:20,080 --> 00:43:24,839
Speaker 1: important to the biomedical industry, which harvests the blood of

768
00:43:24,920 --> 00:43:28,719
Speaker 1: horseshoe crabs to create what is called Limulus ambisite ly

769
00:43:28,920 --> 00:43:32,240
Speaker 1: sate or l A L which is used to test

770
00:43:32,280 --> 00:43:36,640
Speaker 1: medical devices and pharmaceutical drugs for indotoxins. And this is

771
00:43:36,680 --> 00:43:40,560
Speaker 1: because their blood contains potent amba sites which function like

772
00:43:40,640 --> 00:43:44,960
Speaker 1: white blood cells, so enzymes are instantly released when they

773
00:43:44,960 --> 00:43:49,120
Speaker 1: come into contact with bacteria, which is observable at less

774
00:43:49,160 --> 00:43:52,560
Speaker 1: than one part per per trillion, So just a tiny

775
00:43:52,640 --> 00:43:56,200
Speaker 1: drop of the blood can help spot contamination. So it's

776
00:43:56,239 --> 00:44:00,960
Speaker 1: important for drug, implant and environmental safety US and this

777
00:44:01,000 --> 00:44:05,479
Speaker 1: also includes space exploration applications as well. If you want

778
00:44:05,520 --> 00:44:10,759
Speaker 1: to see some footage of horseshoe crab blood harvesting in process,

779
00:44:10,840 --> 00:44:14,760
Speaker 1: you should definitely check out the nat GEO documentary series

780
00:44:14,800 --> 00:44:17,840
Speaker 1: One Strange Rock. We've heard us talk about this in

781
00:44:17,880 --> 00:44:21,440
Speaker 1: the past on the show Excellent Documentary Wonderful footage features

782
00:44:21,440 --> 00:44:24,880
Speaker 1: a number of astronauts and Will Smith narrating all of this,

783
00:44:25,360 --> 00:44:27,640
Speaker 1: but they have a section on there. It's on Disney

784
00:44:27,640 --> 00:44:30,080
Speaker 1: Plus right now, so I highly recommend you check it

785
00:44:30,120 --> 00:44:35,120
Speaker 1: out while you're mainlining all of the Mandalorian goodness there. Uh.

786
00:44:35,200 --> 00:44:38,160
Speaker 1: In fact, it was while watching One Strange Rock that

787
00:44:38,440 --> 00:44:41,279
Speaker 1: my with my family that I was reminded that this

788
00:44:41,280 --> 00:44:44,120
Speaker 1: would be a great topic because my son was watching

789
00:44:44,160 --> 00:44:46,400
Speaker 1: this and they were showing all these these horseshoe crabs

790
00:44:46,440 --> 00:44:50,359
Speaker 1: being lined up and bled, and he just immediately did

791
00:44:50,360 --> 00:44:52,000
Speaker 1: not like it. And he just gets this very stern

792
00:44:52,040 --> 00:44:54,080
Speaker 1: look out his face and he says, human beings are

793
00:44:54,080 --> 00:44:58,480
Speaker 1: the worst and uh, and I had to reassure him, no, Uh,

794
00:44:58,520 --> 00:45:01,560
Speaker 1: these horseshoe crabs are going to to be fine. Uh

795
00:45:01,600 --> 00:45:03,840
Speaker 1: you know that we're not. They're not draining them to death.

796
00:45:04,120 --> 00:45:06,799
Speaker 1: They are draining them and then uh a certain portion

797
00:45:06,840 --> 00:45:08,960
Speaker 1: of their blood and then releasing them into the wild.

798
00:45:09,160 --> 00:45:11,919
Speaker 1: So there is some mortality. Yes, yeah, I was looking

799
00:45:11,960 --> 00:45:15,400
Speaker 1: around on this. Uh, there's a paper from the Department

800
00:45:15,440 --> 00:45:19,560
Speaker 1: of Fisheries and Wildlife Sciences and Horseshoe Crab Research Center.

801
00:45:19,760 --> 00:45:24,799
Speaker 1: This is Virginia Polytechnic Institute and State University from LINKA Hurton. Uh.

802
00:45:24,840 --> 00:45:27,759
Speaker 1: This is a this is a small study, but it

803
00:45:28,120 --> 00:45:30,799
Speaker 1: it looked at them the morality, the mortality rates for

804
00:45:31,040 --> 00:45:33,840
Speaker 1: horseshoe crabs. It's gonna vary depending on the sex of

805
00:45:33,880 --> 00:45:36,760
Speaker 1: the of the horseshoe crab and the amount of blood drawn.

806
00:45:37,200 --> 00:45:40,120
Speaker 1: And also not every specimen that is collected is ultimately

807
00:45:40,160 --> 00:45:42,480
Speaker 1: deemed suitable for a draw. So the source I was

808
00:45:42,480 --> 00:45:46,240
Speaker 1: looking at placed male mortality rate anywhere between zero percent

809
00:45:46,360 --> 00:45:50,040
Speaker 1: at ten percent blood drawn to thirteen points six percent

810
00:45:50,080 --> 00:45:53,239
Speaker 1: at thirty percent blood drawn, while females it range from

811
00:45:53,320 --> 00:45:57,760
Speaker 1: zero at zero to fifteen point four percent at blood

812
00:45:57,800 --> 00:46:01,040
Speaker 1: drawn and hold not go ahead, Well wait why did

813
00:46:01,040 --> 00:46:03,759
Speaker 1: they ask at zero percent drawn? This comes down to

814
00:46:03,800 --> 00:46:05,600
Speaker 1: the fact that it was such a small study that

815
00:46:05,640 --> 00:46:08,839
Speaker 1: there were zero that were that had zero percent drawn

816
00:46:09,040 --> 00:46:11,000
Speaker 1: of this particular study. So, like I say, the very

817
00:46:11,000 --> 00:46:15,320
Speaker 1: small sample size makes these numbers, you know, not the gospel,

818
00:46:15,600 --> 00:46:18,040
Speaker 1: but they give some idea of of what you're looking

819
00:46:18,040 --> 00:46:22,160
Speaker 1: at here. For the females, the more standard blood draw

820
00:46:22,440 --> 00:46:25,080
Speaker 1: get was came with a mortality rate of ten point

821
00:46:25,160 --> 00:46:28,720
Speaker 1: three So thirty percent of a of a crabs blood

822
00:46:28,760 --> 00:46:31,440
Speaker 1: is generally extracted before it is returned to its natural

823
00:46:31,520 --> 00:46:35,439
Speaker 1: environment within seventy two hours and their place further out,

824
00:46:35,560 --> 00:46:40,080
Speaker 1: usually to prevent repeat capture and draining. However, this is

825
00:46:40,120 --> 00:46:44,560
Speaker 1: still a physically stressful situation. You know, not to anthropomorphize

826
00:46:44,600 --> 00:46:48,480
Speaker 1: the creature's experience or anything, but the crabs take three

827
00:46:48,520 --> 00:46:51,279
Speaker 1: to seven days to regain their blood volume and up

828
00:46:51,280 --> 00:46:53,960
Speaker 1: to four months for those amata sites to return to

829
00:46:54,000 --> 00:46:58,320
Speaker 1: baseline levels, and they're also usually harvested during spawning periods

830
00:46:58,320 --> 00:47:01,360
Speaker 1: because this is when their easiest to catch. A June

831
00:47:01,960 --> 00:47:05,279
Speaker 1: nineteen study published in the University of Chicago Press looked

832
00:47:05,280 --> 00:47:08,920
Speaker 1: at the stress placed on the crabs following their bleeding

833
00:47:08,960 --> 00:47:13,640
Speaker 1: and how it might be UH impacting their reproductive potency

834
00:47:14,160 --> 00:47:17,839
Speaker 1: um so owings at All found the following. First of all,

835
00:47:18,200 --> 00:47:23,080
Speaker 1: overall biomedical bleeding may impact the reproductive output of female

836
00:47:23,120 --> 00:47:26,000
Speaker 1: horseshoe crabs during the season in which they were bled.

837
00:47:26,960 --> 00:47:30,200
Speaker 1: Week one following the bleeding, bled animals appeared to spawn

838
00:47:30,320 --> 00:47:33,320
Speaker 1: less than the controlled animals, and they also found that

839
00:47:33,400 --> 00:47:36,760
Speaker 1: control females appeared to spawn on average four point eight

840
00:47:36,840 --> 00:47:40,759
Speaker 1: times UH the rate of bled females, which spawned on

841
00:47:40,800 --> 00:47:43,840
Speaker 1: average just two times. They also found that bled animals

842
00:47:44,200 --> 00:47:48,080
Speaker 1: tended to stay clear of shallow zones places that they

843
00:47:48,080 --> 00:47:51,200
Speaker 1: actually needed to be for breeding purposes, and this might

844
00:47:51,480 --> 00:47:54,920
Speaker 1: this might be due to disorientation in the animal following

845
00:47:54,960 --> 00:47:57,840
Speaker 1: the blood draw or it also just might all of

846
00:47:57,880 --> 00:48:00,160
Speaker 1: this might come down to weakness, like the creature is

847
00:48:00,200 --> 00:48:02,799
Speaker 1: going to be weakened for a state of you know,

848
00:48:03,120 --> 00:48:06,040
Speaker 1: a week or even months following what's gone on here,

849
00:48:06,080 --> 00:48:09,720
Speaker 1: and that may impact their reproductive health as well. So

850
00:48:10,200 --> 00:48:13,600
Speaker 1: all of this can ultimately alter the sex ratio at

851
00:48:13,640 --> 00:48:15,960
Speaker 1: those breeding areas that we talked about at the top

852
00:48:16,000 --> 00:48:19,560
Speaker 1: of the program, which is then going to impact reproduction

853
00:48:19,760 --> 00:48:23,920
Speaker 1: overall for the species in these areas where blood harvesting

854
00:48:24,000 --> 00:48:27,560
Speaker 1: is taking place. So the harvesting of horseshoe crab blood

855
00:48:27,600 --> 00:48:31,800
Speaker 1: probably has saved thousands or millions of lives over the

856
00:48:31,880 --> 00:48:35,120
Speaker 1: years that it's been done, but it's still not good

857
00:48:35,160 --> 00:48:39,520
Speaker 1: to be hurting these populations like this it is, you know,

858
00:48:39,560 --> 00:48:42,160
Speaker 1: and again, like this is a study from just last year,

859
00:48:42,400 --> 00:48:44,640
Speaker 1: so you know, we're we're still learning more and more

860
00:48:44,640 --> 00:48:47,280
Speaker 1: about the impact as we are also looking for ways

861
00:48:47,320 --> 00:48:49,480
Speaker 1: to get better, ways to get away from the use

862
00:48:49,480 --> 00:48:53,600
Speaker 1: of horseshoe crab blood because there are some synthetic solutions now, right, Yeah,

863
00:48:53,640 --> 00:48:56,600
Speaker 1: there are, and we're generally we're looking at a future

864
00:48:56,680 --> 00:48:59,839
Speaker 1: where we're going to depend less on it. Another thing

865
00:48:59,840 --> 00:49:01,560
Speaker 1: to keep in mind is this is not the only

866
00:49:01,640 --> 00:49:04,160
Speaker 1: risk factor for horseshoe crabs. It would be one thing

867
00:49:04,200 --> 00:49:07,399
Speaker 1: if it were, but uh, they are also harvested for

868
00:49:07,480 --> 00:49:09,759
Speaker 1: their eggs, so they can be used as bait for

869
00:49:09,960 --> 00:49:14,160
Speaker 1: eels as well as creatures known as weelky. Forty was

870
00:49:14,200 --> 00:49:16,279
Speaker 1: talking about this in his book The welk is some

871
00:49:16,360 --> 00:49:19,560
Speaker 1: kind of conk like animal that people fishing for it

872
00:49:19,600 --> 00:49:22,520
Speaker 1: have used horseshoe crabs as bait. So you know, these

873
00:49:22,560 --> 00:49:26,040
Speaker 1: are two different human practices that are having varying degrees

874
00:49:26,040 --> 00:49:29,600
Speaker 1: of impact on their reproductive health. And we have to

875
00:49:29,640 --> 00:49:31,200
Speaker 1: come back again to the fact that this is not

876
00:49:31,280 --> 00:49:35,319
Speaker 1: just some mirror outsider species, it's just left over from

877
00:49:35,360 --> 00:49:39,000
Speaker 1: a bygone age. They are keystone species. Their eggs are

878
00:49:39,080 --> 00:49:42,320
Speaker 1: important food source for a number of organisms, again including

879
00:49:42,360 --> 00:49:47,240
Speaker 1: migratory sea birds. So the future promises new biomedical tests

880
00:49:47,560 --> 00:49:50,920
Speaker 1: as well as hopefully alternative baits for the fishing industry,

881
00:49:51,120 --> 00:49:53,560
Speaker 1: and hopefully all this will come together to ensure the

882
00:49:53,640 --> 00:49:57,480
Speaker 1: long term survival of the horseshoe crab. I hope it

883
00:49:57,560 --> 00:49:59,840
Speaker 1: is not the sixth extinction that wipes them out. But

884
00:50:00,000 --> 00:50:02,959
Speaker 1: that's the thing, isn't it. The Great six The mass

885
00:50:03,000 --> 00:50:06,960
Speaker 1: extinction event is proving to be the the human occupation

886
00:50:07,000 --> 00:50:09,319
Speaker 1: of the planet. However, the one thing we have going

887
00:50:09,360 --> 00:50:13,719
Speaker 1: for us is that this extinction event is largely self conscious,

888
00:50:14,040 --> 00:50:16,960
Speaker 1: or at least it's self consciousness is growing. I'm going

889
00:50:16,960 --> 00:50:20,000
Speaker 1: to be an optimist and it can do things like

890
00:50:20,640 --> 00:50:24,360
Speaker 1: curb it's uh, it's fishing practices. It can do things

891
00:50:24,880 --> 00:50:28,880
Speaker 1: that are self reflective and hopefully sustainable. Yeah, save the

892
00:50:28,960 --> 00:50:33,560
Speaker 1: Lemuli folks, they're scuttling masses are precious, absolutely all right.

893
00:50:33,640 --> 00:50:35,799
Speaker 1: So there you have at the Horseshoe Crab. Obviously, we'd

894
00:50:35,800 --> 00:50:38,080
Speaker 1: love to hear from everybody, especially those of you who have,

895
00:50:38,400 --> 00:50:41,480
Speaker 1: you know, any firsthand experience with the horseshoe crab. If

896
00:50:41,520 --> 00:50:44,799
Speaker 1: you have ever eaten the row of horseshoe crabs, let

897
00:50:44,840 --> 00:50:47,240
Speaker 1: us know we'd love to hear about that as well.

898
00:50:47,719 --> 00:50:50,600
Speaker 1: In the meantime, you can find us wherever you get

899
00:50:50,600 --> 00:50:52,799
Speaker 1: your podcasts. Go to stuff to Blow your Mind dot

900
00:50:52,800 --> 00:50:54,920
Speaker 1: com and that'll redirect you to a place where you

901
00:50:54,920 --> 00:50:57,880
Speaker 1: can find the episodes. But wherever you find us, just

902
00:50:57,920 --> 00:51:00,279
Speaker 1: make sure that you subscribe, that you ray, and that

903
00:51:00,400 --> 00:51:03,040
Speaker 1: you review, and don't forget to check out Invention. That's

904
00:51:03,280 --> 00:51:06,600
Speaker 1: our other show that deals with human techno history. Huge

905
00:51:06,640 --> 00:51:10,080
Speaker 1: thanks as always to our excellent audio producer Seth Nicholas Johnson.

906
00:51:10,320 --> 00:51:11,719
Speaker 1: If you'd like to get in touch with us with

907
00:51:11,800 --> 00:51:14,440
Speaker 1: feedback on this episode or any other to suggest topic

908
00:51:14,480 --> 00:51:16,920
Speaker 1: of the future, just to say Hello. You can email

909
00:51:17,000 --> 00:51:27,319
Speaker 1: us at contact at stuff to Blow your Mind dot com.

910
00:51:27,440 --> 00:51:29,640
Speaker 1: Stuff to Blow Your Mind is a production of iHeart Radios.

911
00:51:29,640 --> 00:51:32,000
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913
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