1 00:00:05,720 --> 00:00:07,760 Speaker 1: Hey, Welcome to Stuff to Blow Your Mind. My name 2 00:00:07,800 --> 00:00:10,959 Speaker 1: is Robert Lamb and I'm Joe McCormick, and it's Saturday, 3 00:00:11,080 --> 00:00:14,760 Speaker 1: time for a Vault episode. This episode originally aired on 4 00:00:15,000 --> 00:00:19,520 Speaker 1: January and it's about horseshoe crabs. I remember this was 5 00:00:19,560 --> 00:00:22,360 Speaker 1: a lot of fun. Yeah, it sounds fine, but this 6 00:00:22,400 --> 00:00:23,720 Speaker 1: is one of those. When I was putting it in 7 00:00:23,720 --> 00:00:26,400 Speaker 1: our schedule for the Vault episode, I realized I had 8 00:00:26,480 --> 00:00:28,280 Speaker 1: no memory of this one at all. Really. I mean, 9 00:00:28,320 --> 00:00:31,360 Speaker 1: I vaguely remember researching some of the stuff about the 10 00:00:31,360 --> 00:00:34,600 Speaker 1: blood and the usefulness of horseshoe blood, but I really 11 00:00:34,640 --> 00:00:38,000 Speaker 1: don't remember this episode. Otherwise, I don't know why. I remember. 12 00:00:38,040 --> 00:00:40,480 Speaker 1: This episode led me to discover a really cool book though, 13 00:00:40,520 --> 00:00:43,680 Speaker 1: that was about horseshoe crabs and uh and an evolution. 14 00:00:43,840 --> 00:00:47,000 Speaker 1: So yeah, yeah, it was a good one. Alright, let's 15 00:00:47,040 --> 00:00:52,120 Speaker 1: dive in Welcome to Stuff to Blow Your Mind, a 16 00:00:52,159 --> 00:01:01,000 Speaker 1: production of I Heart Radios has to work. Hey, you, 17 00:01:01,040 --> 00:01:02,800 Speaker 1: Welcome to Stuff to Blow your Mind. My name is 18 00:01:02,880 --> 00:01:05,840 Speaker 1: Robert Lamb and I'm Joe McCormick, and today we're gonna 19 00:01:05,880 --> 00:01:11,839 Speaker 1: be talking about an underappreciated evolutionary marvel, the horseshoe crab. Robert, 20 00:01:11,920 --> 00:01:14,360 Speaker 1: this this episode was your idea, and I'm so glad 21 00:01:14,440 --> 00:01:17,080 Speaker 1: you you thought of this. Yeah, and I'll bring up 22 00:01:17,200 --> 00:01:20,040 Speaker 1: a little later in the episode. What what reminded me 23 00:01:20,120 --> 00:01:22,640 Speaker 1: that the horseshoe crab should be a topic of discussion. 24 00:01:22,680 --> 00:01:24,480 Speaker 1: But but really, this is a creature I feel like 25 00:01:24,520 --> 00:01:28,000 Speaker 1: that I've been admiring my whole life. It's frequently brought up. 26 00:01:28,200 --> 00:01:30,160 Speaker 1: It's frequently pointed out to me. I remember as a 27 00:01:30,240 --> 00:01:33,640 Speaker 1: kid being if not shown an actual horseshoe crab, I 28 00:01:33,640 --> 00:01:35,640 Speaker 1: mean maybe I was shown like the remnants of one 29 00:01:35,680 --> 00:01:37,959 Speaker 1: that had washed up, or picture of one, and it 30 00:01:38,040 --> 00:01:40,280 Speaker 1: was explained to me that, like, this is a unique 31 00:01:40,360 --> 00:01:44,360 Speaker 1: organism that you don't find many things that I really 32 00:01:44,440 --> 00:01:46,399 Speaker 1: like it on this earth, on the Earth today, and 33 00:01:46,400 --> 00:01:48,880 Speaker 1: if you went back far enough in time, you would 34 00:01:48,880 --> 00:01:53,600 Speaker 1: find them in in ages of of strange biological diversity 35 00:01:53,680 --> 00:01:56,640 Speaker 1: that what otherwise seem alien. But the horseshoe crab has 36 00:01:56,720 --> 00:02:00,280 Speaker 1: remained largely constant. It is an olive colored lump from 37 00:02:00,280 --> 00:02:03,400 Speaker 1: the Jurassic period and beyond. So one of the great 38 00:02:03,400 --> 00:02:05,560 Speaker 1: things about it is it's sort of perfect fodder for 39 00:02:05,640 --> 00:02:08,520 Speaker 1: our show, I think, because it's something that if you 40 00:02:08,560 --> 00:02:10,960 Speaker 1: don't go deep on it, it might be uh, you 41 00:02:11,000 --> 00:02:12,680 Speaker 1: might think of it as a kind of like lowly 42 00:02:12,760 --> 00:02:15,640 Speaker 1: and uninteresting, just sort of lump in the mud with 43 00:02:15,639 --> 00:02:18,360 Speaker 1: with some scuttling claws, and you know that there's not 44 00:02:18,440 --> 00:02:21,400 Speaker 1: really much to it. There's a lot to it. This 45 00:02:21,440 --> 00:02:24,239 Speaker 1: creature is marvelous. And to start us off, I want 46 00:02:24,240 --> 00:02:27,360 Speaker 1: to inspire some wonder by by reading a passage with 47 00:02:27,400 --> 00:02:30,720 Speaker 1: a few abridgements from a really excellent book I've been 48 00:02:30,760 --> 00:02:34,919 Speaker 1: reading this week by the British paleontologist Richard Forty, called 49 00:02:35,040 --> 00:02:38,560 Speaker 1: Horseshoe Crabs and Velvet Worms, The Story of Animals and 50 00:02:38,560 --> 00:02:42,000 Speaker 1: Plants that Time Has Left Behind. It was published into 51 00:02:42,040 --> 00:02:44,440 Speaker 1: the two thousand twelve Now velvet Worms by the way 52 00:02:44,480 --> 00:02:47,880 Speaker 1: we spoke about them recently, it was potentially buried if 53 00:02:47,919 --> 00:02:50,880 Speaker 1: you skip our movie episodes, and you shouldn't. Uh. We 54 00:02:50,919 --> 00:02:53,960 Speaker 1: did an episode on the Tangler, that old Vincent Price 55 00:02:54,040 --> 00:02:57,720 Speaker 1: horror movie, and the title character in or the title 56 00:02:57,800 --> 00:03:02,239 Speaker 1: monster in that film, the tingler very closely resembles a 57 00:03:02,320 --> 00:03:05,600 Speaker 1: velvet worm, so we discussed its unique biology so to 58 00:03:05,680 --> 00:03:08,400 Speaker 1: be mentioned in the same sentence as the velvet worm. 59 00:03:08,600 --> 00:03:10,680 Speaker 1: That should I let you know that the horseshoe crab 60 00:03:10,800 --> 00:03:14,120 Speaker 1: is no joke totally so. Richard Forty, the author of 61 00:03:14,160 --> 00:03:16,960 Speaker 1: this book, is a former president of the Geological Society 62 00:03:17,000 --> 00:03:19,080 Speaker 1: of London. He spent much of his career as a 63 00:03:19,080 --> 00:03:22,480 Speaker 1: staff paleontologist at the British Natural History Museum, where his 64 00:03:22,520 --> 00:03:25,000 Speaker 1: research included a special focus on our old friends, the 65 00:03:25,000 --> 00:03:27,600 Speaker 1: trialo bites uh. And he's also done a lot of 66 00:03:27,600 --> 00:03:31,880 Speaker 1: public natural history communication, appearing on BBC documentaries and stuff 67 00:03:31,919 --> 00:03:35,400 Speaker 1: like that. So in the opening chapter of this book, 68 00:03:35,440 --> 00:03:40,680 Speaker 1: Forty is describing a massive gathering of horseshoe crabs that 69 00:03:40,720 --> 00:03:44,520 Speaker 1: he witnessed one night on a beach in Delaware. So 70 00:03:44,600 --> 00:03:47,480 Speaker 1: I'll begin reading here deep in the night, along the 71 00:03:47,480 --> 00:03:51,680 Speaker 1: shores of Delaware Bay. The horseshoe crabs are stirring. The 72 00:03:51,720 --> 00:03:55,520 Speaker 1: tide is now high, and there is no moon. Darkness rules, 73 00:03:55,600 --> 00:03:58,920 Speaker 1: But even in the feeble starlight, the overwhelming flatness of 74 00:03:58,960 --> 00:04:02,240 Speaker 1: the countryside can be made out, except along the room 75 00:04:02,280 --> 00:04:04,800 Speaker 1: of the bay, where old sand dunes have built up 76 00:04:04,800 --> 00:04:08,920 Speaker 1: a levee heave with gentle movements. First, I noticed some 77 00:04:09,040 --> 00:04:13,800 Speaker 1: very odd sounds. There is a general hollow clattering, a 78 00:04:13,920 --> 00:04:17,960 Speaker 1: tapping and grinding sound somewhat like that made by knocking 79 00:04:18,040 --> 00:04:21,400 Speaker 1: coconut shells together, once used on the radio to imitate 80 00:04:21,480 --> 00:04:25,360 Speaker 1: horses hoofs, but altogether less rhythmic and with a kind 81 00:04:25,400 --> 00:04:29,120 Speaker 1: of underlying push. Then, as my eyes get used to 82 00:04:29,160 --> 00:04:33,640 Speaker 1: the darkness low shelly mounds, the size of inverted colanders 83 00:04:33,680 --> 00:04:37,640 Speaker 1: can be seen slowly pushing and jostling all along the 84 00:04:37,680 --> 00:04:41,400 Speaker 1: shore and perhaps six meters up into the sands. They're 85 00:04:41,400 --> 00:04:44,520 Speaker 1: bumping and clambering together. Is the source of those tap 86 00:04:44,560 --> 00:04:48,760 Speaker 1: tapping percussive sounds. The flash of an infrared torch reveals 87 00:04:48,800 --> 00:04:52,240 Speaker 1: more details. The head shield of the horseshoe crab is 88 00:04:52,320 --> 00:04:56,200 Speaker 1: domed upwards and carries a few weak spines at its 89 00:04:56,240 --> 00:04:59,120 Speaker 1: back end to hinge marks a jointed boundary with a 90 00:04:59,240 --> 00:05:03,440 Speaker 1: second large plate spiny at the edge, which can flap downwards, 91 00:05:03,520 --> 00:05:07,120 Speaker 1: and beyond that again projects a stout triangular spike as 92 00:05:07,160 --> 00:05:09,799 Speaker 1: long as the head, which can waggle up and down. 93 00:05:10,520 --> 00:05:13,359 Speaker 1: Here at Kit's stomach. More crabs are gathered on the 94 00:05:13,440 --> 00:05:18,320 Speaker 1: mud flat seaward of the sands, waiting their turn. Strange green, black, 95 00:05:18,520 --> 00:05:23,160 Speaker 1: slowly animated lumps further offshore again in the shallow seawater 96 00:05:23,560 --> 00:05:27,400 Speaker 1: Tail Spikes project briefly above the gentle waves like raised 97 00:05:27,520 --> 00:05:31,400 Speaker 1: radio antenna and are gone, showing we're still more horseshoe 98 00:05:31,400 --> 00:05:34,120 Speaker 1: crabs vie with one another to get their place on 99 00:05:34,200 --> 00:05:37,000 Speaker 1: the sand. So if that doesn't attempt you to buy 100 00:05:37,040 --> 00:05:38,880 Speaker 1: the book, I will say that the whole thing I 101 00:05:38,920 --> 00:05:41,200 Speaker 1: think is great like that Forty is uh he's a 102 00:05:41,200 --> 00:05:43,760 Speaker 1: great scientist but also a really great writer. In this 103 00:05:43,800 --> 00:05:47,560 Speaker 1: book is just a fabulous read. Yeah. I like the 104 00:05:47,839 --> 00:05:50,240 Speaker 1: details he gives to describing it. Like, one thing that 105 00:05:50,400 --> 00:05:52,280 Speaker 1: I think stands out for me is the horseshoe crab 106 00:05:52,920 --> 00:05:56,320 Speaker 1: always looked like an element from a suit of armor. 107 00:05:56,400 --> 00:05:58,680 Speaker 1: You know, it has a looks it looks like a 108 00:05:58,720 --> 00:06:02,080 Speaker 1: little tank um thing along the shoreline. Well, yeah, exactly, 109 00:06:02,120 --> 00:06:03,840 Speaker 1: And there's a good reason it looks like that. I mean, 110 00:06:03,880 --> 00:06:06,080 Speaker 1: that is quite literally what it is. This is a 111 00:06:06,120 --> 00:06:08,840 Speaker 1: creature that is mostly a suit of armor, especially if 112 00:06:08,839 --> 00:06:12,200 Speaker 1: you're looking down from above right, it is quite literally 113 00:06:12,279 --> 00:06:16,400 Speaker 1: biological armor. Now, Forty goes on to explain the marvels 114 00:06:16,400 --> 00:06:18,640 Speaker 1: of the scene. He says, there are thousands of these 115 00:06:18,680 --> 00:06:21,160 Speaker 1: creatures gathered on the beach and coming onto the beach 116 00:06:21,200 --> 00:06:24,240 Speaker 1: from the waves. Uh. He at one point finds one 117 00:06:24,279 --> 00:06:27,880 Speaker 1: horseshoe crab upturned on its back in the sand, desperately 118 00:06:28,279 --> 00:06:31,000 Speaker 1: bending its tail spike up and down in an attempt 119 00:06:31,000 --> 00:06:33,760 Speaker 1: to flip itself back over, which is a strategy that 120 00:06:33,800 --> 00:06:36,200 Speaker 1: I believe would probably work in the water, but not 121 00:06:36,279 --> 00:06:39,840 Speaker 1: so much on the land. Um And despite his status 122 00:06:39,920 --> 00:06:43,400 Speaker 1: as a scientific observer, Forty admits that he's unable to 123 00:06:43,480 --> 00:06:46,600 Speaker 1: resist the urge to right the animal, and he does, 124 00:06:46,800 --> 00:06:49,000 Speaker 1: grasping it by its head shield, and he flips it. 125 00:06:49,480 --> 00:06:52,159 Speaker 1: But once upright, of course, it doesn't say any thanks. 126 00:06:52,240 --> 00:06:54,760 Speaker 1: It just kind of trundles away and gets back to business. 127 00:06:54,760 --> 00:06:58,520 Speaker 1: But what is this business? It is mating. This is 128 00:06:58,560 --> 00:07:01,599 Speaker 1: a giant convention of hor shoe crabs essentially for the 129 00:07:01,680 --> 00:07:05,679 Speaker 1: purpose of an invertebrate orgy. And that's not forty. Forty 130 00:07:05,760 --> 00:07:08,400 Speaker 1: himself uses the word orgy. I think that is the 131 00:07:08,560 --> 00:07:11,960 Speaker 1: correct term for this. So he notes that the largest 132 00:07:12,000 --> 00:07:14,760 Speaker 1: animals on the beach are digging down in the sand, 133 00:07:15,600 --> 00:07:18,840 Speaker 1: so while their dorsal shields hide most of what's going on, 134 00:07:19,240 --> 00:07:24,160 Speaker 1: their jointed limbs underneath our industriously removing sand. And then 135 00:07:24,600 --> 00:07:26,960 Speaker 1: some of the larger crabs end up digging themselves so 136 00:07:27,000 --> 00:07:31,000 Speaker 1: far down that they're almost completely buried, and these larger creatures, 137 00:07:31,080 --> 00:07:33,720 Speaker 1: the ones doing the digging, or the females, they will 138 00:07:33,800 --> 00:07:37,200 Speaker 1: ultimately be burying their freshly laid eggs in the sand 139 00:07:37,280 --> 00:07:41,280 Speaker 1: here on the beach. Meanwhile, smaller crabs are fighting to 140 00:07:41,360 --> 00:07:44,360 Speaker 1: climb on top of the buried females. These smaller ones 141 00:07:44,400 --> 00:07:47,360 Speaker 1: are the males, and the reason they're fighting for positioning 142 00:07:47,400 --> 00:07:50,160 Speaker 1: is that they're competing for a chance to fertilize the 143 00:07:50,160 --> 00:07:53,560 Speaker 1: female's eggs with their sperm cells, which are called milt 144 00:07:54,200 --> 00:07:57,280 Speaker 1: and Uh Forty realizes that much of the tapping he's 145 00:07:57,320 --> 00:08:00,000 Speaker 1: talking about in that passage, I read that clacking noise 146 00:08:00,160 --> 00:08:02,560 Speaker 1: that he heard in the dark comes from what he 147 00:08:02,600 --> 00:08:07,680 Speaker 1: calls tussles for dominance. Male horseshoe crabs knocking one another 148 00:08:07,720 --> 00:08:10,760 Speaker 1: about by the exo skeletons as they fight for a 149 00:08:10,840 --> 00:08:13,960 Speaker 1: chance to be the first in line to reproduce, and 150 00:08:14,000 --> 00:08:17,120 Speaker 1: this can get really violent. Forty notes that finally, uh, 151 00:08:17,480 --> 00:08:20,680 Speaker 1: many of them don't survive this night of mass invertebrate 152 00:08:20,680 --> 00:08:23,080 Speaker 1: sex on the beach. In the morning, the shore is 153 00:08:23,120 --> 00:08:27,720 Speaker 1: just littered with assorted chunks of horseshoe crab carcasses. It's 154 00:08:27,720 --> 00:08:30,400 Speaker 1: an amazing scene, and I wish I could be present 155 00:08:30,440 --> 00:08:33,200 Speaker 1: to see this something I would go to Delaware for that. 156 00:08:33,400 --> 00:08:35,760 Speaker 1: That would get me into Delaware. Yeah, they should put 157 00:08:35,760 --> 00:08:38,440 Speaker 1: it on the license plate, right. Yeah, this does remind 158 00:08:38,520 --> 00:08:41,400 Speaker 1: me of of a story that I've heard before. My 159 00:08:41,440 --> 00:08:44,600 Speaker 1: wife's grandmother had an amusing tale of horseshoe crabs. I 160 00:08:44,640 --> 00:08:46,680 Speaker 1: believe this is a tale from the Great Outer Banks 161 00:08:47,320 --> 00:08:50,280 Speaker 1: of the United States. Uh, though she also lived in 162 00:08:50,280 --> 00:08:52,199 Speaker 1: Australia for a time when she was younger, so it 163 00:08:52,320 --> 00:08:54,080 Speaker 1: might be a tale from Australia, but I'm pretty sure 164 00:08:54,080 --> 00:08:57,959 Speaker 1: it's Outer Banks anyway. The story goes that she happened 165 00:08:58,000 --> 00:08:59,880 Speaker 1: upon a bunch of horseshoe crabs on the beach and 166 00:09:00,040 --> 00:09:03,800 Speaker 1: thought they were in danger. So um, my wife's grandmother 167 00:09:03,920 --> 00:09:06,320 Speaker 1: then devoted an hour or so to collecting them and 168 00:09:06,400 --> 00:09:09,200 Speaker 1: hurling them back into the sea, only to learn later 169 00:09:09,240 --> 00:09:13,120 Speaker 1: that they had come ashore to make so she thought 170 00:09:13,120 --> 00:09:15,880 Speaker 1: that they were like beached whales essentially. Yeah, you know, 171 00:09:16,480 --> 00:09:19,079 Speaker 1: they're usually not there here, they are in mass maybe 172 00:09:19,080 --> 00:09:21,280 Speaker 1: something is wrong. They need help, you know, thrown back 173 00:09:21,320 --> 00:09:23,200 Speaker 1: in before the birds get them, that sort of thing. 174 00:09:23,320 --> 00:09:26,360 Speaker 1: So she meant, well, but it turns out she was 175 00:09:26,440 --> 00:09:30,160 Speaker 1: interfering in their natural process. I bet those were some 176 00:09:30,240 --> 00:09:34,079 Speaker 1: frustrated invertebrates. Uh. Now, these mass matings on the beach 177 00:09:34,440 --> 00:09:38,880 Speaker 1: bear a and actually pretty great ecological significance. Forty describes 178 00:09:39,200 --> 00:09:42,280 Speaker 1: the eggs they lay as tiny and green, and he 179 00:09:42,320 --> 00:09:44,880 Speaker 1: writes that they're they're laid together in these golf ball 180 00:09:44,920 --> 00:09:49,880 Speaker 1: sized clumps of about four thousand to six thousand eggs apiece. Uh. 181 00:09:49,920 --> 00:09:52,360 Speaker 1: He says up to fifteen or so males will have 182 00:09:52,400 --> 00:09:55,280 Speaker 1: the opportunity to fertilize the eggs of a single female, 183 00:09:55,600 --> 00:09:58,480 Speaker 1: and during a reproductive cycle, a single female horseshoe crab 184 00:09:58,559 --> 00:10:01,920 Speaker 1: might lay about eighty two a thousand eggs total. And 185 00:10:02,000 --> 00:10:05,520 Speaker 1: yet Forty notes that on average, it's estimated that only 186 00:10:05,559 --> 00:10:10,040 Speaker 1: about thirty three out of every million eggs survive into adulthood. 187 00:10:10,440 --> 00:10:12,760 Speaker 1: So again this comes back to kind of in the 188 00:10:12,800 --> 00:10:15,240 Speaker 1: invertebrate numbers game, much like we talked about in our 189 00:10:15,360 --> 00:10:18,280 Speaker 1: Christmas Island Crabs episode. Uh. You know, there's a lot 190 00:10:18,320 --> 00:10:20,960 Speaker 1: of larva and only a tiny fraction of them actually 191 00:10:21,000 --> 00:10:25,400 Speaker 1: ever become adult crabs. Uh. But this massive eggs and 192 00:10:25,480 --> 00:10:29,960 Speaker 1: juveniles that don't survive, they're ecologically very important because like 193 00:10:30,040 --> 00:10:32,960 Speaker 1: the Christmas Island crabs. They are an important food source 194 00:10:33,000 --> 00:10:35,880 Speaker 1: for lots of animals living in and passing through the region. 195 00:10:36,480 --> 00:10:41,160 Speaker 1: Longerhead turtles prey on the crabs even into adulthood. That 196 00:10:41,280 --> 00:10:43,840 Speaker 1: is kind of weird imagining eating a horseshoe crab, because 197 00:10:43,880 --> 00:10:46,480 Speaker 1: if you look at one, it just really does not 198 00:10:46,640 --> 00:10:48,600 Speaker 1: look like it would have much good meat. It looks 199 00:10:48,640 --> 00:10:51,440 Speaker 1: like an animal made entirely out of shell and bone. 200 00:10:51,880 --> 00:10:53,760 Speaker 1: So I was looking around on this and in some 201 00:10:53,800 --> 00:10:56,800 Speaker 1: parts of the world that they are sometimes harvested for food, 202 00:10:57,200 --> 00:11:00,560 Speaker 1: but only the eggs or row are edible, according to 203 00:11:00,640 --> 00:11:03,120 Speaker 1: Malaysia Best dot net so, which is a blog post 204 00:11:03,120 --> 00:11:05,400 Speaker 1: about this and some photos. You'll find them on the 205 00:11:05,440 --> 00:11:08,600 Speaker 1: menu and some restaurants either grilled and flipped over for 206 00:11:08,840 --> 00:11:12,000 Speaker 1: row consumption, or someplaces you can get the row already 207 00:11:12,000 --> 00:11:14,480 Speaker 1: scooped out and served to you. And I read that 208 00:11:14,559 --> 00:11:18,280 Speaker 1: the eggs basically have a rubbery texture and a salty taste, 209 00:11:18,320 --> 00:11:21,960 Speaker 1: so nothing really all that exotic in terms of you know, 210 00:11:22,000 --> 00:11:26,199 Speaker 1: eating uh, you know, the the eggs of marine creatures 211 00:11:26,520 --> 00:11:29,520 Speaker 1: like this, But again, the end of the air favorites 212 00:11:29,559 --> 00:11:32,640 Speaker 1: among birds and other creatures, and the horseshoe crab is 213 00:11:32,640 --> 00:11:36,280 Speaker 1: a keystone species for this reason, Like it's we're gonna 214 00:11:36,280 --> 00:11:38,040 Speaker 1: spend a lot of time on this show talking about, 215 00:11:38,040 --> 00:11:40,440 Speaker 1: you know, how ancient they are in their ancient origins. 216 00:11:40,440 --> 00:11:43,080 Speaker 1: It's easy to maybe fall into this notion that they 217 00:11:43,120 --> 00:11:46,360 Speaker 1: are an outcast, that they're not really important, they're just 218 00:11:46,400 --> 00:11:49,000 Speaker 1: a throwback. But no, they have a very important role 219 00:11:49,040 --> 00:11:52,720 Speaker 1: in a number of species. Again, like migratory seabirds depend 220 00:11:52,800 --> 00:11:55,120 Speaker 1: upon them. Yeah, you're exactly right about that. And Forty 221 00:11:55,240 --> 00:11:57,200 Speaker 1: talks about this at length that you know, the birds 222 00:11:57,200 --> 00:11:59,520 Speaker 1: will peck around in the sand to find the hidden caches, 223 00:11:59,640 --> 00:12:04,240 Speaker 1: buried eggs. Um. So this scene that Forty describes so 224 00:12:04,320 --> 00:12:08,000 Speaker 1: vividly is not just an amazing spectacle of nature. We 225 00:12:08,040 --> 00:12:10,360 Speaker 1: sort of alluded to this earlier, but it's also a 226 00:12:10,360 --> 00:12:14,120 Speaker 1: window into the deep history of planet Earth and a 227 00:12:14,200 --> 00:12:17,640 Speaker 1: way to think about the wonders of evolution across geologic time. 228 00:12:18,160 --> 00:12:20,880 Speaker 1: So maybe we should take a closer look at the 229 00:12:20,960 --> 00:12:24,200 Speaker 1: horseshoe crab and its anatomy and its body before we 230 00:12:24,280 --> 00:12:27,640 Speaker 1: kind of zoom out to the evolutionary picture. Yes, absolutely, 231 00:12:27,679 --> 00:12:29,840 Speaker 1: and uh, and we do encourage you look up some 232 00:12:29,880 --> 00:12:32,680 Speaker 1: footage or some images of the creature if you have 233 00:12:32,720 --> 00:12:35,800 Speaker 1: a chance to while while we're discussing it here um, 234 00:12:35,920 --> 00:12:38,960 Speaker 1: because that'll be helpful. Though. I think a lot of you, 235 00:12:39,080 --> 00:12:41,280 Speaker 1: if not most of you, have seen a horseshoe crab 236 00:12:41,360 --> 00:12:43,520 Speaker 1: before and have at least a basic idea in your 237 00:12:43,520 --> 00:12:46,640 Speaker 1: mind what it looks like. I guess maybe let's start 238 00:12:46,640 --> 00:12:49,360 Speaker 1: from looking from above, right the way you would normally 239 00:12:49,400 --> 00:12:51,400 Speaker 1: see one if you're looking down at it on the beach. 240 00:12:51,480 --> 00:12:55,480 Speaker 1: So from above, the horseshoe crab is this closed dome 241 00:12:55,640 --> 00:12:59,559 Speaker 1: of armor that has three obvious body segments. The first 242 00:12:59,559 --> 00:13:03,320 Speaker 1: segment is the headshield technically known as the pro soma, 243 00:13:03,800 --> 00:13:08,040 Speaker 1: which is a solid, rounded, vaguely horsehoof shaped plate of 244 00:13:08,160 --> 00:13:12,440 Speaker 1: protective kitanous material, which forty says is similar to the 245 00:13:12,480 --> 00:13:15,080 Speaker 1: material you'd find making up the wings of a beetle. 246 00:13:15,679 --> 00:13:18,840 Speaker 1: And then it's got on top of that headshield two 247 00:13:18,880 --> 00:13:23,200 Speaker 1: obvious compound eyes poking up on on either side, and 248 00:13:23,240 --> 00:13:26,959 Speaker 1: those compound eyes are used for locating mates. One thing 249 00:13:26,960 --> 00:13:28,840 Speaker 1: I was reading about them that was very interesting is 250 00:13:28,880 --> 00:13:33,880 Speaker 1: that they they have drastically different levels of light sensitivity 251 00:13:33,920 --> 00:13:37,880 Speaker 1: between the night and day cycle. So during the daytime, 252 00:13:37,960 --> 00:13:41,200 Speaker 1: the receptors in those compound eyes are tuned way down, 253 00:13:41,320 --> 00:13:43,000 Speaker 1: I guess, to make them, you know, less likely to 254 00:13:43,040 --> 00:13:45,600 Speaker 1: get blinded by the light coming in from above. But 255 00:13:45,720 --> 00:13:48,800 Speaker 1: in the nighttime they get tuned way up, and that's 256 00:13:48,960 --> 00:13:51,840 Speaker 1: I think primarily used for seeing a mate somewhere on 257 00:13:51,880 --> 00:13:54,520 Speaker 1: the beach and navigating toward it in the dark, because again, 258 00:13:54,559 --> 00:13:57,120 Speaker 1: this a lot of the spawning happens at night. I 259 00:13:57,120 --> 00:13:59,560 Speaker 1: think the eyes are are kind of really key to 260 00:13:59,760 --> 00:14:03,320 Speaker 1: the the human experience of the horseshoe crab, because you know, 261 00:14:04,160 --> 00:14:07,000 Speaker 1: we like things with eyes that we helps us sort 262 00:14:07,040 --> 00:14:08,840 Speaker 1: of connect with them and sort of even think of 263 00:14:08,840 --> 00:14:12,880 Speaker 1: a personality for them. The horseshoe crabs eyes, certainly at 264 00:14:12,920 --> 00:14:16,040 Speaker 1: first glance anyway, they seem to have a certain seriousness 265 00:14:16,040 --> 00:14:19,200 Speaker 1: to them, or even kind of a determination or a 266 00:14:19,200 --> 00:14:22,920 Speaker 1: A seven a sinister quality, and so they're just all business. Yeah, 267 00:14:22,920 --> 00:14:25,240 Speaker 1: they look they look very serious. They don't have like 268 00:14:25,360 --> 00:14:27,880 Speaker 1: goofy eyes. You know, we've discussed animals on the show 269 00:14:27,920 --> 00:14:31,360 Speaker 1: before that from the human perspective may even have googly eyes, 270 00:14:31,400 --> 00:14:35,440 Speaker 1: but like Glenaria, these however, they look very serious and 271 00:14:35,440 --> 00:14:37,800 Speaker 1: so we kind of consider them seriously. I think sometimes 272 00:14:37,880 --> 00:14:40,280 Speaker 1: well it turns out there even more serious than you think, 273 00:14:40,360 --> 00:14:43,040 Speaker 1: because they've got those two big compound eyes that are 274 00:14:43,160 --> 00:14:46,600 Speaker 1: that have that alternating sensitivity good for locating mates. But 275 00:14:46,600 --> 00:14:50,640 Speaker 1: the horseshoe crab actually has something like ten eyes total. Uh. 276 00:14:50,760 --> 00:14:54,880 Speaker 1: These are you know, less easily identifiable as eyes just 277 00:14:54,920 --> 00:14:58,680 Speaker 1: by looking at them, but they've got basically ten photosensitive 278 00:14:58,800 --> 00:15:02,040 Speaker 1: spots or organ that in some way help the creature 279 00:15:02,120 --> 00:15:05,480 Speaker 1: detect light and detect movement. Okay, so that's the big 280 00:15:05,520 --> 00:15:07,920 Speaker 1: first part of it, the domed part of the head shield. 281 00:15:08,200 --> 00:15:10,240 Speaker 1: Then you've got if you're going from front to back, 282 00:15:10,360 --> 00:15:13,600 Speaker 1: you've got the next segment which connects behind the head shield, 283 00:15:13,840 --> 00:15:16,200 Speaker 1: and this is the abdomen, also known as the opus 284 00:15:16,200 --> 00:15:19,760 Speaker 1: the soma. Uh. This is a more flattened plate attached 285 00:15:19,800 --> 00:15:22,160 Speaker 1: to the head shield by a Hinge as forty wrote, 286 00:15:22,560 --> 00:15:25,880 Speaker 1: and uh, and it's got these backward facing spines along 287 00:15:25,920 --> 00:15:30,440 Speaker 1: its lateral edges. And then finally, the horseshoe crab terminates 288 00:15:30,440 --> 00:15:35,760 Speaker 1: in this long, straight, rigid tail known as a telson. Uh. 289 00:15:35,800 --> 00:15:38,080 Speaker 1: And if you've ever seen one of these animals moving 290 00:15:38,200 --> 00:15:40,240 Speaker 1: or being handled, especially if you've seen you know, like 291 00:15:40,280 --> 00:15:44,520 Speaker 1: a demonstration where somebody holds a horseshoe crab upright for 292 00:15:44,560 --> 00:15:46,680 Speaker 1: you to see it's underside. You know, the tail can 293 00:15:46,720 --> 00:15:50,680 Speaker 1: kind of whip up and down dramatically. Now, other Arthur 294 00:15:50,720 --> 00:15:53,560 Speaker 1: pods have Tellson's as well, such as the shrimp, And 295 00:15:53,600 --> 00:15:55,760 Speaker 1: I think the shrimp is a great example because a 296 00:15:55,760 --> 00:15:58,160 Speaker 1: lot of you have probably at least some you probably 297 00:15:58,200 --> 00:16:02,960 Speaker 1: have some experience with shrimp tails, the consuming shrimp tails, 298 00:16:03,200 --> 00:16:08,320 Speaker 1: so in shrimp, lobster's, krill, and crayfish. The the telson 299 00:16:08,440 --> 00:16:12,440 Speaker 1: is important for what is known as the the karadid 300 00:16:12,600 --> 00:16:16,600 Speaker 1: escape reaction, in which a downtail tail flip allows a 301 00:16:16,680 --> 00:16:20,840 Speaker 1: startled individual to dart backwards through the water. Which, again, 302 00:16:20,880 --> 00:16:22,520 Speaker 1: that kind of comes back to you said earlier about 303 00:16:22,560 --> 00:16:25,200 Speaker 1: how the thrashing of the tail would be more useful 304 00:16:25,240 --> 00:16:28,520 Speaker 1: to to right oneself or to escape a stressful situation 305 00:16:28,600 --> 00:16:31,120 Speaker 1: in the water as opposed to on land. Yes, and 306 00:16:31,200 --> 00:16:33,120 Speaker 1: that's a really interesting thing to look at too, because 307 00:16:33,120 --> 00:16:36,240 Speaker 1: when you look at a display like the tail wagging 308 00:16:36,280 --> 00:16:39,200 Speaker 1: up and down, this, you know, the the rigid pointed 309 00:16:39,600 --> 00:16:43,680 Speaker 1: stick there basically, especially when the animal is handled, you 310 00:16:43,760 --> 00:16:46,560 Speaker 1: might guess it's a defensive weapon, right, you'd think, like, okay, 311 00:16:46,600 --> 00:16:48,480 Speaker 1: stinger of a scorpion, and a lot of people do 312 00:16:48,520 --> 00:16:50,600 Speaker 1: assume that about the horseshoe crab that has got a 313 00:16:50,640 --> 00:16:54,440 Speaker 1: stinger on its telson, and that guess would be half 314 00:16:54,520 --> 00:16:57,280 Speaker 1: right and half wrong. The correct part is that there 315 00:16:57,280 --> 00:17:00,960 Speaker 1: probably is an evolutionary relationship at play in the similarity 316 00:17:00,960 --> 00:17:03,040 Speaker 1: with the scorpions tail. Will come back to that in 317 00:17:03,040 --> 00:17:05,600 Speaker 1: a bit, But the wrong part would be to assume 318 00:17:05,680 --> 00:17:08,600 Speaker 1: that it is a stinger weapon. It is not, as 319 00:17:08,720 --> 00:17:12,320 Speaker 1: we were talking about. Primarily, it's used to help the 320 00:17:12,359 --> 00:17:15,679 Speaker 1: horseshoe crab navigate aquatic environment, so it can help the 321 00:17:15,720 --> 00:17:18,640 Speaker 1: animal steer its body while it's swimming. But it can 322 00:17:18,640 --> 00:17:21,280 Speaker 1: also help the animal, like we said, right itself once 323 00:17:21,280 --> 00:17:23,400 Speaker 1: it becomes flipped on its back, and you can imagine 324 00:17:23,400 --> 00:17:26,800 Speaker 1: in its natural habitat this could happen quite a bit 325 00:17:26,880 --> 00:17:28,960 Speaker 1: because this is a creature that's going to be dealing 326 00:17:29,000 --> 00:17:31,800 Speaker 1: with the physical tumult of the title zone. You know, 327 00:17:31,920 --> 00:17:34,240 Speaker 1: you can imagine it might get rolled upside down in 328 00:17:34,240 --> 00:17:36,600 Speaker 1: the surf, where might get rolled over while it's clambering 329 00:17:36,640 --> 00:17:39,520 Speaker 1: around on something in the mud flats, and this popping 330 00:17:39,640 --> 00:17:42,040 Speaker 1: up and down motion of the tail can help flip 331 00:17:42,119 --> 00:17:44,440 Speaker 1: it back over like one of those spring flipping wind 332 00:17:44,520 --> 00:17:48,960 Speaker 1: up toys. Now I just mentioned swimming. One other very 333 00:17:49,000 --> 00:17:51,960 Speaker 1: strange aspect of the horseshoe crab is that when it's 334 00:17:51,960 --> 00:17:56,320 Speaker 1: time to swim, the horseshoe crab usually swims upside down, 335 00:17:56,880 --> 00:18:00,359 Speaker 1: doing a kind of invertebrate backstroke with its head yield 336 00:18:00,400 --> 00:18:04,679 Speaker 1: angled down towards the bottom and it's jointed legs paddling 337 00:18:04,760 --> 00:18:08,000 Speaker 1: towards the sky. If you can find video of this this, 338 00:18:08,160 --> 00:18:10,320 Speaker 1: it will probably recommend you go look at video of 339 00:18:10,400 --> 00:18:13,040 Speaker 1: several things in this episode, because a lot of a 340 00:18:13,040 --> 00:18:16,199 Speaker 1: lot of this animal's movements and behaviors are are fascinating 341 00:18:16,240 --> 00:18:18,280 Speaker 1: to see. But yeah, if you can find video of 342 00:18:18,320 --> 00:18:21,160 Speaker 1: its swimming with its legs inverted up towards the sky, 343 00:18:21,200 --> 00:18:25,080 Speaker 1: it looks very strange, very cool, and it well, yeah, 344 00:18:25,080 --> 00:18:27,280 Speaker 1: it's basically just a backstroke. Well, as long as the 345 00:18:27,280 --> 00:18:30,200 Speaker 1: animals flipped over here, let's discuss what's going on underneath 346 00:18:30,200 --> 00:18:32,440 Speaker 1: the armor. I think that's a great idea. So yeah, 347 00:18:32,440 --> 00:18:35,600 Speaker 1: well you're flipping it over looking at its belly, and 348 00:18:35,680 --> 00:18:38,600 Speaker 1: on this side it is bug city. You've got five 349 00:18:38,680 --> 00:18:41,840 Speaker 1: pairs of jointed walking legs that look kind of like 350 00:18:42,000 --> 00:18:45,960 Speaker 1: crab legs or spider legs, and these are known as pedipalps. 351 00:18:46,720 --> 00:18:49,840 Speaker 1: The first four pairs of legs all end in a 352 00:18:49,840 --> 00:18:52,919 Speaker 1: a pincer claw shaped tip, so imagine kind of a 353 00:18:53,000 --> 00:18:57,240 Speaker 1: regular crab with claws on all of its walking feet. 354 00:18:57,600 --> 00:18:59,600 Speaker 1: But then the final pair of legs ends in what 355 00:18:59,680 --> 00:19:03,440 Speaker 1: looks a kind of strange flower shape, which is apparently 356 00:19:03,640 --> 00:19:06,439 Speaker 1: used mostly for digging, and then towards the front of 357 00:19:06,440 --> 00:19:09,960 Speaker 1: the head. In in front of the walking legs, there's 358 00:19:09,960 --> 00:19:14,000 Speaker 1: another smaller pair of appendages that are known as the chillissary, 359 00:19:14,040 --> 00:19:16,000 Speaker 1: and we'll come back to their significance in a moment, 360 00:19:16,000 --> 00:19:19,760 Speaker 1: but they're primarily used for guiding food toward the mouth. 361 00:19:20,240 --> 00:19:22,320 Speaker 1: So here's maybe one of my This might be my 362 00:19:22,359 --> 00:19:25,800 Speaker 1: favorite partment. Where's the mouth? You might expect, in line 363 00:19:25,840 --> 00:19:29,000 Speaker 1: with other crabs and invertebrates, that the mouth is in 364 00:19:29,080 --> 00:19:32,800 Speaker 1: the front facing part of the head, but nope, in 365 00:19:32,880 --> 00:19:36,160 Speaker 1: horseshoe crabs, the mouth is in the middle of the 366 00:19:36,280 --> 00:19:42,560 Speaker 1: underside between all of the animals jointed spidery legs. So 367 00:19:42,680 --> 00:19:47,080 Speaker 1: as the legs move, any food caught underneath them is 368 00:19:47,119 --> 00:19:52,040 Speaker 1: sort of shuffled inward toward a crevice running between the 369 00:19:52,160 --> 00:19:56,399 Speaker 1: leg pairs, aided by these gripping spines that run along 370 00:19:56,440 --> 00:19:59,920 Speaker 1: the inside of the appendages, so as the legs scuttle, 371 00:20:00,320 --> 00:20:03,680 Speaker 1: the food is also partially chewed up by those legs 372 00:20:03,680 --> 00:20:08,000 Speaker 1: and prepared for digestion. There's this grinding scraping action of 373 00:20:08,040 --> 00:20:11,520 Speaker 1: the exoskeleton parts of the legs and the joints. So, 374 00:20:11,640 --> 00:20:16,320 Speaker 1: in perhaps illicit anthropomorphic terms, the horseshoe crab has crotch, mouth, 375 00:20:16,400 --> 00:20:19,560 Speaker 1: and leg teeth. Yes, But on the other hand, I 376 00:20:19,840 --> 00:20:22,359 Speaker 1: feel like if you really break down how any animal, 377 00:20:22,440 --> 00:20:27,199 Speaker 1: including not especially humans, eat, it's it's all pretty gross. 378 00:20:27,320 --> 00:20:30,760 Speaker 1: Soh No, I'm sure they think the way we eat 379 00:20:30,880 --> 00:20:33,720 Speaker 1: is great, especially when we're eating their eggs. But but 380 00:20:33,760 --> 00:20:35,919 Speaker 1: I do. I do agree that the footage is very 381 00:20:35,920 --> 00:20:38,160 Speaker 1: interesting and one should check it out. Amazing. Yeah, look 382 00:20:38,160 --> 00:20:40,600 Speaker 1: at that there are videos of this online as well. Yeah. 383 00:20:40,680 --> 00:20:43,720 Speaker 1: It also reminds me that a a fictional creature that 384 00:20:43,800 --> 00:20:46,879 Speaker 1: the horseshoe crab is very typically compared to these days is, 385 00:20:46,920 --> 00:20:51,000 Speaker 1: of course, the Zeno morph alien face hugger. Um Like 386 00:20:51,080 --> 00:20:56,080 Speaker 1: even that that Malaysian blog post about eating them eating 387 00:20:56,119 --> 00:20:59,960 Speaker 1: their their eggs at restaurant uh invoked the face hug 388 00:21:00,000 --> 00:21:03,040 Speaker 1: of comparison. It's kind of inevitable at this point, though, 389 00:21:03,080 --> 00:21:07,720 Speaker 1: I'm not sure the face hugger eat. Um No, I'm well, okay, 390 00:21:08,040 --> 00:21:10,040 Speaker 1: I mean that's a whole another description to start talking 391 00:21:10,040 --> 00:21:12,320 Speaker 1: about the face hugger and how it matches up with 392 00:21:12,480 --> 00:21:16,960 Speaker 1: uh with with actual biology. I'll have to save that 393 00:21:17,000 --> 00:21:20,479 Speaker 1: for another episode. But but the face hugger does have 394 00:21:21,880 --> 00:21:24,640 Speaker 1: the you know what, is kind of like a mouth 395 00:21:24,680 --> 00:21:29,160 Speaker 1: that had it definitely has a tubular orifice that emerges 396 00:21:29,200 --> 00:21:32,040 Speaker 1: from the underside and pretty much the same place one 397 00:21:32,040 --> 00:21:36,520 Speaker 1: would find the mouth of the horseshoe crab. But just 398 00:21:36,600 --> 00:21:38,760 Speaker 1: in general, the horseshoe crab and the and the face 399 00:21:38,840 --> 00:21:43,000 Speaker 1: hugger have kind of similar body layouts, even though they're 400 00:21:43,080 --> 00:21:47,600 Speaker 1: they're rather you know, textually different. I can agree with that, though, 401 00:21:47,640 --> 00:21:50,560 Speaker 1: I guess maybe another similarity if the face hugger doesn't 402 00:21:50,560 --> 00:21:53,040 Speaker 1: actually eat, and it's just like a you know, no 403 00:21:53,040 --> 00:21:56,639 Speaker 1: no digestive system, reproductive organism, well I would I think 404 00:21:56,720 --> 00:21:59,280 Speaker 1: you could even class say that the face hugger in 405 00:21:59,560 --> 00:22:04,240 Speaker 1: alien and use a mobile sexual organ Yes, But but 406 00:22:04,320 --> 00:22:06,720 Speaker 1: to bring it back to the horseshoe crabs, forty rights 407 00:22:06,760 --> 00:22:09,199 Speaker 1: that mature adults can sometimes go for months at a 408 00:22:09,240 --> 00:22:13,199 Speaker 1: time without eating, So these things are tough. Uh. And 409 00:22:13,200 --> 00:22:17,320 Speaker 1: then also to continue our exploration of the underside. Behind 410 00:22:17,400 --> 00:22:20,440 Speaker 1: the legs and the mouth crack on the animals underside, 411 00:22:20,440 --> 00:22:23,800 Speaker 1: you will see a series of overlapping leaf like flaps, 412 00:22:24,359 --> 00:22:26,560 Speaker 1: and these are the animals gills, which allow it to 413 00:22:26,640 --> 00:22:30,119 Speaker 1: breathe by absorbing dissolved oxygen from the water. And the 414 00:22:30,160 --> 00:22:33,200 Speaker 1: horseshoe crab can survive out of water for a time 415 00:22:33,280 --> 00:22:36,080 Speaker 1: if it can keep its gills wet. These organs are 416 00:22:36,080 --> 00:22:39,800 Speaker 1: a specific type of underwater breathing apparatus. Unlike many other 417 00:22:39,840 --> 00:22:42,600 Speaker 1: animals gills, these are these are known as book gills. 418 00:22:43,040 --> 00:22:45,520 Speaker 1: Now you might have heard us talk before about other 419 00:22:45,680 --> 00:22:49,879 Speaker 1: arthropods with book lungs, animals such as the spider. And 420 00:22:49,960 --> 00:22:52,200 Speaker 1: with that teasing detail, maybe we should take a break 421 00:22:52,200 --> 00:22:54,399 Speaker 1: and then come back. All right, we'll be right back. 422 00:22:55,560 --> 00:22:59,320 Speaker 1: Thank alright, we're back. So we were talking about the 423 00:22:59,320 --> 00:23:02,080 Speaker 1: horseshoe crab. Ab, we're talking, and we talked. We mentioned 424 00:23:02,080 --> 00:23:04,360 Speaker 1: a little bit about spider. So let's let's get down 425 00:23:04,359 --> 00:23:06,640 Speaker 1: to it. Let's get down to that that basic factoid 426 00:23:07,320 --> 00:23:09,960 Speaker 1: that that I imagine most of you have heard plenty 427 00:23:10,000 --> 00:23:12,439 Speaker 1: of times, and that is that the horseshoe crab is 428 00:23:12,480 --> 00:23:15,639 Speaker 1: not a crab, despite the fact that we will refer 429 00:23:15,720 --> 00:23:17,680 Speaker 1: to it often on as a crab, and you'll find 430 00:23:17,680 --> 00:23:21,360 Speaker 1: plenty of, uh, plenty of studies where scientists will off 431 00:23:21,400 --> 00:23:24,520 Speaker 1: handedly just refer to them as crabs. Everybody keeps calling 432 00:23:24,520 --> 00:23:28,480 Speaker 1: them crabs, but they're not crabs. True. Decapod crabs and 433 00:23:28,560 --> 00:23:31,600 Speaker 1: horseshoe crabs both belong, of course, to the philum Arthropoda. 434 00:23:31,640 --> 00:23:35,480 Speaker 1: They are both are arthropods, meaning they both have hard exoskeletons, 435 00:23:35,520 --> 00:23:38,639 Speaker 1: They've got segmented bodies, and they've got multiple pairs of 436 00:23:38,760 --> 00:23:42,280 Speaker 1: jointed legs, and the sharing of jointed legs is where 437 00:23:42,320 --> 00:23:45,280 Speaker 1: the word arthropod comes from. Arthur pod means jointed leg 438 00:23:45,400 --> 00:23:49,359 Speaker 1: or jointed foot. But after this, the evolutionary histories of 439 00:23:49,520 --> 00:23:54,080 Speaker 1: crabs and horseshoe crabs really diverge. Crabs, along with shrimp, lobsters, 440 00:23:54,160 --> 00:23:57,200 Speaker 1: wood lice, and and many other creatures, belong to the 441 00:23:57,280 --> 00:24:00,439 Speaker 1: sub phil um of Crustacea. We would call them crustations, 442 00:24:00,920 --> 00:24:04,520 Speaker 1: and Forty points out that crustaceans have antennae or feelers 443 00:24:04,680 --> 00:24:07,760 Speaker 1: on the head used for sensing the environment by touch 444 00:24:07,880 --> 00:24:11,119 Speaker 1: and by smell, and Horseshoe crabs don't have these, so 445 00:24:11,280 --> 00:24:16,080 Speaker 1: what do they have? Instead? They have chillissary. Horseshoe crabs 446 00:24:16,119 --> 00:24:21,000 Speaker 1: are not crustaceans their chill serata in evolutionary history, they 447 00:24:21,000 --> 00:24:28,080 Speaker 1: are more closely related to arachnids like spiders, ticks, and scorpions, 448 00:24:28,560 --> 00:24:30,800 Speaker 1: which if you look at the mouth parts of these creatures, 449 00:24:30,880 --> 00:24:33,520 Speaker 1: like spiders and scorpions, you will find these similar little 450 00:24:33,640 --> 00:24:36,920 Speaker 1: mouth parts that that guide food into the orifice. The 451 00:24:37,040 --> 00:24:41,119 Speaker 1: chillis sary. Uh. They're also Horseshoe crabs are also more 452 00:24:41,200 --> 00:24:44,920 Speaker 1: closely related to an extinct branch of chill Serata known 453 00:24:44,960 --> 00:24:49,840 Speaker 1: as the euryptorids, also known as sea scorpions. Now again 454 00:24:50,040 --> 00:24:53,880 Speaker 1: in misleading names. Sea scorpions is somewhat misleading here because 455 00:24:53,920 --> 00:24:57,159 Speaker 1: euryptorids were not actually scorpions and they didn't all live 456 00:24:57,200 --> 00:25:00,320 Speaker 1: in the sea. But they are truly awesome. This is 457 00:25:00,359 --> 00:25:03,399 Speaker 1: one of the great lines of extinct creatures we we 458 00:25:03,520 --> 00:25:06,080 Speaker 1: talked about in the past episode. Didn't I think they've 459 00:25:06,160 --> 00:25:09,399 Speaker 1: come up before? Yeah, So, the Europtorids were briefly a 460 00:25:09,680 --> 00:25:13,000 Speaker 1: diverse order of predatory animals, including the genus of the 461 00:25:13,240 --> 00:25:18,480 Speaker 1: largest arthropod ever known to exist on Earth. Jclopterus, which 462 00:25:18,680 --> 00:25:22,200 Speaker 1: based on some fossil remains found in Germany, is estimated 463 00:25:22,240 --> 00:25:24,439 Speaker 1: to have grown up to about two point five meters 464 00:25:24,600 --> 00:25:28,040 Speaker 1: or over eight feet in length. So that's definitely big 465 00:25:28,160 --> 00:25:30,800 Speaker 1: enough to start its own harmon. Yeah, just try to 466 00:25:30,920 --> 00:25:34,159 Speaker 1: imagine it. So you got an eight foot arthropod, a 467 00:25:34,280 --> 00:25:38,879 Speaker 1: sort of scorpion lobster like creature bigger than your whole body, 468 00:25:39,400 --> 00:25:43,399 Speaker 1: with a plated exoskeleton and claws, scuttling around at the 469 00:25:43,480 --> 00:25:46,000 Speaker 1: water's edge, or just hanging out in the shallows and 470 00:25:46,119 --> 00:25:49,920 Speaker 1: ambush mode h I have before. I sometimes like to 471 00:25:50,000 --> 00:25:54,440 Speaker 1: imagine these types of creatures surviving into modern geologic periods 472 00:25:54,480 --> 00:25:57,200 Speaker 1: and living alongside humans. And I wondered if the ancient 473 00:25:57,240 --> 00:26:00,360 Speaker 1: Egyptians would have had a euryptorid headed god in place 474 00:26:00,440 --> 00:26:03,880 Speaker 1: of the crocodile deity, so back that would be quite 475 00:26:03,920 --> 00:26:07,639 Speaker 1: a quite a god to behold. You know, I mentioned 476 00:26:07,680 --> 00:26:09,119 Speaker 1: that it is something like this would deserve its own 477 00:26:09,119 --> 00:26:12,680 Speaker 1: horror movie. But now I'm remembering the creature in Deep 478 00:26:12,720 --> 00:26:16,960 Speaker 1: Star six, the underwater horror movie from the director of 479 00:26:17,040 --> 00:26:20,840 Speaker 1: the original Friday the Thirteen. Oh. I believe the monster 480 00:26:20,960 --> 00:26:23,480 Speaker 1: in that is a uriptorid. Uh. It is a straight 481 00:26:23,560 --> 00:26:27,400 Speaker 1: up sea scorpion. I remember Miguel Faire exploding in the movie, 482 00:26:27,480 --> 00:26:29,399 Speaker 1: but I do not remember what the creature looked like. 483 00:26:29,640 --> 00:26:31,760 Speaker 1: Yeah he did, I guess he did explode. Um. He 484 00:26:32,280 --> 00:26:33,920 Speaker 1: There's a scene where they're like, don't get in the 485 00:26:34,040 --> 00:26:37,080 Speaker 1: escape pod, you'll go through explosive decompression, and he's like, no, 486 00:26:37,359 --> 00:26:39,960 Speaker 1: I'm scared, and then he blows up. I just remember, 487 00:26:39,960 --> 00:26:42,560 Speaker 1: I'm the most recent time I watched it, I was 488 00:26:42,720 --> 00:26:46,200 Speaker 1: on an airplane on medication, and I remember just thinking 489 00:26:46,240 --> 00:26:51,160 Speaker 1: it was a wonderful film. We'll see how that would 490 00:26:51,160 --> 00:26:54,200 Speaker 1: hold up over time. But yeah, well, I mean all 491 00:26:54,240 --> 00:26:58,320 Speaker 1: those nine underwater horror movies are worth a watch, but 492 00:26:58,440 --> 00:27:00,320 Speaker 1: certainly I think it was a case where they're, Okay, 493 00:27:00,359 --> 00:27:02,560 Speaker 1: we need it underwater monster. Let's look at some real 494 00:27:02,640 --> 00:27:05,080 Speaker 1: underwater monsters from the past. And they found one and 495 00:27:05,119 --> 00:27:07,720 Speaker 1: they said, heck, let's not try and recreate the wheel here, 496 00:27:08,000 --> 00:27:10,840 Speaker 1: let's do that guy. And so that's what they did. Okay, 497 00:27:10,880 --> 00:27:13,879 Speaker 1: So these would be the ancient closer relatives to the 498 00:27:13,960 --> 00:27:16,919 Speaker 1: horseshoe crabs, the the you know, the arachnids, the scorpions, 499 00:27:16,960 --> 00:27:20,399 Speaker 1: even the uptorids. There are a few extant species of 500 00:27:20,480 --> 00:27:24,119 Speaker 1: horseshoe crab like animals, including a few species found in Asia, 501 00:27:24,280 --> 00:27:28,240 Speaker 1: but the most common by far is the Atlantic horseshoe crab, 502 00:27:28,359 --> 00:27:32,359 Speaker 1: which has the scientific name of Limulus polyphemus. So it's 503 00:27:32,400 --> 00:27:35,320 Speaker 1: got the same name as the the cyclopid monster in 504 00:27:35,760 --> 00:27:40,479 Speaker 1: the Odyssey uh and and Limulus polyphemus. The Atlantic horseshoe 505 00:27:40,520 --> 00:27:42,960 Speaker 1: crab can be found primarily along the East coast of 506 00:27:43,000 --> 00:27:46,639 Speaker 1: North America, roughly from Mexico to Maine. So your wife's 507 00:27:46,640 --> 00:27:50,119 Speaker 1: grandmother's story, I think probably more likely happened in in 508 00:27:50,200 --> 00:27:53,879 Speaker 1: the outer banks on these tis. I'm like American percent 509 00:27:53,960 --> 00:27:57,440 Speaker 1: sure it was. It was outer Banks, but yeah. So 510 00:27:58,000 --> 00:28:00,920 Speaker 1: another thing that's interesting about the horseshoe crabs is something 511 00:28:01,000 --> 00:28:04,240 Speaker 1: that's more common to arthur pods generally. But like other arthropods, 512 00:28:04,560 --> 00:28:07,920 Speaker 1: the development of their bodies as they mature happens through 513 00:28:07,960 --> 00:28:11,560 Speaker 1: a fascinating process called molting. So since these animals have 514 00:28:11,720 --> 00:28:15,000 Speaker 1: a hard, rigid exoskeleton, you might wonder how would they 515 00:28:15,000 --> 00:28:17,200 Speaker 1: ever grow? How do they get bigger? Right? You know, 516 00:28:17,560 --> 00:28:19,879 Speaker 1: if you've got you've got your bones on the outside, 517 00:28:20,280 --> 00:28:23,280 Speaker 1: and molting is the answer. Periodically during its life cycle, 518 00:28:23,600 --> 00:28:26,760 Speaker 1: the horseshoe crab will bust out of its own exoskeleton 519 00:28:27,119 --> 00:28:29,960 Speaker 1: and emerge as a softer critter from within, only to 520 00:28:30,080 --> 00:28:34,200 Speaker 1: quickly have its soft, new larger outline harden again pretty 521 00:28:34,280 --> 00:28:37,399 Speaker 1: rapidly in defense against the perils of the sea. Now, 522 00:28:37,520 --> 00:28:41,080 Speaker 1: a normal horseshoe crab takes about ten years of growing 523 00:28:41,160 --> 00:28:44,800 Speaker 1: and molting before it reaches sexual maturity, which seems like 524 00:28:44,880 --> 00:28:48,560 Speaker 1: a very long time for an animal of this kind. Uh, 525 00:28:48,680 --> 00:28:50,760 Speaker 1: you know, imagine it has to grow for ten years 526 00:28:50,880 --> 00:28:54,200 Speaker 1: before it's ready to mate in that orgy on the beach. Yeah, 527 00:28:54,240 --> 00:28:56,240 Speaker 1: I mean, certainly when we compared to something like say 528 00:28:56,240 --> 00:28:58,800 Speaker 1: a cat or a dog or you know, rat, something 529 00:28:58,880 --> 00:29:02,360 Speaker 1: like that, where the it's pretty short turnaround. But this 530 00:29:02,560 --> 00:29:05,480 Speaker 1: is this is ten years. But especially many other invertebrates, 531 00:29:05,520 --> 00:29:09,560 Speaker 1: we should think reach sexual maturity very fast. But after 532 00:29:09,680 --> 00:29:12,840 Speaker 1: reaching sexual maturity, it never molts again, and instead it 533 00:29:12,920 --> 00:29:15,840 Speaker 1: heads to the beach for mating to leave fertilized eggs 534 00:29:15,880 --> 00:29:18,720 Speaker 1: in the wet sand and start the life cycle over again. 535 00:29:19,200 --> 00:29:21,720 Speaker 1: And so this this life cycle has worked pretty well 536 00:29:21,840 --> 00:29:23,720 Speaker 1: for the horseshoe crab, and it's worked that way for 537 00:29:24,000 --> 00:29:27,840 Speaker 1: quite a long time. Yes, the earliest fossil evidence for 538 00:29:28,000 --> 00:29:33,600 Speaker 1: horseshoe crabs is incredibly ancient. The oldest fossil remnants resembling 539 00:29:33,720 --> 00:29:36,720 Speaker 1: these modern animals, the modern horseshoe crabs, go all the 540 00:29:36,760 --> 00:29:41,520 Speaker 1: way back to the Ordovician period. This is so long ago, 541 00:29:41,800 --> 00:29:45,479 Speaker 1: it's unbelievable. Yeah, we're talking about four hundred and fifty 542 00:29:45,680 --> 00:29:50,080 Speaker 1: million years ago. Um. I mean just consider that the 543 00:29:50,240 --> 00:29:53,200 Speaker 1: for instance, the goblin shark is also something that is 544 00:29:53,240 --> 00:29:56,000 Speaker 1: sometimes referred to as a living fossil, and we'll get 545 00:29:56,040 --> 00:29:58,880 Speaker 1: back to that terminology in a second. But the goblin 546 00:29:58,960 --> 00:30:02,000 Speaker 1: shark own late dates back a hundred twenty five million 547 00:30:02,120 --> 00:30:06,680 Speaker 1: years is an extremely long time. Yeah, um, still incredible. 548 00:30:07,040 --> 00:30:11,600 Speaker 1: Crocodilia goes back some nine million years. Hagfish are virtually 549 00:30:11,640 --> 00:30:13,720 Speaker 1: the same as they were three hundred million years ago. 550 00:30:14,120 --> 00:30:17,680 Speaker 1: Lamp rays go back roughly three hundred sixty million years 551 00:30:18,040 --> 00:30:21,360 Speaker 1: not Alloy's have evolved very little since roughly five hundred 552 00:30:21,440 --> 00:30:24,080 Speaker 1: million years ago. Although that's an example of a creature 553 00:30:24,120 --> 00:30:26,400 Speaker 1: to where they were, there were certainly more varied two 554 00:30:26,480 --> 00:30:29,560 Speaker 1: hundred million years ago. Yeah. About this idea of of 555 00:30:29,880 --> 00:30:33,160 Speaker 1: a living fossil, Richard forty actually he kind of warns 556 00:30:33,160 --> 00:30:35,560 Speaker 1: about this phrase. He calls it quote a paradox and 557 00:30:35,640 --> 00:30:38,479 Speaker 1: an oxymoron rolled into one. Well, yeah, because I mean, 558 00:30:38,520 --> 00:30:42,160 Speaker 1: on one level, it is not a fossil. I think 559 00:30:42,200 --> 00:30:44,840 Speaker 1: that much is probably obvious to most people. It is 560 00:30:44,880 --> 00:30:47,600 Speaker 1: not a fossil. A fossil cannot be alive. A fossil 561 00:30:47,720 --> 00:30:53,720 Speaker 1: is inherently the mineralized remains of something that once lived. 562 00:30:53,840 --> 00:30:56,720 Speaker 1: Though he also sort of uses the word cautiously, his 563 00:30:56,880 --> 00:30:59,680 Speaker 1: point is mainly that we shouldn't be lulled into the 564 00:30:59,720 --> 00:31:02,200 Speaker 1: miss stake, an assumption that a species can exist for 565 00:31:02,360 --> 00:31:06,960 Speaker 1: millions of years with no changes, for example, without significant 566 00:31:07,000 --> 00:31:11,000 Speaker 1: genetic change. Genetic changes are always accumulating, They just build 567 00:31:11,120 --> 00:31:13,960 Speaker 1: up over time, even if the overall form of the 568 00:31:14,040 --> 00:31:18,240 Speaker 1: animal stays very similar. Uh. And also the ecological surroundings 569 00:31:18,280 --> 00:31:20,520 Speaker 1: of these organisms change over time. He talks about how 570 00:31:20,640 --> 00:31:25,280 Speaker 1: even if the the the horseshoe crabs of today look 571 00:31:25,440 --> 00:31:28,640 Speaker 1: extremely similar to the horseshoe crabs of the Jurassic Period, 572 00:31:29,040 --> 00:31:31,920 Speaker 1: the animals all around them would have been completely different, 573 00:31:32,320 --> 00:31:34,680 Speaker 1: and thus they there they were probably you know, they 574 00:31:34,720 --> 00:31:37,320 Speaker 1: had a different ecological niche. They were dealing with different 575 00:31:37,360 --> 00:31:40,960 Speaker 1: relationships and different energy dynamics in the in the environment, 576 00:31:41,320 --> 00:31:45,440 Speaker 1: but eating different things, titially being preyed upon by different things. 577 00:31:46,040 --> 00:31:49,200 Speaker 1: But it is truly remarkable to see a type of 578 00:31:49,280 --> 00:31:52,560 Speaker 1: animal that has survived. I think the horseshoe crabs have 579 00:31:52,720 --> 00:31:57,320 Speaker 1: survived five different mass extinction events, definitely four, I think five, 580 00:31:58,000 --> 00:32:02,360 Speaker 1: and they still exist today in in a body plan 581 00:32:02,560 --> 00:32:05,440 Speaker 1: that is pretty close to the same animal you would 582 00:32:05,440 --> 00:32:08,560 Speaker 1: have found four fifty million years ago. And so as 583 00:32:08,560 --> 00:32:12,440 Speaker 1: alternatives to the phrase living fossil, some paleontologists have proposed 584 00:32:12,480 --> 00:32:15,800 Speaker 1: calling these types of organisms stabil a morphs. You know 585 00:32:15,920 --> 00:32:20,840 Speaker 1: that that morph meaning like body basically and stabilo meaning stable, 586 00:32:21,440 --> 00:32:24,840 Speaker 1: meaning that at some point long ago there was a 587 00:32:25,240 --> 00:32:27,600 Speaker 1: body plan that was reached and it just has not 588 00:32:27,840 --> 00:32:31,440 Speaker 1: needed to undergo change much since then. Yeah, this is 589 00:32:31,520 --> 00:32:34,320 Speaker 1: interesting and and definitely touches on something we've discussed in 590 00:32:34,360 --> 00:32:37,440 Speaker 1: the past in terms of of body forms that work. 591 00:32:37,800 --> 00:32:41,080 Speaker 1: And sometimes you see those basic body form that works 592 00:32:41,440 --> 00:32:46,120 Speaker 1: to the degree that it is acquired by by rather 593 00:32:46,400 --> 00:32:50,720 Speaker 1: distantly related relatives, such as such as the basic dolphin 594 00:32:51,480 --> 00:32:54,920 Speaker 1: or the basic dolphin form, and it's you can compare 595 00:32:54,960 --> 00:32:58,200 Speaker 1: that to to various other fish forms and then also 596 00:32:58,360 --> 00:33:03,840 Speaker 1: to the reptilian creatures that preceded them um uh Ichleosaurus, 597 00:33:03,880 --> 00:33:06,880 Speaker 1: for example. I was just looking at a paper a 598 00:33:06,960 --> 00:33:09,400 Speaker 1: while ago. I don't remember where it was, but there 599 00:33:09,480 --> 00:33:12,440 Speaker 1: was something about how nature repeatedly has tried to build 600 00:33:12,560 --> 00:33:17,480 Speaker 1: crabs like crustacean crabs, Yeah, the actual crabs. That it's 601 00:33:17,560 --> 00:33:19,840 Speaker 1: like a form that just kind of nature keeps coming 602 00:33:19,920 --> 00:33:22,920 Speaker 1: back to from different evolutionary pathways and ending up in 603 00:33:23,000 --> 00:33:26,320 Speaker 1: the same place. Yeah, it's like the most logical engineering 604 00:33:26,440 --> 00:33:30,040 Speaker 1: solution to a given environment and a given set of challenges. 605 00:33:30,560 --> 00:33:34,400 Speaker 1: But of course, with the thesaurus, of course went extinct 606 00:33:34,680 --> 00:33:37,760 Speaker 1: for first of some some essential reasons that I think 607 00:33:37,800 --> 00:33:40,400 Speaker 1: we've touched on the past show on the show in 608 00:33:40,440 --> 00:33:43,320 Speaker 1: the past, But with the horseshoe crab, it's rather different. 609 00:33:43,360 --> 00:33:45,280 Speaker 1: It's like they acquired this form and that form has 610 00:33:45,320 --> 00:33:48,920 Speaker 1: remained relatively stable for the duration. Yeah. I mean those 611 00:33:48,920 --> 00:33:51,000 Speaker 1: are two So you can talk in one sense about 612 00:33:51,320 --> 00:33:53,920 Speaker 1: forms that are stable and you see that they're they're 613 00:33:54,040 --> 00:33:57,800 Speaker 1: advantageous because of convergent evolution, different evolutionary pathways sort of 614 00:33:57,840 --> 00:34:00,719 Speaker 1: arrived in the same place. But we're talking about animal 615 00:34:00,800 --> 00:34:03,320 Speaker 1: forms that were achieved at some point in the past 616 00:34:03,880 --> 00:34:07,000 Speaker 1: and then they just kept working over time, and they 617 00:34:07,040 --> 00:34:10,920 Speaker 1: didn't undergo significant changes in their lineages. Uh, you know, 618 00:34:11,080 --> 00:34:13,480 Speaker 1: little changes here and there, but not major changes in 619 00:34:13,520 --> 00:34:16,920 Speaker 1: the body form. And they never went extinct. Yeah, I mean, really, 620 00:34:17,000 --> 00:34:21,600 Speaker 1: to invoke some more alien terminology, this is a perfect organism. 621 00:34:21,960 --> 00:34:27,960 Speaker 1: It it perfectly survives in the environment for which it 622 00:34:28,080 --> 00:34:32,040 Speaker 1: has evolved, and it has remained stable ever since. Then again, 623 00:34:32,200 --> 00:34:37,239 Speaker 1: surviving mass extinction events for four and fifty million years. Crazy. Yeah, 624 00:34:37,560 --> 00:34:40,479 Speaker 1: there's another alternative name for what to call these types 625 00:34:40,520 --> 00:34:43,320 Speaker 1: of creatures that was actually proposed by Darwin's bulldog, Thomas 626 00:34:43,360 --> 00:34:47,520 Speaker 1: Henry Huxley, who just called them persistent types. I think 627 00:34:47,560 --> 00:34:50,719 Speaker 1: that's pretty straightforward. Yeah, but it makes you wonder how 628 00:34:50,880 --> 00:34:54,040 Speaker 1: on Earth is something like this possible? Like what makes 629 00:34:54,200 --> 00:34:57,359 Speaker 1: animals like the horseshoe crab special? How does this type 630 00:34:57,360 --> 00:35:03,359 Speaker 1: of creature persist for so long with out huge morphological changes? Uh? 631 00:35:03,480 --> 00:35:06,400 Speaker 1: And you know, surviving all these extinction events, never you know, 632 00:35:06,560 --> 00:35:10,120 Speaker 1: becoming all that different of an animal fundamentally. Yeah, because 633 00:35:10,160 --> 00:35:12,040 Speaker 1: I can't help but think of think of it in 634 00:35:12,080 --> 00:35:15,719 Speaker 1: comparison to say the business environment, you know, like like 635 00:35:15,840 --> 00:35:19,200 Speaker 1: what are the persistent forms in the business world, Like 636 00:35:19,320 --> 00:35:24,480 Speaker 1: what what brands or franchises or product types just survive 637 00:35:24,920 --> 00:35:29,239 Speaker 1: for the duration through multiple like economic extinction events, and 638 00:35:29,480 --> 00:35:32,520 Speaker 1: also surviving all the things changing around them, you know, 639 00:35:32,719 --> 00:35:36,080 Speaker 1: predators and prey changing the way they behave and the 640 00:35:36,160 --> 00:35:38,520 Speaker 1: way they eat, you know, things in the in the 641 00:35:38,640 --> 00:35:41,439 Speaker 1: natural world that are ever trying to find that new 642 00:35:41,840 --> 00:35:47,000 Speaker 1: niche will allow them to to to themselves survive since 643 00:35:47,120 --> 00:35:53,000 Speaker 1: the early Devonian nature has pivoted to video exactly. Um, 644 00:35:53,560 --> 00:35:56,800 Speaker 1: so it's you know when we say that you know 645 00:35:56,880 --> 00:36:00,960 Speaker 1: they're true survivors, that it's you know action. I mean, 646 00:36:01,080 --> 00:36:03,719 Speaker 1: really you you're tempted to go that far and say, 647 00:36:03,800 --> 00:36:06,680 Speaker 1: like something here is just really working that they have 648 00:36:06,840 --> 00:36:10,600 Speaker 1: not been um surplanted by some of their creature along 649 00:36:10,640 --> 00:36:15,840 Speaker 1: the way. So many terrific seeming organisms have certainly proven 650 00:36:16,120 --> 00:36:19,600 Speaker 1: to have a very tenuous role in the environment, but 651 00:36:19,680 --> 00:36:21,960 Speaker 1: the horseshoe crab remains. Yeah, I mean, we got no 652 00:36:22,239 --> 00:36:25,080 Speaker 1: room to talk, puny, Homo sapiens. What have we been around, 653 00:36:25,160 --> 00:36:27,960 Speaker 1: you know, less than a few million years. Yeah, and 654 00:36:28,160 --> 00:36:30,719 Speaker 1: and we're continuing to work hard and making sure that 655 00:36:30,800 --> 00:36:36,120 Speaker 1: doesn't go too long. Um okay, So actually, so we 656 00:36:36,200 --> 00:36:39,200 Speaker 1: don't know the answer for sure, why the horseshoe crab 657 00:36:39,280 --> 00:36:42,520 Speaker 1: in particular and animals and other organisms like it has 658 00:36:42,640 --> 00:36:46,200 Speaker 1: persisted so long in its basic body type. But Forty 659 00:36:46,320 --> 00:36:50,120 Speaker 1: has some general thoughts about the question of of what 660 00:36:50,360 --> 00:36:53,000 Speaker 1: causes this sort of thing. He's got some arguments, and 661 00:36:53,160 --> 00:36:55,960 Speaker 1: one that I thought was really interesting was that he 662 00:36:56,080 --> 00:36:59,200 Speaker 1: talks about how survival is not just about the endurance 663 00:36:59,239 --> 00:37:02,600 Speaker 1: of the animal, It's also about the endurance of habitat. 664 00:37:03,520 --> 00:37:06,640 Speaker 1: So often the ability of an animal type to survive 665 00:37:06,719 --> 00:37:09,560 Speaker 1: through the eons largely unmodified is a feature of the 666 00:37:09,640 --> 00:37:13,680 Speaker 1: animal's habitat more than the animal itself. Some habitats are 667 00:37:13,760 --> 00:37:18,799 Speaker 1: just better equipped to sustain their adapted inhabitants through ecological 668 00:37:18,920 --> 00:37:22,480 Speaker 1: catastrophe than others. And so what would be an example 669 00:37:22,560 --> 00:37:26,080 Speaker 1: of this, Well, Forty mentions inter tidal zones of the 670 00:37:26,160 --> 00:37:31,600 Speaker 1: ocean and goes into quote shallow subtitle habitats on muddy 671 00:37:31,840 --> 00:37:35,600 Speaker 1: sandy shorelines. Now, why would this be a favored habitat 672 00:37:35,719 --> 00:37:39,680 Speaker 1: for survival through mass extinctions? Well, a big killer for 673 00:37:39,840 --> 00:37:44,239 Speaker 1: ocean dwelling organisms during environment environmental catastrophe appears to be 674 00:37:44,440 --> 00:37:48,600 Speaker 1: antoxy seas, where due to several cascading factors, you know 675 00:37:48,640 --> 00:37:52,440 Speaker 1: and there's a big environmental catastrophe. Oxygen is often removed 676 00:37:52,600 --> 00:37:54,840 Speaker 1: from a lot of the ocean water, and the animals 677 00:37:54,880 --> 00:37:57,040 Speaker 1: in the water can no longer breathe, and they die 678 00:37:57,880 --> 00:38:01,680 Speaker 1: even in these conditions. Fort just that these shallow, muddy 679 00:38:01,840 --> 00:38:06,400 Speaker 1: ocean edge habitats could still be pretty well oxygenated quote. 680 00:38:06,480 --> 00:38:09,440 Speaker 1: After all, the wind still ruffled the waves on shore, 681 00:38:10,000 --> 00:38:12,720 Speaker 1: and so many of the organisms adapted to this environment 682 00:38:13,080 --> 00:38:15,680 Speaker 1: can make it do with very little food to begin with, 683 00:38:15,920 --> 00:38:19,040 Speaker 1: and they tend to bury themselves in sediment at low 684 00:38:19,160 --> 00:38:22,239 Speaker 1: tide and sort of feed on particles of food that 685 00:38:22,400 --> 00:38:25,160 Speaker 1: wash in with the surf. And their access to the 686 00:38:25,280 --> 00:38:28,279 Speaker 1: surface would keep them in oxygen, and their access to 687 00:38:28,360 --> 00:38:32,200 Speaker 1: the tide would keep them supplied with particles of biomaterial 688 00:38:32,360 --> 00:38:36,040 Speaker 1: for food. Uh to quote forty again, I am tempted 689 00:38:36,080 --> 00:38:39,560 Speaker 1: to return to the military metaphor maybe this habitat was 690 00:38:39,640 --> 00:38:42,800 Speaker 1: like a tunnel that simply went under the front line. 691 00:38:43,280 --> 00:38:45,600 Speaker 1: The luck came in if you happen to belong to 692 00:38:45,719 --> 00:38:49,360 Speaker 1: that special battalion with access to the tunnel. And for 693 00:38:49,560 --> 00:38:53,040 Speaker 1: this reason he points out mud flats as a special 694 00:38:53,160 --> 00:38:56,320 Speaker 1: sort of extinction event survivor zone. Of course, we know 695 00:38:56,480 --> 00:39:00,400 Speaker 1: that you would often find horseshoe crabs scuttling around in 696 00:39:00,520 --> 00:39:04,680 Speaker 1: mud flats and tidal areas. Um. Now, now, why don't 697 00:39:05,080 --> 00:39:08,239 Speaker 1: ancient animal forms in zones like this get out competed 698 00:39:08,320 --> 00:39:12,440 Speaker 1: and displaced by new arrivals. Uh to read from forty quote. 699 00:39:12,760 --> 00:39:16,000 Speaker 1: Populations in many habitats are critically limited by the quantity 700 00:39:16,040 --> 00:39:19,560 Speaker 1: of food available. However, in places such as mud flats, 701 00:39:19,640 --> 00:39:23,080 Speaker 1: food may not be the limiting factor for filter feeding. 702 00:39:23,120 --> 00:39:26,040 Speaker 1: Animals are rich food store is carried into the area 703 00:39:26,120 --> 00:39:29,359 Speaker 1: with every high tide, or is brought from nearby land 704 00:39:29,480 --> 00:39:33,520 Speaker 1: during storms. The crucial things to find living space. The 705 00:39:33,640 --> 00:39:36,959 Speaker 1: problem is not the food in the trough, but making 706 00:39:37,040 --> 00:39:39,960 Speaker 1: a place at the stall. So if it can establish 707 00:39:40,000 --> 00:39:43,319 Speaker 1: itself in its borrow lingula, a creature he's talking about 708 00:39:43,560 --> 00:39:46,120 Speaker 1: is able to compete for food on equal terms with 709 00:39:46,239 --> 00:39:50,440 Speaker 1: a later arrival, geologically speaking, like a shrimp. This habitat 710 00:39:50,560 --> 00:39:52,839 Speaker 1: does seem like a good place to be for an 711 00:39:52,960 --> 00:39:57,440 Speaker 1: organism with conservative tendencies, And so he's sort of talking 712 00:39:57,480 --> 00:40:00,319 Speaker 1: again about many of the creatures that survived these mass 713 00:40:00,360 --> 00:40:03,239 Speaker 1: extinctions and go on for long periods of geologic time 714 00:40:03,920 --> 00:40:10,000 Speaker 1: having kind of behaviorally or ecologically conservative behaviors. Uh. To 715 00:40:10,080 --> 00:40:12,640 Speaker 1: quote him again, in one way, it is survival of 716 00:40:12,719 --> 00:40:16,080 Speaker 1: the fittest, but of the fittest habitat with the right 717 00:40:16,160 --> 00:40:20,279 Speaker 1: design specifications to offer long term security. Stick in the 718 00:40:20,400 --> 00:40:23,839 Speaker 1: MUD's last longest. Now, he also points out a few 719 00:40:23,880 --> 00:40:27,040 Speaker 1: other things, a few other cases of evolutionary survival of 720 00:40:27,080 --> 00:40:30,320 Speaker 1: an organism type over geological time, like if there is 721 00:40:30,440 --> 00:40:34,040 Speaker 1: an animal that's a specialist and a specialist niche, and 722 00:40:34,160 --> 00:40:37,279 Speaker 1: then their particular niche, by luck, persists over time. He 723 00:40:37,320 --> 00:40:41,000 Speaker 1: gives the example of like lampreys and hagfish that survive 724 00:40:41,080 --> 00:40:44,840 Speaker 1: as parasites on bony fish. Um. And then uh, and 725 00:40:45,120 --> 00:40:49,560 Speaker 1: he calls these areas that tend to accumulate long term 726 00:40:49,680 --> 00:40:55,520 Speaker 1: evolutionary survivors together time havens. Yeah. I like that uh 727 00:40:55,680 --> 00:40:58,279 Speaker 1: And And finally he points out also an interesting fact 728 00:40:58,360 --> 00:41:01,759 Speaker 1: that longevity seems to be a common feature in long 729 00:41:01,880 --> 00:41:04,920 Speaker 1: surviving animals, but it alone, of course won't preserve you 730 00:41:05,840 --> 00:41:08,920 Speaker 1: remember again that that it takes horseshoe crabs ten years 731 00:41:09,000 --> 00:41:12,360 Speaker 1: to reach sexual maturity, which is an unusually long period 732 00:41:12,400 --> 00:41:14,799 Speaker 1: of time for an arthropod. Alright, on that note, we're 733 00:41:14,800 --> 00:41:16,640 Speaker 1: going to take a quick break. But when we come back, 734 00:41:17,000 --> 00:41:25,279 Speaker 1: we will venture into the blood. Alright, we're back. All right, 735 00:41:25,640 --> 00:41:28,560 Speaker 1: let's talk about blood. So one of the most astonishing 736 00:41:28,640 --> 00:41:32,520 Speaker 1: things about the horseshoe crab is they're amazing blue blood. 737 00:41:34,080 --> 00:41:37,560 Speaker 1: It's literally blue. Now why would this be Humans and 738 00:41:37,640 --> 00:41:40,839 Speaker 1: other mammals have red blood because of the presence of hemoglobin, 739 00:41:40,920 --> 00:41:44,239 Speaker 1: which is an iron based compound that carries oxygen away 740 00:41:44,280 --> 00:41:46,000 Speaker 1: from the lungs to the rest of the body and 741 00:41:46,040 --> 00:41:50,160 Speaker 1: then transports carbon dioxide back the other way. Horseshoe crabs 742 00:41:50,280 --> 00:41:54,759 Speaker 1: do not have hemoglobin. Instead, they have a protein called hemocyanin, 743 00:41:55,080 --> 00:41:58,279 Speaker 1: which is based on copper instead of iron, and the 744 00:41:58,440 --> 00:42:02,799 Speaker 1: copper content makes the horseshoe crabs blood blue. I can't 745 00:42:02,840 --> 00:42:05,320 Speaker 1: help but think of the I corp of Talos, the 746 00:42:05,400 --> 00:42:08,919 Speaker 1: bronze automaton from Greek myth. But more specifically, I guess 747 00:42:09,080 --> 00:42:11,280 Speaker 1: you have blue blood that shows up in science fiction 748 00:42:11,440 --> 00:42:15,080 Speaker 1: like the alien opera singer in the Fifth Element we 749 00:42:15,239 --> 00:42:18,319 Speaker 1: find out as blue blood. Oh yeah, like everyone else. 750 00:42:18,360 --> 00:42:23,080 Speaker 1: I mainly remember multi pass um. So this hemocyanin based 751 00:42:23,120 --> 00:42:26,160 Speaker 1: blood has has some really amazing properties. So Richard Forty 752 00:42:26,239 --> 00:42:28,640 Speaker 1: writes of how on this beach in Delaware when he's 753 00:42:28,640 --> 00:42:31,280 Speaker 1: walking around looking at all these animals, he comes across 754 00:42:31,360 --> 00:42:35,640 Speaker 1: many horseshoe crabs crawling around with signs of old wounds 755 00:42:35,840 --> 00:42:38,239 Speaker 1: that look really like they should have been fatal, like 756 00:42:38,480 --> 00:42:41,279 Speaker 1: a large hole punched in the middle of the head, 757 00:42:41,840 --> 00:42:44,160 Speaker 1: or just part of the thorax missing, or you know, 758 00:42:44,280 --> 00:42:47,920 Speaker 1: broken off tail, whatever, and the survival of such wounds 759 00:42:48,040 --> 00:42:51,400 Speaker 1: may in part be due to the amazing clotting power 760 00:42:51,600 --> 00:42:55,439 Speaker 1: of horseshoe crab blood. Another anatomy fact that we didn't 761 00:42:55,480 --> 00:42:58,239 Speaker 1: get into earlier was about the circulation of the horseshoe crab. 762 00:42:58,360 --> 00:43:01,360 Speaker 1: Like many other arthropods, the horseshoe crab has an open 763 00:43:01,480 --> 00:43:05,000 Speaker 1: circulatory system, and this is very different from our mammalian system, 764 00:43:05,560 --> 00:43:08,800 Speaker 1: known of course conversely as the closed system, where blood 765 00:43:08,920 --> 00:43:11,920 Speaker 1: is entirely contained within vessels. Right if you cut a 766 00:43:11,960 --> 00:43:15,719 Speaker 1: person open the veins, arteries, capillaries, you have to to 767 00:43:15,840 --> 00:43:19,239 Speaker 1: rupture these containers for the blood to spill out. The 768 00:43:19,320 --> 00:43:22,360 Speaker 1: horseshoe crab is is something closer to kind of like 769 00:43:22,440 --> 00:43:25,279 Speaker 1: a box of free range blood. It has a heart 770 00:43:25,360 --> 00:43:29,760 Speaker 1: type pump that circulates blood oxygenated blood from the gills, 771 00:43:30,080 --> 00:43:32,960 Speaker 1: but then the blood sort of sluices around and bathes 772 00:43:33,080 --> 00:43:37,880 Speaker 1: the creatures organs without being contained entirely within vessels. So 773 00:43:38,000 --> 00:43:41,439 Speaker 1: how do horseshoe crabs survive the carnage of these mass 774 00:43:41,520 --> 00:43:44,000 Speaker 1: mating battles, even having like chunks ripped out of the 775 00:43:44,120 --> 00:43:47,600 Speaker 1: thorax or holes punched in the head. Forty Rights quote 776 00:43:47,840 --> 00:43:51,560 Speaker 1: such endurance as possible because the blood of Limulus polyphemus 777 00:43:51,840 --> 00:43:55,400 Speaker 1: has exceptional clotting powers. The animal does not bleed to 778 00:43:55,440 --> 00:43:59,560 Speaker 1: death because it's blood coagulates and walls off damaged areas. 779 00:44:00,120 --> 00:44:03,640 Speaker 1: So this blood is unique, but it has also proven 780 00:44:03,719 --> 00:44:07,880 Speaker 1: quite useful to humans. Uh specifically, it's been become very 781 00:44:07,920 --> 00:44:12,120 Speaker 1: important to the biomedical industry, which harvests the blood of 782 00:44:12,800 --> 00:44:16,560 Speaker 1: horseshoe crabs to create what is called Limulus ambhisite ly 783 00:44:16,760 --> 00:44:20,040 Speaker 1: sate or L A L, which is used to test 784 00:44:20,120 --> 00:44:24,480 Speaker 1: medical devices and pharmaceutical drugs for indotoxins. And this is 785 00:44:24,520 --> 00:44:28,279 Speaker 1: because their blood contains potent amida sites which function like 786 00:44:28,480 --> 00:44:32,759 Speaker 1: white blood cells, so enzymes are instantly released when they 787 00:44:32,800 --> 00:44:36,919 Speaker 1: come into contact with bacteria, which is observable and less 788 00:44:37,000 --> 00:44:40,360 Speaker 1: than one part per per trillion, So just a tiny 789 00:44:40,480 --> 00:44:44,040 Speaker 1: drop of the blood can help spot contamination. So it's 790 00:44:44,080 --> 00:44:48,719 Speaker 1: important for drug implant and environmental safety tests, and this 791 00:44:48,840 --> 00:44:53,279 Speaker 1: also includes space exploration applications as well. If you want 792 00:44:53,360 --> 00:44:58,360 Speaker 1: to see some footage of horseshoe crab blood harvesting in process, 793 00:44:58,680 --> 00:45:02,560 Speaker 1: you should definitely check out the nat GEO documentary series 794 00:45:02,640 --> 00:45:05,640 Speaker 1: One Strange Rock. We've heard us talk about this in 795 00:45:05,680 --> 00:45:09,280 Speaker 1: the past on the show excellent documentary. Wonderful footage features 796 00:45:09,280 --> 00:45:12,680 Speaker 1: a number of astronauts and Will Smith narrating all of this, 797 00:45:13,200 --> 00:45:15,480 Speaker 1: but they have a section on there. It's on Disney 798 00:45:15,480 --> 00:45:17,920 Speaker 1: Plus right now, so I highly recommend you check it 799 00:45:17,960 --> 00:45:21,799 Speaker 1: out while you're mainlining all of the Mandalorian goodness there. 800 00:45:23,040 --> 00:45:25,840 Speaker 1: In fact, it was while watching One Strange Rock that 801 00:45:26,280 --> 00:45:29,080 Speaker 1: my with my family that I was reminded that this 802 00:45:29,120 --> 00:45:31,920 Speaker 1: would be a great topic because my son was watching 803 00:45:32,000 --> 00:45:34,200 Speaker 1: this and they were showing all these these horseshoe crabs 804 00:45:34,239 --> 00:45:38,160 Speaker 1: being lined up and bled and he just immediately did 805 00:45:38,200 --> 00:45:39,799 Speaker 1: not like it. And he just gets this very stern 806 00:45:39,880 --> 00:45:41,880 Speaker 1: look out his face and he says, human beings are 807 00:45:41,920 --> 00:45:45,759 Speaker 1: the worst and uh, and I had to reassure him, no, Uh, 808 00:45:46,360 --> 00:45:49,480 Speaker 1: these horseshoe crabs are going to be fine. Uh, you 809 00:45:49,560 --> 00:45:51,640 Speaker 1: know that we're not. They're not draining them to death. 810 00:45:51,960 --> 00:45:54,640 Speaker 1: They are draining them and then uh a certain portion 811 00:45:54,680 --> 00:45:56,760 Speaker 1: of their blood and then releasing them into the wild. 812 00:45:57,000 --> 00:45:59,680 Speaker 1: So there is some mortality. Yes, yeah, I was looking 813 00:45:59,719 --> 00:46:03,240 Speaker 1: around on this. Uh there's a paper from the Department 814 00:46:03,280 --> 00:46:07,400 Speaker 1: of Fisheries and Wildlife Sciences and Horseshoe Crab Research Center. 815 00:46:07,600 --> 00:46:12,520 Speaker 1: This is Virginia Polytechnic Institute and State University from LINKA Hurton. Uh, 816 00:46:12,680 --> 00:46:15,560 Speaker 1: this is a this is a small study, but it 817 00:46:15,960 --> 00:46:18,640 Speaker 1: it looked at them the morality the mortality rates for 818 00:46:18,880 --> 00:46:21,640 Speaker 1: horseshoe crabs. It's gonna vary depending on the sex of 819 00:46:21,719 --> 00:46:24,560 Speaker 1: the of the horseshoe crab and the amount of blood drawn. 820 00:46:25,040 --> 00:46:27,920 Speaker 1: And also not every specimen that is collected is ultimately 821 00:46:28,000 --> 00:46:30,279 Speaker 1: deemed suitable for a draw. So the source I was 822 00:46:30,320 --> 00:46:34,040 Speaker 1: looking at place male mortality rate anywhere between zero percent 823 00:46:34,200 --> 00:46:37,480 Speaker 1: at ten percent of blood drawn to thirteen points six 824 00:46:37,560 --> 00:46:40,880 Speaker 1: percent at thirty percent blood drawn, while females it range 825 00:46:40,920 --> 00:46:44,520 Speaker 1: from zero at zero to fifteen point four percent at 826 00:46:45,280 --> 00:46:48,200 Speaker 1: blood drawn. And wait, hold on, no, no, go ahead, 827 00:46:48,239 --> 00:46:51,080 Speaker 1: Well wait why did they ask zero percent drawn? This 828 00:46:51,160 --> 00:46:52,480 Speaker 1: comes down to the fact that it was such a 829 00:46:52,520 --> 00:46:55,680 Speaker 1: small study that there were zero that word, that had 830 00:46:55,760 --> 00:46:58,480 Speaker 1: zero percent drawn on this particular study. So, like I say, 831 00:46:58,520 --> 00:47:01,880 Speaker 1: the very small sample size makes these numbers, you know, 832 00:47:02,040 --> 00:47:05,200 Speaker 1: not the gospel, but they give some idea of of 833 00:47:05,280 --> 00:47:08,120 Speaker 1: what you're looking at here. For the females, the more 834 00:47:08,239 --> 00:47:12,320 Speaker 1: standard blood draw was came with a mortality rate of 835 00:47:12,440 --> 00:47:15,680 Speaker 1: ten point three, So thirty percent of a of a 836 00:47:15,760 --> 00:47:18,600 Speaker 1: crabs blood is generally extracted before it is returned to 837 00:47:18,640 --> 00:47:22,640 Speaker 1: its natural environment within seventy two hours and their placed 838 00:47:22,719 --> 00:47:27,000 Speaker 1: further out, usually to prevent repeat capture and draining. However, 839 00:47:27,600 --> 00:47:31,239 Speaker 1: this is still a physically stressful situation. You know, not 840 00:47:31,320 --> 00:47:35,520 Speaker 1: to anthropomorphize the creatures experience or anything, but the crabs 841 00:47:35,600 --> 00:47:38,760 Speaker 1: take three to seven days to regain their blood volume 842 00:47:38,840 --> 00:47:41,320 Speaker 1: and up to four months for those amata sites to 843 00:47:41,360 --> 00:47:45,319 Speaker 1: return to baseline levels. And they're also usually harvested during 844 00:47:45,360 --> 00:47:47,840 Speaker 1: spawning periods because this is when their easiest to catch. 845 00:47:48,640 --> 00:47:51,960 Speaker 1: A June nineteen study published in the University of Chicago 846 00:47:52,120 --> 00:47:56,000 Speaker 1: Press looked at the stress placed on the crabs following 847 00:47:56,080 --> 00:47:59,719 Speaker 1: their bleeding and how it might be uh impacting their 848 00:47:59,760 --> 00:48:05,080 Speaker 1: re productive potency um so owings at All found the following. 849 00:48:05,160 --> 00:48:10,080 Speaker 1: First of all, overall, biomedical bleeding may impact the reproductive 850 00:48:10,080 --> 00:48:12,960 Speaker 1: output of female horseshoe crabs during the season in which 851 00:48:13,040 --> 00:48:17,200 Speaker 1: they were bled. Week one following the bleeding, bled animals 852 00:48:17,239 --> 00:48:20,480 Speaker 1: appeared to spawn less than the controlled animals, and they 853 00:48:20,520 --> 00:48:23,600 Speaker 1: also found that control females appeared to spawn on average 854 00:48:23,680 --> 00:48:27,760 Speaker 1: four point eight times uh the rate of bled females, 855 00:48:27,880 --> 00:48:30,719 Speaker 1: which spawned on average just two times. They also found 856 00:48:30,719 --> 00:48:34,360 Speaker 1: that bled animals tended to stay clear of shallow zones 857 00:48:35,239 --> 00:48:38,200 Speaker 1: places that they actually needed to be for breeding purposes, 858 00:48:38,480 --> 00:48:41,680 Speaker 1: and this might this might be due to disorientation in 859 00:48:41,760 --> 00:48:45,040 Speaker 1: the animal following the blood draw or it also just 860 00:48:45,160 --> 00:48:47,320 Speaker 1: might all of this might come down to weakness, like 861 00:48:47,440 --> 00:48:49,760 Speaker 1: the creature is going to be weakened for a state 862 00:48:49,880 --> 00:48:52,920 Speaker 1: of you know, a week or even months following of 863 00:48:53,040 --> 00:48:55,759 Speaker 1: what's gone on here, and that may impact their reproductive 864 00:48:55,880 --> 00:48:59,839 Speaker 1: health as well. So all of this can ultimately alter 865 00:49:00,080 --> 00:49:03,000 Speaker 1: the sex ratio at those breeding areas that we talked 866 00:49:03,000 --> 00:49:05,200 Speaker 1: about at the top of the program, which is then 867 00:49:05,280 --> 00:49:09,719 Speaker 1: going to impact reproduction overall for the species in these 868 00:49:09,800 --> 00:49:13,799 Speaker 1: areas where blood harvesting is taking place. So the harvesting 869 00:49:14,080 --> 00:49:18,080 Speaker 1: of horseshoe crab blood probably has saved thousands or millions 870 00:49:18,160 --> 00:49:21,000 Speaker 1: of lives over the years that it's been done, but 871 00:49:21,560 --> 00:49:25,120 Speaker 1: it's still not good to be hurting these populations like this, 872 00:49:25,960 --> 00:49:28,360 Speaker 1: it is, you know, and again like this is a 873 00:49:28,360 --> 00:49:31,719 Speaker 1: study from just last year, so you know, we're still 874 00:49:31,840 --> 00:49:34,080 Speaker 1: learning more and more about the impact as we are 875 00:49:34,080 --> 00:49:36,520 Speaker 1: also looking for ways to get better, ways to get 876 00:49:36,560 --> 00:49:39,000 Speaker 1: away from the use of horseshoe crab blood because there 877 00:49:39,000 --> 00:49:42,040 Speaker 1: are some synthetic solutions now, right, Yeah, there are, and 878 00:49:42,600 --> 00:49:44,920 Speaker 1: we're generally we're looking at a future where we're going 879 00:49:45,000 --> 00:49:48,040 Speaker 1: to depend less on it. Another thing to keep in 880 00:49:48,120 --> 00:49:50,239 Speaker 1: mind is this is not the only risk factor for 881 00:49:50,480 --> 00:49:52,480 Speaker 1: horseshoe crabs. It would be one thing if it were, 882 00:49:52,640 --> 00:49:55,880 Speaker 1: but uh, they are also harvested for their eggs, so 883 00:49:56,000 --> 00:49:58,960 Speaker 1: they can be used as bait for eels as well 884 00:49:59,040 --> 00:50:02,560 Speaker 1: as features known as welk. Yeah, forty was talking about 885 00:50:02,600 --> 00:50:04,319 Speaker 1: this in his book, and the welk is some kind 886 00:50:04,360 --> 00:50:07,480 Speaker 1: of conk like animal that people fishing for it have 887 00:50:07,640 --> 00:50:10,520 Speaker 1: used horseshoe crabs as bait. So you know, these are 888 00:50:10,840 --> 00:50:13,920 Speaker 1: two different human practices that are having varying degrees of 889 00:50:14,000 --> 00:50:17,600 Speaker 1: impact on their reproductive health. And we have to come 890 00:50:17,600 --> 00:50:19,160 Speaker 1: back again to the fact that this is not just 891 00:50:19,360 --> 00:50:23,239 Speaker 1: some mirror outsider species. It's just left over from a 892 00:50:23,320 --> 00:50:27,360 Speaker 1: bygone age. They are keystone species. Their eggs are important 893 00:50:27,400 --> 00:50:30,719 Speaker 1: food source for a number of organisms, again including migratory 894 00:50:30,840 --> 00:50:35,560 Speaker 1: sea birds. So the future promises new biomedical tests as 895 00:50:35,640 --> 00:50:39,000 Speaker 1: well as hopefully alternative baits for the fishing industry, and 896 00:50:39,040 --> 00:50:41,320 Speaker 1: hopefully all of this will come together to ensure the 897 00:50:41,520 --> 00:50:45,239 Speaker 1: long term survival of the horseshoe crab. I hope it 898 00:50:45,400 --> 00:50:47,719 Speaker 1: is not the sixth extinction that wipes them out. But 899 00:50:47,800 --> 00:50:51,280 Speaker 1: that's the thing, isn't it. The great sixth mass extinction 900 00:50:51,360 --> 00:50:55,880 Speaker 1: event is proving to be the human occupation of the planet. However, 901 00:50:56,000 --> 00:50:57,719 Speaker 1: the one thing we have going for is is that 902 00:50:57,880 --> 00:51:02,279 Speaker 1: this extinction event is largely self conscious, or at least 903 00:51:02,320 --> 00:51:05,600 Speaker 1: it's self consciousness is growing. I'm going to be an optimist, 904 00:51:05,880 --> 00:51:10,239 Speaker 1: and it can do things like curb it's uh, it's 905 00:51:10,320 --> 00:51:13,880 Speaker 1: fishing practices. It can do things that are self reflective 906 00:51:14,200 --> 00:51:18,360 Speaker 1: and hopefully sustainable. Yeah, save the limuli folks, they're scuttling 907 00:51:18,440 --> 00:51:21,920 Speaker 1: masses are precious, absolutely all right. So there you have 908 00:51:22,000 --> 00:51:24,560 Speaker 1: at the horseshoe crab. Obviously, we'd love to hear from everybody, 909 00:51:24,719 --> 00:51:27,239 Speaker 1: especially those of you who have you know, any firsthand 910 00:51:27,280 --> 00:51:30,200 Speaker 1: experience with the horseshoe crab. If you have ever eaten 911 00:51:30,800 --> 00:51:33,279 Speaker 1: the row of horseshoe crabs, let us know. We'd love 912 00:51:33,360 --> 00:51:36,759 Speaker 1: to hear about that as well. In the meantime, you 913 00:51:36,840 --> 00:51:39,600 Speaker 1: can find us wherever you get your podcasts. Go to 914 00:51:39,600 --> 00:51:41,960 Speaker 1: stuff to Blow your Mind dot com and that'll redirect 915 00:51:42,000 --> 00:51:43,799 Speaker 1: you to a place where you can find the episodes. 916 00:51:44,200 --> 00:51:47,080 Speaker 1: But wherever you find us, just make sure that you subscribe, 917 00:51:47,239 --> 00:51:49,720 Speaker 1: that you rate, and that you review, and don't forget 918 00:51:49,719 --> 00:51:52,480 Speaker 1: to check out Invention. That's our other show that deals 919 00:51:52,680 --> 00:51:55,560 Speaker 1: with human techno history. Huge thanks as always to our 920 00:51:55,600 --> 00:51:58,640 Speaker 1: excellent audio producer Seth Nicholas Johnson. If you'd like to 921 00:51:58,680 --> 00:52:00,320 Speaker 1: get in touch with us with feedback back on this 922 00:52:00,400 --> 00:52:02,840 Speaker 1: episode or any other, to suggest topic for the future, 923 00:52:03,000 --> 00:52:05,759 Speaker 1: just to say hello, you can email us at contact 924 00:52:05,880 --> 00:52:15,560 Speaker 1: at stuff to Blow your Mind dot com. Stuff to 925 00:52:15,600 --> 00:52:17,480 Speaker 1: Blow Your Mind is a production of I Heart Radio's 926 00:52:17,480 --> 00:52:19,839 Speaker 1: How Stuff Works. For more podcasts from my heart Radio, 927 00:52:19,920 --> 00:52:22,600 Speaker 1: visit the iHeart Radio app, Apple Podcasts, or wherever you 928 00:52:22,680 --> 00:52:23,800 Speaker 1: listen to your favorite shows.