WEBVTT - Crabs Eat Everything Around Me, Part 1 0:00:00.160 --> 0:00:04.760 My Day. Welcome to Stuff to Blow your Mind, the 0:00:04.840 --> 0:00:13.920 production of My Heart Radio. Hey you, welcome to Stuff 0:00:13.960 --> 0:00:16.280 to Blow your Mind. My name is Robert Lamb and 0:00:16.440 --> 0:00:20.400 I'm Joe McCormick. And today we're gonna be talking about crabs. 0:00:20.480 --> 0:00:22.759 I think this will be the first episode in a 0:00:22.840 --> 0:00:24.840 in a series that we're doing here at least two 0:00:24.920 --> 0:00:28.080 parts to this, because the crabs are ravenous and we're 0:00:28.120 --> 0:00:31.680 gonna be talking all about crabs eating things. You know, 0:00:31.720 --> 0:00:33.600 this is kind of a holiday tradition for us. So 0:00:33.680 --> 0:00:35.720 I figured how many years ago it was that we did, uh, 0:00:35.840 --> 0:00:37.720 we did Christmas Crabs. We talked about the Crabs of 0:00:37.800 --> 0:00:41.920 Christmas Island as our Christmas episode and and so it 0:00:41.960 --> 0:00:44.600 feels appropriate that as we enter into the holiday season 0:00:44.720 --> 0:00:48.320 here with in November and December, that we should return 0:00:48.360 --> 0:00:51.159 to the world of crabs and the feasts that crabs 0:00:51.200 --> 0:00:53.639 engage in. Have you ever noticed how the crabs come 0:00:53.720 --> 0:00:57.080 earlier every year? At least it feels that way. But yes, 0:00:57.160 --> 0:00:59.600 anyway that this will be a feast day of an episode, 0:00:59.640 --> 0:01:03.560 because will all be about crabs feasting sometimes things feasting 0:01:03.600 --> 0:01:07.920 on crabs, mostly what crabs themselves feast on. It's funny 0:01:07.920 --> 0:01:13.520 how crabs are are a natural source of feasting related content. Uh, Rob, 0:01:13.520 --> 0:01:16.080 I I think you saw my note about this beforehand, 0:01:16.080 --> 0:01:20.880 but I discovered the strangest Google results phenomenon before we 0:01:20.959 --> 0:01:24.480 came in here. What I found out earlier today was 0:01:24.520 --> 0:01:28.160 that when I do a Google search for crabs, it's 0:01:28.200 --> 0:01:31.679 five letter word crabs. You'd think the first result would 0:01:31.720 --> 0:01:34.679 be what like Wikipedia page for this animal, but no, 0:01:35.560 --> 0:01:39.800 the first result is seafood restaurants featuring crabs. They're trying 0:01:39.800 --> 0:01:42.640 to sell me some crab legs and drawn butter. And 0:01:42.680 --> 0:01:45.679 then the second result is the is like a health 0:01:45.800 --> 0:01:50.240 node about pubic lice. And then finally the third thing 0:01:50.280 --> 0:01:56.400 and the result is about the actual animals, the decapod crustaceans. Well, um, yeah, 0:01:56.480 --> 0:01:57.920 after you mentioned this, I had to try it out 0:01:57.960 --> 0:02:00.640 for myself, and granted, and I'm not going in like 0:02:00.720 --> 0:02:04.560 fresh you know, I do use Google quite a bit. Um. 0:02:04.680 --> 0:02:06.600 Uh So for me, when I did a search for 0:02:06.640 --> 0:02:09.240 crabs c R A B s um, the number one 0:02:09.320 --> 0:02:12.680 hit is sponsored seafood content, but then it's the wiki 0:02:12.840 --> 0:02:17.040 for the decapod crustaceans, and then it's pubic lice in 0:02:17.320 --> 0:02:21.400 number at number three. Um. And then it's more pubic lice, 0:02:21.480 --> 0:02:23.680 and then it's some stuff about the crab nebula I 0:02:23.680 --> 0:02:26.639 think video content about the crab nebula uh, and then 0:02:26.639 --> 0:02:29.280 it's back to pubic lice once more, before rounding out 0:02:29.280 --> 0:02:31.800 page one search results with the Britannica dot com article 0:02:31.840 --> 0:02:35.360 about decapod crustaceans. Okay, so as our top three go, 0:02:35.600 --> 0:02:38.720 basically Google just thinks I'm going to be more interested 0:02:38.880 --> 0:02:42.320 in uh in in the lice than you are. I 0:02:42.360 --> 0:02:44.800 have no idea, I mean it could. I mean we 0:02:44.800 --> 0:02:47.840 were both probably searching for crabs all morning um and 0:02:47.840 --> 0:02:50.720 and perhaps you know, in days before as well. So 0:02:50.960 --> 0:02:52.760 it seems like, I mean, I don't know how these 0:02:52.800 --> 0:02:54.959 algorithms work, but it seems like they would have gotten 0:02:55.440 --> 0:02:58.680 into their robotic minds that these are gentlemen who are 0:02:58.720 --> 0:03:01.840 interested in decapod us stations and we should serve them 0:03:01.880 --> 0:03:04.400 up even more. It guy, I don't know, it's all 0:03:04.480 --> 0:03:06.800 mysteries in there. Who knows the mind of the machine 0:03:06.840 --> 0:03:10.680 crabs that that order all those results for us? Um? 0:03:10.840 --> 0:03:13.679 But I wanted to come back to uh this uh 0:03:14.040 --> 0:03:17.400 image and amber. So there's a study that was just 0:03:17.520 --> 0:03:22.400 published in Science Advances earlier this year by Javier Luquay 0:03:22.440 --> 0:03:26.000 at all and it was called Crab and Amber reveals 0:03:26.080 --> 0:03:30.760 an early colonization of non marine environments during the Cretaceous. 0:03:30.800 --> 0:03:34.920 So this discovery concerns a fossil found in a piece 0:03:34.960 --> 0:03:38.880 of amber mind in modern day me and Mar dating 0:03:38.880 --> 0:03:42.200 back roughly a hundred million years or so, so squarely 0:03:42.360 --> 0:03:46.440 in the middle of the Cretaceous period, containing a remarkably 0:03:46.520 --> 0:03:50.960 well preserved specimen of a crab bearing the author's note, 0:03:51.080 --> 0:03:55.600 large compound eyes, delicate mouthparts, and even gills. Basically, it's 0:03:55.800 --> 0:03:58.720 wholly intact. The whole thing is in there. Yeah, it's 0:03:58.800 --> 0:04:01.120 quite impressive looking in the way that it is um 0:04:01.760 --> 0:04:04.600 its body. It's position too, it looks like it is 0:04:04.880 --> 0:04:08.200 like throwing up its clause and defensive position that we've 0:04:08.240 --> 0:04:10.480 all seen and I think, or if you haven't seen 0:04:10.520 --> 0:04:12.040 it in person, you've probably seen a picture of it, 0:04:12.240 --> 0:04:15.440 of a crab like on the beach saying stand back, mammal, 0:04:16.680 --> 0:04:19.200 do not make me pinch you. Um. So it's as 0:04:19.240 --> 0:04:23.400 if through you know, across uh, this is vast stretch 0:04:23.440 --> 0:04:26.200 of time, the crab is warning us to stay back 0:04:26.640 --> 0:04:30.160 with such ferocity that the very forces of geology like 0:04:30.400 --> 0:04:34.320 conspired to preserve this this uh, this stance it's doing. 0:04:34.720 --> 0:04:37.080 And yeah, maybe I maybe I sound silly, but I 0:04:37.160 --> 0:04:39.719 give this image five out of five coal wal hoads. 0:04:39.839 --> 0:04:43.560 I am profoundly stirred by this crab trapped in amber. 0:04:43.880 --> 0:04:46.479 And and not just because it you know, it looks 0:04:46.520 --> 0:04:50.359 like that haunting mosquito and amber prop from Jurassic Park. Um. 0:04:50.360 --> 0:04:53.080 But but there's something a little bit more to this too, 0:04:53.640 --> 0:04:57.360 because it raises these questions like, how did a crab 0:04:57.880 --> 0:05:02.039 dred million years ago get stuck in tree resin to 0:05:02.120 --> 0:05:06.280 become part of a fossilized piece of amber. We don't 0:05:06.279 --> 0:05:09.080 know the answer to this, but the researchers hypothesized, well, 0:05:09.320 --> 0:05:13.960 maybe this was a crab that lived a partially arboreal lifestyle. 0:05:14.000 --> 0:05:16.520 There are crabs today that climb trees as part of 0:05:16.560 --> 0:05:19.880 their lifestyle, so maybe this crab was climbing trees for 0:05:19.920 --> 0:05:23.359 some reason. Uh and uh, and and maybe it's also 0:05:23.440 --> 0:05:27.839 just because it causes you to realize that crabs existed 0:05:28.000 --> 0:05:31.000 and we're already beginning to come out of the oceans 0:05:31.000 --> 0:05:34.720 to move inland from the beaches a hundred million years 0:05:34.720 --> 0:05:38.120 ago when dinosaurs were at their apex. And I always 0:05:38.160 --> 0:05:41.159 love those realization moments where you have like, oh, yes, 0:05:41.240 --> 0:05:44.279 animals of this kind and this kind actually did live 0:05:44.320 --> 0:05:49.440 alongside one another terrestrial dinosaurs and terrestrial or semi terrestrial 0:05:49.600 --> 0:05:53.840 crabs and Robert, I think you'll be very familiar with 0:05:53.920 --> 0:05:56.680 the the the did they fight mindset. Right as soon 0:05:56.720 --> 0:05:59.240 as you imagine that, the my sort of like eight 0:05:59.320 --> 0:06:01.920 year old boys rain starts going did they ever fight 0:06:01.960 --> 0:06:05.080 each other? Dinosaurs versus crabs? I don't know how much 0:06:05.080 --> 0:06:06.720 of a fight that would have been, but I guess 0:06:07.040 --> 0:06:10.279 more more relevantly I could say, did they ever eat 0:06:10.440 --> 0:06:14.400 one another? And? Uh, you actually gotta give you credit 0:06:14.400 --> 0:06:16.760 because you turned up the source on this for the 0:06:16.800 --> 0:06:20.360 copper light study that found a pretty good case that yes, 0:06:20.440 --> 0:06:23.279 at least the eating was going one way. Yeah, but 0:06:23.320 --> 0:06:26.240 the details of this I was surprised at because you know, 0:06:26.320 --> 0:06:30.200 not not to say that that some like smaller, you know, 0:06:30.560 --> 0:06:35.359 beachcombing dinosaur wasn't also hunting and gobbling up crabs. But 0:06:35.440 --> 0:06:39.400 the evidence here points to a different mode of consumption. Right. 0:06:39.520 --> 0:06:44.280 So this is a study published in Scientific Reports in UH. 0:06:44.320 --> 0:06:48.320 The lead author was a Professor Karen Chin, who is 0:06:48.440 --> 0:06:54.720 Curator of Paleontology at Colorado University Boulders Museum of Natural History. 0:06:54.960 --> 0:06:58.039 And uh so this was by by chin Feldman and 0:06:58.120 --> 0:07:05.080 Tashman called consumpt of Crustaceans by mega herbivorous Dinosaurs, dietary flexibility, 0:07:05.080 --> 0:07:08.839 and dinosaur life history strategies. So this is a copper 0:07:08.920 --> 0:07:11.160 light study, and you've gotta love a copper light study. 0:07:11.200 --> 0:07:14.760 Copper light, of course, is fossilized animal dung. This is 0:07:14.880 --> 0:07:18.320 dung that has become a mineral of the Earth. And 0:07:18.360 --> 0:07:22.200 the top line on this is that, uh collections of 0:07:22.360 --> 0:07:27.480 fossilized dinosaur feces from seventy five million years ago found 0:07:27.560 --> 0:07:33.080 in modern day Montana revealed that some giant herbivorous dinosaurs 0:07:33.160 --> 0:07:37.080 weren't always strictly herbivorous. Now, this would not be the 0:07:37.120 --> 0:07:39.520 first time a subject like this has come up on 0:07:39.560 --> 0:07:41.320 the show before. I think it was in our episodes 0:07:41.320 --> 0:07:44.560 on the Minotaur that we talked about evidence of bovines 0:07:44.680 --> 0:07:48.520 cows and bulls and related animals sometimes eating flesh and 0:07:48.520 --> 0:07:52.840 in addition to their mostly vegetable diets. But it looks 0:07:52.880 --> 0:07:56.560 like maybe something similar was going on with giant herbivorous dinosaurs. 0:07:56.560 --> 0:08:00.520 So these feces probably belonged to hadrosaur wars or the 0:08:00.600 --> 0:08:03.960 duck build dinosaurs. And it looks from the contents of 0:08:03.960 --> 0:08:08.880 these copper lights like these giant herbivores sometimes would supplement 0:08:08.920 --> 0:08:14.960 their vegetable diets by eating rotten wood and crustaceans. You 0:08:15.000 --> 0:08:17.880 can tell by these uh these remains preserved in the 0:08:17.920 --> 0:08:23.880 fossilized dung, which are full of wood, fiber and crustacean shells. Now, again, 0:08:24.120 --> 0:08:28.760 this this raises these wonderful questions like how did this happen? Why? 0:08:28.800 --> 0:08:32.240 And you could imagine it's possibly some kind of accident. 0:08:32.400 --> 0:08:35.600 Maybe a duck build dinosaur is eating a rotten log 0:08:35.800 --> 0:08:39.000 for some reason, trying to get some kind of nutrients 0:08:39.080 --> 0:08:42.040 from all this rough rotten wood, and the rotten log 0:08:42.120 --> 0:08:45.760 just happens to be full of crabs. But to come 0:08:45.760 --> 0:08:49.240 back against that, against the accident hypothesis, I just want 0:08:49.240 --> 0:08:52.080 to read briefly from the press release describing this study 0:08:52.520 --> 0:08:56.000 quote the size of the crustacean shell bits in the 0:08:56.000 --> 0:08:59.480 copper lights indicate the crustaceans were at least two inches 0:08:59.520 --> 0:09:03.160 in length and perhaps larger UH. And this is according 0:09:03.200 --> 0:09:07.600 to the lead author Karen Chin. Individual crustaceans comprised from 0:09:07.640 --> 0:09:11.640 twenty six of the width of a common had resour beak, 0:09:12.120 --> 0:09:17.760 suggesting it was unlikely that crustaceans were unwittingly swallowed. Uh So, 0:09:17.800 --> 0:09:21.280 the idea is, it looks like whatever these crustaceans were, 0:09:21.559 --> 0:09:24.400 maybe they were crabs. We don't know for sure what 0:09:24.440 --> 0:09:27.640 they were, but there have been fossilized crab claws found 0:09:27.640 --> 0:09:31.040 from around the same area and going back even further 0:09:31.120 --> 0:09:34.360 in time. So there were crabs around. These crustacean shells 0:09:34.400 --> 0:09:36.560 could have belonged to crabs that were smashed up too 0:09:36.679 --> 0:09:39.000 much in the in the copper light to know for sure, 0:09:39.520 --> 0:09:41.440 but they could have been crabs, and they would have 0:09:41.480 --> 0:09:43.920 been big enough that it kind of seems unlikely they 0:09:43.960 --> 0:09:47.240 just accidentally went into the had resour's mouth. Seems like 0:09:47.240 --> 0:09:49.520 the hadrosour would kind of have to choose to eat 0:09:49.559 --> 0:09:53.120 the crab. Yeah, I mean, I'm also for me, it 0:09:53.200 --> 0:09:55.440 just makes me wondered, like what was the digestive system 0:09:55.440 --> 0:09:58.160 of a hadrosaur, Like it was just it seems like 0:09:58.200 --> 0:10:02.960 an industrial processing plant, you know, it's just rotten wood. Uh, 0:10:03.280 --> 0:10:06.360 it's all these these are these these fairly large like 0:10:06.440 --> 0:10:10.200 whole crustaceans and or their shells embedded in it and 0:10:10.240 --> 0:10:12.480 you just you just eat that down because you're still hungry. 0:10:12.679 --> 0:10:14.960 And it may not have been about just obtaining raw 0:10:15.080 --> 0:10:18.160 calories like they may have been searching for a specific 0:10:18.280 --> 0:10:21.920 nutrient like we see in some other cases of otherwise 0:10:21.920 --> 0:10:25.400 herbivorous animals sometimes eating say bones or something, where they're 0:10:25.400 --> 0:10:28.439 looking out certain types of minerals, maybe calcium or something. 0:10:28.679 --> 0:10:31.679 It could have been the case that maybe eating eating 0:10:31.720 --> 0:10:34.800 crustaceans like crabs for the hadrosaurs was linked to the 0:10:34.840 --> 0:10:37.640 reproductive cycle. They may have been seeking to bulk up 0:10:37.640 --> 0:10:40.680 on calcium or something. We don't know though, but oh 0:10:40.760 --> 0:10:42.840 whatever the answer there, I just I love it so 0:10:43.360 --> 0:10:48.080 mega herbivorous or so called herbivorous dinosaurs eating crabs or 0:10:48.160 --> 0:10:53.120 crab like crustaceans seventy five million years ago and crabs 0:10:53.120 --> 0:10:55.960 a hundred million years ago getting frozen in amber for 0:10:56.040 --> 0:10:59.040 all of time. Uh, it just it just fills my 0:10:59.200 --> 0:11:01.360 you know, I got butter flies under my skin, all 0:11:01.360 --> 0:11:04.760 over my limbs. It's like this makes me so happy. Yeah, 0:11:05.480 --> 0:11:08.160 I mean for the crabs though this is just another 0:11:08.200 --> 0:11:11.200 couple of pages in the history of the crab planet. 0:11:11.400 --> 0:11:14.280 Well right, because it all it raises the question going 0:11:14.320 --> 0:11:15.800 the other way, the one we're saying we didn't know 0:11:15.840 --> 0:11:18.120 if we could answer. But so it looks like some 0:11:18.200 --> 0:11:22.000 dinosaurs in some cases eight crabs or crab like animals, 0:11:22.000 --> 0:11:25.560 other crustaceans. But the other question would be did crabs 0:11:25.559 --> 0:11:28.720 ever eat dinosaurs? I don't know about you. I could 0:11:28.760 --> 0:11:32.760 not find anything, any evidence to directly address that question. 0:11:32.840 --> 0:11:34.920 As far as I know, there is no physical evidence 0:11:34.960 --> 0:11:37.920 anybody is aware of, uh to settle this issue. But 0:11:38.400 --> 0:11:41.080 I would say, if we can't find an answer to 0:11:41.080 --> 0:11:43.679 the question, based on everything else we're going to talk 0:11:43.679 --> 0:11:45.800 about in the series, I think I would argue that 0:11:45.840 --> 0:11:49.280 in the absence of any evidence, our default assumption should 0:11:49.280 --> 0:11:52.160 be yes. I believe so. I think based on what 0:11:52.200 --> 0:11:55.720 we know about the nature of crabs in general and 0:11:55.800 --> 0:11:58.280 the sort of things they do eat, it it only 0:11:58.320 --> 0:12:01.160 makes sense that that they would they would partake of 0:12:01.200 --> 0:12:04.760 dinosaur meat if they came across it in their environment. 0:12:05.080 --> 0:12:06.760 All right, well, I say, from here on out, for 0:12:06.760 --> 0:12:08.560 the rest of the series, we're just going to be 0:12:08.600 --> 0:12:12.520 looking at crabs eating all kinds of stuff. So, uh so, Rob, 0:12:12.520 --> 0:12:15.400 if you're ready, let's let's begin the crab feast. Yeah, 0:12:15.440 --> 0:12:17.719 but like, just like with human face, it's not enough 0:12:17.760 --> 0:12:19.839 to know what you're going to be eating, it's it's 0:12:19.840 --> 0:12:22.600 also about how you're going to eat, uh, you know that, 0:12:23.080 --> 0:12:25.960 So we should we should probably start there with how 0:12:26.160 --> 0:12:31.840 crabs go about, uh consuming their various feasts. Right. So, 0:12:32.160 --> 0:12:35.000 crabs are of course a a diverse subgroup of the 0:12:35.120 --> 0:12:39.319 order of decapod crustaceans. So the decapod is in having 0:12:39.320 --> 0:12:42.520 ten feet. They are crustaceans, so they're you know, creatures 0:12:42.520 --> 0:12:45.160 with an exoskeleton. In order to grow bigger, they have 0:12:45.240 --> 0:12:48.480 to molds theft to shed their hard exoskeleton and come 0:12:48.520 --> 0:12:50.880 out with a soft one, while they can rapidly increase 0:12:50.920 --> 0:12:54.719 in size and then reharden that. Crabs of course live 0:12:54.720 --> 0:12:57.720 in all kinds of environments. They originally come from the ocean, 0:12:57.840 --> 0:13:01.040 but over time and evolutionary history, like we saw with 0:13:01.080 --> 0:13:03.320 the crab preserved in amber, they started to move out 0:13:03.360 --> 0:13:07.240 away from the ocean and eventually into freshwater environments, and 0:13:07.280 --> 0:13:10.440 there are even land crabs. So as to the question 0:13:10.480 --> 0:13:14.040 of how and what do crabs normally consume, well, there 0:13:14.080 --> 0:13:16.240 are a lot of different species of crabs, and some 0:13:16.280 --> 0:13:19.440 of them have different dietary specialization. So there's no one 0:13:19.559 --> 0:13:22.240 answer to that question, but if you just want to 0:13:22.400 --> 0:13:25.720 sort of be general overall, it seems like the majority 0:13:25.800 --> 0:13:30.480 of crabs are not especially picky. Uh. Many crabs appear 0:13:30.559 --> 0:13:34.480 to be omnivorous opportunists who will eat pretty much anything 0:13:34.559 --> 0:13:37.480 they can shove into their mouths, and this can include 0:13:37.559 --> 0:13:41.600 everything from vegetation just gobbling up algae and fresh plant 0:13:41.640 --> 0:13:45.920 material leaf litter to UH to eating meat of course, 0:13:45.920 --> 0:13:49.440 scavenging scavenging carry in which crabs do a lot, or 0:13:49.520 --> 0:13:53.040 just getting little bits of organic or animal detritus, to 0:13:53.360 --> 0:13:56.720 actively hunting live prey with their claws, which some crabs 0:13:56.760 --> 0:13:59.840 do so as to diet. Crabs are all over the map. 0:14:00.080 --> 0:14:02.640 But the next thing I wanted to mention this was 0:14:02.720 --> 0:14:05.440 new information to me when when I was getting ready 0:14:05.440 --> 0:14:07.920 for this episode. So animal bodies, you know, they've usually 0:14:07.920 --> 0:14:10.760 got some kind of special equipment to help them extract 0:14:10.880 --> 0:14:15.240 the maximum amount of nutritional value from their food, and 0:14:15.320 --> 0:14:19.280 this often involves either chemically or mechanically breaking down the 0:14:19.320 --> 0:14:22.920 food from its original form, often to increase the surface 0:14:23.000 --> 0:14:26.040 area or the ease of access to nutrients by the 0:14:26.080 --> 0:14:28.320 digestive system. So there might be some kind of chemical 0:14:28.360 --> 0:14:30.880 breakdown as well, so you know, you know, you know 0:14:30.960 --> 0:14:33.560 the equipment you've got. Humans have teeth that we chew 0:14:33.640 --> 0:14:36.600 with and that that mashes food up and to increased 0:14:36.600 --> 0:14:40.360 surface area. You've got gastric acid secreted by the cells 0:14:40.400 --> 0:14:42.920 in the lining of your stomach. But then you know 0:14:42.960 --> 0:14:46.960 they're all kinds of other strategies. Spiders will vomit digestive 0:14:47.120 --> 0:14:51.040 enzymes over and into their prey to uh sort of 0:14:51.080 --> 0:14:54.280 reduce the nutritious parts down to a fluid or mush 0:14:54.440 --> 0:14:57.320 that they can then slurp up with the mouth. And 0:14:57.320 --> 0:14:59.440 they also do have a form of chewing with their 0:14:59.520 --> 0:15:03.560 jaws what you are called chillissary. But crabs have one 0:15:03.560 --> 0:15:07.360 of the most glorious digestive aids I think I've ever 0:15:07.440 --> 0:15:11.440 read about. So if you ask the question do crabs 0:15:11.480 --> 0:15:13.800 have teeth, I think the answer would have to be 0:15:13.960 --> 0:15:17.440 yes and no in a couple of ways. So obviously 0:15:17.640 --> 0:15:21.359 crabs do not have teeth like us. Uh. They typically 0:15:21.360 --> 0:15:25.280 eat first by using their claws to tear food into 0:15:25.320 --> 0:15:28.200 small chunks before bringing it up to their mouth parts, 0:15:28.760 --> 0:15:31.360 and then they usually have a number of different moving 0:15:31.440 --> 0:15:36.120 mouth parts. These consist of um these things called maxilla heads, 0:15:36.160 --> 0:15:39.040 also known as jaw legs, which are sort of like 0:15:39.200 --> 0:15:43.000 hands within the mouth. These are are modified a little 0:15:43.080 --> 0:15:46.080 leg parts that will sort of grab bits of food 0:15:46.120 --> 0:15:49.000 and pass them inward and onward to other parts of 0:15:49.000 --> 0:15:52.560 the mouth known as the mac silly and the mandibles, 0:15:52.680 --> 0:15:55.840 which can further shred the food apart into smaller pieces 0:15:55.840 --> 0:15:59.560 that can be swallowed. But then once the food is 0:15:59.600 --> 0:16:03.360 swallow load it is inside the digestive system where the 0:16:03.400 --> 0:16:08.080 most amazing feature appears, and it's this. Crabs, along with 0:16:08.200 --> 0:16:12.960 other related crustaceans, have an organ known as a gastric mill, 0:16:13.280 --> 0:16:17.560 which is more or less teeth inside the stomach. They've 0:16:17.560 --> 0:16:21.040 got gut teeth. They can chew with the insides of 0:16:21.080 --> 0:16:24.560 their stomachs. And this is another one that really got me. 0:16:24.640 --> 0:16:27.680 This is also worth googling some pictures of if you can, 0:16:28.160 --> 0:16:31.320 because there there are some, uh some photos you can 0:16:31.320 --> 0:16:33.920 find on the Internet of like gastric mills having been 0:16:33.920 --> 0:16:37.680 extracted from the inside of a of a crabs digestive system. 0:16:37.800 --> 0:16:40.600 And they it's hard to describe how they look. They've 0:16:40.600 --> 0:16:43.560 they've got the kind of they're like a semi translucent, 0:16:43.760 --> 0:16:48.600 pinkish orange uh sci fi weapon hood. I don't know. 0:16:48.680 --> 0:16:52.120 It's but it's also kind of beak like. It's very unnerving. 0:16:52.520 --> 0:16:55.080 I think, what are the interesting things about about the 0:16:55.120 --> 0:16:58.200 way of crab eats? And especially as evident if you're watching, um, say, 0:16:58.240 --> 0:17:01.440 close up video of a crab, is that there even 0:17:01.480 --> 0:17:04.399 more so with other creatures this there's this sense of 0:17:04.560 --> 0:17:09.920 meticulous um disassembly. The crab is not so much I mean, 0:17:09.960 --> 0:17:12.720 it is consuming, but it is also just uh, just 0:17:13.000 --> 0:17:17.359 taking whatever it is consuming completely apart. It is disassembling 0:17:17.440 --> 0:17:20.720 matter and putting it into itself. Well, yeah, the crab 0:17:20.800 --> 0:17:23.959 makes you think about how much how much humans actually 0:17:24.000 --> 0:17:26.439 need to use tools for the kind of disassembly that 0:17:26.520 --> 0:17:30.560 they do leading into into eating say meat or something 0:17:30.600 --> 0:17:33.119 you know. Like so, humans devote a huge amount of 0:17:33.160 --> 0:17:37.000 their technological energy over the history of time into creating 0:17:37.080 --> 0:17:40.760 like tools for butchery of food, cutting food into smaller 0:17:40.800 --> 0:17:44.160 and smaller pieces that are manageable that you can bite into, 0:17:44.280 --> 0:17:47.000 chew up and all that. The crab, they they've got 0:17:47.040 --> 0:17:50.200 their disassembly tools right there on their body. They've got 0:17:50.240 --> 0:17:54.080 the claws, they've got the maxilly and the mandibles, and 0:17:54.119 --> 0:17:58.600 then once the food's inside, they've got additional opportunities for chewing. 0:17:58.680 --> 0:18:01.280 You don't have to stop chewing once you have swallowed. 0:18:02.280 --> 0:18:04.359 So the way the gastrit mill works is that it 0:18:04.480 --> 0:18:07.080 sort of choose the food from inside the stomach by 0:18:07.119 --> 0:18:11.840 grinding it between these hard parts like plates or surfaces 0:18:11.880 --> 0:18:16.159 that are moved around by powerful gut muscles. And so 0:18:16.200 --> 0:18:18.560 while I was reading about the gas strit mill, I 0:18:18.600 --> 0:18:21.840 came across a really interesting piece of research from twenty 0:18:21.960 --> 0:18:24.600 nineteen that I just had to mention as as we're 0:18:24.640 --> 0:18:28.400 going along here, and this was by Jennifer R. A. Taylor, 0:18:28.560 --> 0:18:32.199 Maya S. Devrees, and Damian O. Elias, published in the 0:18:32.280 --> 0:18:36.439 Proceedings of the Royal Society be In in nineteen called 0:18:36.640 --> 0:18:40.480 growling from the Gut co Optation of the gastric mill 0:18:40.560 --> 0:18:45.240 for acoustic communication in ghost crabs. So the short version 0:18:45.359 --> 0:18:47.520 of this discovery is that you've got this animal, the 0:18:47.520 --> 0:18:53.680 ghost crab scientific names quadrata, and it will sometimes make 0:18:53.720 --> 0:18:58.600 a threatening sound by way of having evolved. Quote a 0:18:58.680 --> 0:19:03.120 novel stridulate action apparatus on the clause that is used 0:19:03.200 --> 0:19:08.919 during agonistic interactions. So strigulation is any sound that is 0:19:08.960 --> 0:19:12.199 made by an animal rubbing pieces of its skeleton or 0:19:12.200 --> 0:19:15.840 exoskeleton together. The very common example you can think of 0:19:15.960 --> 0:19:19.720 is the sounds made by crickets or grasshoppers. That's strigulation. 0:19:20.320 --> 0:19:22.919 They rub parts of their legs or their carapists together 0:19:23.320 --> 0:19:25.960 and that makes this chirping sound that is useful to 0:19:26.040 --> 0:19:29.040 the animal for some reason, maybe for maybe for mating, 0:19:29.160 --> 0:19:32.080 or maybe as warning signals or something. The ghost crab 0:19:32.119 --> 0:19:36.160 appears to use this strigulation of rubbing its claws as 0:19:36.280 --> 0:19:39.720 a as a warning sign A sounds like Hey, I'm threatened, 0:19:39.760 --> 0:19:42.199 I am dangerous. I've got these big claws. You do 0:19:42.280 --> 0:19:44.800 not want to get near me. But in addition to 0:19:44.840 --> 0:19:47.720 the strigulation they make with their with their claws, to 0:19:47.800 --> 0:19:50.640 quote from the abstract of this paper by tailor at 0:19:50.640 --> 0:19:55.520 all quote, but they also produce a rasping sound without 0:19:55.640 --> 0:19:59.479 their claw apparatus. We investigated the nature of these sounds 0:19:59.520 --> 0:20:03.720 and showed oh quadratta adopted a unique and redundant mode 0:20:03.720 --> 0:20:07.960 of sound production by co opting the gastric mill, the 0:20:08.040 --> 0:20:12.320 grinding teeth of the foregut. Acoustic characteristics of the sound 0:20:12.400 --> 0:20:15.920 are consistent with strigulation and are produced by both male 0:20:15.960 --> 0:20:21.440 and female crabs during aggressive interactions. Uh so, yes they 0:20:21.480 --> 0:20:25.320 are actually they can like chirp like a cricket with 0:20:25.480 --> 0:20:29.639 the grinding teeth inside their stomachs in order to have 0:20:29.680 --> 0:20:33.320 a redundant way of making this aggressive sound display that 0:20:33.359 --> 0:20:36.960 they do when they're being threatened. And the authors actually 0:20:36.960 --> 0:20:39.920 speculate as to why they would have this redundancy, why 0:20:39.920 --> 0:20:41.960 be able to make this sound with two different parts 0:20:42.000 --> 0:20:45.040 of their body. They write, quote, A key advantage of 0:20:45.160 --> 0:20:49.040 using gastri strigulation over the claw apparatus is that it 0:20:49.080 --> 0:20:52.879 provides signal while freeing up the chel a for postural 0:20:53.000 --> 0:20:56.600 display and attack readiness. So you know, basically this this 0:20:56.680 --> 0:20:59.880 allows you to have claws out to be maximally visually 0:21:00.040 --> 0:21:03.240 rettn ing and maybe maximally dangerous if a fight actually 0:21:03.280 --> 0:21:08.760 does start, while still making the grinding scary sound. So yes, anyway, 0:21:08.880 --> 0:21:13.000 crabs and related crustaceans gastric mills, the chewing doesn't have 0:21:13.119 --> 0:21:16.000 to stop once you go down the gullet. And like 0:21:16.040 --> 0:21:18.440 we said, a lot of crabs are not very picky eaters, 0:21:18.480 --> 0:21:21.399 So who knows, maybe maybe if you could be taken 0:21:21.400 --> 0:21:24.040 apart into small enough pieces, you would go down the gullet. 0:21:30.560 --> 0:21:32.560 I guess from here we're gonna start getting into the 0:21:32.680 --> 0:21:34.879 various meals of the crabs. You know, what do they 0:21:35.000 --> 0:21:40.480 use this uh, this fabulous uh equipment for? And I 0:21:40.520 --> 0:21:42.520 guess that I was thinking that one of the best 0:21:42.520 --> 0:21:46.320 places to start would be talking about crabs eating humans, 0:21:46.920 --> 0:21:48.480 because obviously that's going to be one of the most 0:21:48.480 --> 0:21:52.520 pressing questions to us the humans. Right, Sure, it eats 0:21:52.560 --> 0:21:55.399 but will it eat me? How delicious? Am I? Do 0:21:55.480 --> 0:21:59.600 I deserve to be eaten by crabs? Um? Yeah, I 0:22:00.040 --> 0:22:02.480 think it's an understandable question. I mean, on one hand, 0:22:02.560 --> 0:22:06.520 like we are concerned with with this question with any 0:22:06.560 --> 0:22:08.800 creature on some level, you know, we have to have 0:22:08.920 --> 0:22:12.919 that that that that box checked off or or empty? 0:22:13.040 --> 0:22:15.719 Will it eat me? Is it incapable of eating me? 0:22:15.960 --> 0:22:18.200 Does it want to eat me? Uh? These are always 0:22:18.280 --> 0:22:21.120 questions that we have about other creatures in the animal kingdom, 0:22:21.160 --> 0:22:24.800 and the various horror movies and animal creature flicks that 0:22:24.880 --> 0:22:27.640 we uh we watch they don't help matters either, because, 0:22:27.680 --> 0:22:30.560 on one hand, we have our giant crab movies in 0:22:30.600 --> 0:22:34.359 which giant crabs, you know, in addition to occasionally wanting 0:22:34.359 --> 0:22:36.840 to take over the world or destroy whole cities, they 0:22:36.880 --> 0:22:39.960 want to grab people with their claws and either try 0:22:40.000 --> 0:22:43.040 to eat them or it's implied that that crab is 0:22:43.080 --> 0:22:45.320 grabbing you because it wants to eat you, or, in 0:22:45.359 --> 0:22:48.080 the case of Attack of the Crab Monsters by Roger Corman, 0:22:48.160 --> 0:22:50.800 not just eat you but also absorb your soul and 0:22:50.880 --> 0:22:55.840 intelligence in so doing. Right, But then, uh, we also 0:22:55.880 --> 0:23:00.360 have countless movies in which we see crabs scavenging, uh, 0:23:00.400 --> 0:23:02.840 you know, crawling around on the corpses of humans who 0:23:02.840 --> 0:23:05.800 have probably been dispatched by some kind of slasher or 0:23:05.840 --> 0:23:08.199 some sort of monster that it itself that it that 0:23:08.400 --> 0:23:11.600