WEBVTT - From the Vault: Crabs Eat Everything Around Me, Part 1 0:00:05.680 --> 0:00:08.119 Hey, welcome to Stuff to Blow your Mind. My name 0:00:08.160 --> 0:00:11.320 is Robert Lamb and I'm Joe McCormick, and it's Saturday. 0:00:11.360 --> 0:00:14.360 Time for an episode from the Vault. This one originally 0:00:14.400 --> 0:00:20.320 published November. It's called Crabs Eat Everything Around Me Part one. 0:00:20.560 --> 0:00:23.480 It's about you know, it's about crabs eating stuff. I 0:00:24.000 --> 0:00:25.880 don't think there's any simpler way to put it than that. 0:00:26.560 --> 0:00:31.720 My welcome to Stuff to Blow your Mind production of 0:00:31.760 --> 0:00:40.640 My Heart Radio. Hey you welcome to Stuff to Blow 0:00:40.680 --> 0:00:44.000 your Mind. My name is Robert Lamb and I'm Joe McCormick. 0:00:44.040 --> 0:00:47.160 And today we're gonna be talking about crabs. I think 0:00:47.159 --> 0:00:49.440 this will be the first episode in a in a 0:00:49.520 --> 0:00:51.919 series that we're doing here at least two parts to this, 0:00:52.000 --> 0:00:55.200 because the crabs are ravenous and we're gonna be talking 0:00:55.280 --> 0:00:58.600 all about crabs eating things. You know, this is kind 0:00:58.640 --> 0:01:00.720 of a holiday tradition for so I figured how many 0:01:00.800 --> 0:01:02.480 years ago it was that we did uh, we did 0:01:02.560 --> 0:01:05.000 Christmas Crabs. We talked about the Crabs of Christmas Island 0:01:05.280 --> 0:01:09.160 as our Christmas episode, and and so it feels appropriate 0:01:09.200 --> 0:01:11.520 that as we enter into the holiday season here with 0:01:12.440 --> 0:01:14.920 in November and December, that we should return to the 0:01:14.959 --> 0:01:18.160 world of crabs and the feasts that crabs engage in. 0:01:18.520 --> 0:01:21.160 Have you ever noticed how the crabs come earlier every year? 0:01:21.440 --> 0:01:24.039 At least it feels that way. But yes, anyway that 0:01:24.120 --> 0:01:26.319 this will be a feast day of an episode because 0:01:26.360 --> 0:01:29.960 it will all be about crabs feasting sometimes things feasting 0:01:30.000 --> 0:01:34.320 on crabs, mostly what crabs themselves feast on. It's funny 0:01:34.360 --> 0:01:39.920 how crabs are are a natural source of feasting related content. Uh, Rob, 0:01:39.920 --> 0:01:42.479 I I think you saw my note about this beforehand, 0:01:42.480 --> 0:01:47.320 but I discovered the strangest Google results phenomenon before we 0:01:47.360 --> 0:01:50.880 came in here. What I found out earlier today was 0:01:50.960 --> 0:01:54.560 that when I do a Google search for crabs, it's 0:01:54.640 --> 0:01:58.080 five letter word crabs. You'd think the first result would 0:01:58.120 --> 0:02:01.080 be what like Wikipedia page for this animal, but no, 0:02:01.960 --> 0:02:06.200 the first result is seafood restaurants featuring crabs. They're trying 0:02:06.240 --> 0:02:09.040 to sell me some crab legs and drawn butter. And 0:02:09.080 --> 0:02:12.079 then the second result is the is like a health 0:02:12.200 --> 0:02:16.639 node about pubic lice. And then finally the third thing 0:02:16.680 --> 0:02:22.520 in the result is about the actual animals, the decapod crustaceans. Well, um, 0:02:22.880 --> 0:02:24.359 after you mentioned this, I had to try it out 0:02:24.360 --> 0:02:27.480 for myself. And and granted I'm not going in like fresh, 0:02:27.520 --> 0:02:31.800 you know, I do use Google quite a bit um. Uh. 0:02:31.360 --> 0:02:33.440 So for me, when I did a search for crabs 0:02:33.440 --> 0:02:35.919 c R A B s um, the number one hit 0:02:36.040 --> 0:02:39.560 is sponsored seafood content, but then it's the wiki for 0:02:39.880 --> 0:02:43.960 the decapod crustaceans, and then it's pubic lice in number 0:02:44.040 --> 0:02:47.800 at number three um, and then it's more pubic lice, 0:02:47.880 --> 0:02:50.080 and then it's some stuff about the crab nebula I 0:02:50.080 --> 0:02:53.040 think video content about the crab nebula uh, and then 0:02:53.040 --> 0:02:55.680 it's back to pubic lice once more, before rounding out 0:02:55.720 --> 0:02:58.200 page one search results with the Britannica dot com article 0:02:58.280 --> 0:03:02.560 about decapod crustaceans. Okay, so as our top three go basically, 0:03:02.639 --> 0:03:05.440 Google just thinks I'm going to be more interested in 0:03:05.720 --> 0:03:08.840 uh in in the lice than you are. I have 0:03:08.960 --> 0:03:11.359 no idea. I mean it could. I mean we were 0:03:11.360 --> 0:03:14.520 both probably searching for crabs all morning um and and 0:03:14.600 --> 0:03:18.000 perhaps yeah days before as well. So it seems like, 0:03:18.320 --> 0:03:20.080 I mean, I don't know how these algorithms work, but 0:03:20.120 --> 0:03:23.079 it seems like they would have gotten into their robotic 0:03:23.120 --> 0:03:27.160 minds that these are gentlemen who are interested in decapod crustaceans, 0:03:27.360 --> 0:03:29.640 and we should serve them up even more of it. Guy, 0:03:29.800 --> 0:03:32.200 I don't know, it's all mysteries in there. Who knows 0:03:32.240 --> 0:03:35.040 the mind of the machine crabs that that order all 0:03:35.080 --> 0:03:38.320 those results for us? Um, But I wanted to come 0:03:38.320 --> 0:03:42.360 back to uh this uh image in amber. So there's 0:03:42.400 --> 0:03:46.640 a study that was just published in Science Advances earlier 0:03:46.680 --> 0:03:50.400 this year by Javier lukeway at All, and it was 0:03:50.480 --> 0:03:54.240 called Crab and Amber reveals an early colonization of non 0:03:54.320 --> 0:03:59.360 marine environments during the Cretaceous. So this discovery concerns a 0:03:59.480 --> 0:04:03.440 fossil found in a piece of amber mind in modern 0:04:03.560 --> 0:04:07.040 day me and Mar dating back roughly a hundred million 0:04:07.120 --> 0:04:09.640 years or so, so squarely in the middle of the 0:04:09.680 --> 0:04:14.600 Cretaceous period, containing a remarkably well preserved specimen of a 0:04:14.720 --> 0:04:20.039 crab bearing the author's note, large compound eyes, delicate mouthparts, 0:04:20.040 --> 0:04:23.960 and even gills. Basically it's wholly intact. The whole thing 0:04:24.000 --> 0:04:26.359 is in there. Yeah, it's quite impressive looking in the 0:04:26.400 --> 0:04:29.680 way that it is um its body. It's position too, 0:04:30.040 --> 0:04:32.560 it looks like it is like throwing up its clause 0:04:32.600 --> 0:04:35.440 and a defensive position that we've all seen. And I 0:04:35.440 --> 0:04:37.760 think or you haven't seen it in person, you've probably 0:04:37.760 --> 0:04:39.520 seen a picture of it, of a crab like on 0:04:39.560 --> 0:04:43.760 the beach saying stand back, mammal, do not make me 0:04:43.839 --> 0:04:46.640 pinch you. Um. So it's as if, through you know, 0:04:46.680 --> 0:04:50.760 across uh, this is vast stretch of time, the crab 0:04:50.880 --> 0:04:54.279 is warning us to stay back with such ferocity that 0:04:54.320 --> 0:04:58.760 the very forces of geology like conspired to preserve this 0:04:58.760 --> 0:05:02.040 this uh, this ants it's doing. And yeah, maybe I 0:05:02.160 --> 0:05:04.600 maybe I sound silly, but I give this image five 0:05:04.640 --> 0:05:08.599 out of five coal hods. I am profoundly stirred by 0:05:08.600 --> 0:05:11.640 this crab trapped in amber. And and not just because 0:05:11.720 --> 0:05:14.279 it you know, it looks like that haunting mosquito and 0:05:14.320 --> 0:05:17.719 amber prop from Jurassic Park. But but there's something a 0:05:17.720 --> 0:05:21.480 little bit more to this too, because it raises these 0:05:21.560 --> 0:05:26.239 questions like how did a crabred million years ago get 0:05:26.400 --> 0:05:30.400 stuck in tree resin to become part of a fossilized 0:05:30.720 --> 0:05:33.520 piece of amber. We don't know the answer to this, 0:05:33.600 --> 0:05:37.520 but the researchers hypothesized, well, maybe this was a crab 0:05:37.600 --> 0:05:41.480 that lived a partially arboreal lifestyle. There are crabs today 0:05:41.520 --> 0:05:44.520 that climb trees as part of their lifestyle. So maybe 0:05:44.520 --> 0:05:48.560 this crab was climbing trees for some reason. Uh and uh, 0:05:48.600 --> 0:05:51.440 and and maybe it's also just because it causes you 0:05:51.520 --> 0:05:55.920 to realize that crabs existed and we're already beginning to 0:05:56.000 --> 0:05:58.919 come out of the oceans to move inland from the 0:05:58.960 --> 0:06:03.200 beaches hundred million years ago when dinosaurs were at their apex. 0:06:03.839 --> 0:06:07.560 And I always love those realization moments where you have like, oh, yes, 0:06:07.680 --> 0:06:10.680 animals of this kind and this kind actually did live 0:06:10.720 --> 0:06:16.520 alongside one another, terrestrial dinosaurs and terrestrial or semi terrestrial crabs. 0:06:17.839 --> 0:06:20.920 And Robert, I think you'll be very familiar with the 0:06:20.640 --> 0:06:23.240 the the did they fight mindset. Right as soon as 0:06:23.279 --> 0:06:25.880 you imagine that, the my sort of like eight year 0:06:25.880 --> 0:06:28.680 old boys brain starts going, did they ever fight each other? 0:06:28.760 --> 0:06:31.760 Dinosaurs versus crabs? I don't know how much of a 0:06:31.760 --> 0:06:34.400 fight that would have been, but I guess more more 0:06:34.440 --> 0:06:37.440 relevantly I could say, did they ever eat one another? 0:06:38.360 --> 0:06:41.200 And Uh, you actually gotta give you credit because you 0:06:41.240 --> 0:06:43.840 turned up the source on this for the copper Light 0:06:43.960 --> 0:06:46.960 study that found a pretty good case that yes, at 0:06:47.040 --> 0:06:49.840 least the eating was going one way. Yeah, but the 0:06:49.839 --> 0:06:52.680 details of this I was surprised at because you know 0:06:52.720 --> 0:06:56.600 not not to say that that some like smaller you know, 0:06:56.960 --> 0:07:01.640 beach combing dinosaur wasn't also hunting and gobbling up crabs. 0:07:01.680 --> 0:07:05.760 But the evidence here points to a different mode of consumption, right. 0:07:05.920 --> 0:07:09.040 So this is a study published in Scientific Reports in 0:07:10.720 --> 0:07:14.720 The lead author was a professor Karen Chin, who is 0:07:14.840 --> 0:07:20.680 Curator of Paleontology at Colorado University Boulders Museum of Natural History. 0:07:21.400 --> 0:07:24.440 And uh so this was by by Chin, Feldman and 0:07:24.520 --> 0:07:30.760 Tashman called Consumption of Crustaceans by mega herbivorous Dinosaurs, dietary 0:07:30.800 --> 0:07:34.880 flexibility and Dinosaur life history Strategies. So this is a 0:07:34.920 --> 0:07:37.600 copper light study, and you've gotta love a copper light study. 0:07:37.600 --> 0:07:41.160 Copper light, of course, is fossilized animal dung. This is 0:07:41.280 --> 0:07:44.720 dung that has become a mineral of the Earth. And 0:07:44.800 --> 0:07:48.600 the top line on this is that, uh collections of 0:07:48.760 --> 0:07:53.880 fossilized dinosaur feces from seventy five million years ago found 0:07:54.000 --> 0:07:59.480 in modern day Montana revealed that some giant herbivorous dinosaurs 0:07:59.560 --> 0:08:03.480 weren't always strictly herbivorous. Now, this would not be the 0:08:03.520 --> 0:08:05.920 first time a subject like this has come up on 0:08:05.960 --> 0:08:07.720 the show before, I think It was in our episodes 0:08:07.720 --> 0:08:10.960 on the Minotaur that we talked about evidence of bovines, 0:08:11.080 --> 0:08:14.960 cows and bulls and related animals sometimes eating flesh and 0:08:15.120 --> 0:08:19.240 in addition to their mostly vegetable diets. But it looks 0:08:19.280 --> 0:08:22.960 like maybe something similar was going on with giant herbivorous dinosaurs. 0:08:23.000 --> 0:08:27.200 So these feces probably belonged to hadrosaurs or the duck 0:08:27.240 --> 0:08:30.520 build dinosaurs. And it looks from the contents of these 0:08:30.520 --> 0:08:35.440 copper lights like these giant herbivores sometimes would supplement their 0:08:35.520 --> 0:08:41.559 vegetable diets by eating rotten wood and crustaceans. You can 0:08:41.600 --> 0:08:45.000 tell by these, uh, these remains preserved in the fossilized 0:08:45.080 --> 0:08:50.280 dung which are full of wood, fiber and crustacean shells. Now, again, 0:08:50.520 --> 0:08:55.160 this this raises these wonderful questions like how did this happen? Why? 0:08:55.200 --> 0:08:58.640 And you could imagine it's possibly some kind of accident, 0:08:58.800 --> 0:09:02.920 maybe a duckbill dinosaurs eating a rotten log for some reason, 0:09:03.040 --> 0:09:05.920 trying to get some kind of nutrients from all this 0:09:06.160 --> 0:09:09.240 rough rotten wood, and the rotten log just happens to 0:09:09.320 --> 0:09:12.920 be full of crabs. But to come back against that, 0:09:13.120 --> 0:09:16.320 against the accident hypothesis, I just want to read briefly 0:09:16.400 --> 0:09:20.480 from the press release describing this study. Quote, the size 0:09:20.559 --> 0:09:23.520 of the crustacean shell bits in the copper lights indicate 0:09:23.559 --> 0:09:26.520 the crustaceans were at least two inches in length and 0:09:26.640 --> 0:09:30.640 perhaps larger. Uh. And this is according to the lead author, 0:09:30.760 --> 0:09:35.679 Karen Chin. Individual crustaceans comprised from twenty six of the 0:09:35.840 --> 0:09:39.319 width of a common had restored beak, suggesting it was 0:09:39.520 --> 0:09:44.800 unlikely that crustaceans were unwittingly swallowed. Uh So, the ideas, 0:09:45.160 --> 0:09:49.000 it looks like whatever these crustaceans were, maybe they were crabs. 0:09:49.679 --> 0:09:51.440 We don't know for sure what they were, but there 0:09:51.480 --> 0:09:54.960 have been fossilized crab claws found from around the same 0:09:55.080 --> 0:09:58.200 area and going back even further in time, So there 0:09:58.240 --> 0:10:01.559 were crabs around these station. Shells could have belonged to 0:10:01.640 --> 0:10:03.959 crabs that were smashed up too much in the in 0:10:04.040 --> 0:10:06.400 the copper light to know for sure, but they could 0:10:06.440 --> 0:10:08.600 have been crabs, and they would have been big enough 0:10:08.679 --> 0:10:11.640 that it kind of seems unlikely they just accidentally went 0:10:11.720 --> 0:10:14.440 into the hadrosaur's mouth. It seems like the hadrosaur would 0:10:14.520 --> 0:10:17.120 kind of have to choose to eat the crab. Yeah, 0:10:17.200 --> 0:10:20.320 I mean, I'm also For me, it just makes me wonder, 0:10:20.400 --> 0:10:22.719 like what was the digestive system of a hydrosaur, Like 0:10:22.880 --> 0:10:26.640 it was just it seems like an industrial processing plant. 0:10:26.720 --> 0:10:30.480 You know, it's just rotten wood. Uh, it's all these 0:10:30.800 --> 0:10:34.439 these are these these fairly large like whole crustaceans and 0:10:34.720 --> 0:10:37.079 or their shells embedded in it, and you just you 0:10:37.200 --> 0:10:39.240 just eat that down because you're still hungry. And it 0:10:39.360 --> 0:10:42.240 may not have been about just obtaining raw calories like 0:10:42.320 --> 0:10:45.400 they may have been searching for a specific nutrient like 0:10:45.520 --> 0:10:49.319 we see in some other cases of otherwise herbivorous animals 0:10:49.400 --> 0:10:52.160 sometimes eating say bones or something where they're looking out 0:10:52.200 --> 0:10:55.400 certain types of minerals, maybe calcium or something. It could 0:10:55.440 --> 0:10:58.920 have been the case that maybe eating eating crustaceans like 0:10:59.040 --> 0:11:02.360 crabs for the drsaurs was linked to the reproductive cycle. 0:11:02.520 --> 0:11:04.720 They may have been seeking to bulk up on calcium 0:11:04.840 --> 0:11:07.559 or something. We don't know though, but oh whatever the 0:11:07.640 --> 0:11:10.680 answer there, I just I love it. So mega herbivorous 0:11:10.960 --> 0:11:15.040 or so called herbivorous dinosaurs eating crabs or crab like 0:11:15.360 --> 0:11:19.920 crustaceans seventy five million years ago and crabs a hundred 0:11:19.960 --> 0:11:23.840 million years ago getting frozen in amber for all of time. Uh, 0:11:23.960 --> 0:11:25.960 it just it just fills my you know, I got 0:11:26.080 --> 0:11:28.760 butterflies under my skin, all over my limbs. It's like, 0:11:29.360 --> 0:11:32.720 this makes me so happy. Yeah, I mean for the crabs. 0:11:32.800 --> 0:11:35.800 Though this is just another couple of pages in the 0:11:35.960 --> 0:11:39.240 history of the crab planet, well right, because it all 0:11:39.400 --> 0:11:41.440 it raises the question going the other way, the one 0:11:41.480 --> 0:11:43.040 we're saying we didn't know if we could answer. But 0:11:43.480 --> 0:11:46.480 so it looks like some dinosaurs in some cases eight 0:11:46.600 --> 0:11:50.439 crabs or crab like animals, other crustaceans. But the other 0:11:50.520 --> 0:11:54.160 question would be did crabs ever eat dinosaurs? I don't 0:11:54.200 --> 0:11:57.280 know about you. I could not find anything, any evidence 0:11:57.320 --> 0:11:59.880 to directly address that question. As far as I know, 0:12:00.080 --> 0:12:03.079 there is no physical evidence anybody's aware of, uh, to 0:12:03.160 --> 0:12:06.600 settle this issue. But I would say, if we can't 0:12:06.679 --> 0:12:09.480 find an answer to the question based on everything else 0:12:09.520 --> 0:12:11.360 we're going to talk about in the series, I think 0:12:11.360 --> 0:12:14.000 I would argue that in the absence of any evidence, 0:12:14.080 --> 0:12:17.719 our default assumption should be yes. I believe so. I 0:12:17.840 --> 0:12:20.000 think based on what we know about the nature of 0:12:20.200 --> 0:12:23.560 crabs in general and the sort of things they do eat, 0:12:24.000 --> 0:12:26.760 it it only makes sense that that they would they 0:12:26.800 --> 0:12:29.719 would partake of dinosaur meat if they came across it 0:12:30.280 --> 0:12:33.040 in their environment Alright, well, I say from here on out, 0:12:33.080 --> 0:12:34.800 for the rest of the series, we're just going to 0:12:34.880 --> 0:12:37.800 be looking at crabs eating all kinds of stuff. So, 0:12:38.120 --> 0:12:40.599 uh so, rob if you're ready, let's let's begin the 0:12:40.679 --> 0:12:43.520 crab feast. Yeah. But like just like with human feast, 0:12:43.559 --> 0:12:45.600 it's not enough to know what you're going to be eating. 0:12:45.720 --> 0:12:48.360 It's it's also about how you're going to eat. Uh, 0:12:48.559 --> 0:12:50.800 you know that, So we should we should probably start 0:12:50.880 --> 0:12:58.040 there with how crabs go about, uh consuming their various feasts. Right. So, 0:12:58.600 --> 0:13:01.720 crabs are of course a verse subgroup of the order 0:13:01.840 --> 0:13:06.319 of decapod crustaceans, So the decapod as in having ten feet, 0:13:06.480 --> 0:13:10.040 they are crustaceans. So there, you know, creatures with an exoskeleton. 0:13:10.160 --> 0:13:12.199 In order to grow bigger, they have to molt, so 0:13:12.240 --> 0:13:15.040 they have to shed their hard exoskeleton and come out 0:13:15.080 --> 0:13:17.360 with a soft one while they can rapidly increase in 0:13:17.480 --> 0:13:21.160 size and then reharden that. Crabs of course live in 0:13:21.200 --> 0:13:24.080 all kinds of environments. They originally come from the ocean, 0:13:24.240 --> 0:13:27.400 but over time and evolutionary history, like we saw with 0:13:27.480 --> 0:13:29.679 the crab preserved in amber, they started to move out 0:13:29.760 --> 0:13:33.599 away from the ocean and eventually into freshwater environments, and 0:13:33.720 --> 0:13:36.840 there are even land crabs. So as to the question 0:13:36.920 --> 0:13:40.440 of how and what do crabs normally consume, well, there 0:13:40.480 --> 0:13:42.559 are a lot of different species of crabs, and some 0:13:42.720 --> 0:13:45.840 of them have different dietary specialization, so there's no one 0:13:45.960 --> 0:13:48.559 answer to that question. But if you just want to 0:13:48.800 --> 0:13:52.080 sort of be general overall, it seems like the majority 0:13:52.200 --> 0:13:56.840 of crabs are not especially picky. Uh. Many crabs appear 0:13:56.960 --> 0:14:00.840 to be omnivorous opportunists who will eat pretty much anything 0:14:00.960 --> 0:14:03.880 they can shove into their mouths, and this can include 0:14:03.960 --> 0:14:08.000 everything from vegetation just gobbling up algae and fresh plant 0:14:08.080 --> 0:14:12.280 material leaf litter to uh to eating meat of course, 0:14:12.360 --> 0:14:15.800 scavenging scavenging carry in which crabs do a lot, or 0:14:15.920 --> 0:14:19.440 just getting little bits of organic or animal detritus, to 0:14:19.760 --> 0:14:23.080 actively hunting live prey with their claws, which some crabs 0:14:23.160 --> 0:14:26.200 do so as to diet. Crabs are all over the map. 0:14:26.440 --> 0:14:29.040 But the next thing I wanted to mention this was 0:14:29.160 --> 0:14:31.840 new information to me when when I was getting ready 0:14:31.880 --> 0:14:34.280 for this episode. So animal bodies, you know, they've usually 0:14:34.320 --> 0:14:37.119 got some kind of special equipment to help them extract 0:14:37.280 --> 0:14:41.560 the maximum amount of nutritional value from their food, and 0:14:41.720 --> 0:14:45.640 this often involves either chemically or mechanically breaking down the 0:14:45.720 --> 0:14:49.320 food from its original form, often to increase the surface 0:14:49.400 --> 0:14:52.400 area or the ease of access to nutrients by the 0:14:52.480 --> 0:14:54.680 digestive system, So there might be some kind of chemical 0:14:54.760 --> 0:14:57.240 breakdown as well. So you know, you know, you know 0:14:57.360 --> 0:14:59.920 the equipment. You've got Humans have teeth that we chew 0:15:00.080 --> 0:15:03.720 with and that that mashes food up and increased surface area. 0:15:04.440 --> 0:15:06.960 You've got gastric acid secreted by the cells in the 0:15:07.040 --> 0:15:09.680 lining of your stomach. But then you know they're all 0:15:09.760 --> 0:15:14.480 kinds of other strategies. Spiders will vomit digestive enzymes over 0:15:14.680 --> 0:15:18.000 and into their prey to uh sort of reduce the 0:15:18.120 --> 0:15:21.080 nutritious parts down to a fluid or mush that they 0:15:21.120 --> 0:15:24.120 can then slurp up with the mouth. And they also 0:15:24.200 --> 0:15:26.520 do have a form of chewing with their jaws, which 0:15:26.560 --> 0:15:30.520 are called chillissory. But crabs have one of the most 0:15:30.960 --> 0:15:34.800 glorious digestive aids I think I've ever read about. So 0:15:35.280 --> 0:15:39.000 if you ask the question do crabs have teeth, I 0:15:39.080 --> 0:15:41.280 think the answer would have to be yes and no 0:15:41.720 --> 0:15:44.880 in a couple of ways. So Obviously, crabs do not 0:15:45.080 --> 0:15:48.880 have teeth like us. Uh. They typically eat first by 0:15:49.000 --> 0:15:52.920 using their claws to tear food into small chunks before 0:15:53.000 --> 0:15:55.600 bringing it up to their mouth parts, and then they 0:15:55.680 --> 0:15:58.720 usually have a number of different moving mouth parts. These 0:15:58.760 --> 0:16:03.040 consist of um these things called maxilla heads, also known 0:16:03.120 --> 0:16:06.360 as jaw legs, which are sort of like hands within 0:16:06.480 --> 0:16:10.200 the mouth. These are are modified a little leg parts 0:16:10.320 --> 0:16:13.000 that will sort of grab bits of food and pass 0:16:13.120 --> 0:16:15.760 them inward and onward to other parts of the mouth 0:16:16.480 --> 0:16:19.560 known as the mac silly and the mandibles, which can 0:16:19.720 --> 0:16:22.520 further shred the food apart into smaller pieces that can 0:16:22.560 --> 0:16:26.720 be swallowed. But then once the food is swallowed, it 0:16:26.920 --> 0:16:31.400 is inside the digestive system where the most amazing feature appears, 0:16:31.960 --> 0:16:36.720 and it's this. Crabs, along with other related crustaceans, have 0:16:36.880 --> 0:16:40.440 an organ known as a gastric mill, which is more 0:16:40.600 --> 0:16:44.960 or less teeth inside the stomach. They've got gut teeth. 0:16:45.080 --> 0:16:48.880 They can chew with the insides of their stomachs, And 0:16:49.520 --> 0:16:51.280 this is another one that really got me. This is 0:16:51.320 --> 0:16:54.880 also worth googling some pictures of if you can, because 0:16:55.360 --> 0:16:57.920 there there are some uh some photos you can find 0:16:57.960 --> 0:17:00.280 on the Internet of like gastric mills, how having been 0:17:00.360 --> 0:17:03.680 extracted from the inside of a of a crabs digestive system, 0:17:04.200 --> 0:17:07.000 and they it's hard to describe how they look. They've 0:17:07.000 --> 0:17:09.920 they've got the kind of they're like a semi translucent 0:17:10.200 --> 0:17:14.920 pinkish orange, uh sci fi weapon hood. I don't know 0:17:15.080 --> 0:17:18.480 it's but it's also kind of beak like. It's very unnerving. 0:17:18.920 --> 0:17:21.480 I think, what are the interesting things about about the 0:17:21.520 --> 0:17:24.000 way of crab eats? And especially as evident if you're watching, 0:17:24.160 --> 0:17:26.520 um it's a close up video of a crab eating, 0:17:26.840 --> 0:17:29.080 is that there even more so with other creatures this 0:17:29.280 --> 0:17:34.920 there's this sense of meticulous um disassembly. Uh, the crab 0:17:35.080 --> 0:17:37.159 is not so much I mean, it is consuming, but 0:17:37.240 --> 0:17:41.119 it is also just uh just taking whatever it is 0:17:41.160 --> 0:17:45.119 consuming completely apart. It is disassembling matter and putting it 0:17:45.200 --> 0:17:47.920 into itself. Well, yeah, the crab makes you think about 0:17:47.960 --> 0:17:51.400 how much how much humans actually need to use tools 0:17:51.520 --> 0:17:54.040 for the kind of disassembly that they do leading into 0:17:55.000 --> 0:17:57.720 into eating say meat or something you know, like so 0:17:57.880 --> 0:18:00.600 humans devote a huge amount of their tech know logical 0:18:00.760 --> 0:18:04.120 energy over the history of time into creating like tools 0:18:04.240 --> 0:18:07.679 for butchery of food, cutting food into smaller and smaller 0:18:07.760 --> 0:18:11.119 pieces that are manageable that you can bite into, chew up, 0:18:11.160 --> 0:18:14.600 and all that. The crab they've they've got their disassembly 0:18:14.680 --> 0:18:17.520 tools right there on their body. They've got the claws, 0:18:17.640 --> 0:18:21.120 they've got the maxilly and the mandibles, and then once 0:18:21.240 --> 0:18:25.119 the food's inside, they've got additional opportunities for chewing. You 0:18:25.240 --> 0:18:28.720 don't have to stop chewing once you have swallowed. So 0:18:28.840 --> 0:18:31.080 the way the gastrit mill works is that it's sort 0:18:31.119 --> 0:18:34.080 of choose the food from inside the stomach by grinding 0:18:34.160 --> 0:18:38.320 it between these hard parts like plates or surfaces that 0:18:38.400 --> 0:18:42.840 are moved around by powerful gut muscles. And so while 0:18:42.840 --> 0:18:45.600 I was reading about the gastrit mill, I came across 0:18:45.760 --> 0:18:49.040 a really interesting piece of research from twenty nineteen that 0:18:49.160 --> 0:18:51.800 I just had to mention as as we're going along here, 0:18:52.320 --> 0:18:56.080 and this was by Jennifer R. A. Taylor, Maya S. Devrees, 0:18:56.160 --> 0:18:59.280 and Damian O Alias published in the Proceedings of the 0:18:59.359 --> 0:19:04.080 Royal Society be In in nineteen called Growling from the 0:19:04.280 --> 0:19:08.560 Gut co Optation of the gastric mill for Acoustic communication 0:19:08.680 --> 0:19:12.600 in ghost Crabs. So the short version of this discovery 0:19:12.680 --> 0:19:15.560 is that you've got this animal, the ghost crab scientific 0:19:15.720 --> 0:19:21.719 names quadrata, and it will sometimes make a threatening sound 0:19:22.119 --> 0:19:27.520 by way of having evolved. Quote a novel stridulation apparatus 0:19:27.640 --> 0:19:31.960 on the clause that is used during agonistic interactions. So, 0:19:32.400 --> 0:19:36.359 strigulation is any sound that is made by an animal 0:19:36.560 --> 0:19:40.840 rubbing pieces of its skeleton or exoskeleton together. The very 0:19:40.880 --> 0:19:43.320 common example you can think of is the sounds made 0:19:43.400 --> 0:19:47.600 by crickets or grasshoppers. That's strigulation. They rub parts of 0:19:47.640 --> 0:19:50.520 their legs or their carapists together, and that makes this 0:19:50.680 --> 0:19:53.600 chirping sound that is useful to the animal for some reason, 0:19:53.680 --> 0:19:57.000 maybe for maybe for mating, or maybe as warning signals 0:19:57.160 --> 0:19:59.919 or something. The ghost crab appears to use this stridge 0:20:00.000 --> 0:20:04.400 relation of rubbing its claws as a as a warning sign, 0:20:04.440 --> 0:20:07.280 as signs like Hey, I'm threatened, I am dangerous. I've 0:20:07.280 --> 0:20:09.280 got these big claws. You do not want to get 0:20:09.359 --> 0:20:12.399 near me. But in addition to the strigulation they make 0:20:12.520 --> 0:20:15.280 with their with their claws, to quote from the abstract 0:20:15.359 --> 0:20:18.520 of this paper, by a tailor at all quote, but 0:20:18.760 --> 0:20:23.240 they also produce a rasping sound without their claw apparatus. 0:20:23.720 --> 0:20:26.399 We investigated the nature of these sounds and show that 0:20:26.520 --> 0:20:30.520 oh quadrata adopted a unique and redundant mode of sound 0:20:30.600 --> 0:20:35.359 production by co opting the gastric mill the grinding teeth 0:20:35.440 --> 0:20:38.919 of the fore gut. Acoustic characteristics of the sound are 0:20:39.000 --> 0:20:42.399 consistent with strigulation and are produced by both male and 0:20:42.480 --> 0:20:48.040 female crabs during aggressive interactions. Uh so, yes they are. 0:20:48.160 --> 0:20:51.920 Actually they can like chirp like a cricket with the 0:20:52.240 --> 0:20:56.159 grinding teeth inside their stomachs in order to have a 0:20:56.280 --> 0:20:59.840 redundant way of making this aggressive sound display that they 0:21:00.119 --> 0:21:04.080 when they're being threatened. And the authors actually speculate as 0:21:04.119 --> 0:21:06.640 to why they would have this redundancy why be able 0:21:06.680 --> 0:21:08.920 to make this sound with two different parts of their body? 0:21:09.600 --> 0:21:13.439 They write, quote, A key advantage of using gastrixtrigulation over 0:21:13.520 --> 0:21:17.160 the claw apparatus is that it provides signal while freeing 0:21:17.320 --> 0:21:21.080 up the chel a for postural display and attack readiness. 0:21:21.520 --> 0:21:23.639 So you know, basically this this allows you to have 0:21:23.800 --> 0:21:28.200 claws out to be maximally visually threatening and maybe maximally 0:21:28.280 --> 0:21:31.720 dangerous if a fight actually does start, while still making 0:21:31.880 --> 0:21:36.200 the grinding scary sound. So yes, anyway, crabs and related 0:21:36.240 --> 0:21:40.320 crustaceans gastric mills. The chewing doesn't have to stop once 0:21:40.400 --> 0:21:42.800 you go down the gullet. And like we said, a 0:21:42.880 --> 0:21:45.440 lot of crabs are not very picky eaters, So who knows, 0:21:45.560 --> 0:21:48.600 maybe maybe if you could be taken apart into small 0:21:48.680 --> 0:21:57.000 enough pieces, you would go down the gullet. Than I 0:21:57.000 --> 0:21:59.000 guess from here we're going to start getting into the 0:21:59.080 --> 0:22:01.240 various meals of the crabs. You know, what do they 0:22:01.400 --> 0:22:06.800 use this uh, this fabulous uh equipment for? And I 0:22:06.920 --> 0:22:08.880 guess that I was thinking that one of the best 0:22:08.920 --> 0:22:12.679 places to start would be talking about crabs eating humans, 0:22:13.320 --> 0:22:14.880 because obviously that's going to be one of the most 0:22:14.920 --> 0:22:18.880 pressing questions to us the humans, right. Uh, Sure it eats, 0:22:18.960 --> 0:22:21.760 but will it eat me? How delicious am I? Do 0:22:21.920 --> 0:22:26.280 I deserve to be eaten by crabs? Um? And I 0:22:26.359 --> 0:22:28.840 think it's an understandable question. I mean, on one hand, 0:22:28.960 --> 0:22:32.880 like we are concerned with with this question with any 0:22:32.960 --> 0:22:35.119 creature on some level, you know, we have to have 0:22:35.320 --> 0:22:39.320 that that that that box checked off or or empty? 0:22:39.440 --> 0:22:42.040 Will it eat me? Uh? Is it incapable of eating me? 0:22:42.359 --> 0:22:44.600 Does it want to eat me? Uh? These are always 0:22:44.680 --> 0:22:46.760 questions that we have about other creatures in the animal 0:22:46.880 --> 0:22:51.080 kingdom and the various horror movies and animal creature flicks 0:22:51.160 --> 0:22:54.040 that we uh we watch. They don't help matters either, because, 0:22:54.080 --> 0:22:56.920 on one hand, we have our giant crab movies in 0:22:57.000 --> 0:23:00.760 which giant crabs, you know, in addition to occasionally wanting 0:23:00.800 --> 0:23:03.199 to take over the world or destroy whole cities, they 0:23:03.280 --> 0:23:06.280 want to grab people with their claws and either try 0:23:06.400 --> 0:23:09.440 to eat them, or it's implied that that crab is 0:23:09.480 --> 0:23:11.720 grabbing you because it wants to eat you, or, in 0:23:11.760 --> 0:23:14.479 the case of Attack of the Crab Monsters by Roger Corman, 0:23:14.560 --> 0:23:17.200 not just eat you but also absorb your soul and 0:23:17.320 --> 0:23:22.200