WEBVTT - Jaws of the Giant Clam 0:00:03.040 --> 0:00:06.760 Welcome to Stuff to Blow Your Mind production of iHeartRadio. 0:00:12.760 --> 0:00:14.680 Hey you welcome to Stuff to Blow Your Mind. My 0:00:14.800 --> 0:00:16.079 name is Robert Lamb. 0:00:15.960 --> 0:00:17.239 And I'm Joe McCormick. 0:00:17.560 --> 0:00:20.479 And in this episode, we're gonna be diving deeper on 0:00:20.560 --> 0:00:23.960 a topic that we first explored just a little bit 0:00:24.000 --> 0:00:26.520 on an episode of Automilia Stupendium, which of course is 0:00:26.520 --> 0:00:29.479 one of our shorties that airs on Wednesdays, and that 0:00:29.640 --> 0:00:32.800 is the subject of the Giant Clam. I found this 0:00:32.880 --> 0:00:35.960 to be a fascinating topic to explore because, on one hand, 0:00:36.159 --> 0:00:39.320 the giant clam is just an amazing organism, notable not 0:00:39.360 --> 0:00:42.360 only for its size but also for its unique symbiosis. 0:00:42.800 --> 0:00:45.400 But in addition to this, it's an organism that has 0:00:45.479 --> 0:00:50.919 continually invited creative but highly inaccurate ideas about how they 0:00:50.960 --> 0:00:51.800 actually behave. 0:00:52.520 --> 0:00:54.880 It's not hard to see why people might look at 0:00:54.880 --> 0:00:57.680 this thing and think that it will bite you, because 0:00:57.680 --> 0:01:00.520 it just looks like the whole thing is just a 0:01:00.560 --> 0:01:03.000 pair of jaws like cartoon teeth. 0:01:03.440 --> 0:01:06.160 Yes. Yeah, And as we'll be exploring, I think the 0:01:06.240 --> 0:01:09.760 really interesting thing here is that you see this, this idea, 0:01:09.840 --> 0:01:13.280 this interpretation resonating not only with people who don't know 0:01:13.319 --> 0:01:16.840 any better. Who are you know, one or multiple degrees 0:01:16.880 --> 0:01:20.720 away from this organism and its natural habitat, but also 0:01:20.959 --> 0:01:23.959 people in close proximity to it, or just can be 0:01:24.080 --> 0:01:26.880 overwhelmed by the fact that it looks like a big mouth. 0:01:26.959 --> 0:01:30.360 What if it was like a big mouth? And what 0:01:30.400 --> 0:01:33.840 would the consequences of that be. The most pervasive idea, 0:01:33.880 --> 0:01:35.600 of course, is we're talking about the idea that a 0:01:35.640 --> 0:01:40.040 giant clam might latch onto your leg while you were 0:01:40.200 --> 0:01:44.000 diving or snorkeling, or even in a very cartoon sense, 0:01:44.080 --> 0:01:46.920 swallow you whole. And to be clear, just to go 0:01:46.959 --> 0:01:49.560 ahead and get this out at the top, this has 0:01:49.640 --> 0:01:52.640 never happened. There's no recorded evidence of it ever happening, 0:01:52.680 --> 0:01:55.840 and for reasons we'll discuss, very good reasons. It pretty 0:01:55.920 --> 0:01:58.160 much never could happen. That's right. 0:01:58.240 --> 0:02:03.559 There's like one real famous anecdote of a guy claiming 0:02:03.680 --> 0:02:06.720 that it happened, and he was there and I saw 0:02:06.800 --> 0:02:08.320 one of the babies and the baby looked at me. 0:02:09.160 --> 0:02:12.160 There are strong reasons for thinking that this story is 0:02:12.200 --> 0:02:17.239 not true, and other than that, it's mostly just vague 0:02:17.280 --> 0:02:22.680 generalizations from people not citing any evidence or fictional storytelling. 0:02:22.600 --> 0:02:24.480 Right, right, Ben. You know that there are all sorts 0:02:24.520 --> 0:02:26.320 of things that can go wrong in the water, and 0:02:26.320 --> 0:02:29.760 there are lots of ways you can become injured and 0:02:29.800 --> 0:02:32.120 so forth, but this is not really one of them. 0:02:32.120 --> 0:02:33.720 And I think if you were gonna, if you were 0:02:33.720 --> 0:02:37.080 going to pin your death on a giant clam, it 0:02:37.080 --> 0:02:39.280 would be like you would have to essentially like strap 0:02:39.280 --> 0:02:43.760 yourself to the giant clam and die drown underwater. You 0:02:43.760 --> 0:02:46.520 would have to frame it in a major, insignificant way. 0:02:46.760 --> 0:02:49.200 So yeah, in some ways, this I think is reminiscent 0:02:49.200 --> 0:02:51.160 of our recent look at manta rays in the ways 0:02:51.200 --> 0:02:55.320 that European sailors in particular misinterpreted the great fish as 0:02:55.320 --> 0:02:58.440 a threat. But again, the curious thing about the myth 0:02:58.480 --> 0:03:00.280 of the man eating clam is that while you only 0:03:00.280 --> 0:03:03.520 find it circulating in the nineteenth and twentieth century among 0:03:03.600 --> 0:03:08.000 Europeans and Americans, the idea also exists among native peoples, 0:03:08.000 --> 0:03:10.600 who would have had more hands on understanding of what 0:03:10.639 --> 0:03:14.320 these creatures were all about. But again, we're susceptible to 0:03:15.200 --> 0:03:17.920 on one level, the kind of creative thinking, like you know, 0:03:18.320 --> 0:03:22.000 this can occur separate from a logical interpretation. You know, 0:03:22.120 --> 0:03:23.920 the idea that you know it's not a mouth, but 0:03:24.040 --> 0:03:26.239 what if it is a mouth? And I think we'll 0:03:26.240 --> 0:03:28.480 maybe get into a little bit about how maybe we're 0:03:28.520 --> 0:03:31.799 just hardwired to see the jaws that could consume us, 0:03:31.840 --> 0:03:36.480 even if we know those are not jaws. So yeah, 0:03:36.680 --> 0:03:38.480 it just I think it might just boil down to 0:03:38.520 --> 0:03:41.600 the fact that a giant clam, especially just looks too 0:03:41.680 --> 0:03:43.560 much like a big old mouth for us to move 0:03:43.640 --> 0:03:44.040 past it. 0:03:44.520 --> 0:03:46.839 And if you've never seen one of these, by the way, 0:03:46.920 --> 0:03:50.240 you can look up a giant clam or tridacna clam 0:03:50.280 --> 0:03:57.560 tridac na. These things have a waviness to their shells, 0:03:57.680 --> 0:04:01.520 you know, the way the shell closes it. It is 0:04:01.560 --> 0:04:04.680 not just a straight curved line across. It waves up 0:04:04.720 --> 0:04:07.320 and down like a you know, oscillation of a sound 0:04:07.360 --> 0:04:10.960 wave or something, which sort of suggests teeth and further 0:04:11.040 --> 0:04:13.200 lends itself into the mouth interpretation. 0:04:14.440 --> 0:04:18.880 Now, speaking of mouths, it's interesting that tridacna apparently stems 0:04:18.920 --> 0:04:22.680 from the Latin for three bites, and this goes back 0:04:22.760 --> 0:04:24.640 to the writings of Like Plenty of the Elder and 0:04:24.640 --> 0:04:27.159 even the Conquest of Alexander the Great, where it was 0:04:27.480 --> 0:04:31.560 said that these could supply such meat as to require 0:04:31.640 --> 0:04:34.200 not one, not two, but three bites for you to 0:04:34.279 --> 0:04:37.720 consume it all. So the name actually originates in us 0:04:37.760 --> 0:04:41.680 eating them, rather than any fabulous reversal on that. 0:04:42.720 --> 0:04:44.640 And people do eat them. By the way, A lot 0:04:44.640 --> 0:04:47.480 of people believe the meat of this clam is a 0:04:47.720 --> 0:04:50.120 is a delicacy. A lot of people think it's really delicious. 0:04:50.720 --> 0:04:54.960 This has greatly harmed the clams. They are now in 0:04:55.200 --> 0:04:58.240 a I believe, listed by the IUCN as a critically 0:04:58.360 --> 0:05:02.200 endangered species, and there were efforts at combating this by 0:05:03.279 --> 0:05:06.159 changing over some of the trade in their meat to 0:05:06.320 --> 0:05:11.279 like farmed populations instead of wild populations, receding wild populations 0:05:11.320 --> 0:05:14.599 and things like that. But yeah, people are definitely getting 0:05:14.600 --> 0:05:15.520 some three bites in. 0:05:16.400 --> 0:05:19.560 Yeah, because they're an important part of coral reef environments, 0:05:19.600 --> 0:05:22.640 the coral reef environments that they call home. Now, I 0:05:22.680 --> 0:05:25.120 was excited to look into giant clams. I hadn't really 0:05:25.160 --> 0:05:28.120 I didn't really have giant clams on my mind at all, because, 0:05:28.560 --> 0:05:30.520 aside from maybe in the background, I had kind of 0:05:30.560 --> 0:05:33.279 like a Looney Tunes idea of them, you know, swallowing 0:05:33.279 --> 0:05:36.479 a diving bugs bunny or something to that effect. But 0:05:36.920 --> 0:05:39.440 as I've previously mentioned on the show. Over the summer, 0:05:39.480 --> 0:05:41.520 I had the privilege of visiting the islands of raja 0:05:41.560 --> 0:05:47.080 Ampat in Indonesia, where rich diversity of marine life, and 0:05:47.200 --> 0:05:51.000 this included the giant Tradacna clams, and of course the 0:05:51.040 --> 0:05:56.200 biggest of all Tradacna geigis, and a particularly large one 0:05:56.279 --> 0:05:59.920 in the area was known informally as Wu Tang clam. 0:06:00.600 --> 0:06:03.960 And so I didn't get to dive right down to 0:06:04.000 --> 0:06:06.640 Wu Tang clam because Wu Tang clam was like a 0:06:06.640 --> 0:06:08.560 little deeper than some of the other than many of 0:06:08.560 --> 0:06:10.440 the other giant clams I was seeing, but it was 0:06:10.480 --> 0:06:15.360 still substantially large. And I included a photograph of Wu 0:06:15.400 --> 0:06:18.599 Tang clam for you here, Joe. I'm I'm like ninety 0:06:18.680 --> 0:06:20.680 nine percent sure this is Wu Tang clam. But this 0:06:20.720 --> 0:06:24.479 is a shot from down there at its level with 0:06:24.560 --> 0:06:25.320 proper lighting. 0:06:25.680 --> 0:06:28.520 Oh wow, yeah, just looking at this one image here, 0:06:28.560 --> 0:06:33.520 it is so crusty with life all over it. 0:06:32.839 --> 0:06:34.160 It's hard to. 0:06:34.080 --> 0:06:36.880 See this as just one organism, as one clam with 0:06:36.960 --> 0:06:41.240 its two valves, you know, slightly parted. It looks more 0:06:41.400 --> 0:06:43.760 like a I don't know, a big piece of coral 0:06:43.800 --> 0:06:44.760 reef for something. 0:06:44.960 --> 0:06:47.840 Well, that that underscores the reality here that yeah, they 0:06:47.839 --> 0:06:51.720 are reef builders in the long term, like you know, 0:06:51.920 --> 0:06:54.960 they settle, they grow there in one spot, and when 0:06:55.000 --> 0:06:58.159 they eventually pass on for one reason or another, you 0:06:58.200 --> 0:07:02.320 know they will be the bone of future coral reefs. 0:07:02.320 --> 0:07:04.920 So yeah, that's one of the reasons they're so vitally 0:07:04.960 --> 0:07:06.240 important to these environments. 0:07:06.600 --> 0:07:09.760 Another reason, I think, Rob maybe you can confirm this 0:07:09.800 --> 0:07:12.080 because I guess you have seen them up close. I 0:07:12.120 --> 0:07:16.120 think sometimes people might not recognize they are looking at 0:07:16.120 --> 0:07:20.520 a giant clam, especially if they're like looking down from above, 0:07:20.680 --> 0:07:23.800 because it's not you don't obviously see the shell. You 0:07:23.880 --> 0:07:27.680 might just see a kind of ripply looking sheet of 0:07:27.800 --> 0:07:31.760 the inner flesh of the clam, like the mantle protruding 0:07:31.800 --> 0:07:33.640 from out of the shell. Because in a lot of 0:07:33.680 --> 0:07:36.680 cases they will be perched somewhere in a kind of 0:07:36.680 --> 0:07:39.800 sunlit sea bottom and they're trying to spread out and 0:07:39.880 --> 0:07:42.960 gather sunlight on the fleshy parts. And we can talk 0:07:43.000 --> 0:07:45.360 about the reasons for that in just a minute here. 0:07:45.760 --> 0:07:46.800 But you might not. 0:07:46.720 --> 0:07:49.960 Actually see something that looks like a clam. You might say, 0:07:50.080 --> 0:07:52.080 what is this a big kind of flat ripple a 0:07:52.160 --> 0:07:55.160 sea cucumber or something. Because you're just seeing the mantle. 0:07:55.160 --> 0:07:58.120 Right right, and the mantle tissue, it can be really 0:07:58.160 --> 0:08:02.240 eye catching. Certainly saw this a lot with the various 0:08:02.280 --> 0:08:05.320 giant clams that I was snorkling over. They almost feel 0:08:05.360 --> 0:08:09.120 magical at times, seeming to pulsate with a strange energy, 0:08:09.680 --> 0:08:11.840 and then they would as you would get near them, 0:08:11.880 --> 0:08:14.440 they would sense you for reasons that I'll get into, 0:08:14.560 --> 0:08:17.920 and the smaller varieties in particular would often kind of 0:08:17.960 --> 0:08:21.240 like maybe not close all the way, but kind of tense. Yeah. 0:08:21.280 --> 0:08:23.720 They were very vibrant to look at, and to your point, yeah, 0:08:23.760 --> 0:08:28.200 they are. They are facing mouth up if you will, 0:08:28.840 --> 0:08:31.240 because the mansle tissue needs to be, you know, have 0:08:31.720 --> 0:08:35.760 maximum exposure to sunlight. Whereas the Looney Tunes version of 0:08:35.800 --> 0:08:38.400 the giant clam that might eat bugs, bunny that you 0:08:38.480 --> 0:08:43.199 tend to imagine it positioned less vertically and more horizontally. 0:08:43.440 --> 0:08:45.360 You're right, because it's like a crocodile's mouth. 0:08:45.559 --> 0:08:49.360 Yes. Yeah, So, as I was passing over these these clans, 0:08:49.520 --> 0:08:53.040 the interesting thing is I still knew enough about clams 0:08:53.080 --> 0:08:56.040 and giant clams to know that these things were not 0:08:56.880 --> 0:08:59.120 a danger to me. They were not actually going to 0:08:59.200 --> 0:09:01.720 try and bite me or anything to that effect. And 0:09:01.840 --> 0:09:06.000 yet there is this undeniable resemblance to some sort of 0:09:06.080 --> 0:09:11.840 a big fleshy mouth or secondary secondarily perhaps some sort 0:09:11.840 --> 0:09:16.560 of yonic imagery. And so these associations I thought about 0:09:16.559 --> 0:09:19.880 this fair amount as I was passing over them snorkeling, Like, 0:09:20.360 --> 0:09:23.520 these associations connect with us, I think on a primal level, 0:09:23.559 --> 0:09:26.640 and it's hard not to at least casually think of 0:09:26.679 --> 0:09:32.320 what you're seeing in anthropomorphic terms, comparing them to basic 0:09:32.440 --> 0:09:36.480 human physiological analogues and analogs that are like very closely 0:09:36.559 --> 0:09:41.120 tied in to our survival and reproduction and so forth. Yeah, 0:09:41.800 --> 0:09:44.560 mostly we're going to talk about giant clams as mouths. 0:09:44.559 --> 0:09:48.520 But on the subject of yonic imagery, we do certainly 0:09:48.559 --> 0:09:52.400 see interpretations of clamshells in general in the giant clamshell, 0:09:52.480 --> 0:09:57.080 as well as vulva in its use as fertility emblems 0:09:57.440 --> 0:10:00.360 as well as currency in some cultures in the past. 0:10:01.760 --> 0:10:05.120 Sometimes you'll even see like Bodicelli's rendition of the Birth 0:10:05.160 --> 0:10:07.520 of Venus sided in there as well, though the shell 0:10:07.600 --> 0:10:09.640 that he depicts in that painting is a scallop shell, 0:10:09.679 --> 0:10:14.040 I believe, and not actually a clamshell, but it is 0:10:14.280 --> 0:10:17.720 presented on a scale that is more in keeping with 0:10:17.760 --> 0:10:18.719 a giant clamshell. 0:10:19.760 --> 0:10:22.800 Though I think actually in that that's also bigger than 0:10:22.840 --> 0:10:24.439 any known giant clam. 0:10:24.840 --> 0:10:27.360 Yeah, as we'll discuss giant clamshells, I think about the 0:10:27.400 --> 0:10:29.280 maximum you're going to get is like four feet. 0:10:29.040 --> 0:10:32.040 Across, Yeah, which is very big, still very big. 0:10:32.080 --> 0:10:37.000 It's still enormous. But you know, they can't fit a venus. Yeah, 0:10:37.000 --> 0:10:38.520 you couldn't fit a whole venus in there. You'd have 0:10:38.559 --> 0:10:41.600 to really scrunch your up. Still seashells in general, you know, 0:10:41.640 --> 0:10:45.280 pop up and Renaissance paintings, paintings sometimes with erotic suggestions 0:10:45.280 --> 0:10:49.160 and their usage. Though quite incidentally, there is a venus 0:10:49.480 --> 0:10:53.439 genus of clam. I was reading about this recently. Eighteenth 0:10:53.480 --> 0:10:58.040 century Swedish naturalist and father of modern taxonomy, Carl Linaeus 0:10:58.280 --> 0:11:02.640 famously described the venus claim in quite sexual terms, which 0:11:02.679 --> 0:11:06.000 was pretty controversial at the time. Critics charged that he 0:11:06.120 --> 0:11:10.440 quote indulged in obscene illusions. Suffice to say, it seems 0:11:10.679 --> 0:11:14.160 quite a common interpretation, second only to the view of 0:11:14.200 --> 0:11:15.400 the clam as a mouth. 0:11:15.960 --> 0:11:19.600 Was Linnaeus not otherwise really known for very expressive or 0:11:19.640 --> 0:11:21.080 controversial descriptions. 0:11:21.679 --> 0:11:23.800 Correct. That's my understanding is that this was kind of 0:11:23.840 --> 0:11:26.480 an outlier where suddenly everyone was like, whoa, whoa, what 0:11:26.520 --> 0:11:31.599 are you doing? But you know, I guess the controversy 0:11:31.640 --> 0:11:32.920 died down after a while. 0:11:33.160 --> 0:11:37.040 Yeah, it does seem like a biology is a funny 0:11:37.080 --> 0:11:38.719 domain to get upset about that in. 0:11:39.120 --> 0:11:44.080 Yeah, yeah, all right, Well, speaking of biology, let's let's 0:11:44.160 --> 0:11:46.079 let's go through some of the basics of the giant 0:11:46.160 --> 0:11:49.920 clam here, particularly so again we're talking about for the 0:11:49.920 --> 0:11:53.160 most part, we're talking about Tridacna gaigis, and it can 0:11:53.200 --> 0:11:55.600 be found in coral reefs of the South Pacific and 0:11:55.640 --> 0:11:59.160 Indian Oceans. They can reach sizes of up to two 0:11:59.200 --> 0:12:01.520 hundred and fifty kerls are five hundred and fifty pounds, 0:12:01.559 --> 0:12:04.679 and they can grow to somewhere over four feet or 0:12:04.720 --> 0:12:09.480 one point two meters long or across. So again, maybe 0:12:09.480 --> 0:12:13.760 not quite man swallowing size like we would see in 0:12:13.760 --> 0:12:17.080 our fiction, but still incredibly big. Like they still look 0:12:17.160 --> 0:12:19.840 like a they can still look like a massive like 0:12:20.040 --> 0:12:24.480 bio chest there on the seafloor. Yeah. Now, the giant clam, 0:12:24.520 --> 0:12:28.360 to be sure here, doesn't really have a mouth, especially 0:12:28.360 --> 0:12:30.480 in the way, you might read it as again the 0:12:30.480 --> 0:12:35.440 bugs bunny swallowing mouth. Instead, we have the valves, and 0:12:35.440 --> 0:12:37.760 they are bivalves. Remember, so we have the like the 0:12:38.440 --> 0:12:45.120 two shells that essentially howls the organism, and inside they 0:12:45.120 --> 0:12:47.280 have a pair of siphons, one for drawing in food 0:12:47.320 --> 0:12:51.160 and water and another for expelling waste. Furthermore, they are 0:12:51.200 --> 0:12:54.280 filter feeders and they have no need for any jaw 0:12:54.440 --> 0:12:58.040 like mechanics. There's no chewing that takes place with the 0:12:58.040 --> 0:13:01.640 two valve. They simply close, or in the case of 0:13:01.720 --> 0:13:05.760 the giant clams, nearly close their shells for protection. The 0:13:05.800 --> 0:13:08.760 giant clams can't actually close them all the way for 0:13:08.800 --> 0:13:12.480 a couple of reasons. And here's another big kicker. They 0:13:12.480 --> 0:13:17.600 close their shells exceedingly slowly. One of the main predators 0:13:17.600 --> 0:13:21.960 that they're closing their shells for protection against are sea stars, 0:13:22.400 --> 0:13:24.960 which you are quite a threat to a number of 0:13:26.120 --> 0:13:30.079 coral reef dwelling organisms. But they themselves are also slow 0:13:30.120 --> 0:13:34.280 moving creatures. So for this very specific encounter, the closing 0:13:34.360 --> 0:13:37.400 of the shell is actually pretty fast, but it's as 0:13:37.440 --> 0:13:40.360 fast as it needs to be, and it's not man 0:13:40.440 --> 0:13:41.320 catching fast. 0:13:42.600 --> 0:13:44.679 Yes, And the other thing you mentioned is they often 0:13:44.920 --> 0:13:48.480 don't close their shells completely because you will still see 0:13:48.520 --> 0:13:51.280 some of the flesh of the clam kind of protruding, 0:13:51.360 --> 0:13:54.560 like they've got to both expel water and retract their 0:13:54.640 --> 0:13:57.000 tissues inside in order. 0:13:56.760 --> 0:14:02.360 To close exactly. Now, the varied colorization of the mantle 0:14:02.400 --> 0:14:07.199 tissues on the giant clam is due to ariticide cells 0:14:07.720 --> 0:14:14.240 that feed light to symbiotic single celled dinoflagelet algae or zooxanthellae. 0:14:14.840 --> 0:14:16.520 And this is where we get into the really cool 0:14:16.520 --> 0:14:21.280 example of symbiosis going on here. The clam acquires these 0:14:21.560 --> 0:14:25.880 zooxanthellae via constant filter feeding in the water, it also 0:14:25.960 --> 0:14:31.560 acquires basic basic plectonic organisms that it actually eats, and thus, 0:14:31.680 --> 0:14:33.680 during the day the clam is going to open wide 0:14:33.720 --> 0:14:37.600 and extend its mantle tissue to absorb the sunlight necessary 0:14:37.600 --> 0:14:40.400 for the algae to conduct photosynthesis, and in return, the 0:14:40.440 --> 0:14:42.880 algae produced sugars and proteins that the clam needs to 0:14:42.880 --> 0:14:47.160 survive along with its more traditional filter diet, which it 0:14:47.240 --> 0:14:50.320 requires less off. So the giant clam has a dual 0:14:50.400 --> 0:14:53.400 feeding strategy and this is thought to have evolved some 0:14:53.440 --> 0:14:54.800 sixty four million years ago. 0:14:55.040 --> 0:14:58.240 Yeah, two different ways of eating. It is photosynthesizing with 0:14:58.320 --> 0:15:01.680 the help of these organized that it has absorbed and 0:15:01.720 --> 0:15:04.720 taken into itself. And then it's also filter feeding. It's 0:15:04.720 --> 0:15:07.400 sucking through water and filtering out little bits that it 0:15:07.440 --> 0:15:07.840 can eat. 0:15:08.280 --> 0:15:11.560 Yeah, and so that's that's one of the interesting like 0:15:11.640 --> 0:15:14.760 observations you can make as you like snorkel over them. 0:15:14.880 --> 0:15:18.280 Is like that mantle tissue is like it really seems engorged, 0:15:18.880 --> 0:15:21.440 uh and and very out there because because it is, 0:15:21.520 --> 0:15:26.680 it is, you know, collecting sunlight, and yeah, so fascinating 0:15:26.680 --> 0:15:29.840 that it has this dual feeding strategy. The giant clam 0:15:29.880 --> 0:15:33.520 also boasts thousands of pinhole eye spots along the mantle's 0:15:33.640 --> 0:15:36.960 edge that allowed to detect changes in light, not only 0:15:37.000 --> 0:15:40.160 the cycles of night and day, but also tailtale shadows 0:15:40.200 --> 0:15:44.600 of approaching predators. And so this gets into you know, 0:15:44.640 --> 0:15:48.680 the observation that I had as I was snorkeling over again, 0:15:48.880 --> 0:15:52.360 the smaller of the giants, they would sometimes like tense 0:15:52.440 --> 0:15:54.640 up a little bit. They wouldn't close all the way, 0:15:54.640 --> 0:15:57.280 but there would be like a visual like rippling or 0:15:57.400 --> 0:16:00.600 movement of the mantle tissue and even the valves. Yeah. 0:16:00.680 --> 0:16:02.800 Yeah, and I've seen video of the same thing happening. 0:16:02.840 --> 0:16:05.080 If you say, you move your hand over the top 0:16:05.120 --> 0:16:07.560 of one and cast a shadow over it, sometimes it 0:16:07.600 --> 0:16:10.080 will kind of tense and partially close. 0:16:10.400 --> 0:16:13.360 Which, again the logical mind knows that, you know, it 0:16:13.480 --> 0:16:16.880 is just responding to the presence of another organism, which 0:16:16.920 --> 0:16:18.800 may or may not be something that is a threat 0:16:18.840 --> 0:16:22.360 to it. But you also can't help but illogically read 0:16:22.400 --> 0:16:25.440 it as like little mouths that are kind of going 0:16:25.600 --> 0:16:30.640 at you, you know. So again, I think it's almost 0:16:30.680 --> 0:16:33.960 impossible not to read them on additional levels as well. 0:16:34.200 --> 0:16:36.320 Yeah, well, I mean I think the way to think 0:16:36.320 --> 0:16:38.560 of it is that what you're seeing there is a 0:16:38.640 --> 0:16:41.160 retracting impulse, not a biting. 0:16:40.760 --> 0:16:43.680 Impulse, exactly. Yeah, it is a retracting not a biting 0:16:44.560 --> 0:16:47.160 Because yeah, I think the other way we tend to, 0:16:48.440 --> 0:16:50.920 you know, artificially think about them, and certainly in like 0:16:51.080 --> 0:16:53.000 modern looney tune sense, is to think of them as 0:16:53.040 --> 0:16:56.160 a bear trap. Yes, and we'll turn to some actual 0:16:56.240 --> 0:17:00.680 examples from twentieth century cinema that depicts them essentially as 0:17:00.720 --> 0:17:03.160 a bear trap just waiting down there for divers to 0:17:03.200 --> 0:17:03.760 pass through it. 0:17:04.000 --> 0:17:17.560 Yeah, before we get to twentieth century cinema, there are 0:17:17.880 --> 0:17:22.400 older stories of giant clams. As you know various forms 0:17:22.440 --> 0:17:26.200 of monsters or man killers. The giant clam has appeared 0:17:26.320 --> 0:17:30.520 in some myths and legends of various people's of the 0:17:30.520 --> 0:17:35.000 Pacific Islands, sometimes as a benign creature, but sometimes as 0:17:35.040 --> 0:17:39.840 a dangerous or monstrous creature. One interesting example I found 0:17:40.040 --> 0:17:45.000 is in a to Amotuan version of the story of 0:17:45.200 --> 0:17:49.399 the Polynesian hero Rata. I can't remember if Rata's come 0:17:49.480 --> 0:17:52.280 up on the show before, but Rata is basically a 0:17:53.080 --> 0:17:57.119 culture hero that you will find throughout Polynesian storytelling and 0:17:57.200 --> 0:18:01.280 lots of different Pacific Island cultures. There are Rata stories 0:18:01.640 --> 0:18:07.960 among the Maori, among Tahitians, to Emotuans, and others, sometimes 0:18:07.960 --> 0:18:11.320 with a different name a slightly different name in different regions. 0:18:11.840 --> 0:18:15.800 The Rata stories differ in many details, but the most 0:18:15.840 --> 0:18:20.240 common elements are that he is a young, brave, resourceful 0:18:20.320 --> 0:18:23.320 hero who has to go on a dangerous quest to 0:18:23.520 --> 0:18:28.040 avenge the death of his father or to avenge some 0:18:28.080 --> 0:18:32.760 other kind of crime against his family, and in doing 0:18:32.840 --> 0:18:36.040 so he has to build a mighty canoe, which involves 0:18:36.080 --> 0:18:39.520 felling a tree protected by spirits or magical beings of 0:18:39.560 --> 0:18:43.640 the forest. Sometimes in older English sources these beings are 0:18:43.640 --> 0:18:48.280 translated as elves or goblins. More recent sources, I think, 0:18:48.560 --> 0:18:52.359 will call them things like forest spirits or something. But 0:18:53.400 --> 0:18:56.280 once in this great canoe that he has made, Rada 0:18:56.280 --> 0:18:59.520 has to go on a journey, sometimes with companions, to 0:18:59.680 --> 0:19:03.760 avenge his family or avenge his father, and battle terrifying 0:19:03.840 --> 0:19:07.720 monsters along the way. And so in one version of 0:19:07.760 --> 0:19:10.919 the Rada journey, I found one of those monsters he 0:19:11.000 --> 0:19:13.560 fights is a giant clam. 0:19:13.640 --> 0:19:15.040 So this is a. 0:19:15.000 --> 0:19:18.359 Telling of a version found among the Tuamotuan people of 0:19:18.400 --> 0:19:22.679 the Tuamotu Islands and of Tahiti, told by a local 0:19:22.720 --> 0:19:27.520 scholar named Taroi to a Missus Walker, and compiled into 0:19:27.560 --> 0:19:31.879 a book called Ancient Tahiti by the British Tahitian folkloristan 0:19:31.960 --> 0:19:36.680 scholar Tearia Henry, who lived eighteen forty seven to nineteen fifteen. 0:19:37.160 --> 0:19:39.520 So I'm going to read the excerpt of the text, 0:19:39.960 --> 0:19:42.199 and of course I have to apologize in advance for 0:19:42.200 --> 0:19:43.520 any mispronunciations. 0:19:43.720 --> 0:19:44.440 I'll do my best. 0:19:44.440 --> 0:19:47.359 Here they were sailing on their course when the great 0:19:47.440 --> 0:19:51.240 au or swordfish came into sight, and Rata mistook it 0:19:51.320 --> 0:19:54.359 for land. But Tava said it was not land, but 0:19:54.480 --> 0:19:58.480 another foe. So Rada stood prepared again for battle, and 0:19:58.520 --> 0:20:02.399 when the monster approached the the canoe, intending to pierce it, 0:20:02.720 --> 0:20:05.439 he killed it with his spear and presented the body 0:20:05.480 --> 0:20:09.520 to the elves as before. Thus that demon was exterminated 0:20:09.720 --> 0:20:13.439 and his flesh eaten by all. They sailed on, and 0:20:13.480 --> 0:20:17.080 they met the great Urua, the Kavala fish, which looked 0:20:17.119 --> 0:20:20.879 like land, but Tava told Rada it was the Kavala fish, 0:20:20.920 --> 0:20:24.120 sent by King Puna to kill him. The fish darted 0:20:24.200 --> 0:20:27.359 forward to carry away Rada, but he stood ready, and 0:20:27.440 --> 0:20:29.840 as soon as it approached him, he thrust his spear 0:20:29.960 --> 0:20:32.479 into its throat and killed it, and it was also 0:20:32.720 --> 0:20:36.840 eaten by all. Next they met the great Pahua Tutahi, 0:20:37.240 --> 0:20:40.760 a giant clam which appeared like a mountain looming up 0:20:40.760 --> 0:20:44.000 from the sea. But Tava said, it is not land. 0:20:44.280 --> 0:20:47.639 It is the giant clam, and Rada prepared for the 0:20:47.680 --> 0:20:51.880 inevitable encounter. As his vessel was being drawn up into it. 0:20:52.359 --> 0:20:55.200 The clam had opened its great valves and was sucking 0:20:55.200 --> 0:20:58.960 in the waves upon which the canoe. Tua Rata was sailing. 0:21:00.160 --> 0:21:02.480 Stood at the bow with his spear, and as soon 0:21:02.520 --> 0:21:04.920 as they reached the center of the clam, he pierced 0:21:04.960 --> 0:21:08.199 it through its vital part, severing its flesh from the 0:21:08.200 --> 0:21:11.320 shell so that it could not close upon him. He 0:21:11.400 --> 0:21:14.960 presented the clam to his spirit company to annihilate, and 0:21:15.000 --> 0:21:17.680 as soon as the canoe was safely away, the dead 0:21:17.760 --> 0:21:23.160 clam sank into the deep sea. So several interesting things 0:21:23.200 --> 0:21:26.760 here in the story. It sounds like he's talking about 0:21:26.840 --> 0:21:30.119 cutting the adductor muscle, which is something we see later 0:21:30.200 --> 0:21:33.480 when people are talking about how to fight this clam. 0:21:34.080 --> 0:21:36.679 In this case, it says that Rada, you know, he 0:21:36.760 --> 0:21:39.280 stabbed it at its vital part with the spear. Severing 0:21:39.280 --> 0:21:41.879 its flesh from the shell makes it sound, and that 0:21:41.920 --> 0:21:45.119 prevented the shell from closing. Right, So it sounds like 0:21:45.160 --> 0:21:48.440 he is saying he attacked. He attacked the adductor muscle, 0:21:48.480 --> 0:21:52.239 which the clam uses to close the shell. Another thing 0:21:52.280 --> 0:21:54.240 I want to note here is that I think there 0:21:54.280 --> 0:21:57.359 could be a temptation to take a story like this 0:21:57.640 --> 0:22:03.000 as evidence that the storyteller or the storyteller's audience would 0:22:03.040 --> 0:22:07.680 be expected to believe that giant clams are actually dangerous, 0:22:07.840 --> 0:22:10.040 that you know, they will come in eat your boat 0:22:10.160 --> 0:22:13.760 or something. But I'm not sure that's actually right. In 0:22:13.800 --> 0:22:17.719 this telling, the giant clam is not only a giant clam, 0:22:17.760 --> 0:22:22.160 as in a tridacta geigis. It is a giant giant 0:22:22.240 --> 0:22:25.560 clam described as looming over the sea like a mountain 0:22:25.720 --> 0:22:30.000 and capable of swallowing an entire canoe. So to me, 0:22:30.240 --> 0:22:33.280 that doesn't necessarily mean that the teller of the story 0:22:34.200 --> 0:22:36.639 wanted to you to get the idea that a regular 0:22:36.800 --> 0:22:41.640 sized giant clam poses a threat to human beings, though 0:22:41.640 --> 0:22:43.840 that belief does appear to be common enough around the 0:22:43.840 --> 0:22:47.120