WEBVTT - Hunters of the Dark Ocean, Part 3 0:00:03.000 --> 0:00:06.760 Welcome to Stuff to Blow Your Mind production of iHeartRadio. 0:00:12.480 --> 0:00:15.120 Hey, welcome to Stuff to Blow Your Mind. My name 0:00:15.160 --> 0:00:15.760 is Robert. 0:00:15.600 --> 0:00:18.439 Lamb and I am Joe McCormick, and we're back with 0:00:18.520 --> 0:00:21.760 part three in our series on predators in the deep 0:00:21.880 --> 0:00:25.880 and dark parts of the Ocean. Now for a brief 0:00:25.920 --> 0:00:29.280 recap on the previous episodes in the series. The ocean 0:00:29.400 --> 0:00:32.559 can be thought of as having several different zones if 0:00:32.600 --> 0:00:36.480 you imagine them stacked vertically, each with different environmental conditions 0:00:36.520 --> 0:00:41.400 regarding the availability of light, the availability of food, temperature, pressure, 0:00:41.520 --> 0:00:45.320 and so forth. And to be sure, the majority of 0:00:45.479 --> 0:00:49.000 marine fauna do live relatively close to the surface of 0:00:49.040 --> 0:00:52.920 the water, where sunlight can reach the phytoplankton and the 0:00:52.960 --> 0:00:56.560 other photo autotrophs that form the base of the food chain. 0:00:56.680 --> 0:01:00.680 Up there, they photosynthesize things, eat them, things eat those things, 0:01:00.720 --> 0:01:05.480 and so on. Now, in centuries past, there were thinkers 0:01:05.600 --> 0:01:09.520 such as the naturalist Edward Forbes, who observed that you know, 0:01:09.560 --> 0:01:13.600 the deeper you trawl or plunge into the water looking 0:01:13.640 --> 0:01:17.560 for life, the less you find. And from that he 0:01:17.720 --> 0:01:20.720 extrapolated that you know, below a certain depth there will 0:01:20.760 --> 0:01:24.000 be no fauna at all. Within the sea. This was 0:01:24.040 --> 0:01:27.640 the so called azoic hypothesis. We of course now know 0:01:27.760 --> 0:01:31.560 that that is not true. And while conditions are harsher 0:01:32.000 --> 0:01:36.000 and life forms may be less dense and less diverse 0:01:36.240 --> 0:01:39.040 in the depths than they are near the surface, there 0:01:39.120 --> 0:01:44.000 is nevertheless a fascinating world of animal interactions taking place 0:01:44.160 --> 0:01:48.080 in the deeper, darker zones of the ocean, even going 0:01:48.120 --> 0:01:49.960 all the way down to the very bottom, down to 0:01:50.000 --> 0:01:53.400 the abyssle ocean floor, and even into the sort of 0:01:53.480 --> 0:01:58.400 inverted island communities of the deep ocean trenches. Now, when 0:01:58.400 --> 0:02:01.080 you look at the animals within the environments, some of 0:02:01.120 --> 0:02:04.520 them are grazers, you know, grazing on microbial mats. Some 0:02:04.560 --> 0:02:08.120 of them are scavengers. But some are also predators and 0:02:08.160 --> 0:02:10.880 even top predators. And that's what we've been looking at 0:02:10.919 --> 0:02:15.520 in this series, Hunters in the Dark Parts of the Ocean. Now, 0:02:15.560 --> 0:02:17.880 in part one, we started by talking about a couple 0:02:17.880 --> 0:02:22.160 of specific organisms. One was a type of predatory amphipod 0:02:22.240 --> 0:02:27.880 crustacean called Dulcabella common chaka the sweet, Sweet, Sweet, Beautiful Darkness, 0:02:28.680 --> 0:02:31.839 newly discovered and documented in a paper by Weston at 0:02:31.840 --> 0:02:35.239 All from November twenty twenty four This was a crustacean 0:02:35.280 --> 0:02:38.520 predator found in the Hadel zone at a depth of 0:02:38.600 --> 0:02:42.440 almost eight thousand meters in the Atacama Trench, and this 0:02:42.560 --> 0:02:45.919 led us down a tangent of looking at bizarre amphipod 0:02:45.960 --> 0:02:48.840 body forms that was very fun. But we also in 0:02:48.919 --> 0:02:54.960 that episode talked about predatory sciphonophores, which can have unbelievably 0:02:55.000 --> 0:02:58.280 weird body forms as well. There's the one we talked 0:02:58.280 --> 0:03:01.640 about that's long as a waial thin rail, and we 0:03:01.720 --> 0:03:05.400 discussed a specific sighting documented in twenty twenty one of 0:03:05.400 --> 0:03:11.160 a large unidentified predatory cephonophore in Hadl waters. Now in 0:03:11.200 --> 0:03:14.520 Part two, I started off by talking about an abyssle 0:03:14.560 --> 0:03:17.960 predatory fish found more than four thousand meters deep in 0:03:18.040 --> 0:03:21.680 the Pacific, known as the gridi fish, which was notable, 0:03:21.680 --> 0:03:26.120 at least to me, for having these absolutely bizarre bean 0:03:26.280 --> 0:03:30.360 shaped neon yellow plate like depressions in the top of 0:03:30.400 --> 0:03:34.280 its head that apparently function as light sensitive spots for 0:03:34.400 --> 0:03:38.400 hunting bioluminescent prey. And then after that, Rob talked about 0:03:38.440 --> 0:03:41.920 a couple of deep swimming cephalopods, the strawberry squid, which 0:03:41.960 --> 0:03:44.960 inhabits a sort of boundary zone in the midwater with 0:03:45.000 --> 0:03:48.440 a little bit of twilight above and dark water below, 0:03:48.920 --> 0:03:52.800 which requires an interesting adaptation of two different kinds of 0:03:52.880 --> 0:03:56.120 eyes on opposite sides of its body, one for seeing 0:03:56.160 --> 0:03:59.480 shadows moving against the faint sunlight above and one for 0:03:59.520 --> 0:04:04.440 seeing glowing self illuminated organisms from below. After that, we 0:04:04.480 --> 0:04:08.440 also talked about the dumbo octopus, a very very cute, 0:04:08.880 --> 0:04:12.200 interesting little critter that seems to have forsaken many of 0:04:12.200 --> 0:04:15.840 the defense mechanisms of its cephalopod kin because it lives 0:04:16.000 --> 0:04:19.520 deep where predators are less of a concern. And we're 0:04:19.520 --> 0:04:21.880 back today to talk about more. Yeah. 0:04:22.000 --> 0:04:25.760 Yeah, we have at least a couple of different classifications 0:04:25.760 --> 0:04:28.440 of critics that I think everyone is going to be 0:04:29.120 --> 0:04:32.200 fascinated by, and at least well, I think both of 0:04:32.240 --> 0:04:37.720 them are probably anticipated as well now right, Actually, just 0:04:38.040 --> 0:04:42.080 a couple hours ago, I was in my regular Wednesday 0:04:42.240 --> 0:04:47.200 midday yoga class and my teacher, Allison, asked what I 0:04:47.240 --> 0:04:51.040 was working on, and I mentioned deep sea fish, and 0:04:51.440 --> 0:04:54.919 she mentioned that the late great David Lynch's two thousand 0:04:54.960 --> 0:04:59.080 and six book Catching the Big Fish evokes deep sea 0:04:59.120 --> 0:05:03.320 fish as a those kind of treasures of introspection and meditation. 0:05:04.440 --> 0:05:05.880 I don't know if anyone out there familiar with this 0:05:05.880 --> 0:05:08.159 book and to understand it's kind of an autobiography but 0:05:08.200 --> 0:05:11.359 also a self help guide and gets into some of 0:05:11.400 --> 0:05:18.000 the meditative concepts that David Lynch gravitated towards. I'm going 0:05:18.040 --> 0:05:21.080 to read a quick quote here from it. Quote ideas 0:05:21.080 --> 0:05:23.520 are like fish. If you want to catch little fish, 0:05:23.880 --> 0:05:25.920 you can stay in the shallow water. But if you 0:05:25.960 --> 0:05:28.200 want to catch the big fish, you've got to go deeper, 0:05:28.839 --> 0:05:31.960 down deep. The fish are more powerful and more pure. 0:05:32.440 --> 0:05:36.719 They're huge and abstract, and they're beautiful. Everything, anything that 0:05:36.839 --> 0:05:40.080 is a thing, comes up from the deepest level. Modern 0:05:40.080 --> 0:05:44.360 physics calls that level the unified field. The more your consciousness, 0:05:44.440 --> 0:05:48.200 your awareness is expanded, the deeper you go toward this source, 0:05:48.600 --> 0:05:53.400 and the bigger fish you can catch. So I think 0:05:53.440 --> 0:05:56.520 that's pretty cool. We can quibble about deep sea gigantism 0:05:56.600 --> 0:05:59.120 and the relative small size of some of the deep 0:05:59.160 --> 0:06:02.599 sea organisms been discussing here, but in general I will say, yes, 0:06:02.920 --> 0:06:05.640 these are the waters where you find organisms as deeply 0:06:05.680 --> 0:06:07.800 weird as a David Lynch film. 0:06:08.080 --> 0:06:10.440 If my hum sounded quibbli, it was more about the 0:06:11.000 --> 0:06:15.200 consciousness physics kind of connection there but no, I followed 0:06:15.240 --> 0:06:17.960 the metaphor absolutely with the deep sea biology. Yeah, the 0:06:18.000 --> 0:06:21.200 fish are certainly they've got to be more pure in 0:06:21.279 --> 0:06:24.120 whatever that means. It just feels right, and as we'll 0:06:24.240 --> 0:06:29.039 discuss today, probably more reeking. So are you ready for 0:06:29.080 --> 0:06:29.760 the snailfish. 0:06:30.040 --> 0:06:31.240 Let's talk about the snailfish. 0:06:31.520 --> 0:06:34.160 Okay. In part one of this series, one of the 0:06:34.160 --> 0:06:38.960 things we got into briefly was an experiment that was 0:06:39.040 --> 0:06:42.799 designed to monitor what would happen when a dolphin carcass 0:06:43.080 --> 0:06:47.080 was dropped into the Hadele zone. And as a reminder, 0:06:47.120 --> 0:06:50.800 the Hadl zone is the deepest forty five percent of 0:06:50.839 --> 0:06:54.640 the ocean in terms of vertical depth, often defined as 0:06:54.680 --> 0:06:58.760 the space deeper than six thousand meters from the surface. Now, 0:06:58.800 --> 0:07:01.960 while the Hadele zone is almost half of the ocean's 0:07:02.000 --> 0:07:05.640 maximum depth, it takes up less than one percent of 0:07:05.680 --> 0:07:09.600 the ocean's horizontal seafloor area because it's limited to these 0:07:09.640 --> 0:07:13.400 deep sea trenches and trench systems. So just in terms 0:07:13.480 --> 0:07:16.760 of depth, these regions are going way beyond even the 0:07:16.800 --> 0:07:19.800 abysstal depth of most of the world's ocean floor, but 0:07:20.000 --> 0:07:22.920 in terms of space taken up on the surface of 0:07:22.920 --> 0:07:27.320 the Earth, very limited they're little, tiny islands. So what 0:07:27.560 --> 0:07:30.840 this study wanted to examine was what happens when a 0:07:31.000 --> 0:07:34.480 large dead animal, in effect a huge cache of food, 0:07:35.040 --> 0:07:39.000 hits the floor of an ocean trench. This obviously happens 0:07:39.080 --> 0:07:42.520 naturally all the time, but we're not around to observe 0:07:42.560 --> 0:07:45.560 it from the beginning when it does happen, And so 0:07:45.640 --> 0:07:49.160 they staged these They staged these events where a dolphin 0:07:49.200 --> 0:07:51.480 carcass would fall down into hadel waters and then they 0:07:51.520 --> 0:07:55.680 would monitor what happens. One of the findings was of 0:07:55.720 --> 0:08:00.480 a kind of dynamic interaction pattern where first scavenger like 0:08:00.600 --> 0:08:04.280 impipod crustaceans would show up to eat the soft tissue 0:08:04.400 --> 0:08:08.680 of the dolphin's body. But how fast the crustaceans were 0:08:08.720 --> 0:08:12.840 able to consume that soft tissue was in part controlled 0:08:12.960 --> 0:08:16.520 by the presence of secondary predators who showed up to 0:08:16.680 --> 0:08:20.360 eat the amphipod scavengers who were eating the carcass. And 0:08:20.480 --> 0:08:23.680 one group of secondary predators mentioned in that research was 0:08:23.840 --> 0:08:27.320 the snailfish. So I wanted to explore more about these creatures, 0:08:27.360 --> 0:08:29.720 figure out what they are and what's special about them. 0:08:30.000 --> 0:08:34.000 Yeah, who's showing up this deep to interfere with the 0:08:34.040 --> 0:08:37.000 work of the initial scavengers. 0:08:36.840 --> 0:08:40.120 So snail fishes are any of more than one hundred 0:08:40.280 --> 0:08:45.880 known species of ray finned fishes grouped into the family Liparidy. 0:08:46.679 --> 0:08:48.959 They take different forms, but they tend to be small, 0:08:49.120 --> 0:08:51.880 with the largest growing only about a foot in length, 0:08:52.440 --> 0:08:56.880 and not all snailfish are deep trench dwellers. Various species 0:08:56.920 --> 0:09:00.679 can be found in habitats throughout the ocean. You'll find 0:09:00.760 --> 0:09:04.679 some of them in shallow, even shallow coastal waters, and 0:09:04.760 --> 0:09:09.440 some are in much deeper waters. In general, snailfish tend 0:09:09.640 --> 0:09:14.920 to be good at adapting to extreme environments, so a 0:09:14.960 --> 0:09:19.560 lot of snailfish species gravitate toward cold waters, such as 0:09:19.600 --> 0:09:23.600 in the Arctic and the Antarctic. A snailfish is often 0:09:23.720 --> 0:09:26.679 shaped sort of like a tadpole, so you can think 0:09:26.679 --> 0:09:30.600 of a big, bulbous head and a narrowing tail, and 0:09:30.720 --> 0:09:34.880 the deep dwelling varieties are often pale or translucent pink 0:09:34.920 --> 0:09:38.559 in color. So to picture a deep sea snailfish, imagine 0:09:38.600 --> 0:09:42.120 a fish in the form of a fat, pale, pink 0:09:42.200 --> 0:09:46.400 tadpole without scales on its body and instead a kind 0:09:46.400 --> 0:09:50.880 of loose, milky sea through skin, which is usually covered 0:09:51.000 --> 0:09:55.280 in a gelatinous slime, and occasionally that skin will be 0:09:55.400 --> 0:09:56.760 prickly or spiny. 0:09:57.480 --> 0:10:00.000 They're kind of like how you included a picture here 0:10:00.120 --> 0:10:02.640 of one, and I get a vibe of like a 0:10:02.800 --> 0:10:09.080 sort of a like a pink person faced monster super 0:10:09.080 --> 0:10:11.640 baby that lives in the deep. You know, like they're 0:10:12.400 --> 0:10:18.400 they're weirdly kind of cute. You want to attribute various 0:10:18.440 --> 0:10:22.439 emotional states to them, And I was looking, right, I 0:10:22.480 --> 0:10:24.679 found other Like I found various headlines that refer to 0:10:24.760 --> 0:10:27.439 them as cuties. So it's not just like me and 0:10:27.520 --> 0:10:31.559 my own like weird sensibilities. Like a lot of people 0:10:31.559 --> 0:10:33.480 seem to think that snailfish are kind of cute. 0:10:34.000 --> 0:10:35.480 Let's put a pin in that. We'll come back to 0:10:35.520 --> 0:10:37.080 how cute they are. But I think you're right. I 0:10:37.080 --> 0:10:40.320 think they are at once cute and gross, which is 0:10:40.320 --> 0:10:41.600 the best kind of cute. 0:10:41.920 --> 0:10:44.840 Yeah, yeah, I mean, babies have been nailing that for ages. 0:10:45.480 --> 0:10:49.000 So there's a lot that is interesting about snail fishes. 0:10:49.000 --> 0:10:53.120 But snailfishes have one very impressive credential that is relevant 0:10:53.120 --> 0:10:56.439 to our topic today, and that is, at least as 0:10:56.480 --> 0:11:00.320 of April twenty twenty three, a snailfish whole. It's the 0:11:00.360 --> 0:11:03.720 record for the deepest diving fish that has ever been 0:11:03.840 --> 0:11:06.800 directly observed by humans. And I do have to put 0:11:06.800 --> 0:11:09.640 an asterisk on there, because I was reading in one 0:11:09.720 --> 0:11:15.559 article there are claimed observations of fish that have been 0:11:15.640 --> 0:11:19.520 cited lower but like, not directly imaged or documented, And 0:11:20.040 --> 0:11:23.720 for various theoretical reasons we'll get into those other claims 0:11:23.800 --> 0:11:27.880 seem unlikely to be true. But so yeah, I guess 0:11:27.880 --> 0:11:31.000 we'll put a question mark on this the best confirmed 0:11:31.080 --> 0:11:33.520 sighting of the deepest diving fish ever. 0:11:33.960 --> 0:11:35.600 Yeah, because there are a lot of things that are 0:11:35.640 --> 0:11:39.680 possible down there, just based on how little relatively we 0:11:39.760 --> 0:11:41.680 know about it. And you can go all the way 0:11:41.679 --> 0:11:44.120 back to you know, we talked in past episodes about 0:11:44.120 --> 0:11:48.160 the observations on the bath sphere, you know, and the 0:11:48.240 --> 0:11:52.000 varying degrees to which those reported observations have matched up 0:11:52.120 --> 0:11:55.040 or haven't matched up with subsequent human discoveries. 0:11:55.320 --> 0:11:59.040 Yeah, that's right. But as far as well documented cases go, 0:11:59.240 --> 0:12:01.920 this is the deepest anybody's ever seen a fish. And 0:12:02.000 --> 0:12:05.040 note that this is not the deepest organism or the 0:12:05.080 --> 0:12:08.600 deepest animal ever observed in a reliable way, just the 0:12:08.640 --> 0:12:13.560 deepest fish now here. I'm relying on a University of 0:12:13.559 --> 0:12:18.560 Western Australia press release about this discovery, which was made 0:12:18.600 --> 0:12:21.920 by a team of scientists from Australia and from Japan. 0:12:22.720 --> 0:12:25.200 And I'm also relying on an April twenty twenty three 0:12:25.320 --> 0:12:28.840 right up in Scientific American by Tom metcalf. So the 0:12:28.960 --> 0:12:32.680 location of this record breaking discovery was within the izu 0:12:32.920 --> 0:12:36.800 Ogasawara Trench, which is south of Japan, at a depth 0:12:36.840 --> 0:12:41.479 of eighty three hundred and thirty six meters. The previous 0:12:41.520 --> 0:12:45.160 record before this for the deepest confirmed sighting of a 0:12:45.200 --> 0:12:48.480 fish was held by a Mariana snail fish more on 0:12:48.480 --> 0:12:51.800 that species and a bit at eighty one hundred and 0:12:51.880 --> 0:12:55.160 seventy eight meters depth, and that was within the Mariana 0:12:55.160 --> 0:12:58.240 Trench back in twenty seventeen. This new find, which was deeper, 0:12:58.360 --> 0:13:01.240 was in this other trench south of Japan, izu Ugasawara. 0:13:02.320 --> 0:13:05.240 This new record holding fish in twenty twenty three beat 0:13:05.280 --> 0:13:07.920 the previous record by one hundred and fifty eight meters 0:13:07.960 --> 0:13:10.280 and as far as I can tell, the observation still 0:13:10.320 --> 0:13:14.520 has not been surpassed. This sighting took place during an 0:13:14.559 --> 0:13:18.200 exploration of several trench environments in the Pacific around Japan 0:13:18.320 --> 0:13:22.480 in twenty twenty two. The expedition was conducted by a 0:13:22.520 --> 0:13:27.240 research ship called the DSSV Pressure Drop, so the research 0:13:27.280 --> 0:13:31.040 team used baited cameras plunked down into the deepest parts 0:13:31.040 --> 0:13:33.720 of several trenches, and at one of these baited cameras, 0:13:33.760 --> 0:13:37.480 at this kind of unlikely depth of again eighty three 0:13:37.559 --> 0:13:41.319 hundred and thirty six meters, a fish appeared. Interestingly, this 0:13:41.360 --> 0:13:46.040 solitary deep diver was a relatively small juvenile snail fish, 0:13:46.440 --> 0:13:49.960 which seems to be able to venture a bit deeper 0:13:50.000 --> 0:13:52.720 than the normal adult range for its species. More on 0:13:52.760 --> 0:13:56.520 that in a moment. The fish in question was idd 0:13:56.679 --> 0:14:02.960 as the genus Pseudoliparus, but the exact species couldn't be verified. Also, 0:14:03.120 --> 0:14:05.920 just two days after the deep fish was caught on camera, 0:14:06.320 --> 0:14:09.760 two more snail fish were actually caught like trapped in 0:14:09.840 --> 0:14:13.199 baited traps at a depth of eighty twenty two meters 0:14:13.600 --> 0:14:16.040 and brought up and rapidly preserved. In this case, the 0:14:16.080 --> 0:14:18.920 fish were identified down to the species level, and these 0:14:18.920 --> 0:14:23.000 were pseudo lyperis at Belle Yavy and rob I attached 0:14:23.040 --> 0:14:25.280 a picture from the s expedition for you to look at, 0:14:25.280 --> 0:14:29.000 with several of these snail fishes crowding around a baited trap. 0:14:29.000 --> 0:14:31.080 I'm not sure quite what that is on the trap. 0:14:31.080 --> 0:14:34.360 It might be might be a mackerel or something, but yeah, 0:14:34.600 --> 0:14:36.360 some kind of bait they've got there. And I think 0:14:36.400 --> 0:14:40.440 the idea is that the dead fish attracts the crustaceans 0:14:40.520 --> 0:14:43.720 probably amphipods that come to eat the dead fish, and 0:14:43.760 --> 0:14:48.280 then the snail fish show up to eat the scavengers. Yeah. 0:14:48.360 --> 0:14:50.680 Yeah, And I have to say a little kind of 0:14:50.760 --> 0:14:56.400 cute here looks looks absolutely boopable. And for an example 0:14:57.000 --> 0:15:01.200 of a headline that invokes the cuteness, Atlas Obscura has 0:15:01.240 --> 0:15:04.040 an article about this with the title the world's deepest 0:15:04.080 --> 0:15:05.720 living fish is surprisingly cute. 0:15:06.320 --> 0:15:09.080 It is. It is kind of cute. Again, it's kind 0:15:09.080 --> 0:15:11.920 of on the boundary of cute and ugly or cute 0:15:11.920 --> 0:15:14.560 engross kind of in the way that we talked about 0:15:14.560 --> 0:15:17.400 this with some of the creatures that come to the 0:15:17.440 --> 0:15:20.240 bathhouse in Spirited Away. You know, they're right on that 0:15:20.360 --> 0:15:22.760 line there, where like are they ugly and gross or 0:15:22.800 --> 0:15:25.880 are they adorable? It's a tough call. 0:15:26.440 --> 0:15:29.080 And I think this is compounded by the fact that 0:15:29.240 --> 0:15:33.120 some of the more famous deep sea fish, though to 0:15:33.160 --> 0:15:37.080 be clear fish that don't dive down as deep as 0:15:37.400 --> 0:15:40.240 the snail fish, but the more famous deep sea fish, 0:15:40.240 --> 0:15:41.560 one of which we'll get to in a bit here, 0:15:42.440 --> 0:15:46.600 are generally regarded as like severely grotesque and like aggressively 0:15:46.760 --> 0:15:50.800 weird looking and not cute. So it can come as 0:15:50.840 --> 0:15:52.120 a bit of a shock where people are like, you 0:15:52.120 --> 0:15:54.040 want to see the deepest fish ever. You're like, yeah, 0:15:54.080 --> 0:15:56.000 I'm in for a horror show, and then you look 0:15:56.000 --> 0:15:58.320 at it and you're like, well, you know, oh, quite 0:15:58.400 --> 0:16:01.080 quite cute when I take into account expectations. 0:16:01.440 --> 0:16:04.400 Give them a snuggle now. On the other hand, I 0:16:04.480 --> 0:16:07.360 did also come across an AP article by a writer 0:16:07.520 --> 0:16:11.680 named Nick Perry which was covering some hatel snailfish discoveries, 0:16:12.160 --> 0:16:15.520 and in that article it said that deep sea trench 0:16:15.600 --> 0:16:19.120 snailfish look like quote guts stuffed in cellophane. 0:16:20.280 --> 0:16:24.040 Well, I mean, aren't we all really, but okay, fair 0:16:24.120 --> 0:16:26.520 enough they do. Also, yeah, there is that they do 0:16:26.600 --> 0:16:30.080 look like little pink bags of guts. I guess I 0:16:30.120 --> 0:16:30.600 can see it. 0:16:31.000 --> 0:16:33.640 So I was thinking about the depth of this one 0:16:33.680 --> 0:16:37.000 record holder again, that's eight three hundred and thirty six meters. 0:16:37.040 --> 0:16:40.800 That is so deep. That's like five point seventeen miles down. 0:16:41.520 --> 0:16:44.400 So this is a five mile fish, and according to 0:16:44.400 --> 0:16:47.840 the researchers who led this team, there are strong reasons 0:16:47.880 --> 0:16:50.680 for thinking that if we ever find a fish living 0:16:50.720 --> 0:16:54.360 deeper than this, it won't be by much. And again, 0:16:54.560 --> 0:16:57.680 this limit applies not necessarily to animals. You'll probably find 0:16:58.400 --> 0:17:01.560 crustaceans and other types of an animals even deeper. But fish, 0:17:02.160 --> 0:17:04.480 they're saying, you're probably not going to find one much 0:17:04.520 --> 0:17:07.439 deeper than this, and that's because there appear to be 0:17:07.680 --> 0:17:14.040 biochemical circumstances that place a pretty rigid theoretical maximum depth 0:17:14.800 --> 0:17:18.160 on how far you can go if you are a fish. Now, 0:17:18.200 --> 0:17:21.479 why would that be? How would that work? Well? Fish 0:17:21.520 --> 0:17:25.119 that live under extremely high pressure are only able to 0:17:25.200 --> 0:17:30.840 do so because of compounds in their cells called osmolites, 0:17:31.480 --> 0:17:34.639 such as the molecule you might have read about this before, 0:17:35.320 --> 0:17:41.600 trimethylamine in oxide or TMAO. Osmolites like TMAO act as 0:17:41.880 --> 0:17:46.920 protein stabilizers. So within an animal's cells, you can think 0:17:46.960 --> 0:17:50.640 of proteins as sort of the machine parts that make 0:17:50.840 --> 0:17:56.640 most cellular functions possible. Proteins need to maintain their particular 0:17:56.880 --> 0:18:00.360 folded structure in order to do what they do, much 0:18:00.400 --> 0:18:03.160 the same way that the parts in a machine need 0:18:03.240 --> 0:18:06.199 to maintain their shape and the way they move, or 0:18:06.240 --> 0:18:10.000 the machine will stop working. But physical stresses like heat 0:18:10.080 --> 0:18:14.240 and pressure can denature and deform proteins or prevent them 0:18:14.280 --> 0:18:17.560 from folding correctly. And this is one of the difficulties 0:18:17.600 --> 0:18:21.359 of life in the high pressure conditions of the deep sea. 0:18:21.600 --> 0:18:25.560 Hydrostatic pressure does violence to the proteins in your cells, 0:18:26.000 --> 0:18:30.720 and so high osmolite concentrations are an adaptation deep sea 0:18:30.760 --> 0:18:34.520 animals use to get around this problem to stabilize their 0:18:34.560 --> 0:18:39.760 proteins against the high pressure environment and basically keep the 0:18:39.800 --> 0:18:42.840 machine parts stable and working the way they're supposed to. 0:18:43.960 --> 0:18:46.680 And one interesting side note that I was reading about 0:18:46.960 --> 0:18:50.840 dig you know that osmolites, these compounds that stabilize proteins, 0:18:50.960 --> 0:18:56.960 are the main cause of the fishy smell of decomposing seafood. 0:18:57.119 --> 0:18:59.639 So as a dead marine organism, you know, like a 0:18:59.680 --> 0:19:02.720 fish that's not frozen, it starts to rot in the sun, 0:19:03.400 --> 0:19:09.240 begins to decay. Bacteria break down the trimethylamine inoxide or 0:19:09.240 --> 0:19:15.040 TMAO into volatile trimethylamine, which smells fishy. That is the 0:19:15.080 --> 0:19:19.600 main part of what the fishy smell is interesting. Come 0:19:19.640 --> 0:19:22.639 back to that in the second. So marine biologists have 0:19:22.800 --> 0:19:25.679 found that as you go deeper and deeper in the 0:19:25.680 --> 0:19:29.960 ocean and the pressure gets greater, the fish species that 0:19:30.040 --> 0:19:34.920 live at each depth zone have higher concentrations of osmolites. 0:19:35.080 --> 0:19:40.640 Makes sense, right, That trend continues until you reach the 0:19:40.680 --> 0:19:46.040 maximum possible concentration of osmolites in the body tissues, which 0:19:46.119 --> 0:19:49.960 according to theoretical models, would be the concentration that would 0:19:50.000 --> 0:19:55.240 allow fish to survive at about eighty four hundred meters. So, 0:19:55.520 --> 0:19:58.439 according to this model, the fish that was observed in 0:19:58.520 --> 0:20:03.000 this expedition like eighty three hundred and something meters. It 0:20:03.040 --> 0:20:07.560 was within about seventy meters of the theoretical limit of 0:20:07.720 --> 0:20:13.239 fish biology. You basically can't get enough osmolytes into the 0:20:13.280 --> 0:20:17.000 cells to stabilize proteins any deeper than this, which is 0:20:17.040 --> 0:20:20.280 why researchers don't expect to find a fish much deeper 0:20:20.320 --> 0:20:21.040 than this one. 0:20:21.359 --> 0:20:23.320 You know, this makes me think back to that paper 0:20:23.359 --> 0:20:27.280 were discussed in the first episode by Daskuupta. At all 0:20:27.520 --> 0:20:30.320 depth in predation regulate consumption of dolphin carcasses in the 0:20:30.359 --> 0:20:36.920 hatal zone. Again, they dropped two dolphin carcasses at one 0:20:36.920 --> 0:20:40.960 of the sites snailfish were interfering with the initial scavengers, 0:20:40.960 --> 0:20:44.520 and on the other site they were not. I'm going 0:20:44.600 --> 0:20:46.560 to have to go back and look at the depths 0:20:46.680 --> 0:20:49.520 that they were discussing there and see, because it makes 0:20:49.520 --> 0:20:52.240 me wonder, well, did maybe the snailfish didn't arrive at 0:20:52.280 --> 0:20:54.400 one of the drop sites because it was too deep 0:20:54.440 --> 0:20:57.280 for them? And to be clear, this would this would 0:20:57.359 --> 0:21:00.639 not be out of keeping with the general inclusions that 0:21:00.680 --> 0:21:04.160 were made in that paper, which were that the exact 0:21:04.520 --> 0:21:07.000 like shape of the whale fall site is going to 0:21:07.119 --> 0:21:10.919 depend on the depth and on the you know, the 0:21:10.920 --> 0:21:13.520 the organisms that are in its vicinity. So again I'm 0:21:13.520 --> 0:21:14.480 gonna have to go back and look. 0:21:14.400 --> 0:21:16.800 At that, right, So it could be that if a 0:21:17.000 --> 0:21:19.880 if a whale carcass falls in a deeper zone that's 0:21:19.960 --> 0:21:23.200 outside of the range you know, it's too deep for fishes, 0:21:23.240 --> 0:21:27.520 basically for predatory fishes, then the scavenging amphipods have you know, 0:21:27.600 --> 0:21:40.679 easier time of it. Yeah, exactly. Now there's something I 0:21:40.720 --> 0:21:44.200 wanted to come back to about the fact that the 0:21:44.240 --> 0:21:50.280 breakdown of osmolites, specifically TMAO, causes the fishy smell that 0:21:50.320 --> 0:21:56.080 we associate with decaying seafood. Pairing that fact with the 0:21:56.560 --> 0:22:02.480 increasing osmolite concentrations that go up with depth, the depth 0:22:02.520 --> 0:22:05.240 of a fish's natural habitat. If you put those two 0:22:05.240 --> 0:22:10.240 facts together, that made me wonder, do abystle or hatel 0:22:10.440 --> 0:22:14.520 fish smell the worst? Like, would the deeper fish be 0:22:14.600 --> 0:22:17.320 the most foul smelling of all the fishiest of all 0:22:17.400 --> 0:22:20.159 fishy smells. I was looking to see if there was 0:22:20.200 --> 0:22:23.720 any any research into this. I don't know if there's 0:22:23.720 --> 0:22:27.000 direct research into this exact question, but I did find 0:22:27.119 --> 0:22:31.320 a marine biologist commenting on it. So I found a 0:22:31.359 --> 0:22:35.000 twenty twenty four ap article by Nick Perry about research 0:22:35.119 --> 0:22:39.200 on hal snailfish, and this article cites a marine biologist 0:22:39.359 --> 0:22:43.879 named Paul Yancey of Whitman College in Washington State, who 0:22:43.920 --> 0:22:47.320 directly says, yes, indeed, the deeper the fish lives, the 0:22:47.400 --> 0:22:52.080 worse it will stink. So hatel snailfish quite likely have 0:22:52.240 --> 0:22:55.600 like the ultimate fish smell. They've got to be a contender. 0:22:55.600 --> 0:22:57.920 I don't know if anybody's tested this directly, but it 0:22:58.000 --> 0:23:01.080 seems a priori that would be the assumption that they 0:23:01.080 --> 0:23:04.880 are the kings of stink. I also have to mention 0:23:04.960 --> 0:23:07.720 this article was the source of that comparison of trench 0:23:07.760 --> 0:23:10.879 snailfish to guts wrapped in cellophane. And there was another 0:23:10.960 --> 0:23:13.840 good one in here, not directly from the author, but 0:23:13.880 --> 0:23:18.119 it quotes a New Zealand marine ecologist and named Ashley Rodin, 0:23:18.640 --> 0:23:21.960 who caught a number of hadel snailfish from more than 0:23:22.000 --> 0:23:25.640 seven thousand meters depth in twenty twenty three. And Rodin 0:23:25.760 --> 0:23:29.879 describes holding on to one of these fish after bringing 0:23:29.920 --> 0:23:32.520 it up from I think a mackerel bated trap, and 0:23:32.640 --> 0:23:36.119 Rodin says, quote, it was like a water filled condom, 0:23:36.680 --> 0:23:40.320 a sloppy, gelatinous mass that moves between your hands. It 0:23:40.400 --> 0:23:43.080 was very cool and very strange to see its organs 0:23:43.280 --> 0:23:47.840 and everything. But anyway, back to the discovery of the 0:23:47.840 --> 0:23:51.600 deepest fish ever from the trench south of Japan. According 0:23:51.680 --> 0:23:56.440 to Professor Alan Jamison, the chief scientist of the expedition, quote, 0:23:56.760 --> 0:23:59.480 the real take home message for me is not necessarily 0:23:59.520 --> 0:24:02.560 that they are living at eighty three hundred and thirty 0:24:02.600 --> 0:24:05.760 six meters, but rather we have enough information on this 0:24:05.920 --> 0:24:09.600 environment to have predicted that these trenches would be where 0:24:09.640 --> 0:24:13.080 the deepest fish would be. In fact, until this expedition, 0:24:13.480 --> 0:24:16.240 no one had ever seen nor collected a single fish 0:24:16.320 --> 0:24:19.840 from this entire trench. Now, next, I want to look 0:24:19.840 --> 0:24:23.320 at a particular species of hadel snailfish. This is the 0:24:23.480 --> 0:24:31.000 Marianna snailfish or pseudo Lyparis sweary i SwRI. It's one 0:24:31.040 --> 0:24:34.320 of these deep adapted species. It's believed to grow about 0:24:34.400 --> 0:24:36.640 a foot long. And I'm going to say this one 0:24:36.680 --> 0:24:39.840 looks even more tadpoley than most of them do. I've 0:24:39.840 --> 0:24:41.760