WEBVTT - Interview Interlude Playlist, Part 8: Marah Hardt 0:00:02.960 --> 0:00:06.080 Welcome to Stuff to Blow your Mind from housetop works 0:00:06.120 --> 0:00:16.280 dot com. For corals that live beneath to see their 0:00:16.400 --> 0:00:20.119 days are marked by celibacy, excepting one night when the 0:00:20.160 --> 0:00:23.880 moon is just right, they engage in a million strong orgy. 0:00:24.520 --> 0:00:27.400 But for them to secure the prize, corals must be 0:00:27.600 --> 0:00:31.120 ever wise, for there is a catch. In order to dispatch, 0:00:31.720 --> 0:00:38.519 their orgasms must be synchronized. Hey, welcome to stuff to 0:00:38.520 --> 0:00:40.279 blow your mind. My name is Robert Lamb and I'm 0:00:40.360 --> 0:00:43.480 Christian Seger. And that may have sounded like the Dr. 0:00:43.600 --> 0:00:47.600 Seuss version of Coral Sex, but actually it was a 0:00:47.840 --> 0:00:51.080 bit from mar j Hart Sex in the Sea, which 0:00:51.080 --> 0:00:53.200 we've talked about on the show before and we're gonna 0:00:53.200 --> 0:00:55.360 do again this episode. Yeah, it's a great book. We 0:00:55.360 --> 0:00:57.960 talked about it in our previous episode that was devoted 0:00:58.000 --> 0:01:00.800 to the weird sexual ways of the Asso Docks, the 0:01:00.840 --> 0:01:06.080 bone Worm, the bone eating worm of Ocean, And in 0:01:06.120 --> 0:01:09.959 that episode, Corals came up and we said, hey, there's 0:01:09.959 --> 0:01:11.920 a lot of stuff to discuss here. Why don't we 0:01:11.959 --> 0:01:13.760 just have you back on in the summer, We'll do 0:01:13.800 --> 0:01:16.399 a whole episode on corals, and we wanted to time 0:01:16.400 --> 0:01:19.480 it for this summer because we're in corals spawning season 0:01:19.640 --> 0:01:22.400 right now, as mar will discuss with us. So the 0:01:22.440 --> 0:01:24.280 way this episode is going to be set up is 0:01:24.480 --> 0:01:26.880 we're gonna give you just like a brief primer on 0:01:27.040 --> 0:01:31.240 corals and their reproduction, and then we're gonna talk tomorrow 0:01:31.319 --> 0:01:34.039 because she's the expert on this, and we really get 0:01:34.080 --> 0:01:38.480 into all the details, especially because Mara just got back 0:01:38.800 --> 0:01:41.920 a week ago from the what sounds like the world's 0:01:41.959 --> 0:01:46.160 biggest conference on coral ecology, so she had a lot 0:01:46.200 --> 0:01:48.480 of like groundbreaking news for us. Yeah, some of some 0:01:48.520 --> 0:01:50.880 of it rather sobering, but some of it very exciting 0:01:50.920 --> 0:01:52.960 as well. You know, I think one of the big 0:01:53.080 --> 0:01:54.920 tay comes here that I got out of the research 0:01:55.040 --> 0:01:57.680 that I hope that that that listeners get to is 0:01:57.720 --> 0:02:00.760 this idea that and I feel like this sometimes lost 0:02:00.840 --> 0:02:05.720 in our media absorption of the information, is that coral 0:02:05.760 --> 0:02:10.560 reefs corals are not just like a background organism. They 0:02:10.600 --> 0:02:15.400 are the bedrock of these ecological systems, making life possible 0:02:15.760 --> 0:02:18.880 in areas that would otherwise just be barren and lifeless. 0:02:19.280 --> 0:02:21.560 I think for a lot of people, the way that 0:02:21.639 --> 0:02:24.040 they think about them is almost as if that they're 0:02:24.080 --> 0:02:27.519 like plant life and I have to admit, even for myself, 0:02:27.639 --> 0:02:30.120 until we sat down and really did the research for 0:02:30.160 --> 0:02:34.360 this episode, I didn't quite understand their anatomy. And so 0:02:34.600 --> 0:02:36.880 maybe that we can sort of help set that up 0:02:36.919 --> 0:02:41.120 for the audience for you out there. And uh, then 0:02:41.280 --> 0:02:44.800 when we talk tomorrow about just how dire the consequences 0:02:44.840 --> 0:02:48.400 are right now for coral ecology, that'll, you know, drive 0:02:48.480 --> 0:02:52.600 home the importance of trying to help these critters out. Yeah. 0:02:52.639 --> 0:02:54.399 I feel like at times we almost have an amateur 0:02:54.440 --> 0:02:57.720 aquarium um view of it, where we think, oh, I'm 0:02:57.760 --> 0:03:00.480 the fish is what I'm excited about. Anything else is 0:03:00.520 --> 0:03:02.120 just like a plant that we throw in, or maybe 0:03:02.160 --> 0:03:05.639 like a ceramic Buddha that flows to the bottom right. 0:03:05.800 --> 0:03:07.920 And then in looking at the coral reefs to we 0:03:07.919 --> 0:03:09.959 we see the finished picture. We see the corals, we 0:03:10.040 --> 0:03:12.640 see all the fish and all the creatures. I feel 0:03:12.639 --> 0:03:15.400 that it's kind of like looking at Las Vegas and 0:03:15.440 --> 0:03:17.720 seeing all this life, all the light and the fountains 0:03:17.760 --> 0:03:19.680 and saying, look at that life is just splendid there. 0:03:19.680 --> 0:03:25.240 It's just going just going splendidly without realizing that without Hoover, damn, 0:03:25.360 --> 0:03:28.680 without the with the necessary um um, you know, water 0:03:28.760 --> 0:03:32.280 system in place, there would be no life there at all. Yep, yeah, exactly. 0:03:32.400 --> 0:03:38.480 Corals are a hugely important ecosystem for and this is 0:03:38.480 --> 0:03:42.680 a stat a quarter of all marine fish species, so 0:03:42.800 --> 0:03:46.280 they're very important. They're not just pretty structures that happen 0:03:46.320 --> 0:03:50.040 to be underwater. They also benefit us, and by us, 0:03:50.040 --> 0:03:54.880 I mean human beings by buffeting coastal regions from strong waves. 0:03:55.120 --> 0:03:57.960 And I'll get into it a little bit further. Uh, 0:03:58.040 --> 0:04:01.760 they promote our economy and huge way is too. So Uh, 0:04:01.960 --> 0:04:05.520 these are super important. And they have totally weird, bizarre 0:04:05.680 --> 0:04:08.320 orgy sex too, which is fun to talk about. So 0:04:08.400 --> 0:04:11.120 let's get into it. Let's talk about coral reefs and 0:04:11.160 --> 0:04:14.880 coral polyps and what's the story here. So they're actually 0:04:15.520 --> 0:04:19.720 made of two things. Now, when we think about corals, 0:04:19.760 --> 0:04:21.640 or at least the way I did, I always thought 0:04:21.640 --> 0:04:26.640 of just the limestone skeletons, right, these these formations. But 0:04:26.760 --> 0:04:32.600 corals themselves are actually tiny little polyps. Uh, and they 0:04:32.720 --> 0:04:38.320 excrete the limestone that creates these skeletons. Now, I said earlier, 0:04:38.400 --> 0:04:41.000 we talk a lot about sort of the dire threats 0:04:41.000 --> 0:04:44.039 that they're facing. They're actually being destroyed at a rate 0:04:44.160 --> 0:04:46.840 that will see seventy of them gone in less than 0:04:46.920 --> 0:04:49.080 forty years. That was one stat that I read when 0:04:49.080 --> 0:04:52.800 we just talked tomorrow. She said ten percent of all 0:04:52.880 --> 0:04:57.599 reefs are already permanently lost are expected to be lost 0:04:57.640 --> 0:05:01.400 in the next few decades. So that's that's the lot um. 0:05:01.400 --> 0:05:03.359 And why is that? Well, we talked to her about 0:05:03.360 --> 0:05:06.360 that as well. But real quick primer, if you even 0:05:06.440 --> 0:05:10.000 shift one degree of temperature in the water that they're in, 0:05:10.040 --> 0:05:13.480 it can damage them, causing them to expel the algae 0:05:13.520 --> 0:05:18.560 that's within them, which they have a symbiotic relationship with 0:05:19.120 --> 0:05:21.880 this and this is the key to their ability to 0:05:22.080 --> 0:05:26.760 colonize these these rather hostile regions. Absolutely, yeah uh. And 0:05:26.800 --> 0:05:31.760 they're also facing external threats from hurricanes, predators, pollution, over fishing, 0:05:32.200 --> 0:05:35.640 and from us. Just talking tomorrow, she did a great 0:05:35.760 --> 0:05:38.640 job of explaining what a bleaching event is, which is 0:05:39.160 --> 0:05:43.599 the actual impact of these temperature changes causing the algae 0:05:43.600 --> 0:05:47.040 to separate from the coral polyps and basically either killing 0:05:47.080 --> 0:05:49.040 them or making it so that they don't have enough 0:05:49.120 --> 0:05:53.800 energy to reproduce. So why should you care? Here's why. 0:05:53.920 --> 0:05:56.360 If you want just a purely selfish reason, If all 0:05:56.400 --> 0:06:00.000 you care about is your own well being. It's import 0:06:00.320 --> 0:06:06.760 to our economy. Actually, uh, they provide jobs for fishing, construction, 0:06:07.240 --> 0:06:11.440 and believe it or not, pharmaceuticals. There's an estimated three 0:06:11.520 --> 0:06:15.640 hundred and seventy five billion dollars a year that come 0:06:15.680 --> 0:06:19.479 out of coral reefs, So that's pretty huge. We don't 0:06:19.520 --> 0:06:22.279 want to lose these, even on just like a purely 0:06:22.360 --> 0:06:26.840 selfish monetary level, outside of any kind of like altruistic 0:06:26.880 --> 0:06:31.159 ecological level. Okay, alright, let's roll into the basic biology 0:06:31.480 --> 0:06:35.520 of corals. Okay, So corals were originally thought to be planted, 0:06:35.600 --> 0:06:37.520 so I wasn't alone in that. And if you're out 0:06:37.520 --> 0:06:40.280 there and you thought the same thing, scientists thought that too. 0:06:40.400 --> 0:06:44.200 But they're actually tiny, little soft bodied creatures and their 0:06:44.240 --> 0:06:47.840 carnivores too. They're fixed to one spot as a polyp, 0:06:47.880 --> 0:06:51.159 and it's they basically have these barbed stinging cells that 0:06:51.200 --> 0:06:54.520 are called nematocysts, and these are what they used to 0:06:54.560 --> 0:06:58.160 capture food, like little tiny fish or zoo plankton. They're 0:06:58.200 --> 0:07:01.680 only about three millimeters long, and they grow to become 0:07:01.720 --> 0:07:05.080 reefs that stretched from miles. When they combine together with 0:07:05.120 --> 0:07:09.480 their limestone and their huge colonies, the polyps themselves are 0:07:09.560 --> 0:07:13.000 basically and and Mara says this as well. They're basically 0:07:13.040 --> 0:07:16.040 just a gut with a mouth that's surrounded by tentacles. 0:07:16.040 --> 0:07:18.640 So it's like a teeny tiny little Lovecraft monster. Yeah, 0:07:18.720 --> 0:07:21.520 the thing that you discredited as a mere plant turned 0:07:21.520 --> 0:07:27.080 out to be closer to your heart exactly. Now, we 0:07:27.160 --> 0:07:29.720 talked about the symbiosis that they have with algae. Well, 0:07:29.720 --> 0:07:32.800 the algae that they live together with are called zoos 0:07:32.880 --> 0:07:36.360 in Theelli and uh Um I believe Mara says that 0:07:36.400 --> 0:07:39.360 it's okay to refer to them as zooks. That's that's 0:07:39.400 --> 0:07:42.800 kind of like the the in crowd nickname that they have. 0:07:43.280 --> 0:07:46.400 But they're an algae that lives inside the cell walls 0:07:46.520 --> 0:07:50.560 of corals, and the algae provides them with byproducts of 0:07:50.600 --> 0:07:55.720 photosynthesis that then feeds the polyp. The polyps subsequently shelters 0:07:55.760 --> 0:07:58.320 the algae and provides them with the chemicals that they 0:07:58.360 --> 0:08:04.720 need for photosynthesis. So up to of the algaees energy 0:08:04.840 --> 0:08:07.320 is transferred into the polyps. So you can see now 0:08:07.360 --> 0:08:09.520 why if that algae is forced to flee because of 0:08:09.560 --> 0:08:14.680 coral bleaching, why the polyp would be weakened significantly. Okay, 0:08:14.720 --> 0:08:17.960 so this energy helps them to do things like produce 0:08:18.040 --> 0:08:21.520 the limestone that they are covered in, and that's made 0:08:21.520 --> 0:08:25.120 of calcium carbonate. They secrete it from their base and 0:08:25.160 --> 0:08:28.000 it creates a protective skeleton that they basically hide in 0:08:28.120 --> 0:08:32.960 from predators. And because they rarely exist alone, they also 0:08:33.160 --> 0:08:37.000 joined together with other polyps as a colony and act 0:08:37.160 --> 0:08:41.320 basically like a single organism colonies. Now I just told 0:08:41.360 --> 0:08:45.920 you one polyp is like three millimeters. Colonies can weigh tons. 0:08:45.960 --> 0:08:49.400 These things are huge, uh, and they have many branches 0:08:49.440 --> 0:08:53.400 that form out, and this is what we call reefs. Okay, 0:08:53.440 --> 0:08:55.200 so let's get to the nitty gritty of what this 0:08:55.280 --> 0:08:58.840 is about, all right. That today's episode is about coral 0:08:59.200 --> 0:09:02.960 sex re production. And they reproduce in two ways, or 0:09:03.000 --> 0:09:06.000 they grow in two ways. The first is they just 0:09:06.120 --> 0:09:09.400 keep adding limestone to their base and they secrete upward 0:09:09.400 --> 0:09:13.120 and outward, right, so the reef gets bigger that way. 0:09:13.440 --> 0:09:16.319 The main way what we end up talking to Ma 0:09:16.679 --> 0:09:21.480 about primarily is reproduction, and they produce a sexually and 0:09:21.679 --> 0:09:25.840 sexually a sexual reproduction is where they divide and create 0:09:26.000 --> 0:09:29.280 identical clones of themselves. And we're gonna talk tomorrow about 0:09:29.280 --> 0:09:31.640 why that's not always such a good thing. But they 0:09:31.640 --> 0:09:35.440 can basically make fragments of themselves and then reattached to 0:09:35.600 --> 0:09:38.240 different parts of a reef and then continue to grow. 0:09:39.800 --> 0:09:43.160 Sexual reproduction this is the weird stuff, and this is 0:09:43.160 --> 0:09:45.440 what we spend a lot of time talking with Mara about. 0:09:46.240 --> 0:09:48.640 This is basically when they send out their eggs and sperm, 0:09:48.760 --> 0:09:52.160 and it works like this. Their sexual reproduction only occurs 0:09:52.240 --> 0:09:55.320 once a year, shortly after a full moon. It's called 0:09:55.360 --> 0:09:58.880 broadcast spawning, and this is where the colonies release a 0:09:58.960 --> 0:10:02.760 cloud of rightly colored eggs and sperm into the ocean. 0:10:03.240 --> 0:10:06.160 And these bundles are not only buoyant, but they are 0:10:06.200 --> 0:10:10.280 also attached to their parental polyps by like umbilical strings 0:10:10.280 --> 0:10:13.720 of mucus. Mara describes it as being like this pink 0:10:13.880 --> 0:10:17.280 cloud of snow flakes floating upward. It it sounds kind 0:10:17.280 --> 0:10:19.920 of beautiful, actually, if if you get the opportunity to 0:10:20.000 --> 0:10:23.400 see it. Shrimp and worms that are around there part 0:10:23.440 --> 0:10:25.920 of the ecology of the coral reef. They're gonna eat 0:10:25.960 --> 0:10:28.880 this stuff as it floats upward. But but basically the 0:10:28.960 --> 0:10:32.920 polyps turn pink right before they release it. One of 0:10:32.960 --> 0:10:35.440 the articles that I read for research on this described 0:10:35.480 --> 0:10:39.400 it as milky, pink waters. The eggs are then ejected, 0:10:39.440 --> 0:10:41.640 they float upward to the surface and they wait to 0:10:41.679 --> 0:10:45.240 get fertilized. But they have nothing to protect them, so 0:10:45.280 --> 0:10:47.880 the first twelve hours that they're out there in development, 0:10:47.920 --> 0:10:52.200 they're real fragile. Mara actually describes these globules. She says 0:10:52.240 --> 0:10:54.040 this in her book and in our interview with her, 0:10:54.040 --> 0:10:56.280 and I like it. She says they look like pink 0:10:56.320 --> 0:11:00.320 orange nerd candies, which is pretty fun um and gave 0:11:00.360 --> 0:11:03.079 me like a really good picture because I, I don't 0:11:03.120 --> 0:11:05.680 know about you, Robert, but I've never been to a 0:11:05.720 --> 0:11:08.160 beach area that has coral reefs, and I grew up 0:11:08.160 --> 0:11:10.560 on the ocean. Um. I had not really experienced it 0:11:10.640 --> 0:11:13.120 until earlier this year when I went to Jamaica and 0:11:13.200 --> 0:11:17.080 got to Snarling h with the with my wife and 0:11:17.160 --> 0:11:19.080 see some of it in action, and I was just 0:11:19.160 --> 0:11:22.040 really blown away by it. Because there's one thing to see, 0:11:22.160 --> 0:11:25.839 like the super HD footage and it's beautiful, but it 0:11:25.880 --> 0:11:28.520 seems like another world. It's like watching Avatar, but totally 0:11:28.600 --> 0:11:31.640 to actually poke around there and see it in real life, 0:11:31.679 --> 0:11:34.920 it's it's quite amazing. So one of the things we 0:11:34.920 --> 0:11:37.600 talked tomorrow about that no one quite has the exact 0:11:37.679 --> 0:11:42.040 answer to is how these corals are timing it so 0:11:42.080 --> 0:11:46.120 that they all spawn at the exact same time every year. 0:11:46.520 --> 0:11:49.800 And there's a theory that the solar they're they're taking 0:11:49.880 --> 0:11:52.920 solar cues or wind cues to figure out the month 0:11:53.000 --> 0:11:55.600 that they should spawn in, and then they're taking nooner 0:11:55.720 --> 0:11:58.960 cues somehow to figure out which day they should spawn in. 0:11:59.720 --> 0:12:03.199 Us Alian scientists have recently found out, however, that when 0:12:03.240 --> 0:12:07.000 they're exposed to even tiny little waves, that coral can 0:12:07.040 --> 0:12:11.720 break into identical pieces that can each develop their own larvae. 0:12:11.760 --> 0:12:15.120 So this is the clone process. It's similar their stem 0:12:15.160 --> 0:12:18.600 cells then reassemble and continue to develop. So there are 0:12:18.640 --> 0:12:22.400 a lot of identical twin coral polyps out there. But 0:12:22.559 --> 0:12:25.320 as we talk about with Mara, that's not very that's 0:12:25.320 --> 0:12:27.760 not exactly a good thing if you need diversity to 0:12:27.840 --> 0:12:32.400 sort of protect you from ecological problems. So, but we 0:12:32.520 --> 0:12:35.200 have billions of naked embryos on the surface of the 0:12:35.200 --> 0:12:38.240 ocean during these spawnings, there's a potential to create even 0:12:38.240 --> 0:12:41.760 more clones. When they conducted this first experiment that I 0:12:41.800 --> 0:12:44.760 was speaking of in Australia, fifty of the embryos that 0:12:44.800 --> 0:12:49.280 they exposed, fragmented and then reorganized so they could develop larvae. 0:12:49.320 --> 0:12:52.720 So the cloning thing is is fairly prevalent. Now. Sent 0:12:53.640 --> 0:12:58.320 of the zooks algae corals, those are hermaphrodites, and they're 0:12:58.320 --> 0:13:01.959 basically both male and fee male. They can release sperm 0:13:02.040 --> 0:13:04.719 and eggs, but some are only male and some are 0:13:04.760 --> 0:13:09.120 only female. Uh. Some even fertilize their own eggs internally 0:13:09.160 --> 0:13:11.760 if they can snatch up the sperm. This is called brooding. 0:13:12.240 --> 0:13:17.400 They also release fully developed larvae. Now, the sexuality of 0:13:17.440 --> 0:13:22.040 these uh particular polyps tends to be consistent across the 0:13:22.080 --> 0:13:26.920 different species of corals that we're talking about here. Another 0:13:27.000 --> 0:13:32.400 number seventy of the zooks corals also spawn eggs and 0:13:32.480 --> 0:13:37.040 sperm for external fertilization. So the broadcast spawning we're talking 0:13:37.080 --> 0:13:42.600 about is their majority of their reproductive process. So this 0:13:42.679 --> 0:13:44.760 is this is contrary to the brooding that I was 0:13:44.760 --> 0:13:48.760 speaking about earlier. Now, when species brewed like I'm talking 0:13:48.800 --> 0:13:51.760 about this is when they're fertilizing their eggs internally, they 0:13:51.800 --> 0:13:56.000 can store the unfertilized ova for weeks at a time, 0:13:56.040 --> 0:14:00.920 whereas spawning species requires this very specific time frame of 0:14:01.080 --> 0:14:05.120 hours that we talked about with Mara, sometimes colonies of 0:14:05.320 --> 0:14:11.400 different species spawned simultaneously. This is when hybridization occurs. We 0:14:11.600 --> 0:14:15.040 know that it happens, we just don't really know the extent. 0:14:15.559 --> 0:14:18.520 And as we'll talk about with Mara, most hybrids are sterile, 0:14:19.480 --> 0:14:22.920 but it's hopefully avoided when most species of polyps spend 0:14:22.960 --> 0:14:26.640 their time spawning at different intervals. Um we talk about 0:14:26.680 --> 0:14:30.360 that as well with particular kinds of species the boulder 0:14:30.400 --> 0:14:33.080 coral and what was the other one, lobe star coral 0:14:33.800 --> 0:14:36.400 and and indeed there are also some some interesting twists 0:14:36.400 --> 0:14:39.960 and turns with hybridization that I think everyone will will 0:14:40.000 --> 0:14:43.000 be rather delighted by. Yeah, and we were totally surprised 0:14:43.000 --> 0:14:46.280 by two because it's a brand new research. Another thing 0:14:46.320 --> 0:14:49.840 that's super fascinating about this broadcast spawning. It can happen 0:14:49.920 --> 0:14:55.000 over vast distances. Corals can basically take extended sea voyages 0:14:55.040 --> 0:14:57.800 once they float to the top, and they can survive 0:14:57.960 --> 0:15:01.560 for months before they fully integrate and sink back down 0:15:01.600 --> 0:15:05.480 to the bottom. Now, when an egg does get fertilized 0:15:05.600 --> 0:15:09.440 after the embryo forms, it's it actually swims, so so 0:15:09.480 --> 0:15:11.680 sinking isn't really the right term I should have used there. 0:15:11.680 --> 0:15:15.560 It swims to the bottom to anchor itself. And scientists 0:15:15.640 --> 0:15:20.920 thought until four that all coral reproduction was internal like 0:15:21.000 --> 0:15:24.960 this brooding method. But then in Science magazine somebody published 0:15:24.960 --> 0:15:27.600 a description of the mass spawning event at the Great 0:15:27.600 --> 0:15:30.920 Barrier reef. And here we are now, you know, spending 0:15:30.920 --> 0:15:33.560 an entire episode talking about it. So this is relatively 0:15:33.640 --> 0:15:38.880 new science to humans. A study in a Smithsonian article 0:15:38.920 --> 0:15:42.360 that I read for this that's called watching Coral sex 0:15:42.520 --> 0:15:47.120 indicated that if corals spawn just fifteen minutes out of 0:15:47.160 --> 0:15:49.920 sync with their majority of the rest of their species, 0:15:50.200 --> 0:15:54.800 it greatly reduces their chance of reproductive success. So you know, 0:15:55.000 --> 0:15:57.440 this is why it's so important that it happens all 0:15:57.480 --> 0:15:59.800 at the same time and that the area is protected. 0:16:00.160 --> 0:16:02.880 Just a lot of factors that go into the ecology 0:16:02.880 --> 0:16:07.120 of keeping these reefs safe. Uh. And then to go 0:16:07.200 --> 0:16:12.080 along with Mara's nerd candy example, one of the other 0:16:12.120 --> 0:16:15.360 scientists described it as being a little bit like tapioca. 0:16:16.120 --> 0:16:18.680 That like, you're basically floating in a sea of I 0:16:18.720 --> 0:16:23.400 think tapioca. It's like swimming and bubble tea essentially. Yeah, 0:16:23.440 --> 0:16:26.520 that's a good one. I like that bubble tea. All right, Well, 0:16:26.520 --> 0:16:28.600 we're gonna take a quick break and when we come back, 0:16:28.880 --> 0:16:39.040 we're gonna call up Mara and discuss coral sex. Hi, Mara, 0:16:39.160 --> 0:16:41.160 thanks so much for coming on the show again for 0:16:41.200 --> 0:16:43.760 a summertime discussion of corals. So we had such a 0:16:43.760 --> 0:16:46.400 great time chatting with you before on the the Oppidas 0:16:46.440 --> 0:16:49.200 episode that we recorded, so it's nice to have you 0:16:49.600 --> 0:16:52.400 back on to discuss corals. Thank you so much for 0:16:52.440 --> 0:16:54.440 having me. I'm I'm really excited to be here and 0:16:54.440 --> 0:16:56.560 to be able to chat with you guys about definitely 0:16:56.760 --> 0:17:00.360 one of my favorite animals, which are corals somorrow. I 0:17:00.400 --> 0:17:03.440 didn't realize this until like almost five minutes ago. I've 0:17:03.440 --> 0:17:05.840 read through the book, We've talked to you before, but 0:17:06.000 --> 0:17:09.399 you have a background as a coral reef ecologist, right, 0:17:10.640 --> 0:17:14.960 that's right. Yeah, They're where I really um got started 0:17:15.000 --> 0:17:18.240 in my career doing me in science. So they hold 0:17:18.240 --> 0:17:22.280 a very special place in my heart. Quarrels and sharks. Okay, awesome, 0:17:22.359 --> 0:17:25.840 Well good, because we got a lot of questions because 0:17:25.880 --> 0:17:30.920 because quarrels have a very strange reproductive practice. This is true, 0:17:31.080 --> 0:17:35.640 they do. They're they're pretty amazing, especially given that they 0:17:35.640 --> 0:17:39.359 can't move, and they are pretty simple animals that I 0:17:39.359 --> 0:17:41.840 don't like to use the word simple, but you know, 0:17:41.920 --> 0:17:45.040 basically they're they're sort of this jelly like blob that 0:17:45.160 --> 0:17:49.200 sits with extending little tentacles out of a little hard 0:17:49.240 --> 0:17:53.239 cup that they manufacture themselves. So for folks out there 0:17:53.240 --> 0:17:56.639 who are familiar with finding Demo um and know that 0:17:56.680 --> 0:17:59.560 he lives in an anemone, which is uh, I don't 0:17:59.560 --> 0:18:03.240 want my it up, and then with me, uh, they're 0:18:03.280 --> 0:18:07.320 they're close cousins of those animals, and so they fit 0:18:07.400 --> 0:18:09.879 in these little cups all day long with their tentacles 0:18:10.000 --> 0:18:14.960 outstretched into into the environment, sort of taking little particles 0:18:14.960 --> 0:18:17.479 out of the water to feed on. But they have 0:18:17.520 --> 0:18:21.159 some other cool tricks up there. The sexual reproduction and 0:18:21.240 --> 0:18:25.760 corals is pretty amazing. Yeah, you you presented so well 0:18:25.800 --> 0:18:27.800 in the book. I almost almost hate to ask you 0:18:27.840 --> 0:18:30.240 described to describe it here, you know, I'd almost rather 0:18:30.320 --> 0:18:32.680 encourage the readers to read it. But can you take 0:18:32.960 --> 0:18:35.320 just a few minutes to describe for us the synchronized 0:18:35.840 --> 0:18:42.520 hotel orgy of the corals? Sure, i'd be to So again, 0:18:42.600 --> 0:18:45.800 corals can't move right, so they're stuck. They're cemented to 0:18:45.840 --> 0:18:48.359 the sea floor. This means they can't go out in 0:18:48.480 --> 0:18:51.840 date to find their mates there. They have to allow 0:18:51.960 --> 0:18:54.320 their gammets, which are their eggs and their sperm, to 0:18:54.440 --> 0:18:58.560 do the dating and meeting for them. And I should 0:18:58.600 --> 0:19:00.280 say there's two types of coral in the when I'm 0:19:00.280 --> 0:19:04.200 about to describe it does this big synchronized orgy. These 0:19:04.200 --> 0:19:08.439 are called broadcast spawners. So they release both their sperm 0:19:08.520 --> 0:19:12.080 and their eggs into the water column. And the best 0:19:12.080 --> 0:19:14.679 way to ensure that their sperm and eggs are going 0:19:14.720 --> 0:19:17.399 to mix the sperm and eggs of other corals and 0:19:17.400 --> 0:19:20.400 be able to make the next generation is to time 0:19:20.440 --> 0:19:24.760 that release with their neighbors. So if you imagine that 0:19:25.080 --> 0:19:27.200 corals are sort of sitting in their little cups, and 0:19:27.240 --> 0:19:29.840 their cups sort of form these big colonies, and then 0:19:29.840 --> 0:19:32.520 there's multiple colonies along the reefs, it's kind of like 0:19:32.600 --> 0:19:36.840 thinking that, um, the sperm and eggs are are getting 0:19:36.880 --> 0:19:40.119 together in a hotel room, right, and these corals have 0:19:40.320 --> 0:19:43.920 to make sure that they're going to synchronize their mate 0:19:44.119 --> 0:19:47.600 their release. But then it's also like that couple in 0:19:47.600 --> 0:19:50.960 that hotel room that synchronizing their release is also coordinating 0:19:51.280 --> 0:19:54.200 with their neighbors maybe in the two rooms on either side, 0:19:54.840 --> 0:19:58.040 and then those neighbors are also synchronizing with their neighbors, 0:19:58.080 --> 0:20:01.520 and so the whole floor of the hotel are all 0:20:01.560 --> 0:20:05.240 coming together and being able to synchronize their climax exactly 0:20:05.280 --> 0:20:08.359 the same time. And then actually, because there's miles and 0:20:08.400 --> 0:20:11.920 miles of reef and millions and millions of corals, you've 0:20:11.920 --> 0:20:14.879 actually got to blow it out to imagine that every 0:20:14.880 --> 0:20:18.000 single hotel room across say, the entire city of New 0:20:18.080 --> 0:20:20.960 York is full of couples that are all climax thing 0:20:21.400 --> 0:20:25.960 exactly the same time. So it's pretty phenomenal when you 0:20:26.000 --> 0:20:29.560 think about the scale at which this synchronization is occurring. 0:20:29.640 --> 0:20:34.120 And you know, given uh sort of bar pop culture, 0:20:34.200 --> 0:20:36.560 and again I talked about you know, if you look 0:20:36.600 --> 0:20:38.639 at any cover of Cosmo, it's all about how to 0:20:39.160 --> 0:20:41.400 you know, connect better with your partner. We we seem 0:20:41.440 --> 0:20:44.160 to struggle to do this on a one on one basis. Meanwhile, 0:20:44.200 --> 0:20:48.160 corals are doing that's across millions of individuals, no problem, 0:20:48.359 --> 0:20:52.399 year after year, down to you know, really really fine timing. 0:20:52.520 --> 0:20:56.800 So we're talking within you know, within moments uh of 0:20:56.800 --> 0:20:59.200 of their their sort of buddy colonies up and down 0:20:59.240 --> 0:21:01.600 the reef, and this is a once a year occurrence, 0:21:03.000 --> 0:21:06.160 it is. So what happens is coral sort of spend 0:21:06.200 --> 0:21:10.520 the entire year celibates, building up the energy and storing 0:21:10.560 --> 0:21:15.439 the energy to make these staddy balls of sperm and eggs. 0:21:15.600 --> 0:21:18.000 So it's called a bundle. And the bundle looks like, 0:21:18.680 --> 0:21:20.679 for those of you who know nerd candies, kind of 0:21:20.680 --> 0:21:25.159 a small pinkish orange colored spear, and it takes a 0:21:25.160 --> 0:21:28.119 lot of energies to pack all these eggs and sperms together, 0:21:28.640 --> 0:21:31.119 so they wait and again. Um, it's a once a 0:21:31.200 --> 0:21:35.800 year event and it normally happens um for different species. 0:21:35.840 --> 0:21:39.960 It'll happen within a two to three day window around 0:21:39.960 --> 0:21:43.720 the full moon, and it normally happens in the summertime, 0:21:43.880 --> 0:21:48.880 so there's likely some water temperature cues. There's definitely cues 0:21:48.920 --> 0:21:52.240 from from the sunset. It often happens at night after 0:21:52.280 --> 0:21:57.080 sunset and moon phase also coordinated around that that full 0:21:57.119 --> 0:22:00.760 moon time, so there's a whole bunch of virominal cues 0:22:00.760 --> 0:22:03.560 that they're using to kind of start to align and 0:22:03.600 --> 0:22:05.760 then and then let it all go. But it's yeah, 0:22:05.800 --> 0:22:09.240 so each coral will only go once they've got one 0:22:09.680 --> 0:22:13.280 little sperm egg bundle to release and that's it. Uh So, 0:22:13.680 --> 0:22:16.560 within a colony you might have one or two days 0:22:16.800 --> 0:22:20.560 of different polyps going off, but in general there's one 0:22:20.680 --> 0:22:24.200 peak night where the vast majority of of all these 0:22:24.240 --> 0:22:26.920 animals are releasing at the same time. Now, of course 0:22:26.920 --> 0:22:29.159 there's a reason for all of this. So what what 0:22:29.240 --> 0:22:34.720 are the core advantages to this once a year sexual blowout. Yeah, 0:22:34.800 --> 0:22:40.280 so again, um, it's really expensive to manufacture these, especially 0:22:40.320 --> 0:22:43.639 the eggs um and all the sperm, and you really 0:22:43.640 --> 0:22:46.000 want to make sure that in the environment like an 0:22:46.000 --> 0:22:49.280 ocean where there's lots of currents and lots of predators, 0:22:49.640 --> 0:22:52.840 so that you are getting your your sperm and eggs 0:22:52.840 --> 0:22:55.879 to mix with other sperm and eggs from your fellow 0:22:55.920 --> 0:22:59.520 species so that you can make next generation. And by 0:23:00.119 --> 0:23:04.320 coordinating the timing really precisely, you up the odds that 0:23:04.440 --> 0:23:07.200 your sperm and eggs are going to bump into another 0:23:07.600 --> 0:23:09.879 coral sperm and eggs and be able to fertilize and 0:23:09.920 --> 0:23:13.840 make make that viable a little larvae. But it also 0:23:13.920 --> 0:23:17.200 helps to release all these millions and millions of gammets 0:23:17.560 --> 0:23:20.359 all at once because it's sort of swamps out the 0:23:20.400 --> 0:23:25.280 predators as well, and the sex facts of coral. That 0:23:25.400 --> 0:23:29.160 sort of starts really peacefully, and it's just really it's 0:23:29.200 --> 0:23:32.919 really quite a miraculous event to witness, and and folks 0:23:32.960 --> 0:23:35.199 can see this because it happens on shaller wreaths. You 0:23:35.200 --> 0:23:38.400 can take a flashlight and even just snorkel um down 0:23:38.440 --> 0:23:40.280 in the Caribbean or off the Great Day or reef 0:23:40.359 --> 0:23:43.399 and be able to actually watch this happen um. But 0:23:43.680 --> 0:23:47.280