1 00:00:06,160 --> 00:00:08,760 Speaker 1: Hey, welcome to Stuff to Blow your Mind. It is 2 00:00:08,800 --> 00:00:11,280 Speaker 1: another Vault day here for you. So we have the 3 00:00:11,320 --> 00:00:16,160 Speaker 1: Parrotfish Part two. It originally published five three, twenty twenty four. 4 00:00:16,440 --> 00:00:19,720 Speaker 1: I hope you enjoy. 5 00:00:20,520 --> 00:00:24,600 Speaker 2: Welcome to Stuff to Blow Your Mind production of iHeartRadio. 6 00:00:30,360 --> 00:00:32,560 Speaker 1: Hey, welcome to Stuff to Blow your Mind. My name 7 00:00:32,600 --> 00:00:33,640 Speaker 1: is Robert Lamb. 8 00:00:33,600 --> 00:00:36,000 Speaker 3: And I am Joe McCormick, and we're back with Part 9 00:00:36,040 --> 00:00:40,160 Speaker 3: two in our series on parrotfish, a group of related 10 00:00:40,240 --> 00:00:44,879 Speaker 3: fishes containing about ninety to one hundred species worldwide, notable 11 00:00:45,000 --> 00:00:48,839 Speaker 3: for their powerful beak like mouths made out of rows 12 00:00:48,840 --> 00:00:53,600 Speaker 3: of fused teeth. In the previous episode, we talked about 13 00:00:53,640 --> 00:00:57,680 Speaker 3: some basics about the biology and taxonomy of parrotfish species. 14 00:00:58,200 --> 00:01:01,960 Speaker 3: We talked about their diet and feeding behavior. Parrot Fish 15 00:01:01,960 --> 00:01:06,520 Speaker 3: are usually considered herbivores or something equivalent to herbivores. They 16 00:01:06,560 --> 00:01:11,040 Speaker 3: survive by grazing for algae, microorganisms, to trite us, and 17 00:01:11,080 --> 00:01:15,399 Speaker 3: sometimes invertebrate animals like coral polyps along the surfaces of 18 00:01:15,560 --> 00:01:20,400 Speaker 3: rocks and coral skeletons within coral reef environments. We talked 19 00:01:20,480 --> 00:01:24,280 Speaker 3: about the fact that some parrotfish species end up biting 20 00:01:24,600 --> 00:01:28,959 Speaker 3: or scraping off significant chunks of hard matter from the 21 00:01:29,080 --> 00:01:31,960 Speaker 3: rocks and coral that they scour for food, and then 22 00:01:32,080 --> 00:01:37,440 Speaker 3: grinding up these coral skeletons and minerals in their phryngial mills. 23 00:01:37,680 --> 00:01:40,720 Speaker 3: It's kind of like horror movie machinery in the back 24 00:01:40,760 --> 00:01:42,560 Speaker 3: of their throats. I think we compared it to like 25 00:01:42,600 --> 00:01:47,200 Speaker 3: a bone transmission gear and then defecating what's left in 26 00:01:47,240 --> 00:01:50,240 Speaker 3: the form of sand. And so as a result, parrotfish 27 00:01:50,280 --> 00:01:53,440 Speaker 3: are major figures in the erosion of coral reefs and 28 00:01:53,520 --> 00:01:56,240 Speaker 3: in the production of sand. So if you walk across 29 00:01:56,320 --> 00:01:59,240 Speaker 3: a white sandy beach in the tropics where there are 30 00:01:59,240 --> 00:02:02,320 Speaker 3: coral reefs nearby, there is a good chance that most 31 00:02:02,400 --> 00:02:05,279 Speaker 3: of the sand under your feet was at one point 32 00:02:05,360 --> 00:02:09,040 Speaker 3: parrotfish poop. This is true of reef islands built entirely 33 00:02:09,080 --> 00:02:12,200 Speaker 3: out of reef sediment, like the Maldives, but also true 34 00:02:12,240 --> 00:02:15,080 Speaker 3: of some white sandy beaches in places like Hawaii and 35 00:02:15,120 --> 00:02:18,760 Speaker 3: the Caribbean. We talked also about writings on parrotfish from 36 00:02:18,760 --> 00:02:23,120 Speaker 3: the ancient world, how the Romans prized certain parrotfishes as 37 00:02:23,240 --> 00:02:26,160 Speaker 3: food items, and why they thought they were in first 38 00:02:26,200 --> 00:02:30,200 Speaker 3: place among the culinary uses of fish. How they developed 39 00:02:30,240 --> 00:02:32,840 Speaker 3: a range of beliefs about these fish, some of which 40 00:02:32,880 --> 00:02:36,720 Speaker 3: were fairly biologically accurate, such as the belief that these 41 00:02:36,760 --> 00:02:40,760 Speaker 3: fish are herbivorous grazers they sort of are, and that 42 00:02:40,800 --> 00:02:44,160 Speaker 3: they produce audible sounds underwater as they scrape the rocks 43 00:02:44,200 --> 00:02:47,400 Speaker 3: and coral for food, also true. Other beliefs not quite 44 00:02:47,480 --> 00:02:50,200 Speaker 3: so accurate. For example, Rob, didn't you talk about this 45 00:02:50,280 --> 00:02:53,680 Speaker 3: idea that they like cooperate altruistically to save one another 46 00:02:53,720 --> 00:02:54,440 Speaker 3: from traps? 47 00:02:55,040 --> 00:02:59,280 Speaker 1: Yes, and in this became an enduring and long lasting 48 00:02:59,320 --> 00:03:02,799 Speaker 1: symbol of free which doesn't really hold up to how 49 00:03:02,800 --> 00:03:03,760 Speaker 1: they actually behave. 50 00:03:04,200 --> 00:03:07,040 Speaker 3: But we also talked last time about some interesting beliefs 51 00:03:07,080 --> 00:03:11,119 Speaker 3: about parrotfishes in Hawaiian mythology, where the parrotfish is sort 52 00:03:11,160 --> 00:03:14,440 Speaker 3: of a progenitor of other sea life and enters into 53 00:03:14,520 --> 00:03:18,560 Speaker 3: a pact with a Hawaiian mythical hero who can sort 54 00:03:18,560 --> 00:03:22,360 Speaker 3: of call upon his friendship with the parrotfish in order 55 00:03:22,400 --> 00:03:25,600 Speaker 3: to produce an abundance of fish catch for the people. 56 00:03:26,320 --> 00:03:29,440 Speaker 3: And then finally, we also talked about research on parrotfish teeth, 57 00:03:29,480 --> 00:03:32,400 Speaker 3: which are made out of some of the hardest, stiffest, 58 00:03:32,400 --> 00:03:36,040 Speaker 3: and most resilient biominerals known even to the extent that 59 00:03:36,080 --> 00:03:39,360 Speaker 3: they are being investigated as a model for high durability 60 00:03:39,640 --> 00:03:43,480 Speaker 3: synthetic materials in the lab. So that was part one, 61 00:03:43,520 --> 00:03:46,160 Speaker 3: and today we're back to talk some more about parrotfish. 62 00:03:46,480 --> 00:03:49,080 Speaker 1: Yeah, and I just want to drive home that if 63 00:03:49,080 --> 00:03:52,600 Speaker 1: you haven't had the opportunity to observe parrotfish in the wild, 64 00:03:53,440 --> 00:03:56,360 Speaker 1: and you find yourself traveling to or in an area 65 00:03:56,760 --> 00:04:00,920 Speaker 1: where there are reef environments and there is some manner 66 00:04:00,960 --> 00:04:04,680 Speaker 1: of snorkeling going on, go check it out. Oftentimes, you 67 00:04:04,720 --> 00:04:08,520 Speaker 1: know there are various snorkeling companies and and you know 68 00:04:08,560 --> 00:04:12,560 Speaker 1: small businesses that are that are very approachable. You don't 69 00:04:12,600 --> 00:04:15,120 Speaker 1: have to have a lot of experience to try these out. Again, 70 00:04:15,120 --> 00:04:19,160 Speaker 1: these are often we're talking like shallow water environments, and 71 00:04:19,320 --> 00:04:23,440 Speaker 1: in these environments there's almost always some sort of parrotfish 72 00:04:23,480 --> 00:04:27,400 Speaker 1: to observe. And if that's not your cup of tea, 73 00:04:27,920 --> 00:04:30,200 Speaker 1: I want to add that for anyone who would like 74 00:04:30,200 --> 00:04:32,880 Speaker 1: to see various parrotfish in action as well as other fish, 75 00:04:33,240 --> 00:04:36,839 Speaker 1: I highly recommend checking out Coral City Camera. It's that's 76 00:04:36,839 --> 00:04:39,600 Speaker 1: just Coralcitycamera dot com, or you can look it up 77 00:04:39,600 --> 00:04:43,479 Speaker 1: and search it's an underwater camera streaming live from an 78 00:04:43,600 --> 00:04:47,600 Speaker 1: urban coral reef in Miami, Florida. Uh, it's it's pretty cool, 79 00:04:47,800 --> 00:04:51,360 Speaker 1: and if you watch long enough, you will see some parrotfish. 80 00:04:50,800 --> 00:04:53,760 Speaker 3: In action, pursuing their new career as streamers. 81 00:04:54,279 --> 00:04:57,920 Speaker 1: Yes. Yes, so we're going to get into parrotfish reproduction 82 00:04:58,440 --> 00:05:01,000 Speaker 1: here in a bit. But first up, we have this 83 00:05:01,640 --> 00:05:04,400 Speaker 1: other delightful area to look at something that I wasn't 84 00:05:04,400 --> 00:05:07,280 Speaker 1: familiar with at all concerning parrotfish. Joe, do you want 85 00:05:07,279 --> 00:05:08,640 Speaker 1: to get into their mucus? 86 00:05:08,839 --> 00:05:11,360 Speaker 3: Oh? Do? I? I feel like I'm already into their mucus. 87 00:05:11,440 --> 00:05:15,039 Speaker 3: I've been in it all day. So I mentioned in 88 00:05:15,080 --> 00:05:18,920 Speaker 3: the previous episode that the topic of parrotfish was one 89 00:05:18,960 --> 00:05:21,840 Speaker 3: that I initially got interested in just by looking at pictures. 90 00:05:21,920 --> 00:05:22,080 Speaker 2: You know. 91 00:05:22,200 --> 00:05:25,400 Speaker 3: I was looking at like a photo of a parrotfish mouth, 92 00:05:25,680 --> 00:05:28,200 Speaker 3: and I started thinking, what is going on with this 93 00:05:28,279 --> 00:05:32,040 Speaker 3: awesome palisade of fused together teeth? And so there is 94 00:05:32,120 --> 00:05:35,279 Speaker 3: another parrotfish subtopic that I think one could come to 95 00:05:35,360 --> 00:05:40,240 Speaker 3: in exactly the same manner, and that is their mucus cocoons. 96 00:05:40,920 --> 00:05:45,279 Speaker 3: If you look for photos of parrotfish sleeping, you will 97 00:05:45,320 --> 00:05:49,440 Speaker 3: find images of these animals nestled down into cozy little 98 00:05:49,560 --> 00:05:52,839 Speaker 3: niches in the seafloor or within the reef structure, sometimes 99 00:05:52,880 --> 00:05:56,040 Speaker 3: kind of in a recess or a little heidi hole 100 00:05:56,080 --> 00:05:59,719 Speaker 3: in the reef, surrounded by what looks like some kind 101 00:05:59,800 --> 00:06:04,200 Speaker 3: of of film. Sometimes it looks like the parrotfish is 102 00:06:04,360 --> 00:06:09,360 Speaker 3: enclosed within a gauzy, transparent orb covered like sometimes covered 103 00:06:09,360 --> 00:06:12,640 Speaker 3: in glitter. If you see these in motion and rob 104 00:06:12,880 --> 00:06:15,240 Speaker 3: below the photos here, I did attach a link to 105 00:06:15,279 --> 00:06:17,080 Speaker 3: a video in the outline that you can look at 106 00:06:17,120 --> 00:06:19,839 Speaker 3: so you can see it moving. If you see these 107 00:06:19,880 --> 00:06:22,479 Speaker 3: in motion, they will they will appear to undulate in 108 00:06:22,560 --> 00:06:26,039 Speaker 3: the water, so they're kind of jelly like in movement 109 00:06:26,120 --> 00:06:30,760 Speaker 3: and substance. In other cases, this film looks like the 110 00:06:30,839 --> 00:06:34,679 Speaker 3: fish is wrapped up inside a huge funnel spider web 111 00:06:34,760 --> 00:06:38,640 Speaker 3: that's just covered in sand. Which funny thing about that 112 00:06:38,720 --> 00:06:41,880 Speaker 3: the sand may of course be the parrotfish's own excretion 113 00:06:42,040 --> 00:06:42,640 Speaker 3: from earlier. 114 00:06:43,120 --> 00:06:45,760 Speaker 1: MM. Yeah, I'm looking at the video footage right now. 115 00:06:45,800 --> 00:06:49,560 Speaker 1: It's it's slimy but beautiful. 116 00:06:50,200 --> 00:06:54,919 Speaker 3: So what is this gossamer bubble around a slumbering fish. 117 00:06:55,640 --> 00:06:59,479 Speaker 3: This is what's known as the parrotfish's mucous cocoon. Or 118 00:06:59,520 --> 00:07:04,840 Speaker 3: sometimes in the scientific literature, it's mucus envelope, described by 119 00:07:04,839 --> 00:07:08,039 Speaker 3: an author named H. E. Win in a scientific article 120 00:07:08,320 --> 00:07:13,080 Speaker 3: in nineteen fifty five as a quote thin, transparent and 121 00:07:13,160 --> 00:07:17,960 Speaker 3: gelatinous mucoid substance which starts as a fold at the 122 00:07:18,080 --> 00:07:22,680 Speaker 3: mouth and progresses backwards in folds to surround the body. 123 00:07:24,160 --> 00:07:28,680 Speaker 3: So parrotfish are daytime animals. They sleep during the night, 124 00:07:28,760 --> 00:07:32,240 Speaker 3: they wake and feed during the day, and some species 125 00:07:32,280 --> 00:07:36,679 Speaker 3: have been observed to spend roughly an hour before sleep 126 00:07:37,280 --> 00:07:41,680 Speaker 3: generating this jelly like sleeping bag out of mucus from 127 00:07:41,760 --> 00:07:44,520 Speaker 3: their mouths before actually getting to sleep, so it's like 128 00:07:44,560 --> 00:07:49,040 Speaker 3: a bedtime routine. As night is falling, they start spitting 129 00:07:49,080 --> 00:07:52,200 Speaker 3: out the mucus and it starts to envelop their body 130 00:07:52,240 --> 00:07:55,920 Speaker 3: from front to back. So the fish are making themselves 131 00:07:56,040 --> 00:08:00,320 Speaker 3: bedtime slime sacks. But why now? First, this is a 132 00:08:00,360 --> 00:08:03,400 Speaker 3: side note. I just wanted to say it is normal 133 00:08:03,840 --> 00:08:07,600 Speaker 3: for all kinds of fish species, not just parrotfish or 134 00:08:07,640 --> 00:08:12,360 Speaker 3: the other related fish. Like some rasses that make these 135 00:08:12,400 --> 00:08:15,240 Speaker 3: slime sacks. It is normal for all kinds of fish 136 00:08:15,360 --> 00:08:17,640 Speaker 3: to be covered in a thin layer of mucus on 137 00:08:17,680 --> 00:08:22,000 Speaker 3: the outside of their skin. This omnipresent slime barrier can 138 00:08:22,040 --> 00:08:25,200 Speaker 3: provide a number of benefits, one of which is OSMO regulation, 139 00:08:25,600 --> 00:08:30,640 Speaker 3: and that's maintaining the balance of internal water and solutes 140 00:08:30,840 --> 00:08:34,920 Speaker 3: such as electrolytes, so for example, and OSMO regulation function 141 00:08:35,040 --> 00:08:38,439 Speaker 3: within our bodies human bodies is maintaining the right level 142 00:08:38,480 --> 00:08:42,120 Speaker 3: of salt in our body fluids. Mucous coverings on all 143 00:08:42,200 --> 00:08:46,960 Speaker 3: kinds of fish help with OSMO regulation. But these mucous 144 00:08:47,160 --> 00:08:49,960 Speaker 3: coverings on the skin also cut down on friction. So 145 00:08:50,000 --> 00:08:53,840 Speaker 3: the slippery layer of mucus on the fish's skin makes 146 00:08:53,880 --> 00:08:57,200 Speaker 3: it easier for the fish to swim along. It's like 147 00:08:57,240 --> 00:09:01,400 Speaker 3: a lubricant for the interface with the surrounding water. It's 148 00:09:01,440 --> 00:09:04,880 Speaker 3: also just physical protection of the skin from contact trauma 149 00:09:05,000 --> 00:09:08,559 Speaker 3: such as cuts and scrapes. It in some cases provides 150 00:09:09,120 --> 00:09:13,200 Speaker 3: UV radiation protection. In some cases might protect the fish 151 00:09:13,240 --> 00:09:17,040 Speaker 3: from noxious chemicals or pollutants in the water, and provides 152 00:09:17,120 --> 00:09:19,120 Speaker 3: the fish protection against drying out. 153 00:09:20,200 --> 00:09:22,440 Speaker 1: So this is of course one of the potential issues. 154 00:09:22,480 --> 00:09:24,679 Speaker 1: And just handling fish such as then like ketch and 155 00:09:24,760 --> 00:09:27,760 Speaker 1: release and so forth. The slime isn't just something that's 156 00:09:27,760 --> 00:09:29,760 Speaker 1: on the fish. It's an active barrier. 157 00:09:30,360 --> 00:09:33,800 Speaker 3: Yeah, but that's all just the normal mucous coating common 158 00:09:33,840 --> 00:09:36,400 Speaker 3: to many many fish. What we're talking about here is 159 00:09:36,400 --> 00:09:41,760 Speaker 3: specifically this baggy mucous hyper sleep pod that forms around 160 00:09:41,760 --> 00:09:45,160 Speaker 3: some parrotfish and rasses through the night. So I started 161 00:09:45,160 --> 00:09:47,720 Speaker 3: looking at scientific papers about this to see what I 162 00:09:47,720 --> 00:09:50,960 Speaker 3: could find out. So first I was looking at a 163 00:09:51,080 --> 00:09:54,920 Speaker 3: marine zoology paper from the year nineteen seventy that investigated 164 00:09:54,920 --> 00:09:58,200 Speaker 3: a few species of parrotfish to see how and under 165 00:09:58,240 --> 00:10:02,160 Speaker 3: what conditions the fish would make these cocoons. So this 166 00:10:02,200 --> 00:10:05,360 Speaker 3: is by John E. Byrne, who was a professor of 167 00:10:05,440 --> 00:10:08,800 Speaker 3: zoology at the University of Hawaii. The paper is called 168 00:10:08,880 --> 00:10:13,840 Speaker 3: Mucus envelope formation in two species of Hawaiian parrotfishes, and 169 00:10:13,880 --> 00:10:17,200 Speaker 3: the paper begins by citing previous research by Win and 170 00:10:17,280 --> 00:10:21,040 Speaker 3: co authors on parrotfish from the coral reefs of Bermuda, 171 00:10:21,600 --> 00:10:25,480 Speaker 3: which were observed to make mucus envelopes at night. So 172 00:10:25,720 --> 00:10:28,960 Speaker 3: when and a co author named Bardak argued that the 173 00:10:29,000 --> 00:10:33,480 Speaker 3: purpose of the mucus cocoon of the slimesack was to 174 00:10:33,600 --> 00:10:38,959 Speaker 3: protect the parrotfish from predators while it was sleeping. And 175 00:10:39,000 --> 00:10:42,439 Speaker 3: this is a hypothesis that I've seen repeated in a 176 00:10:42,520 --> 00:10:47,280 Speaker 3: number of sources that maybe somehow the mucus covering will 177 00:10:47,280 --> 00:10:50,640 Speaker 3: help alert the fish more quickly if a predator gets 178 00:10:50,679 --> 00:10:53,520 Speaker 3: close to it, or may in some way help mask 179 00:10:53,720 --> 00:10:57,520 Speaker 3: the fish, maybe mask the fish is sent from predators, 180 00:10:57,960 --> 00:11:00,640 Speaker 3: or provide some kind of benefit along these lines. 181 00:11:01,080 --> 00:11:04,400 Speaker 1: Okay, So either to some degree a cloaking system, a 182 00:11:04,440 --> 00:11:07,160 Speaker 1: cloaking device, if you will, or perhaps some sort of 183 00:11:07,200 --> 00:11:10,040 Speaker 1: like added security trip wire made out of mucus. 184 00:11:10,640 --> 00:11:12,800 Speaker 3: There you go. Now we'll get to another explanation in 185 00:11:12,920 --> 00:11:14,560 Speaker 3: just a bit here, but we're not there quite yet. 186 00:11:14,600 --> 00:11:16,960 Speaker 3: First we're gonna look at like how and how and 187 00:11:17,080 --> 00:11:19,760 Speaker 3: when these things form. So the author of the study, 188 00:11:19,880 --> 00:11:24,520 Speaker 3: John Burn, begins by investigating envelope formation in a couple 189 00:11:24,559 --> 00:11:28,720 Speaker 3: of different species of parrotfish. There's scare Us dubious, commonly 190 00:11:28,760 --> 00:11:34,160 Speaker 3: known as the regal parrotfish, and scaus parsp pair. Oh wow, 191 00:11:34,640 --> 00:11:38,520 Speaker 3: here's a word, pers bisilatis. There you go, which is 192 00:11:38,559 --> 00:11:42,160 Speaker 3: commonly called the spectacled parrotfish. Both are found in the 193 00:11:42,160 --> 00:11:45,920 Speaker 3: reefs around Hawaii, and I think the spectacled parrotfish may 194 00:11:45,920 --> 00:11:49,200 Speaker 3: be one of the keyfish referred to as oohu and 195 00:11:49,280 --> 00:11:51,920 Speaker 3: some of the Hawaiian legends that we talked about in 196 00:11:51,960 --> 00:11:52,880 Speaker 3: the last episode. 197 00:11:53,160 --> 00:11:55,359 Speaker 1: Yeah. Yeah, So burn. 198 00:11:55,360 --> 00:11:58,439 Speaker 3: Did some experiments on these two species in his laboratory, 199 00:11:58,840 --> 00:12:03,320 Speaker 3: varying conditions of light and darkness within their aquaria, making 200 00:12:03,440 --> 00:12:07,720 Speaker 3: observations of behavior, and then examining the mucus producing organs. 201 00:12:08,080 --> 00:12:13,280 Speaker 3: So Previous field observations had found that as daylight intensities decrease. 202 00:12:13,320 --> 00:12:17,679 Speaker 3: As daylight goes down, fewer parrotfishes can be found swimming 203 00:12:17,679 --> 00:12:21,160 Speaker 3: around the reefs for the night time, these fish will 204 00:12:21,480 --> 00:12:25,000 Speaker 3: disperse their schools and go into recesses within the reef 205 00:12:25,040 --> 00:12:28,640 Speaker 3: to hide and sleep, and that's where they generate these cocoons. 206 00:12:29,760 --> 00:12:33,080 Speaker 3: Within the lab environment, Burne found that if you shine 207 00:12:33,120 --> 00:12:36,640 Speaker 3: a constant light on these fish for twenty four hours straight, 208 00:12:37,080 --> 00:12:39,719 Speaker 3: they will actually never make a mucus cocoon. You just 209 00:12:39,840 --> 00:12:41,920 Speaker 3: keep shining the light on them, at least for twenty 210 00:12:41,920 --> 00:12:44,920 Speaker 3: four hours. He didn't push the experiment to go that 211 00:12:45,040 --> 00:12:48,120 Speaker 3: much longer, because you know, it might just end up 212 00:12:48,120 --> 00:12:50,960 Speaker 3: harming them overall. But for twenty four hours straight, you 213 00:12:51,000 --> 00:12:53,880 Speaker 3: shine a light on them and it, you know, nothing happens. 214 00:12:54,200 --> 00:12:55,600 Speaker 1: Yeah, corp, of course, I mean, there are a lot 215 00:12:55,640 --> 00:12:58,439 Speaker 1: of things I'm not going to do of some sort 216 00:12:58,440 --> 00:13:03,360 Speaker 1: of an intelligent being from highly advanced species shines artificial 217 00:13:03,400 --> 00:13:04,880 Speaker 1: light on me for twenty four hours. 218 00:13:05,040 --> 00:13:07,360 Speaker 3: That's right, So the constant light means you never make 219 00:13:07,400 --> 00:13:10,559 Speaker 3: a pod. However, when darkness was introduced, you turned the 220 00:13:10,640 --> 00:13:14,520 Speaker 3: lights off. This triggered twenty two of the thirty parrot 221 00:13:14,559 --> 00:13:18,200 Speaker 3: fish tested to build mucous envelopes, and it was the 222 00:13:18,240 --> 00:13:22,360 Speaker 3: same frequency in the two different species. The fish took 223 00:13:22,520 --> 00:13:25,880 Speaker 3: different amounts of time to finish building their envelopes after 224 00:13:25,920 --> 00:13:29,000 Speaker 3: the light was turned off. The minimum was like thirty minutes, 225 00:13:29,080 --> 00:13:32,360 Speaker 3: maximum was two hundred and forty minutes. Average building time 226 00:13:32,559 --> 00:13:36,880 Speaker 3: was about seventy minutes. However, if you kept the fish 227 00:13:37,000 --> 00:13:39,640 Speaker 3: the parrot fish in the dark after it made its cocoon, 228 00:13:40,360 --> 00:13:42,760 Speaker 3: it did not stay in the cocoon forever. Eventually it 229 00:13:42,760 --> 00:13:46,760 Speaker 3: would emerge on its own. So what did they do 230 00:13:46,840 --> 00:13:50,120 Speaker 3: when they made these things? They would typically rest their 231 00:13:50,160 --> 00:13:54,040 Speaker 3: bodies on the floor of the tank and the seafloor 232 00:13:54,080 --> 00:13:57,000 Speaker 3: in the wild in an upright position, almost always with 233 00:13:57,120 --> 00:14:00,559 Speaker 3: one side of the body resting against a vertical surface 234 00:14:00,679 --> 00:14:02,960 Speaker 3: like a rock or a coral wall, or, in the 235 00:14:02,960 --> 00:14:06,280 Speaker 3: case of the lab experiments, the aquarium wall, and then 236 00:14:06,320 --> 00:14:10,240 Speaker 3: the cocoon begins. It begins formation at the front of 237 00:14:10,280 --> 00:14:15,080 Speaker 3: the fish around its mouth, and folds of mucus slowly 238 00:14:15,200 --> 00:14:19,160 Speaker 3: move back along the length of the body toward the tail. 239 00:14:19,200 --> 00:14:23,880 Speaker 3: Though interestingly, the mucus never completely closes over the body. 240 00:14:24,240 --> 00:14:26,800 Speaker 3: There is always at least a one to two centimeter 241 00:14:27,000 --> 00:14:29,840 Speaker 3: gap at the back end of the bubble, and Burn 242 00:14:29,960 --> 00:14:34,760 Speaker 3: believes this hole is to evacuate respiratory water that's forced 243 00:14:34,760 --> 00:14:39,360 Speaker 3: out of the buckle cavity, so sort of a breathing hole. Now, 244 00:14:39,480 --> 00:14:41,440 Speaker 3: I mentioned that in a lot of these photos, the 245 00:14:41,480 --> 00:14:44,840 Speaker 3: mucus coccoon seems to sparkle as if it is covered 246 00:14:44,840 --> 00:14:49,080 Speaker 3: in glitter. Burn writes that quote fine debris adhered to 247 00:14:49,120 --> 00:14:54,160 Speaker 3: the envelope's exterior and the outline was thus more clearly defined. However, 248 00:14:54,200 --> 00:14:57,000 Speaker 3: he says this coating of sediment and debris makes the 249 00:14:57,040 --> 00:15:00,840 Speaker 3: bubble appear thin and delicate. This is how Wind described 250 00:15:00,880 --> 00:15:05,280 Speaker 3: it in that article from the fifties. But Burn did 251 00:15:05,320 --> 00:15:10,480 Speaker 3: an experiment by injecting pigmented particles into the cocoon and 252 00:15:10,600 --> 00:15:13,720 Speaker 3: revealed that actually appearances can be deceiving here because the 253 00:15:13,760 --> 00:15:16,800 Speaker 3: cocoon often does look very thin. It's like a you know, 254 00:15:16,880 --> 00:15:21,880 Speaker 3: wispy spider web or this very very thin kind of 255 00:15:21,880 --> 00:15:24,760 Speaker 3: gossamer like material. But in fact he found when he 256 00:15:24,960 --> 00:15:28,720 Speaker 3: injected the pigmented particles in there, the mucus structure was 257 00:15:28,920 --> 00:15:32,040 Speaker 3: up to six centimeters thick in some places. So it's 258 00:15:32,080 --> 00:15:33,960 Speaker 3: not as wispy as it looks. 259 00:15:33,960 --> 00:15:35,880 Speaker 1: Okay, This would just be the case of there being 260 00:15:35,920 --> 00:15:40,720 Speaker 1: like a thin layer of particles on top of this 261 00:15:41,200 --> 00:15:45,720 Speaker 1: otherwise translucent or semi translucent mucus shielding. They would give 262 00:15:45,720 --> 00:15:48,080 Speaker 1: it the appearance of being super thin when in fact 263 00:15:48,120 --> 00:15:49,640 Speaker 1: it is probably thicker. 264 00:15:49,920 --> 00:15:53,680 Speaker 3: That's right. So dissection of the fish revealed that the 265 00:15:54,440 --> 00:15:59,280 Speaker 3: presence of gland tissue in the buckle cavity correlated with 266 00:15:59,400 --> 00:16:01,960 Speaker 3: whether or not the fish would make a cocoon. It 267 00:16:02,040 --> 00:16:05,320 Speaker 3: was found that fish that did not have this gland 268 00:16:05,440 --> 00:16:08,800 Speaker 3: tissue in the mouth cavity, they did not form the 269 00:16:08,920 --> 00:16:13,680 Speaker 3: mucus cocoons. So that's how they're made and win. But 270 00:16:13,720 --> 00:16:17,000 Speaker 3: what are they for? Well, again, the burn paper mentions 271 00:16:17,040 --> 00:16:20,920 Speaker 3: this hypothesis that the mucus sleeping bag somehow protects the 272 00:16:21,000 --> 00:16:25,520 Speaker 3: fish from large predators. A commonly mentioned predator in the 273 00:16:25,560 --> 00:16:28,000 Speaker 3: reef environment would be the more eel. You know, and 274 00:16:28,000 --> 00:16:30,400 Speaker 3: it can get down there in the recesses and attack. 275 00:16:31,000 --> 00:16:34,720 Speaker 3: But apparently there's some doubt about this because, for example, 276 00:16:34,720 --> 00:16:37,920 Speaker 3: when faced with reef dwelling predators such as more eels, 277 00:16:38,320 --> 00:16:42,040 Speaker 3: there is some evidence that sleeping fish within within a 278 00:16:42,120 --> 00:16:46,680 Speaker 3: cocoon are still vulnerable, like they still get eaten. But 279 00:16:46,800 --> 00:16:49,840 Speaker 3: actually I came across an interesting twenty eleven paper that 280 00:16:49,960 --> 00:16:53,480 Speaker 3: looked directly into the function of the mucus cocoon and 281 00:16:53,800 --> 00:16:57,040 Speaker 3: came to a different conclusion. So this was published in 282 00:16:57,080 --> 00:17:00,920 Speaker 3: the journal Biology Letters by Grutterer at All and the 283 00:17:01,040 --> 00:17:03,360 Speaker 3: title is this will give some of the findings away 284 00:17:03,720 --> 00:17:09,080 Speaker 3: fish mucus cocoons the mosquito nets of the sea. This 285 00:17:09,160 --> 00:17:12,399 Speaker 3: was in the year twenty eleven. So in this paper 286 00:17:12,440 --> 00:17:16,280 Speaker 3: the authors look at another hypothesis, which is the idea 287 00:17:16,359 --> 00:17:21,600 Speaker 3: that mucus envelopes actually protect the fish inside from parasites 288 00:17:21,880 --> 00:17:27,840 Speaker 3: such as ectoparasitic nathid isopods. These are these little bloodsucking 289 00:17:27,920 --> 00:17:32,160 Speaker 3: parasites that live throughout the ocean, often compared to terrestrial 290 00:17:32,240 --> 00:17:36,719 Speaker 3: mosquitoes and ticks. Raw I attached to a little photo 291 00:17:36,760 --> 00:17:38,479 Speaker 3: of these things for you to look at. They're kind 292 00:17:38,480 --> 00:17:41,320 Speaker 3: of shrimp like in appearance maybe look like a cross 293 00:17:41,359 --> 00:17:44,600 Speaker 3: between a shrimp and a tick. Yeah yeah, And the 294 00:17:44,600 --> 00:17:48,159 Speaker 3: authors point out that during the daytime, when parrotfish are 295 00:17:48,240 --> 00:17:51,760 Speaker 3: swimming around, they actually get some help. They get some 296 00:17:51,840 --> 00:17:56,239 Speaker 3: protection against blood drinking isopods from cleaner fish. You know, 297 00:17:56,320 --> 00:17:59,359 Speaker 3: this is a relationship where a smaller fish that wants 298 00:17:59,400 --> 00:18:03,440 Speaker 3: to eat these parasites will come along and help pick 299 00:18:03,480 --> 00:18:06,040 Speaker 3: them off to sort of groom the outside of the 300 00:18:06,480 --> 00:18:11,080 Speaker 3: larger fish. But how do the fish protect themselves at night. 301 00:18:11,600 --> 00:18:14,640 Speaker 3: The idea behind this experiment was that maybe the mucus 302 00:18:14,640 --> 00:18:18,640 Speaker 3: cocoon functions like a mosquito net to protect the sleeping 303 00:18:18,720 --> 00:18:24,399 Speaker 3: fish from these heimatophagous parasites. So they tested this hypothesis 304 00:18:24,440 --> 00:18:29,199 Speaker 3: on the coral reef parrotfish Chlorurus sordid us. And the 305 00:18:29,200 --> 00:18:31,160 Speaker 3: way they tested it was they got some of these fish, 306 00:18:31,200 --> 00:18:34,440 Speaker 3: they separated them into groups that would sleep with and 307 00:18:34,600 --> 00:18:38,240 Speaker 3: without the benefit of cocoons in the presence of these 308 00:18:38,240 --> 00:18:41,560 Speaker 3: isopod parasites. And actually, the way they did it was 309 00:18:41,600 --> 00:18:45,240 Speaker 3: they took a subset of cocoon fish and found a 310 00:18:45,240 --> 00:18:47,480 Speaker 3: way to sort of gently push them out of their 311 00:18:47,560 --> 00:18:53,119 Speaker 3: envelopes without waking them up. So what do they find Yes, indeed, 312 00:18:53,200 --> 00:18:57,480 Speaker 3: the fish without the mucus bag experienced way more attacks 313 00:18:57,520 --> 00:19:01,359 Speaker 3: by parasites. How much more well, about ninety five percent 314 00:19:01,400 --> 00:19:05,320 Speaker 3: of the fish without cocoons were attacked by isopods and 315 00:19:05,359 --> 00:19:08,640 Speaker 3: only about ten percent of the fish with cocoons were attacked. 316 00:19:08,800 --> 00:19:12,000 Speaker 1: So huge difference, all right, Right, so yeah, coming back 317 00:19:12,000 --> 00:19:15,400 Speaker 1: to the mosquito net comparisons, Like, initially we looked at 318 00:19:15,400 --> 00:19:17,600 Speaker 1: it and we're like, this mosquito net must protect the 319 00:19:17,640 --> 00:19:21,680 Speaker 1: sleeper from bears, but in reality it protects them from 320 00:19:21,920 --> 00:19:25,000 Speaker 1: mosquitoes and similar insects that sort of thing. 321 00:19:25,359 --> 00:19:30,360 Speaker 3: Or maybe even something downstream from mosquitoes in the analogy here, 322 00:19:30,400 --> 00:19:34,960 Speaker 3: because the authors also investigated the question of how energetically 323 00:19:35,080 --> 00:19:39,199 Speaker 3: costly it is for the fish to make these mucous orbs, 324 00:19:39,680 --> 00:19:42,320 Speaker 3: and they calculated that it takes about two point five 325 00:19:42,400 --> 00:19:46,399 Speaker 3: percent of a fish's daily energy budget to make the 326 00:19:46,520 --> 00:19:50,040 Speaker 3: mucus bag. Now, when I first saw that figure, I 327 00:19:50,119 --> 00:19:52,280 Speaker 3: kind of thought, oh, hey, that seems fairly cheap, only 328 00:19:52,280 --> 00:19:55,800 Speaker 3: two point five percent. But actually I was reading some 329 00:19:56,359 --> 00:19:59,919 Speaker 3: news reporting on this that quoted the lead author, Alexandra Grutterer, 330 00:20:00,600 --> 00:20:03,560 Speaker 3: and she framed it a different way. She said, quote 331 00:20:03,680 --> 00:20:06,320 Speaker 3: the amount of effort that goes into building these cocoons, 332 00:20:06,359 --> 00:20:09,879 Speaker 3: which requires fish to have developed very large glands about 333 00:20:09,880 --> 00:20:13,879 Speaker 3: the size of a quarter to produce the cocoons, is extraordinary. 334 00:20:14,480 --> 00:20:18,239 Speaker 3: Parasites must exert an enormous pressure on these fish in 335 00:20:18,359 --> 00:20:20,840 Speaker 3: order for the fish to have evolved such a specific 336 00:20:20,880 --> 00:20:24,760 Speaker 3: way of avoiding the parasites. So what could be so pressing? 337 00:20:24,840 --> 00:20:26,600 Speaker 3: Is it really just that you don't want to get 338 00:20:26,600 --> 00:20:29,119 Speaker 3: bitten by these isopods and have them drink some of 339 00:20:29,160 --> 00:20:33,800 Speaker 3: your blood? Well, Grutterer mentions the possibility that the blood 340 00:20:34,000 --> 00:20:37,600 Speaker 3: directly lost to the parasite might not be the only cost. 341 00:20:38,080 --> 00:20:43,480 Speaker 3: These isopods may also transmit a secondary endo parasite which 342 00:20:43,600 --> 00:20:48,280 Speaker 3: lives in the fish's blood, much like how mosquitoes transmit 343 00:20:48,400 --> 00:20:52,920 Speaker 3: malaria in humans. So the mosquitoes themselves are annoying and 344 00:20:53,040 --> 00:20:56,240 Speaker 3: you don't like the mosquitoes, but the malaria is much 345 00:20:56,280 --> 00:21:00,119 Speaker 3: more concerning than the mosquito. Malaria can be deadly in 346 00:21:00,160 --> 00:21:03,080 Speaker 3: a similar way. It's possible that it's worth it for 347 00:21:03,160 --> 00:21:07,680 Speaker 3: these fish to build these slimy bionets to protect themselves 348 00:21:07,960 --> 00:21:11,879 Speaker 3: from blood disease. Wow, so it seems like a good trade. 349 00:21:11,960 --> 00:21:15,040 Speaker 3: You spend a little energy to weave a slime tube 350 00:21:15,560 --> 00:21:19,080 Speaker 3: before bed. Every night, you sleep without these tiny shrimp 351 00:21:19,119 --> 00:21:22,720 Speaker 3: monsters drinking your blood, possibly giving you diseases of the blood. 352 00:21:23,200 --> 00:21:25,199 Speaker 3: And it all works out. And in fact, there was 353 00:21:25,200 --> 00:21:29,280 Speaker 3: one more observation from grutter speaking to the media that 354 00:21:30,359 --> 00:21:33,480 Speaker 3: kind of maybe there's a strategy to recoop some of 355 00:21:33,480 --> 00:21:37,160 Speaker 3: that nightly cost. So Grutterer says, quote, I have observed 356 00:21:37,160 --> 00:21:40,359 Speaker 3: on occasion a fish at dawn with what appeared to 357 00:21:40,400 --> 00:21:44,560 Speaker 3: be mucus stuffed in its mouth. And then she goes 358 00:21:44,600 --> 00:21:47,000 Speaker 3: on to say she has seen other fish, not parrotfish, 359 00:21:47,000 --> 00:21:51,959 Speaker 3: but related fish that also produce mucus cocoons pecking it 360 00:21:52,240 --> 00:21:55,600 Speaker 3: at its old cocoons in the morning. So like recooping 361 00:21:55,600 --> 00:21:59,000 Speaker 3: some of that nightly cost by eating the mucus that 362 00:21:59,040 --> 00:21:59,960 Speaker 3: you created before. 363 00:22:00,760 --> 00:22:03,320 Speaker 1: I mean, that's just it's economically sound. It's like if 364 00:22:03,440 --> 00:22:08,040 Speaker 1: humans produce, say an ectoplasm defense shield at night, you 365 00:22:08,080 --> 00:22:10,680 Speaker 1: would want to to recoup that cost, and that might 366 00:22:10,760 --> 00:22:13,199 Speaker 1: mean consuming all that actoplasm again and getting all that 367 00:22:14,000 --> 00:22:17,840 Speaker 1: liquid back into your body. You know, it reminds us 368 00:22:17,840 --> 00:22:21,880 Speaker 1: of other examples we've looked at in biology, such as 369 00:22:22,080 --> 00:22:26,200 Speaker 1: various reptiles that will eat their own shed skin because 370 00:22:26,359 --> 00:22:27,840 Speaker 1: you know, why waste that, you know. 371 00:22:28,040 --> 00:22:31,640 Speaker 3: Yeah, so may still provide some kind of benefit against 372 00:22:31,960 --> 00:22:36,600 Speaker 3: larger macroscopic predators too. Not certain about that, but it 373 00:22:36,640 --> 00:22:38,840 Speaker 3: does seem like there's a very good case that these 374 00:22:38,920 --> 00:22:42,200 Speaker 3: mucous bags help prevent against parasite attacks. 375 00:22:42,359 --> 00:22:55,440 Speaker 1: Very fascinating, all right, And so for the rest of 376 00:22:55,480 --> 00:22:57,720 Speaker 1: the episode, we're going to turn to the world of 377 00:22:57,760 --> 00:23:02,000 Speaker 1: parrot fish reproduction and pair fish sex. So, as we 378 00:23:02,040 --> 00:23:04,000 Speaker 1: teach out in the first episode, one of the other 379 00:23:04,600 --> 00:23:09,720 Speaker 1: amazing aspects of parrotfish biology broadly is that they change 380 00:23:09,760 --> 00:23:13,480 Speaker 1: sex during the course of a normal lifetime. That's to say, 381 00:23:13,880 --> 00:23:16,680 Speaker 1: this is not something that occurs, you know, only when 382 00:23:16,680 --> 00:23:20,479 Speaker 1: certain environmental conditions are right. It occurs as part of 383 00:23:20,520 --> 00:23:22,440 Speaker 1: a normal life cycle. 384 00:23:22,520 --> 00:23:25,000 Speaker 3: And within a fairly predictable pattern, right. 385 00:23:25,200 --> 00:23:27,520 Speaker 1: That's right. Yeah, And they're going to be a couple 386 00:23:27,560 --> 00:23:29,879 Speaker 1: of exceptions. Again, as we've been distressing, there are a 387 00:23:30,040 --> 00:23:35,840 Speaker 1: number of different species of parrotfish, but still the vast 388 00:23:35,840 --> 00:23:40,960 Speaker 1: majority of them do follow this example that we're going 389 00:23:41,000 --> 00:23:46,640 Speaker 1: to be discussing. So they are proto gynos that means 390 00:23:46,680 --> 00:23:52,040 Speaker 1: female first, hermaphrodites that always turn into males if they 391 00:23:52,080 --> 00:23:54,920 Speaker 1: live long enough, so they're born female and then at 392 00:23:54,920 --> 00:23:58,199 Speaker 1: a certain point during their development they become male and 393 00:23:58,280 --> 00:24:00,560 Speaker 1: live out the rest of their life as a male. 394 00:24:00,840 --> 00:24:03,439 Speaker 3: And this would feedback into something we talked about in 395 00:24:03,440 --> 00:24:08,280 Speaker 3: the first episode, which is sometimes difficulty in identifying parrotfish 396 00:24:08,320 --> 00:24:11,880 Speaker 3: species because they undergo these changes, and these changes come 397 00:24:11,960 --> 00:24:14,280 Speaker 3: with changes to their outer appearance. 398 00:24:14,520 --> 00:24:17,719 Speaker 1: That's right along the way, multiple changes in colorization take place, 399 00:24:18,119 --> 00:24:20,520 Speaker 1: some of which have to do with just aging, some 400 00:24:20,600 --> 00:24:23,680 Speaker 1: of which have to do with changing their sex, and 401 00:24:23,840 --> 00:24:29,480 Speaker 1: others that have to do with diet and other factors. 402 00:24:29,920 --> 00:24:33,639 Speaker 1: This pointed out by the National Marine Sanctuary Foundation as 403 00:24:33,800 --> 00:24:38,160 Speaker 1: resources about the parrotfish. I also want to point out though, 404 00:24:38,200 --> 00:24:43,240 Speaker 1: that according to NAA fishery biologist Ronald J. Saals, gonecharism 405 00:24:43,280 --> 00:24:45,679 Speaker 1: has been reported for I think three species within the 406 00:24:45,720 --> 00:24:48,720 Speaker 1: parrotfish family, which is to say, there are at least 407 00:24:48,720 --> 00:24:51,920 Speaker 1: three species of parrotfish where we have the more typical 408 00:24:51,960 --> 00:24:55,720 Speaker 1: scenario of male female division as opposed to what we 409 00:24:55,800 --> 00:25:03,480 Speaker 1: predominantly see in parrotfish, which again is this this sequential 410 00:25:03,520 --> 00:25:08,800 Speaker 1: hermaphroditism in which the fish are born female and then 411 00:25:08,840 --> 00:25:11,440 Speaker 1: if they live long enough, become male, live out the 412 00:25:11,440 --> 00:25:14,320 Speaker 1: rest of their life as males. And so the basic 413 00:25:14,359 --> 00:25:18,320 Speaker 1: scenario is most parrotfish are born females, continue to grow 414 00:25:18,760 --> 00:25:23,440 Speaker 1: to reproduce externally as females, generally in the harem of 415 00:25:23,480 --> 00:25:27,199 Speaker 1: a larger protective male who also tends to a grazing territory, 416 00:25:27,720 --> 00:25:30,600 Speaker 1: and in time, if that female lives long enough and 417 00:25:30,680 --> 00:25:35,720 Speaker 1: grows large enough, she transitions into a larger terminal, reproductive male. 418 00:25:36,400 --> 00:25:36,960 Speaker 3: Interesting. 419 00:25:37,600 --> 00:25:41,560 Speaker 1: Now, in general, parrotfish experience what I've seen referred to 420 00:25:41,600 --> 00:25:46,520 Speaker 1: as moderate longevity. It's going to vary depending on the 421 00:25:46,560 --> 00:25:50,400 Speaker 1: particular specimen, and I think it even the general generalities 422 00:25:50,440 --> 00:25:52,560 Speaker 1: about how long they live is going to vary. I've 423 00:25:52,600 --> 00:25:57,440 Speaker 1: seen in general parrotfish life span sited seven to ten years. 424 00:25:57,760 --> 00:26:00,360 Speaker 1: I've seen it cited as less than twenty. I've also 425 00:26:00,359 --> 00:26:03,439 Speaker 1: seen it sighted as five to six. Again, we have 426 00:26:03,440 --> 00:26:05,320 Speaker 1: a number of different species we're talking about here, and 427 00:26:05,359 --> 00:26:08,360 Speaker 1: I'll throw out additional numbers for a specific species here 428 00:26:08,359 --> 00:26:11,399 Speaker 1: in a bit. We also have to remind ourselves that 429 00:26:11,440 --> 00:26:14,960 Speaker 1: these are creatures living in the ocean, and so there 430 00:26:14,960 --> 00:26:18,520 Speaker 1: are a whole number of factors from blood diseases to 431 00:26:18,920 --> 00:26:22,720 Speaker 1: parasites to eels trying to eat them. To human fishermen 432 00:26:22,760 --> 00:26:23,439 Speaker 1: and so forth. 433 00:26:23,600 --> 00:26:26,159 Speaker 3: It's just hard to imagine like ten straight years of 434 00:26:26,200 --> 00:26:28,520 Speaker 3: biting and scraping on rocks with your teeth. 435 00:26:28,840 --> 00:26:35,800 Speaker 1: Yeah, we're literally scraping by right now. Parrotfish display what 436 00:26:36,000 --> 00:26:38,960 Speaker 1: is referred to as indeterminate growth, which means that there's 437 00:26:39,000 --> 00:26:42,200 Speaker 1: not a full sized growth limit. They just keep growing 438 00:26:42,280 --> 00:26:45,920 Speaker 1: as long as they're alive. And so parrotfish just continue 439 00:26:45,960 --> 00:26:49,000 Speaker 1: to grow at a consistent rate. And this is important 440 00:26:49,040 --> 00:26:52,560 Speaker 1: to consider in making sense of their sex changes because 441 00:26:53,040 --> 00:26:57,080 Speaker 1: one of, if not the primary hypotheses for why they 442 00:26:57,119 --> 00:26:59,879 Speaker 1: do this, why they evolve to do this, does relate 443 00:26:59,920 --> 00:27:03,760 Speaker 1: to their size. Maximum size again, it's going to depend 444 00:27:03,840 --> 00:27:06,879 Speaker 1: on the species. I see ranges like one to four feet. 445 00:27:07,760 --> 00:27:09,640 Speaker 1: But let's go ahead and just talk about the biggest 446 00:27:09,640 --> 00:27:12,320 Speaker 1: parrotfish just to give us like a nice frame of reference, 447 00:27:12,920 --> 00:27:16,440 Speaker 1: because also the largest parrotfish is also pretty gnarly. 448 00:27:17,800 --> 00:27:20,040 Speaker 3: Is this the bumphead we talked about last time? 449 00:27:20,160 --> 00:27:22,080 Speaker 1: It is the bumphead, So we have a little more 450 00:27:22,119 --> 00:27:25,320 Speaker 1: on the bump head here. The bump head, according to 451 00:27:25,920 --> 00:27:28,760 Speaker 1: the NOAA, reaches size as a four point two feet 452 00:27:28,800 --> 00:27:30,840 Speaker 1: long and up to one hundred pounds, So one hundred 453 00:27:30,840 --> 00:27:34,600 Speaker 1: and thirty centimeters forty six kilograms, And not only are 454 00:27:34,640 --> 00:27:37,119 Speaker 1: they the largest parrotfish, but they're among the largest reef 455 00:27:37,119 --> 00:27:41,800 Speaker 1: fish period. Reef environments are generally shallow and tight, so 456 00:27:41,880 --> 00:27:45,120 Speaker 1: you know, they're not inviting places for larger fish. And 457 00:27:45,280 --> 00:27:49,560 Speaker 1: their namesake bump is used like a rams horns in 458 00:27:49,880 --> 00:27:54,800 Speaker 1: male to male competitions, though females also have smaller bumps, which, 459 00:27:54,840 --> 00:27:57,919 Speaker 1: of course, if the parrotfish lives long enough, is going 460 00:27:57,960 --> 00:27:59,960 Speaker 1: to grow in size once they have changed sect. 461 00:28:00,960 --> 00:28:03,680 Speaker 3: Okay, so these are fish that just keep growing, even 462 00:28:03,720 --> 00:28:08,000 Speaker 3: though that's not necessarily the best for them in all ways, 463 00:28:08,040 --> 00:28:11,640 Speaker 3: like it might limit what coral surfaces they can access 464 00:28:11,680 --> 00:28:12,359 Speaker 3: and so forth. 465 00:28:12,560 --> 00:28:15,520 Speaker 1: Well, these guys are just bigger anyway. This is just 466 00:28:15,720 --> 00:28:17,840 Speaker 1: But this would I guess, seem to be like the 467 00:28:17,880 --> 00:28:21,639 Speaker 1: maximum size that seems to fit into the evolutionary economy 468 00:28:22,080 --> 00:28:24,879 Speaker 1: of living around the reef. Okay, like I guess it 469 00:28:24,880 --> 00:28:27,760 Speaker 1: would be. It would be hard to argue that parrotfish 470 00:28:27,960 --> 00:28:31,439 Speaker 1: should get larger than this, because we have no living 471 00:28:31,480 --> 00:28:35,520 Speaker 1: parrotfish that get larger than this. I see, the market 472 00:28:35,520 --> 00:28:39,440 Speaker 1: won't allow it. You know, Now, bump head parrotfish can 473 00:28:39,520 --> 00:28:42,720 Speaker 1: live to be forty years old. I've read they don't 474 00:28:42,720 --> 00:28:46,040 Speaker 1: reach sexual maturity until five to eight years old, and 475 00:28:46,080 --> 00:28:50,520 Speaker 1: sadly their numbers are down except in protected reef environments. 476 00:28:51,040 --> 00:28:53,440 Speaker 3: So I believe based on what I've read, these are 477 00:28:53,480 --> 00:28:56,080 Speaker 3: the ones that are classic. When we talked about the 478 00:28:56,080 --> 00:29:01,760 Speaker 3: different classifications of parrotfish feed behaviors based on like sort 479 00:29:01,800 --> 00:29:04,240 Speaker 3: of how hard they gouge the rock or the coral, 480 00:29:04,680 --> 00:29:07,800 Speaker 3: and these would be like the excavators, right, like they 481 00:29:07,840 --> 00:29:09,640 Speaker 3: are plowing into that stuff. 482 00:29:09,840 --> 00:29:11,960 Speaker 1: Yeah, these guys take the big bites. I was reading 483 00:29:11,960 --> 00:29:14,600 Speaker 1: a little bit more about this on the NOAA website 484 00:29:14,640 --> 00:29:16,600 Speaker 1: and they said that, yeah, they take out those big 485 00:29:16,640 --> 00:29:19,800 Speaker 1: bites that also end up taking out a little bit 486 00:29:19,800 --> 00:29:21,840 Speaker 1: of live coral. But they stress that this is still 487 00:29:21,920 --> 00:29:24,120 Speaker 1: very healthy for the coral in all the ways we 488 00:29:24,200 --> 00:29:28,000 Speaker 1: already mentioned. I don't remember if we mentioned this. I 489 00:29:28,040 --> 00:29:29,640 Speaker 1: don't remember if we mentioned this or not. But there's 490 00:29:29,640 --> 00:29:33,280 Speaker 1: also the idea that they'll break down dead reef and 491 00:29:33,360 --> 00:29:36,720 Speaker 1: of course turn that into sand, dead bits and branches 492 00:29:36,760 --> 00:29:39,680 Speaker 1: that might otherwise break off in storms and damage other 493 00:29:39,720 --> 00:29:40,560 Speaker 1: parts of the reef. 494 00:29:41,120 --> 00:29:43,560 Speaker 3: Oh yeah, I see, So it's better for it to 495 00:29:43,920 --> 00:29:46,320 Speaker 3: better for this chunk to get ground up in a 496 00:29:46,400 --> 00:29:50,720 Speaker 3: parrotfish's pharyngial mill and pooped out as sand rather than 497 00:29:50,800 --> 00:29:53,120 Speaker 3: knocked off in the storm and hit some other healthy 498 00:29:53,160 --> 00:29:53,840 Speaker 3: part of the reef. 499 00:29:54,120 --> 00:29:56,960 Speaker 1: Yeah, because it's one of the interesting things about about 500 00:29:57,720 --> 00:30:01,200 Speaker 1: reef environments, and this is something you're def only instructed 501 00:30:01,240 --> 00:30:05,560 Speaker 1: about anytime you go out and snorkel or scuba dive. 502 00:30:05,640 --> 00:30:08,840 Speaker 1: Certainly I imagine around these these is that there is 503 00:30:08,920 --> 00:30:11,960 Speaker 1: like a hardness to them. Certainly they can also be 504 00:30:12,080 --> 00:30:14,840 Speaker 1: very like you certainly don't want to stand on them 505 00:30:14,960 --> 00:30:17,440 Speaker 1: or walk on them or touch them for a number 506 00:30:17,480 --> 00:30:20,560 Speaker 1: of reasons, because a lot of times they can be 507 00:30:20,640 --> 00:30:22,720 Speaker 1: quite harmful and scrape you out, they can cut you. 508 00:30:22,720 --> 00:30:25,280 Speaker 1: You don't want any of that. But on top of that, 509 00:30:25,320 --> 00:30:27,520 Speaker 1: they can be actually quite delicate, and they can be 510 00:30:27,560 --> 00:30:29,840 Speaker 1: easily broken. And so this would be another case of 511 00:30:29,880 --> 00:30:32,640 Speaker 1: where if the parrotfish are doing their thing, that limits 512 00:30:32,680 --> 00:30:36,480 Speaker 1: the amount of damage that they're going to sustain via 513 00:30:36,520 --> 00:30:38,240 Speaker 1: their own dead parts. 514 00:30:38,760 --> 00:30:39,160 Speaker 3: I see. 515 00:30:39,360 --> 00:30:42,560 Speaker 1: But anyway back to sex changes in parrotfish in general. So, 516 00:30:42,640 --> 00:30:46,480 Speaker 1: according to Jennifer Hodge, a postdoctoral researcher in the Department 517 00:30:46,480 --> 00:30:49,640 Speaker 1: of Evolution and Ecology in the UC Davis College of 518 00:30:49,680 --> 00:30:56,320 Speaker 1: Biological Sciences in twenty twenty. The indeterminate growth factor may 519 00:30:56,360 --> 00:30:58,200 Speaker 1: in fact be key. I was reading a couple of 520 00:31:00,160 --> 00:31:03,040 Speaker 1: from a couple of sources. Here. One is a UC 521 00:31:03,200 --> 00:31:08,000 Speaker 1: Davis article by Andy Fell covering her work titled male 522 00:31:08,080 --> 00:31:11,920 Speaker 1: size advantage drives evolution and sex change of sex change 523 00:31:11,920 --> 00:31:15,120 Speaker 1: in Refish. And then also there is a full paper 524 00:31:15,160 --> 00:31:16,880 Speaker 1: I was looking at, and this is by Hodge at 525 00:31:16,880 --> 00:31:21,640 Speaker 1: All titled Correlated Evolution of sex allocation and Mating system 526 00:31:21,960 --> 00:31:25,920 Speaker 1: in Rasses and Parrotfishes, published in The American Naturalist the 527 00:31:26,000 --> 00:31:26,560 Speaker 1: same year. 528 00:31:26,840 --> 00:31:31,160 Speaker 3: Okay, so how would this indeterminate growth factor affect how 529 00:31:31,360 --> 00:31:34,719 Speaker 3: sex is distributed and developed in a fish species. 530 00:31:35,120 --> 00:31:38,520 Speaker 1: It basically comes down to the fact the observation that 531 00:31:39,960 --> 00:31:43,480 Speaker 1: reproduction among parrotfish and also some of these other fish, 532 00:31:43,680 --> 00:31:47,800 Speaker 1: but for our interests here, the parrotfish is often dominated 533 00:31:47,840 --> 00:31:49,880 Speaker 1: by large males. 534 00:31:49,720 --> 00:31:52,800 Speaker 3: Meaning that like, a larger male has a better chance 535 00:31:52,840 --> 00:31:53,920 Speaker 3: of mating more. 536 00:31:54,560 --> 00:31:58,840 Speaker 1: Right, and that and that male large males and this 537 00:31:58,880 --> 00:32:03,160 Speaker 1: would be the terminal mail in parrotfish fishes. They are 538 00:32:03,200 --> 00:32:06,520 Speaker 1: the ones dominating like all of the mating. So if 539 00:32:06,560 --> 00:32:08,840 Speaker 1: you are not a large male, you are just not 540 00:32:09,000 --> 00:32:13,400 Speaker 1: going to be effective at reproduction. If you are a 541 00:32:13,440 --> 00:32:17,880 Speaker 1: small parrotfish male, your chances of passing on your genes 542 00:32:18,320 --> 00:32:20,959 Speaker 1: is rather slim. And remember the genetic mission is to 543 00:32:21,040 --> 00:32:25,880 Speaker 1: pass on your genes. Now, as a small parrotfish female, however, 544 00:32:26,040 --> 00:32:28,960 Speaker 1: it's less of an issue. The bigger males, they have 545 00:32:29,040 --> 00:32:32,200 Speaker 1: the advantage. They're going to form these harems. If you 546 00:32:32,240 --> 00:32:34,000 Speaker 1: are a small female, you can be part of that 547 00:32:34,040 --> 00:32:37,920 Speaker 1: harem and you are doing your reproductive part as a parrotfish. 548 00:32:37,960 --> 00:32:41,480 Speaker 1: And so that's according to this hypothesis, this is where 549 00:32:41,600 --> 00:32:46,800 Speaker 1: the evolution of sequential hermaphrotitism evolves as a strategy by 550 00:32:46,800 --> 00:32:51,040 Speaker 1: which all individuals have a better shot at participating in reproduction. 551 00:32:51,160 --> 00:32:54,760 Speaker 1: So start off small and female, you definitely get to reproduce. 552 00:32:55,120 --> 00:32:57,080 Speaker 1: And then if you live long enough and you grow 553 00:32:57,080 --> 00:33:01,400 Speaker 1: big enough, you shift to the male set, and then 554 00:33:01,640 --> 00:33:04,240 Speaker 1: you have the size to prove effective. You're better at 555 00:33:04,240 --> 00:33:07,720 Speaker 1: controlling territory resources, harems, etc. 556 00:33:08,520 --> 00:33:12,760 Speaker 3: That's interesting, Okay, So it gives more individuals of the 557 00:33:12,800 --> 00:33:15,360 Speaker 3: species a chance to mate more often. 558 00:33:16,440 --> 00:33:18,960 Speaker 1: Yes, yeah, that's the way I understand it. And I 559 00:33:19,040 --> 00:33:23,800 Speaker 1: was looking again at the writings of in Oa's fishery 560 00:33:23,800 --> 00:33:27,920 Speaker 1: biologist Ronald J. Salce and Salce points out that, yeah, 561 00:33:27,920 --> 00:33:32,760 Speaker 1: the largest parrotfish are always terminal males, and he points 562 00:33:32,800 --> 00:33:36,240 Speaker 1: out that the species, the various species in the genus 563 00:33:36,280 --> 00:33:41,120 Speaker 1: Skeras typically exhibit the following reproductive characteristics. So we see this. 564 00:33:41,280 --> 00:33:45,480 Speaker 1: First of all, there is this proto Guynus female first hermaphrotitism, 565 00:33:46,280 --> 00:33:48,640 Speaker 1: There are breeding territories, there are harems, and there is 566 00:33:48,720 --> 00:33:50,160 Speaker 1: external fertilization. 567 00:33:50,720 --> 00:33:53,520 Speaker 3: Oh yeah, the external fertilization is a good point, because 568 00:33:53,680 --> 00:33:55,760 Speaker 3: I don't want to give the wrong idea when I 569 00:33:55,800 --> 00:33:59,440 Speaker 3: was mentioning mating that it's like, you know, the kind 570 00:33:59,440 --> 00:34:02,640 Speaker 3: of active you might be picturing that. Instead, there's a 571 00:34:02,720 --> 00:34:07,120 Speaker 3: there's an external meeting of the game meats of these animals. 572 00:34:06,840 --> 00:34:10,360 Speaker 1: Right, And I think, I don't know humans, maybe we 573 00:34:10,400 --> 00:34:12,920 Speaker 1: have a problem imagining fish sex in general. But somehow 574 00:34:12,920 --> 00:34:15,320 Speaker 1: this makes it a little easier to sort of picture 575 00:34:15,360 --> 00:34:17,480 Speaker 1: how all this is happening. I think it's all out 576 00:34:17,480 --> 00:34:20,520 Speaker 1: in the open. So SAAL's points out though that in 577 00:34:20,560 --> 00:34:24,200 Speaker 1: the past, and really maybe not in the two distant past, 578 00:34:24,520 --> 00:34:27,680 Speaker 1: we've had these other hypotheses that there might be a 579 00:34:27,719 --> 00:34:32,800 Speaker 1: social trigger for the change in sex. But apparently, based 580 00:34:32,800 --> 00:34:35,600 Speaker 1: on what he wrote, this hasn't necessarily been observed, or 581 00:34:35,640 --> 00:34:39,400 Speaker 1: at least not in all cases or in a broad 582 00:34:39,520 --> 00:34:44,400 Speaker 1: array of cases, because we have scenarios where large terminal 583 00:34:44,440 --> 00:34:48,360 Speaker 1: males are removed from a population, such as by fishing, 584 00:34:48,760 --> 00:34:52,520 Speaker 1: and the females don't just switch over at an earlier age, 585 00:34:52,560 --> 00:34:55,000 Speaker 1: but rather have more difficulty finding a mate. 586 00:34:55,440 --> 00:34:57,919 Speaker 3: Oh okay, so it might be kind of baked in 587 00:34:58,000 --> 00:34:59,800 Speaker 3: that they need to reach a certain size. 588 00:35:00,239 --> 00:35:02,080 Speaker 1: Seems to be the case now, I don't, But again, 589 00:35:02,080 --> 00:35:04,680 Speaker 1: we're dealing with hypotheses here. I don't think that there 590 00:35:04,800 --> 00:35:07,960 Speaker 1: that anything is like one hundred percent proven out here. 591 00:35:07,960 --> 00:35:09,600 Speaker 1: There's still a lot of work that needs to be 592 00:35:09,640 --> 00:35:11,640 Speaker 1: done because a lot of it comes down to, Okay, 593 00:35:11,640 --> 00:35:15,400 Speaker 1: you can have this general idea that this practice evolved 594 00:35:15,520 --> 00:35:20,200 Speaker 1: because large males dominate reproduction and and it makes more 595 00:35:20,239 --> 00:35:23,040 Speaker 1: sense from a reproductive standpoint to start off as female 596 00:35:23,040 --> 00:35:25,120 Speaker 1: and then become male. But then what is the trigger 597 00:35:25,200 --> 00:35:28,520 Speaker 1: is it? Is it purely based on how big you grow? 598 00:35:29,080 --> 00:35:34,320 Speaker 1: Or are there environmental or social triggers? And Uh, ultimately 599 00:35:34,320 --> 00:35:38,160 Speaker 1: the size advantage explanation is just one hypothesis. Uh, there's 600 00:35:38,200 --> 00:35:41,200 Speaker 1: an you know, other hypotheses put more emphasis on possible 601 00:35:41,280 --> 00:35:46,560 Speaker 1: social or in mental environmental triggers such as changes and 602 00:35:46,600 --> 00:35:49,439 Speaker 1: in population density, that sort of thing, in the same 603 00:35:49,480 --> 00:35:52,320 Speaker 1: way that we see examples and say the world of salamanders, 604 00:35:52,360 --> 00:35:55,080 Speaker 1: where uh, you know something they're too many, or you know, 605 00:35:55,440 --> 00:35:58,879 Speaker 1: something goes on demographically in a collect in a certain group, 606 00:35:58,960 --> 00:36:02,680 Speaker 1: then you may have biological changes that result. But I 607 00:36:02,680 --> 00:36:06,840 Speaker 1: guess broadly if there are, if there are social or 608 00:36:06,960 --> 00:36:10,880 Speaker 1: environmental triggers that are involved in theory, we would be 609 00:36:10,920 --> 00:36:14,560 Speaker 1: able to observe them, you know, such as response to 610 00:36:14,600 --> 00:36:17,880 Speaker 1: overfishing of large males in response to changes in the 611 00:36:17,960 --> 00:36:21,640 Speaker 1: environment and so forth. Now there are individual species of 612 00:36:21,680 --> 00:36:26,000 Speaker 1: parrotfish where we might see some of those, like social triggers. 613 00:36:26,040 --> 00:36:29,360 Speaker 1: Perhaps I've seen discussion of the stop light parrotfish in 614 00:36:29,400 --> 00:36:34,440 Speaker 1: particular as perhaps being influenced by population density, growth and 615 00:36:34,560 --> 00:36:38,520 Speaker 1: mortality rates. So if terminal the idea here being that 616 00:36:38,600 --> 00:36:42,200 Speaker 1: it may be the case that terminal males in stop 617 00:36:42,280 --> 00:36:46,920 Speaker 1: light parrotfish populations, if they experience higher mortality rates so 618 00:36:46,960 --> 00:36:49,279 Speaker 1: more of them are dying, or if they are just 619 00:36:49,360 --> 00:36:55,160 Speaker 1: smaller overall sizes in the terminal males, then this change 620 00:36:55,200 --> 00:37:00,239 Speaker 1: may trigger earlier onset of the sex change in the 621 00:37:00,239 --> 00:37:04,520 Speaker 1: female parrotfish in that population. So, like I say, it's 622 00:37:04,560 --> 00:37:08,120 Speaker 1: still would line up with this idea that this evolved 623 00:37:08,200 --> 00:37:13,799 Speaker 1: because male parrotfish, large male parrotfish dominate reproduction. But it 624 00:37:13,800 --> 00:37:16,480 Speaker 1: would maybe be a slightly different case of like what 625 00:37:16,680 --> 00:37:20,720 Speaker 1: is actually causing it based on my understanding looking at 626 00:37:20,719 --> 00:37:23,520 Speaker 1: this documentation. But I like to say there's still I 627 00:37:23,520 --> 00:37:25,879 Speaker 1: think a lot of work going on here. Two thanks. 628 00:37:25,960 --> 00:37:29,239 Speaker 1: Keep in mind, though there is no evidence that any 629 00:37:29,280 --> 00:37:33,799 Speaker 1: species of parrotfish can undergo a sex change, reversal, or 630 00:37:33,880 --> 00:37:37,880 Speaker 1: a second sex change. Like it is, it is sequential, 631 00:37:38,480 --> 00:37:43,480 Speaker 1: sequential hermaphroditism. So it's female, then male. There are no 632 00:37:43,640 --> 00:37:46,239 Speaker 1: known cases where a male can then change back to 633 00:37:46,320 --> 00:37:49,160 Speaker 1: female do to you do to any kind of you know, 634 00:37:49,239 --> 00:37:52,760 Speaker 1: social pressure, environmental or what have you. It is female 635 00:37:52,760 --> 00:37:56,120 Speaker 1: and then male and again sequential hermaphroditism of one form 636 00:37:56,160 --> 00:37:57,560 Speaker 1: or another can be found in other fish. As I 637 00:37:57,600 --> 00:38:00,680 Speaker 1: mentioned the ras is. Apparently you see some version of 638 00:38:00,680 --> 00:38:05,759 Speaker 1: this in some molluscs and crustaceans. The size reproduction hypothesis 639 00:38:05,840 --> 00:38:09,200 Speaker 1: is widely e employed across the board, but I've also 640 00:38:09,239 --> 00:38:12,319 Speaker 1: seen I think the prevention of inbreeding being brought in 641 00:38:12,360 --> 00:38:15,279 Speaker 1: as another possible reason though I'm not sure if that 642 00:38:15,400 --> 00:38:19,319 Speaker 1: really pans out, particularly with the parrotfish. That may just 643 00:38:19,560 --> 00:38:24,760 Speaker 1: really have more to do with hermaphroditism as an evolutionary 644 00:38:25,120 --> 00:38:26,040 Speaker 1: trait in general. 645 00:38:26,520 --> 00:38:30,720 Speaker 3: But the sequential version you're saying, it seems that there's 646 00:38:30,760 --> 00:38:34,800 Speaker 3: a similar evolutionary explanation given across these different classes of animals, 647 00:38:34,840 --> 00:38:37,000 Speaker 3: which is that it likely has to do with a 648 00:38:37,080 --> 00:38:44,640 Speaker 3: relationship between the animal's size and its likelihood of successful reproduction, yes, exactly, 649 00:38:44,760 --> 00:38:49,480 Speaker 3: or specifically the size of males and successful reproduction, and 650 00:38:49,520 --> 00:38:51,280 Speaker 3: the fact that the animals just keep growing. 651 00:38:51,640 --> 00:38:55,120 Speaker 1: Yeah, So it's fascinating. Yeah, this is like a factoid 652 00:38:55,120 --> 00:38:57,480 Speaker 1: about parrotfish that I'd long heard, but I'd never really 653 00:38:57,600 --> 00:39:00,000 Speaker 1: looked into it. I guess one of the problems is 654 00:39:00,040 --> 00:39:01,799 Speaker 1: when you're in the water, it's it's really hard to 655 00:39:01,840 --> 00:39:04,239 Speaker 1: research stuff. You're just like, oh, I'm gonna take your 656 00:39:04,239 --> 00:39:06,040 Speaker 1: word for it, and I'm I'm gonna look at it 657 00:39:06,960 --> 00:39:09,080 Speaker 1: and then I'll try to remember to read about it later. 658 00:39:18,960 --> 00:39:21,439 Speaker 3: Man, you would never guess that there is so much 659 00:39:21,440 --> 00:39:24,960 Speaker 3: interesting stuff about these fish just watching them scrape the rocks. 660 00:39:25,320 --> 00:39:28,360 Speaker 1: Yeah, yeah, I mean just observing them, and I've observed 661 00:39:28,400 --> 00:39:29,799 Speaker 1: in plenty of times in the past. You know, it's 662 00:39:29,840 --> 00:39:31,400 Speaker 1: like you look at them and you're like, well, they're 663 00:39:31,400 --> 00:39:35,879 Speaker 1: a little bit goofy looking, they're beautifully colored, and then 664 00:39:35,920 --> 00:39:37,680 Speaker 1: you learn a little bit more about them, but there's still, 665 00:39:37,800 --> 00:39:40,319 Speaker 1: you know, greater depths of interest there. I guess that's 666 00:39:40,360 --> 00:39:42,919 Speaker 1: the that's the nature of most fish in the sea. 667 00:39:43,320 --> 00:39:44,400 Speaker 1: Never take them for granted. 668 00:39:44,680 --> 00:39:47,560 Speaker 3: In between recording these two episode parts, did you end 669 00:39:47,640 --> 00:39:51,320 Speaker 3: up googling more human parrot fish bites? 670 00:39:51,600 --> 00:39:51,960 Speaker 1: I did. 671 00:39:52,080 --> 00:39:54,080 Speaker 3: I don't know why I did. I shouldn't have. 672 00:39:54,320 --> 00:39:55,359 Speaker 1: Why would you do that? 673 00:39:55,560 --> 00:39:57,840 Speaker 3: I don't know. I regret it. I wish I hadn't 674 00:39:57,840 --> 00:39:58,799 Speaker 3: done it. I just did. 675 00:40:00,160 --> 00:40:02,160 Speaker 1: The only thing of that nature that I did run 676 00:40:02,160 --> 00:40:04,520 Speaker 1: across is when I was looking up pictures and looking 677 00:40:04,520 --> 00:40:09,400 Speaker 1: at articles about the big boys, the bumphead parrotfish is 678 00:40:09,400 --> 00:40:12,000 Speaker 1: there was an image of some coral with some big, 679 00:40:12,120 --> 00:40:15,280 Speaker 1: chunky bites taken out of it, and that was pretty impressive, 680 00:40:15,960 --> 00:40:17,960 Speaker 1: and it did cross my mind. It's like that I 681 00:40:18,000 --> 00:40:20,880 Speaker 1: would not want those bites taken out of my own flesh. 682 00:40:21,080 --> 00:40:23,120 Speaker 3: Yeah, I would not want that to be my bones. 683 00:40:23,360 --> 00:40:24,480 Speaker 1: Yeah. 684 00:40:24,520 --> 00:40:27,920 Speaker 3: But to emphasize yet again, as we did last time, parrotfisher. 685 00:40:28,520 --> 00:40:32,000 Speaker 3: There's no indication that they're very aggressive or looking to 686 00:40:32,040 --> 00:40:35,680 Speaker 3: bite humans that like, these stories come from people who 687 00:40:35,680 --> 00:40:38,240 Speaker 3: were getting up in the parrotfish's business. 688 00:40:38,200 --> 00:40:42,000 Speaker 1: Right, Yeah. I think I saw one account and this 689 00:40:42,120 --> 00:40:44,640 Speaker 1: is like, you know, this is I guess inherently unverified 690 00:40:45,360 --> 00:40:49,160 Speaker 1: of snorkelers or divers where someone was just sort of 691 00:40:49,880 --> 00:40:54,279 Speaker 1: casually bitten by a parrotfish. But in that thread, like 692 00:40:54,320 --> 00:40:56,759 Speaker 1: everyone was like, wow, that's weird. It's never happened to me. 693 00:40:56,960 --> 00:41:00,480 Speaker 1: So I don't know, you know, in the wild one 694 00:41:00,520 --> 00:41:04,320 Speaker 1: officer certainly possible. Who knows what that that parrotfish was 695 00:41:04,360 --> 00:41:05,120 Speaker 1: going through that day? 696 00:41:05,480 --> 00:41:08,400 Speaker 3: Yeah. I guess any species of any fish could in 697 00:41:08,440 --> 00:41:11,960 Speaker 3: some case be aggressive, but it's not like generally thought like, 698 00:41:12,000 --> 00:41:15,279 Speaker 3: oh wow, you gotta be careful, like they're they're coming for. 699 00:41:15,200 --> 00:41:17,799 Speaker 1: You, right, Yeah, I don't think they're they're coming for you. 700 00:41:17,920 --> 00:41:20,839 Speaker 3: Yeah, I'm just because I'm imagining so like, you know, 701 00:41:20,920 --> 00:41:23,719 Speaker 3: the James Bond villain has a pool of piranhas that 702 00:41:23,760 --> 00:41:26,640 Speaker 3: he drops his henchman into when they make a mistake, 703 00:41:26,680 --> 00:41:29,160 Speaker 3: And I'm just thinking like, could they have gone with 704 00:41:29,200 --> 00:41:31,680 Speaker 3: a pool of parrotfish? How would that work out differently? 705 00:41:31,880 --> 00:41:35,320 Speaker 1: We have cotajo bodhi, mister bond with a fine layer 706 00:41:35,400 --> 00:41:39,879 Speaker 1: of algae in coral dust, you will now drop you 707 00:41:40,120 --> 00:41:43,400 Speaker 1: into that of parrotfish. 708 00:41:43,920 --> 00:41:48,640 Speaker 3: M No, not the bump edge. Okay, does that do 709 00:41:48,680 --> 00:41:49,640 Speaker 3: it for parrotfish? 710 00:41:49,719 --> 00:41:51,319 Speaker 1: I think it does. You know, they may have more 711 00:41:51,360 --> 00:41:53,480 Speaker 1: mysteries that we didn't explore, but I think we hit 712 00:41:53,760 --> 00:41:57,040 Speaker 1: all the really interesting stuff here. But hey, if you 713 00:41:57,200 --> 00:42:01,080 Speaker 1: know of other dimensions to the parrot fish or various 714 00:42:01,120 --> 00:42:04,200 Speaker 1: parrotfish species that we didn't talk about, write in because 715 00:42:04,239 --> 00:42:07,000 Speaker 1: we would love to hear from you. Just a reminder 716 00:42:07,120 --> 00:42:09,239 Speaker 1: that's Stuff to Blow your Mind Here is primarily a 717 00:42:09,280 --> 00:42:12,520 Speaker 1: science and culture podcast, with core episodes on Tuesdays and Thursdays, 718 00:42:12,840 --> 00:42:16,000 Speaker 1: listener mail on Mondays, short form episode on Wednesdays, and 719 00:42:16,040 --> 00:42:18,239 Speaker 1: on Fridays. We set aside most serious concerns to just 720 00:42:18,239 --> 00:42:20,759 Speaker 1: talk about a weird film on Weird House Cinema. 721 00:42:20,960 --> 00:42:24,760 Speaker 3: Huge thanks as always to our excellent audio producer JJ Posway. 722 00:42:25,080 --> 00:42:26,680 Speaker 3: If you would like to get in touch with us 723 00:42:26,719 --> 00:42:29,240 Speaker 3: with feedback on this episode or any other, to suggest 724 00:42:29,239 --> 00:42:31,480 Speaker 3: a topic for the future, or just to say hello, 725 00:42:31,760 --> 00:42:34,520 Speaker 3: you can email us at contact at stuff to Blow 726 00:42:34,520 --> 00:42:42,560 Speaker 3: your Mind dot com. 727 00:42:43,040 --> 00:42:46,000 Speaker 2: Stuff to Blow your Mind is production of iHeartRadio. For 728 00:42:46,080 --> 00:42:48,839 Speaker 2: more podcasts from my heart Radio, visit the iHeartRadio app, 729 00:42:49,000 --> 00:43:02,120 Speaker 2: Apple podcasts, or wherever you listen to your favorite shows. 730 00:43:02,280 --> 00:43:02,560 Speaker 3: West