Speaker 1: Hey, you welcome to Stuff to Blow your Mind. This
Speaker 1: is Robert Lamb. Today's Saturday, so of course we have
Speaker 1: a vault episode for you. This is going to be
Speaker 1: the Parrotfish Part one. It originally published five twenty one,
Speaker 1: twenty twenty four. I hope you enjoy.
Speaker 2: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 1: Hey you welcome to Stuff to Blow your Mind.
Speaker 3: My name is Robert Lamb and I am Joe McCormick.
Speaker 3: And today on the podcast we're going to be beginning
Speaker 3: a look at parrotfish or parrotfishes. This is one of
Speaker 3: those topics that literally just started with me looking at
Speaker 3: a picture. I was staring at a picture of a
Speaker 3: bizarre goofy, goofy appearing animal and thinking I want to
Speaker 3: know more about this critter, and then discovering that indeed,
Speaker 3: this organ is a is a peculiar and fascinating story,
Speaker 3: and there is so much more to it than you
Speaker 3: might guess just by looking at it at its strange
Speaker 3: beak or toothy mouth.
Speaker 1: Yeah, parrotfish are pretty fascinating. I've snorkeled among the parrotfish
Speaker 1: many times and can attest that they're curious looking fish.
Speaker 1: They're pleasure to watch. They're often very colorful. So I'm
Speaker 1: going to throw in more of my observations as we proceed.
Speaker 1: But I think, on the other hand, in coral reef environments,
Speaker 1: where I've done most of my snorkeling, and where a
Speaker 1: lot of snorkeling takes place, they can actually be easy
Speaker 1: to take for granted because they're generally around and you
Speaker 1: know significant numbers that these environments. Often these are protected
Speaker 1: reefs that I've been to, they're not particularly shy, they're
Speaker 1: easily found in shallow water, so you know, oftentimes you're
Speaker 1: dealing with like reef environments that are either very accessible
Speaker 1: just from the shore or just a very short boat
Speaker 1: ride sort of a situation. So in a way, it's
Speaker 1: easy to take them for granted because they're there, you
Speaker 1: see them, and then you end up focusing a lot
Speaker 1: more of your attention looking for some of the harder
Speaker 1: to find organisms that are going to live in these
Speaker 1: reef environments. So it's actually a great opportunity to stop
Speaker 1: and focus on this remarkable fish that I honestly had
Speaker 1: never really thought about devoting a whole episode or series
Speaker 1: of episodes too. But there's more than enough to talk about.
Speaker 3: I've never snorkeled and seen them in person, so I'm
Speaker 3: envious of this experience and maybe I will someday. I
Speaker 3: look forward to that. But I've seen video and in
Speaker 3: some cases that there's almost a feeling of like bees
Speaker 3: buzzing around a shrub that's covered in flowers. You know,
Speaker 3: it's just kind of the general gentle grazing activity of
Speaker 3: some animals surrounding a plant like structure, but in this
Speaker 3: case it's of the big skeleton of stony corals.
Speaker 1: Yeah, the grazing observation is key, and it's something that
Speaker 1: has long been observed for these creatures, as we'll discuss
Speaker 1: going back into ancient times, even when we didn't have
Speaker 1: snorkelers as we think of them today, you still had
Speaker 1: individuals fishing in shallow environments, sometimes fishing for the parrotfish
Speaker 1: in question, and observing that, Hey, these creatures appear to
Speaker 1: be grazing, unlike most of the fish that we are observing.
Speaker 3: So parrotfish are not one species, but a larger group
Speaker 3: of fish containing about ninety something individual species. I've seen
Speaker 3: different estimates on the numbers. I think it's older ones
Speaker 3: that say, maybe like eighty species. Others say closer to
Speaker 3: one hundred, but I think ninety something is about right.
Speaker 3: They range broadly in terms of size and appearance. In fact,
Speaker 3: they range broadly in terms of appearance even within a species,
Speaker 3: as we'll get to maybe in this part or maybe later,
Speaker 3: but some adult parrotfish are less than a foot in length,
Speaker 3: and some of the largest are almost four feet or
Speaker 3: about one point two meters in length, so they can
Speaker 3: range from medium small to quite large. These fish are
Speaker 3: sometimes taxonomized as a family called scarid and in other
Speaker 3: cases regarded as a subfamily of Labridy, which are commonly
Speaker 3: known as the rasses. I think you can see some
Speaker 3: morphological similarities with the fish called rasses, kind of the
Speaker 3: way they swim, the way they use their pectoral fins,
Speaker 3: and stuff like that. But a characteristic come into many
Speaker 3: parrotfishes is that they tend to live around coral reefs,
Speaker 3: especially in the tropics.
Speaker 1: I also want to throw in there that there are
Speaker 1: occasionally fish that are just sort of commonly called a
Speaker 1: parrotfish or informally called a parrotfish, that are not parrotfish,
Speaker 1: mainly the blood red parrot chick lid, which apparently is
Speaker 1: a popular aquarium species.
Speaker 3: This is not.
Speaker 1: Actually related to proper parrotfish that we're going to be
Speaker 1: talking about here today. And I've also seen some some
Speaker 1: fossil evidence that is sometimes categorized as a parrotfish in
Speaker 1: a way that I'm not sure actually lines up with
Speaker 1: what we're talking about here. But if you've seen a
Speaker 1: picture of a parrotfish proper parrotfish, indeed, go ahead and
Speaker 1: look one up if you're in a position to do so.
Speaker 1: I think it's hard to miss what we're talking about.
Speaker 1: These are very recognizable fish, though again they do very
Speaker 1: greatly in coloration.
Speaker 3: Size, that's right. Yeah, So if you look up pictures
Speaker 3: of them, you'll see that they're often kind of elongated
Speaker 3: in body. They have different shapes. Some are more kind
Speaker 3: of that elongated oval shape and others are blunter in
Speaker 3: the front with like blunt heads. They're in fact, our
Speaker 3: parrotfish called like the blunt head pair of parrotfish or
Speaker 3: the steep head parrotfish. The coloration you'll see on them
Speaker 3: depends on some facts about them and not just their species,
Speaker 3: but sometimes they have quite bright patterns of almost neon color,
Speaker 3: surprising colors to see in nature. Very you know, tropical
Speaker 3: kind of color signals. There's one picture I kept seeing
Speaker 3: where the fish had a color pattern that reminded me
Speaker 3: of the as design from paper cups in the nineties.
Speaker 3: But if you also threw some hot pink in there.
Speaker 3: So there's a lot to take in when you look
Speaker 3: at look at a parrot fish. But before you notice
Speaker 3: any of that, but you know, the head shape, the
Speaker 3: body shape, the coloration patterns, what you will probably notice
Speaker 3: first about any given parrotfish is the mouth. I mean,
Speaker 3: look at these chompers. Rob I've included just several pictures.
Speaker 3: I know you've seen them in person, so your experience
Speaker 3: of the teeth the beak is probably more direct and
Speaker 3: visceral and profound even than mine. But I was just
Speaker 3: looking at these pictures for quite a while the other day,
Speaker 3: and my God, that these beaks, these mouths, it's it's incredible.
Speaker 1: Yeah, Yeah, their mouths are quite fascinating in some of
Speaker 1: the photos. Yeah, they can actually look a little intimidating, though,
Speaker 1: I would say based on the species that I've primarily
Speaker 1: been exposed to in Hawaii and the Caribbean, they tend
Speaker 1: to look more silly then than threatening. But they're definitely
Speaker 1: very cool looking, not taking anything away from that.
Speaker 3: Yeah, So I guess it varies from species to species.
Speaker 3: So parrotfish have these rows of fused teeth on the
Speaker 3: outside of their jaws, which, in some cases, as the
Speaker 3: name implies, look very similar to the beak of a parrot.
Speaker 3: It can look like a bird's beak, But in other cases,
Speaker 3: these fused rows of teeth look like jagged monster jaws,
Speaker 3: sort of like a horseshoe shaped ceramic saw blade. But
Speaker 3: in other cases still they are like a big goofy
Speaker 3: cartoon overbite, like Alfred Y Newman's mouth got hit with
Speaker 3: the radiation from the amazing Colossal Man.
Speaker 1: Now I want to throw in one more note here
Speaker 1: about species classifications coloration. It is worth noting that with
Speaker 1: parrotfish that classifications in naming have long proof challenging because
Speaker 1: they tend to show different colorizations depending on an individual's
Speaker 1: age and sex. So, for example, was pointed out by
Speaker 1: the Waikiki Aquarium, the spectacled parrotfish is reddish brown when
Speaker 1: it's a juvenile, then it develops a pale tail spot
Speaker 1: when it becomes a reproductive female, and then develops bright
Speaker 1: blue green coloration. With pink markings when it becomes male.
Speaker 1: So you can imagine a lot of the early confusion
Speaker 1: at figuring out, well, what is a different species of parrotfish,
Speaker 1: and you will have multiple species of parrotfish in a
Speaker 1: given region, and then what is just parrotfish are the
Speaker 1: same species that's just in a different phase of its
Speaker 1: life cycle.
Speaker 3: That's right. In fact, I was even reading like some
Speaker 3: blog posts by marine biologists who had worked with these
Speaker 3: animals firsthand, talking about just how difficult it was sometimes
Speaker 3: to identify these fish because of all the variation even
Speaker 3: within species. But to come back to the main attraction,
Speaker 3: the teeth, the beaks. The crazy thing is, as much
Speaker 3: as these look like biting teeth in some cases, in
Speaker 3: reality they are scraping teeth. Because parrotfish are primarily herbivores
Speaker 3: for the most part, they do not eat by swimming
Speaker 3: around biting semi circular chunks out of other fish, as
Speaker 3: you might imagine just looking at their mouths. They mostly
Speaker 3: eat by grazing along the hard surfaces of coral reefs,
Speaker 3: scraping away algae and soft bits of coral and other
Speaker 3: bits of organic matter, along with some hard bits of
Speaker 3: the coral skeletons with their teeth, So that's what the
Speaker 3: teeth are for. These are for grazing. These are the
Speaker 3: life of a herbivore, not the life of a predator.
Speaker 1: Now, of course, as this we'll be discussing here. Coral,
Speaker 1: of course is hard matter. And one of the crazy
Speaker 1: things about snorkeling with parrotfish is that you don't just
Speaker 1: get to watch them, you get to listen to them.
Speaker 1: So as they feast on the algae that's growing on
Speaker 1: the coral, they're scraping the coral, and it's producing a
Speaker 1: sound in the snorkeler's ear that I would compare to
Speaker 1: kind of a static paper crunching or even the snap
Speaker 1: crackle crunch of rice crispies and milk. It's one of
Speaker 1: those things when when you first explore. When I first
Speaker 1: experienced it, I wasn't exactly sure what I was listening to,
Speaker 1: because it's kind of like, oh, is there something in
Speaker 1: my ears and it's just just the sound of the
Speaker 1: ocean and so forth. But no, it it becomes clear,
Speaker 1: and it's often pointed out to one that yeah, this
Speaker 1: is the sound of these the parrotfish feeding, and yeah,
Speaker 1: it's pretty remarkable. So you listen to them, you watch them,
Speaker 1: and they just become part of the background sound escape
Speaker 1: to your snortling.
Speaker 3: It's a funny other comparison to bees, almost, you know,
Speaker 3: the way the buzzing of a bee just kind of
Speaker 3: like blends in becomes the ambient sound of a landscape.
Speaker 3: The tooth and beak scraping on coral sound produced by
Speaker 3: these animals is maybe comparable to the buzzing of bees.
Speaker 1: Yeah, and it's also consistent, like that's the other thing.
Speaker 1: They're constantly grazing, and therefore it is a constant soundtrack.
Speaker 1: It's not like say, the occasional sound of a woodpecker
Speaker 1: in a forest, Like it's just NonStop. So it's just
Speaker 1: in the background, and you could easily if you didn't
Speaker 1: know what you were listening to, you might not realize
Speaker 1: that this is the sound of organisms feeding.
Speaker 3: Now, I think there are probably other people out there
Speaker 3: like me, Rob, I don't know if you fall into
Speaker 3: this category of people whose minds are easily captured and
Speaker 3: revolted by just imagining kind of tooth trauma. Like I
Speaker 3: very easily can like get a shiver across my whole
Speaker 3: body when I imagine, say, trying to bite down on
Speaker 3: a rock, And that is what you have to constantly
Speaker 3: imagine when you're thinking about these animals. It's not technically
Speaker 3: a rock, though I guess in some cases they do
Speaker 3: scrape rocks as well, but most often it's going to
Speaker 3: be like a rock. It will be the skeletons of
Speaker 3: stony corals. But can you just imagine that, as painful
Speaker 3: as it might be, imagine having to live by like seeing,
Speaker 3: you know, a moss covered rock and thinking I'm going
Speaker 3: to use my front teeth to scrape that bad boy clean,
Speaker 3: and I'm going to bite off some chunks of the
Speaker 3: rock as I'm getting the moss off of it. Delicious.
Speaker 1: Yeah, yeah, it can be a bit squeamish. It can
Speaker 1: make one a bit squamish sometimes imagining these other dental
Speaker 1: scenarios in the natural world.
Speaker 3: So I want to talk a bit more later about
Speaker 3: how parrotfish eat and get their nutrition, and a bit
Speaker 3: more about their teeth. But before we do that, Rob,
Speaker 3: I think you've found some interesting stuff about writings on
Speaker 3: parrotfish from the ancient world. Yeah.
Speaker 1: I did, And this was a whole avenue that I
Speaker 1: had not been down. I had no idea this was
Speaker 1: a thing. So again, given that species of parrotfish are
Speaker 1: found around the world, and that they can frequently be
Speaker 1: found in shallow water, and that they have traditionally been
Speaker 1: caught for culinary purposes for food, it should come as
Speaker 1: no surprise that these fish were known to people so
Speaker 1: the ancient world, you know, even in times when folks
Speaker 1: didn't have axe to the underwater world in any way
Speaker 1: comparable to what we have today, they still knew what
Speaker 1: these fish were, and in some cases they had some
Speaker 1: rather insightful ideas about what they were doing. In other cases,
Speaker 1: there are some very long standing misconceptions about what parrotfish do.
Speaker 1: So in this we're going to actually bring up the
Speaker 1: work of our dear old friend Roman historian Plenty of
Speaker 1: the Elder, who is one of several sources of antiquity
Speaker 1: that discusses the parrotfish, you know, and of course there's
Speaker 1: a lot of shared content and so forth going on.
Speaker 1: The fish would have been known as the scars. This
Speaker 1: is of course, now where we get the name of
Speaker 1: the genus for parrotfish, and we might assume that in
Speaker 1: particular we're dealing with discussions of the Mediterranean parrotfish, though
Speaker 1: based on what I was reading. Also, you had like
Speaker 1: the red sea parrotfish that was also known to various
Speaker 1: cultures of antiquity. So Plenty of the Elder in the
Speaker 1: Natural History seventy nine CE rites at the present day
Speaker 1: the first place, and this is he's speaking from a
Speaker 1: culinary perspective here. First place at the Roman table is
Speaker 1: given to the scars, the only fish that is said
Speaker 1: to ruminate and to feed on grass and not on
Speaker 1: other fish. It is most commonly found in the Carpathian Sea,
Speaker 1: and never of its own accord passes lectum a promontory
Speaker 1: of trois now. Nineteenth century naturalist George Cuvier and his
Speaker 1: annotations to Plenty points out again that the first place
Speaker 1: here is in reference to the Roman dinner table, where
Speaker 1: this fish was celebrated for several attributed characteristics that I'll
Speaker 1: get to in a minute, and was also typically quote
Speaker 1: salted with the intestines in it. M okay, and some
Speaker 1: Roman authors actually absolutely insisted that you do not eat
Speaker 1: this fish without the intestines included. It's just too delicious
Speaker 1: this way.
Speaker 3: Oh boy, So like, are you saying they would eat
Speaker 3: the intestines directly or it's like you got to leave
Speaker 3: the intestines in there to give them meat some flavor.
Speaker 1: You've got to leave them in. Yeah, okay, And I
Speaker 1: know they were often in many cultures salted and then traded,
Speaker 1: So I'm offhand, I'm not entirely sure if this is
Speaker 1: a definite case of we're talking about salted parrotfish with
Speaker 1: the intestines still in, or some other form of preparing them.
Speaker 1: But at any right, they really liked it. There are
Speaker 1: also Roman references to eating parrotfish livers as a delicacy.
Speaker 3: Mm so all the value here is just for their
Speaker 3: flesh as food. This is a first place distinction that
Speaker 3: would probably not be so flattering to the fish itself, right.
Speaker 1: Right, And the Romans weren't alone in appreciating eating parrotfishes.
Speaker 1: We'll get to some other far flowing examples. Plenty of
Speaker 1: humans have eaten parrotfish and still eat parrotfish. The Greeks
Speaker 1: love them. There's some I think twenty species of Mediterranean parrotfish. Again,
Speaker 1: there's the red sea parrotfish, considered a delicacy in antiquity,
Speaker 1: And in both of these cases, I believe they were
Speaker 1: often dried and then widely traded. I've read that in fact,
Speaker 1: they were easily dried. I'm not sure about the particulars
Speaker 1: of that, but I'll take their word on it that, Okay,
Speaker 1: this is a fish that is easier to dry and
Speaker 1: prepare and then trade across distances. You don't have to
Speaker 1: eat it fresh by the seaside. Anyway, it was celebrated
Speaker 1: at the Roman table, not just because you ate it
Speaker 1: salted and with the guts in it, but also for
Speaker 1: several reasons, according to Cuvier, and I think a lot
Speaker 1: of these seem to get down to the fact that
Speaker 1: I'm assuming the Romans liked a great story at the table.
Speaker 1: You know, it's not just about what the fish smells like,
Speaker 1: taste like, looks like on the plate, but also what
Speaker 1: is the story of it, what ideas are wrapped up
Speaker 1: in this particular organism. So here that first of all,
Speaker 1: it was thought to be the only ruminating fish.
Speaker 3: So so wait, does that mean ruminating as in like
Speaker 3: a like chewing the cud like a cow or a sheep.
Speaker 1: Yes, though basically I think what this comes down. First
Speaker 1: of all, they're not truly chewing the cut. They're not
Speaker 1: truly ruminating, you know, they're not chewing something that has
Speaker 1: previously been chewed and swallowed. They are grazing like a cow.
Speaker 1: And I think it has to do with observations of
Speaker 1: these animals grazing, and it's like, oh, look they're they're
Speaker 1: like a cow. They're ruminating. But still the idea that
Speaker 1: they're ruminating, the idea that they're chewing their cut continues
Speaker 1: to be mentioned all through antiquity on all the way
Speaker 1: up through like medieval besty areas those some voices such
Speaker 1: as Saint Ambrose in the fourth century said that did
Speaker 1: point out the chud the cud chewing thing is not accurate,
Speaker 1: that's not what they're doing. So but but still a
Speaker 1: lot of misinformation about these fish persisted for a very
Speaker 1: long time now. As Aristotle also observed in History of Animals,
Speaker 1: the parrett fish were thought to be vegetarians, and indeed,
Speaker 1: I guess you could say they're essentially herbivores. Many sources
Speaker 1: will classify them as such, but also note that they're
Speaker 1: maybe more more correct to say that they're algavores. But
Speaker 1: still ancient people observe that these fish are not eating
Speaker 1: in the same way that other fish are.
Speaker 3: Wow, this is something I feel like I should know.
Speaker 3: The answer to, but I actually don't what is it called.
Speaker 3: If you mostly eat you know, algae or plant things
Speaker 3: that are like plants, plants, or types of bacteria microorganisms,
Speaker 3: but sometimes you eat animals. But the animals are not
Speaker 3: like you know, large moving animals, they're you know, basically
Speaker 3: small invertebrate animals like corals.
Speaker 1: Yeah, I guess you would be some sort of a
Speaker 1: coral war or something to that effect, right, But on
Speaker 1: a number of the different fish databases that I was
Speaker 1: looking at, yeah, sometimes they'll say herbivore, sometimes they'll say herbivore, algivore,
Speaker 1: and then sometimes there's kind of an omnivore note as well.
Speaker 1: I guess there's always a margin of error, as we've
Speaker 1: discussed here, like even things like a cow, which we
Speaker 1: think of is kind of a pure herbivore. There are examples,
Speaker 1: as we've discussed on the show in the past, where
Speaker 1: they have been observed to if meat is available, they
Speaker 1: might eat set meat.
Speaker 3: But it is true that in the cases where parrotfish
Speaker 3: are eating animals, they're not generally like chasing after other
Speaker 3: fish and eating them or something. I don't know if
Speaker 3: that might happen in some particular case but that's not
Speaker 3: generally what parrotfish do. They're mostly going to be eating algae,
Speaker 3: and then if they're eating animals, they're like marine invertebrate animals.
Speaker 1: Yeah, so I mean we can, I think basically say
Speaker 1: that ancient people were correct in this judgment. Now, and
Speaker 1: I guess maybe it made the story at the dinner
Speaker 1: table a little more interesting. They're like, this is the
Speaker 1: cow of the sea, that sort of thing. Now, the
Speaker 1: third attribute that Kuvia mentions is quote because it had
Speaker 1: the faculty of producing a sound. Now, perhaps I'm not
Speaker 1: completely understanding Cuvier's point here, but I guess this is
Speaker 1: referring to that constant chewing sound, that constant grazing sound
Speaker 1: that one hears if your head is below water with
Speaker 1: the fish. And again, this is not something that I
Speaker 1: would think actually impacts one's enjoyment of dinner. But again,
Speaker 1: I guess they liked a good story.
Speaker 3: You know, sometimes people they say they want their steak
Speaker 3: rare by saying I want it still mooing. It's kind
Speaker 3: a kind of a gruesome way to ask for it.
Speaker 3: But people do say that. Can you say that, like,
Speaker 3: I want my parrot fish steak rare? I want it
Speaker 3: still scraping, I guess.
Speaker 1: So the fourth attribute that he mentions is quote for
Speaker 1: its salacious propensities numbers being taken by means of a
Speaker 1: female attached to a string. This, I guess alluding to
Speaker 1: a supposed method of catching them. And I suppose the
Speaker 1: Romans just like Randy food, though I'm not sure it
Speaker 1: was actually considered an afrodisiac because I didn't see it
Speaker 1: listed in another source I was looking at that had
Speaker 1: to do with various foods of the Romans did believe
Speaker 1: were aphrodisiacs.
Speaker 3: Uh huh okay.
Speaker 1: And then fifthly for its quote remarkable sagacity and affording
Speaker 1: assistance to another when taken in the net.
Speaker 3: Huh, Now what would that mean?
Speaker 1: So this is referring to something that is that that
Speaker 1: pops up in various old sources as well, and again
Speaker 1: continues to persist for centuries. May be particularly referring to
Speaker 1: a passage in Ovid. Ovid has the following passage quote,
Speaker 1: the scas is caught by a stratagem beneath the waves,
Speaker 1: and it length dreads the bait. Fraught with treachery, it
Speaker 1: dares not strike the osers. This refers to a reed
Speaker 1: basket with an effort of its head, but turning away
Speaker 1: as it loosens the twigs with frequent blows of its tail,
Speaker 1: it makes its passage and escapes safely into the deep. Moreover,
Speaker 1: if perchance any kind scarus swimming behind sees it struggling
Speaker 1: with the osures, he takes hold of its tail in
Speaker 1: his mouth and it is thus turned away, and so
Speaker 1: it makes its escape. So, okay, they have this idea
Speaker 1: that these fish, these parrotfish, are essentially I don't think
Speaker 1: you social would be the term, but they are. They
Speaker 1: help each other out. They're capable of some form of
Speaker 1: altruism where if they see another one of their kinds
Speaker 1: stuck in one of these wicker basket traps, they will
Speaker 1: try and help them out.
Speaker 3: Huh.
Speaker 1: And so this idea ends up sticking around for against
Speaker 1: centuries and centuries. The idea that the scais or parrotfish
Speaker 1: is not only a cud chewing herbivore of the sea,
Speaker 1: but also a friendly fish that looks out for it's fellows.
Speaker 3: Well, that's fascinating, But I wonder what would this belief
Speaker 3: about their like friendly behavior be based on. So the
Speaker 3: idea is they help each other avoid traps, or say
Speaker 3: each other from traps. Is there any modern research on this?
Speaker 1: So the main source I found on this, and this
Speaker 1: is where I got turned onto the idea, it was
Speaker 1: the blog of Fishtories. It's like histories and fish combined.
Speaker 1: That's f I S H T O r I E
Speaker 1: S dot net. It is a blog maintained by Sophia Hendricks,
Speaker 1: an information scientist and historian of science. She discusses this
Speaker 1: whole weird scenario with imagery of the parrotfish, because indeed
Speaker 1: there's there's there's imagery associated. I included this illustration here
Speaker 1: for you here Joe from a munch latter later source.
Speaker 1: But but she does point out that based on what
Speaker 1: we can tell, the fish are actually anything but friendly
Speaker 1: to each other in these scenarios. Wicker baskets like this
Speaker 1: are still used in some places to catch fish, she
Speaker 1: points out. But she writes that the parrotfish have actually
Speaker 1: been observed too violently attacked their fellow parrotfish that become
Speaker 1: caught in the reeds of the fishing basket. So I
Speaker 1: don't know that there's really much evidence to back this up.
Speaker 1: I also get to an example here in a bit
Speaker 1: involving traditional Hawaiian techniques for catching parrotfish that also uses
Speaker 1: the basket, like the idea of being essentially that the
Speaker 1: parrotfish are roaming around the corals feeding and they kind
Speaker 1: of have these paths that they follow. They also tend
Speaker 1: to sort of group together, and you may have what
Speaker 1: seems to be a leader of the pack. And if
Speaker 1: you set up these baskets at the right time, you
Speaker 1: can catch them, and you can end up catching a
Speaker 1: bunch of them even and you can then release the
Speaker 1: ones you don't want, make use of the ones you
Speaker 1: want to harvest. So I don't know. On one level,
Speaker 1: it seems like, OK, you're ending up with an artificial
Speaker 1: environment scenario here, where you're dealing essentially with captive fish
Speaker 1: doing things in a captive environment and a high stakes
Speaker 1: environment for them that they might not do otherwise, and
Speaker 1: that may mean attacking each other that I guess could
Speaker 1: also mean some sort of observational behavior, especially without the
Speaker 1: aid of any kind of like snorkeling mask and so forth,
Speaker 1: it might look like one's helping the others out. I'm
Speaker 1: not sure, but still the idea becomes entrenched and the
Speaker 1: image of the parrotfish helping each other escape from fishing
Speaker 1: baskets ends up becoming a symbol of friendship. Oh yeah,
Speaker 1: so this is something that she discusses at length in
Speaker 1: another paper. This is something that published in Emblems of
Speaker 1: the Natural World from twenty fifteen Ichthyology and Emblematics in
Speaker 1: Conrad Gesner's Historia Piscium and Joham Kamarius's Kamarus the Youngers
Speaker 1: Simbola at Emblemata. She points out that Plenty was one
Speaker 1: of the key sources for this misconception, but plenty of
Speaker 1: others sources in the ancient world echoed at Plutarch chimes
Speaker 1: in on it, and so some sources identified this as
Speaker 1: a sign of intelligence in the parrotfish, while other fishes
Speaker 1: were often held up as examples of a lack of intelligence,
Speaker 1: and fish, such as then Conrad Gessner's sixteenth century work
Speaker 1: Historian Animalium, the mackerel was held up as a stupid fish.
Speaker 3: For example, how do you get that distinction as a fish?
Speaker 1: I don't know, I mean, maybe they just it's probably
Speaker 1: a little bit unfair, right in some cases the macvil
Speaker 1: looks to and you're basing everything on the human perspective
Speaker 1: and human expectations of what an animal's intelligence is, you know,
Speaker 1: whereas ultimately you can I think you can approach these
Speaker 1: scenarios by saying, well, yeah, the parrotfish is in a
Speaker 1: way a genius. It's as smart as it needs to
Speaker 1: be to do the things that it does.
Speaker 3: Well. Actually, you know what, I wonder if some of
Speaker 3: this I have no idea if it applies in this case,
Speaker 3: but I wonder if some general ideas about smartfish versus
Speaker 3: dumbfish come just from the experience of fishing for different
Speaker 3: types of fish, because I know, you know, and people
Speaker 3: who are into fishing right in and let us know
Speaker 3: if this matches your experience. In my experience, people who
Speaker 3: like to fish will like say that a fish that
Speaker 3: is harder to catch is a smart fish, and one
Speaker 3: that's easier to catches like a dumb fish. And I
Speaker 3: don't know if intelligence actually has anything to do with
Speaker 3: how easy they are to catch or not. You know,
Speaker 3: might just have to do with like ingrained behavioral patterns,
Speaker 3: someone responding distress or something.
Speaker 1: Yeah. Yeah, And it's kind of curious because it sounds
Speaker 1: like if you have the right traps for it, catching
Speaker 1: parrotfish is generally not considered super challenging. So but you know,
Speaker 1: we have this other narrative that emerges again that they're
Speaker 1: helping each other and that they can sort of help
Speaker 1: each other escape from these traps and so forth. Now
Speaker 1: I mentioned Hawaiian traditions because again, you know, you have
Speaker 1: parrotfish all over and you do have them in the
Speaker 1: Hawaiian Islands and in Hawaii. The parrotfish was historically known
Speaker 1: in the Hawaiian language as uhu. The fish are prominent
Speaker 1: there and they were eaten by Hawaiians. Traditionally. There's a
Speaker 1: saying in Hawaiian, according to the online Hawaiian dictionary Ulucal,
Speaker 1: that translates to my craving makes my mouth water for
Speaker 1: the parrotfish passing before my eyes. The Hawaii Coral Reef
Speaker 1: Network points out that not only were they a delicacy,
Speaker 1: but their liver was especially favored. So again, you know,
Speaker 1: you know, other side of the world, you still have
Speaker 1: people eating parrotfish and also realizing that the liver is
Speaker 1: apparently really good.
Speaker 3: Interesting.
Speaker 1: Now, the fish itself, to the Hawaiians, had connotations of
Speaker 1: physical beauty, as in one's love interest, but also in
Speaker 1: terms of a desirable bachelor. There was also apparently a
Speaker 1: tradition that held that a fisherman could observe the behavior
Speaker 1: of a pair of fish and it would serve as
Speaker 1: a kind of portent as to what was going on
Speaker 1: back home. So like, you know, certain things the parrotfish
Speaker 1: was doing. It's like, okay, everything's cool back of the house.
Speaker 1: Other things the parrotfish might be doing. It's like you
Speaker 1: need to go back and check on your wife, that
Speaker 1: sort of thing. Now, the parrotfish who also factors into
Speaker 1: one of the stories of a legendary figure in Hawaiian mythology.
Speaker 1: And I could not find a like a solid pronunciation
Speaker 1: guide for this name, so I hope I'm saying it
Speaker 1: somewhere close to correctly, and my apologies if I'm not
Speaker 1: punia Kaya. This is in these stories. He's a dashing
Speaker 1: young man who one day leaves his parents' house because
Speaker 1: he feels this call of the ocean. He wants to
Speaker 1: go fishing, and so he catches this young, supernatural fish
Speaker 1: the first Ooh, and it makes it his pet, and
Speaker 1: then he releases it where it becomes the parent of
Speaker 1: all fish, and so afterwards he's able to go call
Speaker 1: upon the fish to the or fellow fish to the fishermen. Yeah.
Speaker 1: I was reading more about this in Native Use of
Speaker 1: Fish in Hawaii by Margaret Titcomb, and the author makes
Speaker 1: a connection to the manner in which parrotfish move along
Speaker 1: in a school, often single file, seemingly led by a leader.
Speaker 1: So that, yeah, this special trap was devised by the
Speaker 1: early Hawaiians for use during a particular season. The trap
Speaker 1: allowed them to allow the fish to file into the
Speaker 1: trap led by the leader, but then they're unable to escape,
Speaker 1: and they keep the trap in use during the May
Speaker 1: June July season, collect enough fish for personal use, and
Speaker 1: then release the rest, though another source I've looked at
Speaker 1: seems to indicate that excess fish might have been harvested
Speaker 1: to feed pigs and dogs, So I don't know. There
Speaker 1: may be some variety in the practice, or there might
Speaker 1: be a misconception on one side or the other, but
Speaker 1: at any rate, this is how they caught them, and
Speaker 1: I guess by virtue of that leader fish leads into
Speaker 1: this idea that there's kind of like a fish that
Speaker 1: is a friend of the people that will help you
Speaker 1: catch more fish.
Speaker 3: Like it's the leader of the school is deliberately leading
Speaker 3: them into the trap for you.
Speaker 1: Yeah, though not so much that it's like a trader fish,
Speaker 1: but more than like it is this fish that a
Speaker 1: like a legendary figure made a deal with that's sort
Speaker 1: of thing. So yeah, this was a new one to
Speaker 1: me as well. I don't think i'd heard this in
Speaker 1: my previous trips to Hawaii. So and there may be
Speaker 1: some more interesting partfish mythologies out there that I'll have
Speaker 1: to turn up for the next episode.
Speaker 3: That's really interesting. I like it. As I promised earlier,
Speaker 3: I wanted to come back and talk a bit more
Speaker 3: about how parrotfish eat and a little bit about the
Speaker 3: equipment they used to do it and what happens after
Speaker 3: they do it after they eat. So one source I
Speaker 3: was looking at here is a chapter in the Biology
Speaker 3: of Parrotfishes by CRC Press twenty eighteen. And this chapter
Speaker 3: was by Peter S. Wainwright and Samantha A. Price. It's
Speaker 3: called Innovation and Diversity of the Feeding Mechanism in Parrotfishes.
Speaker 3: And I'll probably come back to this in subsequent episodes
Speaker 3: as well. But about the authors, Peter C. Wainwright is
Speaker 3: a biologist at UC Davis and Samantha A. Price is
Speaker 3: a biologist at Clemson, and so the authors here say
Speaker 3: that how parrotfishes eat to the various species of parrotfish,
Speaker 3: how they eat is quote one of the fundamental ecological
Speaker 3: processes in coral reef ecosystems. So when you think about parrotfish,
Speaker 3: you shouldn't just think of them as something you occasionally
Speaker 3: see in a coral reef, but rather they are an
Speaker 3: integral part of how coral reef ecosystems work, and kind
Speaker 3: of the whole ecosystem doesn't really work without them. Now,
Speaker 3: as we mentioned earlier, the feeding process of parrotfish involves
Speaker 3: a lot of scraping and biting into hard stony materials.
Speaker 3: Parrotfishes swim around coral reefs using their teeth to scrape
Speaker 3: edible stuff off the outside of coral, and they break
Speaker 3: off some coral and bring it along with them in
Speaker 3: the process. Now, what is that edible stuff on the
Speaker 3: outside of the coral. The authors say that it includes
Speaker 3: primarily algae. Algae is a big part, but also detritis,
Speaker 3: and in a marine context this usually means dead organic material,
Speaker 3: so parts of dead organisms, fecal matter, all that yummy stuff.
Speaker 3: Sometimes it will include bacteria, little colonies of bacteria, and
Speaker 3: then they just say, quote a wide range of encrusting invertebrates,
Speaker 3: so all kinds of little invertebrate animals that could be
Speaker 3: found on a coral reef. This might include coral polyps themselves,
Speaker 3: and it might also include things like sponges. Now, a
Speaker 3: couple of sources I was looking at sort of classified
Speaker 3: several different types of parrotfish feeding strategies, and the main
Speaker 3: variation here seemed to be how how deep the parrotfish
Speaker 3: would cut into the stony parts of the coral. So
Speaker 3: you might have some that are referred to more as
Speaker 3: browsers or grazers, that tend to typically just take the
Speaker 3: soft parts off the surface of the coral. You've got
Speaker 3: scrapers which scrape the coral a little harder and get
Speaker 3: some of what's underneath. And then you've got what are
Speaker 3: called excavators, which are really just taking chunks out of
Speaker 3: the hard stuff. So the parrotfishes swim along on the reef,
Speaker 3: scraping the stuff off with their outer teeth or excavating
Speaker 3: bits of it and inevitably leaving scars on the rock
Speaker 3: or the coral skeletons as they go. And then all
Speaker 3: of this mixture of both hard and soft parts goes
Speaker 3: into the mouth, where it is subjected to a second obstacle,
Speaker 3: which is the trial of the inner jaws. Because parrotfishes
Speaker 3: don't only have these fascinating outer teeth, they have a
Speaker 3: second set of teeth at the back of their mouth,
Speaker 3: known as the fyringeal jaw. Now you might have read
Speaker 3: about pharyngeal jaws with respect to other animals that have them.
Speaker 3: A number of fish and creatures that live in the
Speaker 3: sea have them, and a well known example is the
Speaker 3: more eel.
Speaker 1: That's right, Yeah, And of course, you know, those of
Speaker 1: you who've watched any amount of science fiction, you might
Speaker 1: also note that very angel jaws from in the world
Speaker 1: of fictional monsters, we do have, of course, the alien xenomorph,
Speaker 1: at least the main morph of the creature that we
Speaker 1: see in those films, where we see this inner jaw
Speaker 1: that functions as both a feeding mechanism and a puncturing weapon,
Speaker 1: while elsewhere in the alien universe we see other morphs,
Speaker 1: such as the deacon and the neo morph, that boast
Speaker 1: extendable inner jaws rather than a secondary set of jaws.
Speaker 1: But yeah, generally you often see some like comparative biology
Speaker 1: write ups, and I think I've done right up to
Speaker 1: this and this nature in the past, where when you're
Speaker 1: comparing xenomorph physiology to the now world, the more a
Speaker 1: eel is like a prime stopping point of comparison.
Speaker 3: Now, the exact design of the fyrngeal jaw in the
Speaker 3: xenomorphos a little bit extra like. I'm not aware of
Speaker 3: any examples in the in the natural world where like
Speaker 3: the inner jaw comes out of the mouth and stabs
Speaker 3: like a spear, like bites through the torso of a
Speaker 3: prey animal. The inner jaws in the cases I'm aware of,
Speaker 3: tend to stay mostly within the outer jaws, but they
Speaker 3: do do something fascinating and perhaps to some horrifying. So
Speaker 3: in the case of the more a eel, which is
Speaker 3: a predator, the fyryngial jaw helps the eel capture and
Speaker 3: swallow large live prey animals without allowing them to escape.
Speaker 3: So the eel first bites the prey with its regular
Speaker 3: outer jaws. These are the jaws you'd see, you know,
Speaker 3: with the teeth. They have backward curving teeth, and those
Speaker 3: the orientation of the teeth, the backward curving nature of
Speaker 3: them helps them keep the keep the prey in place
Speaker 3: without allowing it to back out and escape. And then
Speaker 3: while the eel is holding the prey in place with
Speaker 3: these outer jaws, the inner jaws reach up from out
Speaker 3: of the eel's throat to bite the animal and pull
Speaker 3: it further inside the mouth and down into the esophagus.
Speaker 3: So it's a two step capture and conveyance mechanism. Now
Speaker 3: just to stick with the more eel in a sidebar
Speaker 3: for a second, I got interested in this. The evolutionary
Speaker 3: reasoning for this is an interesting question. Apparently, most predatory
Speaker 3: fish rely in large part on suction to capture and
Speaker 3: swallow their prey. So these other fish use their muscles
Speaker 3: to rapidly expand the mouth through the throat cavity, and
Speaker 3: so when it expands like this, it creates a negative
Speaker 3: pressure and it sucks in water from outside the mouth,
Speaker 3: including the prey in that water. And this suction mechanism
Speaker 3: can either be the action that pulls the prey into
Speaker 3: the mouth in the first place, or it can also
Speaker 3: be that after a predatory fish bites the prey with
Speaker 3: its jaws, the suction mechanism then pulls the prey farther
Speaker 3: into the mouth and down into the esophagus.
Speaker 1: Yeah, the scorpion fish is a great example of this,
Speaker 1: and you can find some great video footage of this
Speaker 1: where it's an ambush predator down there, hidden on the
Speaker 1: floor of the sea, and then as its prey comes by,
Speaker 1: it just kind of goes woomf and just rapidly sucks
Speaker 1: it into its mouth and it's just gone like that.
Speaker 1: And the scorpion fish is of course you'll note get
Speaker 1: very robust looking, kind of frog ish looking, and that
Speaker 1: is key here too, Right.
Speaker 3: So I was reading a two thousand and seven National
Speaker 3: Science Foundation press release about research on moray eels published
Speaker 3: in Nature that year, and the studies lead author, a
Speaker 3: UC Davis scientist named Rita Meta, says that her study
Speaker 3: found because of the way more eel bodies are shaped,
Speaker 3: they're not able to generate much suction in the mouth cavity,
Speaker 3: so instead they have this secondary set of jaws in
Speaker 3: the throat. More eels are predators that often live in
Speaker 3: coral reefs and they hide in little holes, gaps and
Speaker 3: niches in the reef, and so a possible reason given
Speaker 3: for this evolutionary difference why they have the feryngial jaws
Speaker 3: instead of the suction mechanism is that by having pharyngeal jaws,
Speaker 3: they can attack and swallow relatively large prey in tight,
Speaker 3: confined little spaces where there would not be enough room
Speaker 3: for them to expand the mouth or throat cavity to
Speaker 3: create suction.
Speaker 1: Fascinating, it makes perfect sense.
Speaker 3: So that's an interesting idea, But I also think it's
Speaker 3: an interesting parallel. You've got more eels and parrotfishes, which
Speaker 3: are both coral reef dwellers and both have forryngial jaws,
Speaker 3: but they use these inner jaws for totally different purposes. Again,
Speaker 3: in the eel, it's to pull the prey down the
Speaker 3: throat once it's in the mouth. Parrotfishes are again not
Speaker 3: generally going to be chasing large live prey. They're mostly herbivores,
Speaker 3: and they eat by scraping or gouging the coral and
Speaker 3: getting stuff off the outside or in the layers underneath
Speaker 3: the surface. This material that they scrape off of rocks
Speaker 3: and coral, which mostly includes algae and other microbial organisms,
Speaker 3: but also dead organic matter and coral skeleton bits, is
Speaker 3: pulled down into the pharyngeal teeth where to quote Wainwright
Speaker 3: and Price, it is quote mixed with mucus and ground
Speaker 3: to a fine slurry before being passed to the intestines.
Speaker 3: And Rob I was just looking up some photos of
Speaker 3: parrotfish phyngeal teeth, and oh boy, what what are we
Speaker 3: looking at here? These are some organs like they're clearly
Speaker 3: specialized for grinding down this mixture of hard and soft
Speaker 3: substances into a mucous, lubricated slurry. But some of these
Speaker 3: pieces of parrotfish anatomy look like a car transmission gear
Speaker 3: made out of bone. Others look like a bone pine cone.
Speaker 3: It's it's interesting.
Speaker 1: Yeah, yeah, yeah, it does kind of look like interlocking
Speaker 1: gear teeth.
Speaker 3: Yeah, it's crazy. So the digestive system extracts nutrients from
Speaker 3: this slurry, and then the parrotfish excretes what is left over,
Speaker 3: which is a big part of which is sand. Because
Speaker 3: they're grinding down this coral. They bite off and scrape
Speaker 3: off pieces of coral, grind up that coral with the
Speaker 3: nightmare throat teeth, and then they poop sand. So I've
Speaker 3: read it described that if you swim around with these buddies,
Speaker 3: you will see them just like letting out kind of
Speaker 3: poofs of sand or blasting clouds of sand into the
Speaker 3: water column.
Speaker 1: Yeah. Absolutely, yeah, Like they're just they're kind of constantly
Speaker 1: doing it. I mean, it makes sense. They're grazing and
Speaker 1: they're kind of like goats, and they're kind of pooping
Speaker 1: like goats, except it's coming out in this kind of
Speaker 1: like puff of sand. And I know you included some
Speaker 1: photos here where it's like more than a puff. It
Speaker 1: looks like they're crop dusting. It's quite impressive.
Speaker 3: In fact, parrotfish poop so much sand. They are by
Speaker 3: themselves a significant source of the bioroosion of coral and
Speaker 3: a significant source of fine grained white sand in certain environments,
Speaker 3: as in, when you are walking along a beautiful white
Speaker 3: sand beach on some tropical island, there is a very
Speaker 3: good chance a large proportion of the sand under your
Speaker 3: feet is parrotfish poop.
Speaker 1: That's right. They are beach creation machines, and some of
Speaker 1: the estimates for individual sand creation are quite stunning.
Speaker 3: Unbelievable to me. Actually, Like I had no idea about
Speaker 3: this going in, So you might be thinking, yeah, how
Speaker 3: much sand can these fish really poop? Again? It depends
Speaker 3: where you are. There are obviously other sand creation mechanisms
Speaker 3: in the sea, so this is not the only one.
Speaker 3: But in some place parrotfish are responsible for a lot
Speaker 3: of the sand that's there. One example I came across
Speaker 3: is a paper in the journal Geology from twenty fifteen
Speaker 3: by Perry at All called Linking reef Ecology to island building.
Speaker 3: Parrotfish identified as major producers for island building sediment in
Speaker 3: the Maldives and so again this is by Perry at All,
Speaker 3: and so the Maldives Archipelago. This is an island chain
Speaker 3: that contains approximately twelve hundred individual reef islands, which are
Speaker 3: islands that are made entirely out of sediment that is
Speaker 3: produced from underwater coral reefs. So the primary reason these
Speaker 3: islands exist is that there are coral reef ecosystems on
Speaker 3: an underwater platform. Of course, the reefs themselves are mostly
Speaker 3: made up of the calcium carbonate skeletons of stony coral polyps,
Speaker 3: and over time these coral reefs decompose into sediments like
Speaker 3: sand and gravel. Parry at All right quote all coral
Speaker 3: reef islands are inherently dependent on their surrounding reef habitats
Speaker 3: not only because they provide the foundations for island development,
Speaker 3: but also because they are the primary production sites for
Speaker 3: the sediments necessary to sustain island building, growth and maintenance.
Speaker 3: So without sediments from the coral reefs decomposing into sand
Speaker 3: and gravel, you may not have an island here. But
Speaker 3: the authors of this study say before their research, how
Speaker 3: exactly that sediment is produced from the coral reef is
Speaker 3: poorly quantified, so they investigated they're looking at where does
Speaker 3: the sediment come from, and they used the example of Vakaru,
Speaker 3: which is an interior reef island in the Maldives. They
Speaker 3: found that the area around this island produces about six
Speaker 3: hundred and eighty five thousand kilograms of sediment per year,
Speaker 3: about seventy five percent of which comes from a place
Speaker 3: they call the outer reef flat. So if you look
Speaker 3: at the island from above, you'll see the part that
Speaker 3: rises above water and is forested and has plants and
Speaker 3: all that, the beach surrounding it, and then there's sort
Speaker 3: of an inner lagoon and then an inner reef ring
Speaker 3: and an outer reef ring. So most of the sediment
Speaker 3: is coming from that outer ring of coral reef environments
Speaker 3: in the water, about seventy five percent of the sediment
Speaker 3: comes from the outer reef flat. Now within that outer reef,
Speaker 3: which creates about seventy five percent of the island's yearly
Speaker 3: supply of new sand, the author's discovered that more than
Speaker 3: eighty five percent of the sand is produced by parrotfish.
Speaker 3: And if you're curious what the second place was. The
Speaker 3: runner up producer of reef sand in a distant second
Speaker 3: place at about eight point eight percent in the outer
Speaker 3: reef is a type of macroalgy called halimata, which makes
Speaker 3: like calcified body parts and then those get shed and
Speaker 3: eventually decompose a breakdown into sand. But almost all of
Speaker 3: it is coming from what the parrotfish excrete. So parrotfish
Speaker 3: are continually defecating this island into existence, and they remain
Speaker 3: critical for maintaining its existence the author's right quote. The
Speaker 3: generation of sediments suitable for maintaining this reef island is
Speaker 3: thus critically dependent on a narrow zone of high productivity reef,
Speaker 3: but most especially on the maintenance of healthy parrotfish populations
Speaker 3: that can convert reef framework to sand grade sediment, and
Speaker 3: so the parrotfish are crucial for the health of island
Speaker 3: environments like this. But this is not just true of
Speaker 3: these tiny coral reef islands that are generated from coral
Speaker 3: reef sediments, even on many other coasts and larger islands,
Speaker 3: where the island itself might be, you know, have other
Speaker 3: geological explanations, like it's not just sand rising out of
Speaker 3: the water. It might be a volcanic island or the
Speaker 3: coast of a continent or something. In places where there
Speaker 3: are coral reefs, beaches in many cases are still largely
Speaker 3: parrotfish lavatory constructions. A figure sighted in several reputable looking sources,
Speaker 3: though I couldn't find the exact origin of it, is
Speaker 3: that around seventy percent of the sand on the White
Speaker 3: Sandy Beaches of Hawaii is parrotfish excretion. It's hard to imagine,
Speaker 3: like you're walking on a beach or even on a
Speaker 3: whole island, and to imagine it having a biological fish
Speaker 3: digestive system origin of this kind.
Speaker 1: I know, it's just it's crazy. It's one of those
Speaker 1: mind blowing facts though that again, it gets pointed out
Speaker 1: a lot when you are going to these places and snorkeling,
Speaker 1: it becomes easy to sort of take for granted and
Speaker 1: you have to sort of remind yourself. Then when you're
Speaker 1: walking on the beach, it's like, no, for real, all
Speaker 1: this sand and it's still kind of you know, beggars
Speaker 1: the imagination.
Speaker 3: Yeah. Now, another thing that's interesting is that, of course
Speaker 3: we know now that parrotfishes are very important for the
Speaker 3: for creating the sand that in some cases makes it
Speaker 3: possible to have an island and like these reef island
Speaker 3: environments or helps replenish the beaches. But you might think,
Speaker 3: on the other hand, well, the parrotfishes are the enemy
Speaker 3: of the coral reefs though, because they're preying on, you know,
Speaker 3: the coral. They're like scrape in the coral. In fact,
Speaker 3: it is thought that parrotfishes help protect coral reefs because
Speaker 3: as they're going along taking bites out of the barrel
Speaker 3: coral reefs, they might be leaving scars in them, biting
Speaker 3: pieces off, taking chunks out, But by grazing in this way,
Speaker 3: they prevent the reefs from becoming overgrown by things like
Speaker 3: algae and other encrusting invertebrates like sponges and stuff. So
Speaker 3: they may eat some coral as they munch along, but
Speaker 3: overall they keep the coral reefs healthy.
Speaker 1: That's right. This is a very important fact concerning like
Speaker 1: necessary conservation for parrotfish because and it goes beyond that too,
Speaker 1: Like I was reading that by constantly eating algae off
Speaker 1: the coral. Again, they're constantly in doing this cleaning the coral,
Speaker 1: creating new surfaces on the coral. And this is where
Speaker 1: baby corals can attach and grow, so that's in play.
Speaker 1: And on top of this, yeah, they're keeping like seaweed,
Speaker 1: which remember is a microalgae. They're keeping seaweed growth in check.
Speaker 1: And this is apparently one of the prime results of
Speaker 1: parrotfish overfishing in parts of the Caribbean and the Pacific
Speaker 1: seaweed overgrowth. And I was even reading this is from
Speaker 1: Kramer at all. In twenty seventeen's prehistorical and historical declines
Speaker 1: in Caribbean coral reef accretion rates driven by loss of parrotfish.
Speaker 1: The authors here say that we see this connection proven
Speaker 1: out in sediment fossils. There's a strong observable connection between
Speaker 1: declines and coral accretion rates and parrotfish abundance. So and
Speaker 1: it's more evidence that we need to conserve parrotfish in
Speaker 1: order to help prevent coral reef environments from becoming quote,
Speaker 1: algael dominated habitats. And yeah, so this is worth keeping
Speaker 1: in mind. If you're traveling somewhere and parrotfish is on
Speaker 1: the menu, it's advisable to eat something else. And indeed,
Speaker 1: there are a number of efforts and protections in places
Speaker 1: around the world to help protect these populations like the
Speaker 1: parrotfish are a vital part of those coral environments which
Speaker 1: are already threatened in a number of ways. This is
Speaker 1: one that we can we can we can do a
Speaker 1: lot to help coral reefs, but not eating parrotfish is
Speaker 1: perhaps even more accessible than some of the things we
Speaker 1: need to do to protect them.
Speaker 3: Now, there's one more brief thing I wanted to get
Speaker 3: into before we wrap up part one here, and that
Speaker 3: is about the material makeup of parrotfish teeth. I was
Speaker 3: reading about this in a press release for the Lawrence
Speaker 3: Berkeley National Laboratory. This was published in twenty seventeen. It's
Speaker 3: called X raysor Reveal the Biting Truth about Parrotfish Teeth
Speaker 3: by Glenn Roberts, Junior. And so this is talking about
Speaker 3: research conducted at the Berkeley Lab, which used X rays
Speaker 3: to examine parrotfish teeth and better understand what makes them
Speaker 3: so resilient in the face of essentially scraping, biting, and
Speaker 3: chewing on rocks all day. You know, on these these
Speaker 3: coral skeletons are are not soft, you know, they're hard
Speaker 3: calcium carbonate, and they're just these teeth are relentlessly munching.
Speaker 3: So the particular parrotfish species in question was the steep
Speaker 3: head parrotfish also known as the blunt head parrotfish scientific
Speaker 3: name Chlorurus micro rhinos. And in this analysis, the researchers
Speaker 3: found that the resilience of prot parrotfish teeth was due
Speaker 3: to this woven microstructure of minerals in the enameloid of
Speaker 3: the teeth, and the article compares it in fact in
Speaker 3: structure to chain mail, which I thought was interesting. So this,
Speaker 3: this microstructure creates a tooth the material that is incredibly
Speaker 3: hard at the biting surface. The article points out that
Speaker 3: the hardness of the biting surface is about five hundred
Speaker 3: and thirty tons of pressure per square inch and they
Speaker 3: compare this to the weight of eighty eight African elephants
Speaker 3: on a single square inch of space. Now that microstructure
Speaker 3: of the teeth fits into a larger structure, the sort
Speaker 3: of morphology of the jaw, which is that these parrotfish
Speaker 3: have like fifteen rows of teeth totaling about one thousand teeth,
Speaker 3: all fused together, biologically glued or cemented together into this
Speaker 3: single beak like structure, and the stiffness of the underlying
Speaker 3: mineral crystals increases as it goes toward the tip the
Speaker 3: biting surface. And the article quotes one of the researchers
Speaker 3: involved named PUPA. Gilbert, who is a professor in the
Speaker 3: physics department at the University of Wisconsin Madison, who says, quote,
Speaker 3: fish teeth are the coolest biominerals of all. They are
Speaker 3: the stiffest, among the hardest, and the most resistant to
Speaker 3: fracture and to abrasion ever measured. And so given the
Speaker 3: incredible material qualities of these parrotfish teeth and beaks, researchers
Speaker 3: are looking into ways that the woven crystals of parrotfish
Speaker 3: teeth might be used as an inspiration for human engineering,
Speaker 3: a design pattern that could be reproduced in synthetic materials
Speaker 3: to create a tougher, more resilient product.
Speaker 1: Now, just a couple of notes about these teeth for one.
Speaker 1: On one hand, to come back to the alien xenomorph.
Speaker 1: You know, it is interesting that they're sometimes described, at
Speaker 1: least for some of the morphs, as possessing metal teeth,
Speaker 1: and here we have the parrotfish, whose teeth are sometimes
Speaker 1: described as being stronger than many metals metals, so it's
Speaker 1: kind of interesting comparison there. Also, you know, inevitably there
Speaker 1: is the question in the same way that we can't
Speaker 1: look at a creature that is biting coral and you know,
Speaker 1: think about our own teeth biting coral, we also can't
Speaker 1: help but look at a creature with interesting teeth and
Speaker 1: wonder what happens if I get bitten by one of these?
Speaker 1: So I mean to be clear, you know, humans are
Speaker 1: not on the menu for the parrotfish. There are accounts
Speaker 1: of parrotfish rarely biting humans, though it does seem very rare,
Speaker 1: and the incidents I was looking at, most of them
Speaker 1: seem to be related to incidents with fishermen who were
Speaker 1: actively harvesting them or you know, engaging with a trap
Speaker 1: or something. But they have bitten humans before, so it
Speaker 1: can happen. But I mean that can be said of
Speaker 1: a lot of creatures, like you know, a horse can
Speaker 1: bite you.
Speaker 3: Oh lord, why did I google this? But I did?
Speaker 1: Oh did you just google? You may have googled one
Speaker 1: that comes up a lot.
Speaker 3: Came across a news article that claims to be a
Speaker 3: photo of a wound from somebody who was bitten by
Speaker 3: a parrotfish, and it looks it's grotesque. Listeners be warned.
Speaker 1: Yeah, there's a particular story that comes up in search
Speaker 1: involving a fisherman, that is that was bitten in a
Speaker 1: delicate area by one of these these parrotfish. So uh yeah,
Speaker 1: I you know, weighed carefully if you decide to pursue these,
Speaker 1: uh these stories for yourself. But yeah, it can happen,
Speaker 1: it has happened, but uh, these are generally not considered
Speaker 1: you know, risky fish, and people snorkel around them almost
Speaker 1: constantly without issue.
Speaker 3: They're not looking to bite you. They're they're just trying
Speaker 3: to go about their business. They're scraping.
Speaker 1: They're buzz't like bees, they have so much coral to scrape,
Speaker 1: Like biting you takes time away from vital coral scraping time,
Speaker 1: all right, well, we're gonna go and close up this
Speaker 1: episode now, but we actually have even more exciting content
Speaker 1: to cover about the parrotfish we didn't. We briefly mentioned their, their, their,
Speaker 1: their sex changing ability, so we're going to get into
Speaker 1: that for sure. Uh. There's also some other stuff that
Speaker 1: will and I think in ways get us even closer
Speaker 1: to that xenomorpha area again.
Speaker 3: So yeah, we're gonna have some cocoonings, some all kinds
Speaker 3: of good stuff to get into next time.
Speaker 1: Yeah, yeah, so tune in for that. In the meantime,
Speaker 1: I love to hear from anyone else out there who
Speaker 1: has personal experience being around parrotfish. You know, we're not
Speaker 1: encouraging anyone to actively seek out and eat parrotfish, but
Speaker 1: you know, it has been a tradition of cuisines. So
Speaker 1: if you would like to ride in and share your
Speaker 1: culinary experience with parrotfish, If you have tasted a parrotfish liver, yes,
Speaker 1: we would like to know what that is like that
Speaker 1: We just would like to know. We'd like to know
Speaker 1: what the Romans were into when they were consuming their
Speaker 1: parrot fish meals. So write in. It's all fair game
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Speaker 1: it to be anonymous. Or you can say hey, this
Speaker 1: is information for you, but don't actually read this. That's
Speaker 1: fair as well. Just write in. We would love to
Speaker 1: hear from you. Just a reminder that Stuff to Blow
Speaker 1: Your Mind is primarily a science and culture podcast, with
Speaker 1: core episodes on Tuesdays and Thursdays, listener mail on Mondays,
Speaker 1: short form episode on Wednesdays, and on Fridays. We set
Speaker 1: aside most serious concerns to just talk about a weird
Speaker 1: film on Weird House Cinema.
Speaker 3: Huge thanks as always to our excellent audio producer JJ Posway.
Speaker 3: If you would like to get in touch with us
Speaker 3: with feedback on this episode or any other, to suggest
Speaker 3: a topic for the future, or just to say hello,
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