Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: 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 parrot fishes. This is one
Speaker 3: of those topics that literally just started with me looking
Speaker 3: at a picture. I was staring at a picture of
Speaker 3: a bizarre, goofy, goofy appearing animal and thinking I want
Speaker 3: to know more about this critter, and then discovering that, indeed,
Speaker 3: this organism is a peculiar and fascinating story, and there
Speaker 3: is so much more to it than you might guess
Speaker 3: just by looking at it at its strange beak or
Speaker 3: toothy mouth.
Speaker 2: Yeah, parrotfish are pretty fascinating. I've snorkeled among the parrotfish
Speaker 2: many times and can a test that they are. They're
Speaker 2: curiously fish, They're pleasure to watch, They're often very colorful.
Speaker 2: So I'm going to throw in more of my observations
Speaker 2: as we proceed. But I think, on the other hand,
Speaker 2: in coral reef environments, where I've done most of my snorkeling,
Speaker 2: and where a lot of snorkeling takes place. They can
Speaker 2: actually be easy to take for granted because they're generally
Speaker 2: around in significant numbers that these environments. Often these are
Speaker 2: protected reefs that I've been to, they're not particularly shy,
Speaker 2: They're easily found in shallow water, so you know, oftentimes
Speaker 2: you're dealing with like reef environments that are either very
Speaker 2: accessible just from the shore or just a very short
Speaker 2: boat ride sort of a situation. So in a way,
Speaker 2: it's easy to take them for granted because they're there,
Speaker 2: you see them, and then you end up focusing a
Speaker 2: lot more of your attention looking for some of the
Speaker 2: harder to find organisms that are going to live in
Speaker 2: these reef environments. So it's actually a great opportunity to
Speaker 2: stop and focus on this remarkable fish that I honestly
Speaker 2: had never really thought about devoting a whole episode or
Speaker 2: series of episodes too. But there's more than enough to
Speaker 2: 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 the big skeleton of stony corals.
Speaker 2: Yeah, the grazing observation is key, and it's something that
Speaker 2: has long been observed for these creatures, as we'll discuss.
Speaker 2: You know, going back into ancient times, even when we
Speaker 2: didn't have snorkelers as we think of them today, you
Speaker 2: still had individuals fishing in shallow environments, sometimes fishing for
Speaker 2: the parrotfish in question, and observing that, hey, these creatures
Speaker 2: appear to be grazing, unlike most of the fish we
Speaker 2: 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 Labyridy, 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. These they're pectoral fins and stuff like that.
Speaker 3: But a characteristic com into many parrotfishes is that they
Speaker 3: tend to live around coral reefs, especially in the tropics.
Speaker 2: I also want to throw in there that there are
Speaker 2: occasionally fish that are just sort of commonly called a
Speaker 2: parrotfish or informally called a parrotfish, that are not parrotfish,
Speaker 2: mainly the blood red parrot chick lid, which apparently is
Speaker 2: a popular aquarium species. This is not actually related to
Speaker 2: proper parrotfish that we're going to be talking about here today.
Speaker 2: And I've also seen some some fossil evidence that is
Speaker 2: sometimes categorized as a parrotfish in a way that I'm
Speaker 2: not sure actually lines up with what we're talking about here.
Speaker 2: But if you've seen a picture of a parrotfish, proper parrotfish, indeed,
Speaker 2: go ahead and look one up if you're in a
Speaker 2: position to do so. I think it's hard to miss
Speaker 2: what we're talking about. These are very recognizable fish, though
Speaker 2: again they do very 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, are
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 jazz 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 a parrot fish. But before you notice any of that,
Speaker 3: but you know, the head shape, the body shape, the
Speaker 3: coloration patterns, what you will probably notice first about any
Speaker 3: given parrotfish is the mouth. I mean, look at these chompers,
Speaker 3: rob I've included just several pictures. I know you've seen
Speaker 3: them in person, so your experience of the teeth the
Speaker 3: beak is probably more direct and visceral and profound even
Speaker 3: than mine. But I was just looking at these pictures
Speaker 3: for quite a while the other day, and my god,
Speaker 3: these beaks, these mouths, it's it's incredible.
Speaker 2: Yeah. Yeah, their mouths are quite fascinating in some of
Speaker 2: the photos. Yeah, they can actually look a little intimidating, though,
Speaker 2: I would say, based on the species that I've primarily
Speaker 2: been exposed to in Hawaii and the Caribbean, they tend
Speaker 2: to look more silly than threatening. But they're definitely very
Speaker 2: 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 very similar to the beak of
Speaker 3: a parrot. It can look like a bird's beak, but
Speaker 3: in other cases these fused rows of teeth look like
Speaker 3: jagged monster jaws, sort of like a horseshoe shaped ceramic
Speaker 3: saw blade. But in other cases still they are like
Speaker 3: a big goofy cartoon overbite, like Alfred y Newman's mouth
Speaker 3: got hit with the radiation from the amazing colossal Man.
Speaker 2: Now I want to throw in one more note here
Speaker 2: about species classifications coloration. It is worth noting that with
Speaker 2: parrotfish that classifications and naming have long proof challenging because
Speaker 2: they tend to show different colorizations depending on an individual's
Speaker 2: age and sex. So, for examples pointed out by the
Speaker 2: Waikiki Aquarium, the spectacled parrotfish is reddish brown when it's
Speaker 2: a juvenile, then it develops a pale tail spot when
Speaker 2: it becomes a reproductive female, and then develops bright blue
Speaker 2: green coloration with pink markings when it becomes male. So
Speaker 2: you can imagine a lot of the early confusion at
Speaker 2: figuring out, well, what is a different species of parrotfish?
Speaker 2: And you will have multiple species of parrotfish in a
Speaker 2: given region, and then what is just parrotfish are the
Speaker 2: same species that's just in a different phase of its life.
Speaker 3: Cycle, that's right. In fact, I was even reading, like
Speaker 3: some blog posts by marine biologists who had worked with
Speaker 3: these animals firsthand, talking about just how difficult it was
Speaker 3: sometimes to identify these fish because of all the variation
Speaker 3: even 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 2: Now, of course, as this we'll be discussing here, Coral,
Speaker 2: of course is hard matter, and one of the crazy
Speaker 2: things about snorkeling with parrotfish is that you don't just
Speaker 2: get to watch them, you get to listen to them.
Speaker 2: So as they feast on the algae that's growing on
Speaker 2: the coral, they're scraping the coral and it's producing a
Speaker 2: sound in the snorkeler's ear that I would compare to
Speaker 2: kind of a static paper crunching or even the snap
Speaker 2: crackle crunch of rice crispies and milk. It's one of
Speaker 2: those things when when you first explore. When I first
Speaker 2: experienced it, I wasn't exactly sure what I was listening to,
Speaker 2: because it's kind of like, is there something in my
Speaker 2: ear and it's just just the sound of the ocean
Speaker 2: and so forth. But no, it it becomes clear, and
Speaker 2: it's often pointed out to one that yeah, this is
Speaker 2: the sound of these the parrotfish feeding, and yeah, it's
Speaker 2: it's pretty remarkable. So you listen to them, you watch them,
Speaker 2: and they just become part of the background sound escape
Speaker 2: 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 2: Yeah, and it's also consistent, like that's the other thing.
Speaker 2: They're constantly grazing, and therefore it is a constant soundtrack.
Speaker 2: It's not like say the occasional sound of a woodpecker
Speaker 2: in a forest, Like it's just NonStop. So it's just
Speaker 2: in the background, and you could easily if you didn't
Speaker 2: know what you were listening to, you might not realize
Speaker 2: that this is the sound of organisms feeding.
Speaker 3: Now, I think there were probably other people out there
Speaker 3: like me, Rob. I don't know if you've 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 2: Yeah, yeah, it can be a bit squeamish. It can
Speaker 2: make one a bit squamish sometimes imagining these other dental
Speaker 2: scenarios in the natural world.
Speaker 3: So I want to talk a bit more late or
Speaker 3: about how parrotfish eat and get their nutrition, and a
Speaker 3: bit 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.
Speaker 2: Yeah. I did. And this was a whole avenue that
Speaker 2: I had not been down. I had no idea this
Speaker 2: was a thing. So again, given that species of parrotfish
Speaker 2: are found around the world, and that they can frequently
Speaker 2: be found in shallow water, and that they have traditionally
Speaker 2: been caught for culinary purposes for food, it should come
Speaker 2: as no surprise that these fish were known to people
Speaker 2: of the ancient world. You know, even in times when
Speaker 2: folks didn't have access to the underwater world in any
Speaker 2: way comparable to what we have today, they still knew
Speaker 2: what these fish were, and in some cases they had
Speaker 2: some rather insightful ideas about what they were doing. In
Speaker 2: other cases, there are some very long standing misconceptions about
Speaker 2: what parrotfish do. So in this we're going to actually
Speaker 2: bring up the work of our dear old friend Roman
Speaker 2: historian Plenty of the Elder, who is one of several
Speaker 2: sources of antiquity that discusses the parrot fish, you know,
Speaker 2: and of course there's a lot of shared content and
Speaker 2: so forth going on. The fish would have been known
Speaker 2: as the scaris. This is of course, now where we
Speaker 2: get the name of the genus for parrotfish, and we
Speaker 2: might assume that in particular we're dealing with discussions of
Speaker 2: the Mediterranean parrotfish, though based on what I was reading,
Speaker 2: also you had like the red sea parrotfish that was
Speaker 2: also known to various cultures of antiquity. So Plenty of
Speaker 2: the Elder in the Natural History seventy nine CE rites
Speaker 2: at the present day the first place, and this is
Speaker 2: he's speaking from a culinary perspective here. First place at
Speaker 2: the Roman table is given to the scas the only
Speaker 2: fish that is said to ruminate and to feed on grass,
Speaker 2: and not on other fish commonly found in the Carpathian Sea,
Speaker 2: and never of its own accord passes lectum a promontory
Speaker 2: of trois now. Nineteenth century naturalist George Cuvier and his
Speaker 2: annotations to Plenty points out again that the first place
Speaker 2: here is in reference to the Roman dinner table, where
Speaker 2: this fish was celebrated for several attributed characteristics that I'll
Speaker 2: get to in a minute, and was also typically quote
Speaker 2: salted with the intestines in it. M m okay, and
Speaker 2: some Roman authors actually absolutely insisted that you do not
Speaker 2: eat this fish without the intestines included. It's just too
Speaker 2: delicious 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 the meat some flavor.
Speaker 2: You've got to leave them in Yeah, okay. And I
Speaker 2: know they were often in many cultures salted and then traded,
Speaker 2: So I'm offhand, I'm not entirely sure if this is
Speaker 2: a deaf in case of we're talking about salted parrotfish
Speaker 2: with the intestines still in, or some other form of
Speaker 2: preparing them. But at any right, they really liked it.
Speaker 2: There are also Roman references to eating parrotfish livers as.
Speaker 3: A delicacy, so all the value here is just for
Speaker 3: their flesh as food. This is a first place distinction
Speaker 3: that would probably not be so flattering to the fish itself.
Speaker 2: Right right, And the Romans weren't alone in appreciating eating parrotfishes.
Speaker 2: We'll get to some other far flowing examples. Plenty of
Speaker 2: humans have eaten parrotfish and still eat parrotfish. The Greeks
Speaker 2: love them. There's some I think twenty species of Mediterranean parrotfish. Again,
Speaker 2: there's the red sea parrotfish, considered a delicacy in antiquity.
Speaker 2: And in both of these cases I believe they were
Speaker 2: often dried and then widely traded. I've read that, in fact,
Speaker 2: they were easily dried. I'm not sure about the particulars
Speaker 2: of that, but but I I'll take the word on
Speaker 2: it that, Okay, this is a fish that is easier
Speaker 2: to dry and prepare and then trade across distances. You
Speaker 2: don't have to eat it fresh by the seaside. Anyway,
Speaker 2: it was celebrated at the Roman table, not just because
Speaker 2: you ate it salted and with the guts in it,
Speaker 2: but also for several reasons, according to Cuvier. And I
Speaker 2: think a lot of these seem to get down to
Speaker 2: the fact that I'm assuming the Romans liked a great
Speaker 2: story at the table. You know, it's not just about
Speaker 2: what the fish smells like, taste like, looks like on
Speaker 2: the plate, but also what is the story of it,
Speaker 2: what ideas are wrapped up in this particular organism. So
Speaker 2: hear that first of all, it was thought to be
Speaker 2: the only ruminating fish.
Speaker 3: So wait, does that mean ruminating as in like chewing
Speaker 3: the cud like a cow or a sheep.
Speaker 2: Yes, though basically I think what this comes down. First
Speaker 2: of all, they're not truly chewing the cut. They're not
Speaker 2: truly ruminating, you know, they're not chewing something that is
Speaker 2: previously been chewed and swallowed. They are grazing like a cow.
Speaker 2: And I think it has to do with observations of
Speaker 2: these animals grazing, and it's like, oh, look, they're like
Speaker 2: a cow. They're ruminating. But still the idea that they're
Speaker 2: ruminating the idea that they're chewing their cut continues to
Speaker 2: be mentioned all through antiquity on all the way up
Speaker 2: through like medieval besty areas, though some voices such as
Speaker 2: Saint Ambrose in the fourth century said that did point
Speaker 2: out the chud. The cud chewing thing is not accurate,
Speaker 2: that's not what they're doing. So but still a lot
Speaker 2: of misinformation about these fish persisted for a very long
Speaker 2: time now. As Aristotle also observed in History of Animals,
Speaker 2: the parrettfish were thought to be vegetarians, and indeed, I
Speaker 2: guess you could say they're essentially herbivores. Many sources will
Speaker 2: classify them as such, but also note that they're maybe
Speaker 2: more more correct to say that they're algavores. But still, well,
Speaker 2: ancient people observe that these fish are not eating in
Speaker 2: 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 2: Yeah, I guess you would be some sort of a
Speaker 2: coral war or something to that effect, right, But on
Speaker 2: a number of the different fish databases that I was
Speaker 2: looking at, yeah, sometimes they'll say herbivore, sometimes they'll say
Speaker 2: herbivore algivore, and then sometimes there's kind of an omnivore
Speaker 2: note as well. I guess there's always a margin of error,
Speaker 2: as we've discussed here, like even things like a cow,
Speaker 2: which we think of is kind of a pure herbivore.
Speaker 2: There are examples, as we've discussed on the show in
Speaker 2: the past, where they have been observed to if meat
Speaker 2: is available, they 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 2: Yeah. So I mean we can, I think basically say
Speaker 2: that ancient people were correct in this judgment. Now, and
Speaker 2: I guess maybe it made the story at the dinner
Speaker 2: table a little more interesting. They're like, this is the
Speaker 2: cow of the sea, that sort of thing. Now, the
Speaker 2: third attribute that Kuvia mentions is quote because it had
Speaker 2: the faculty of producing a sound. Now, perhaps I'm not
Speaker 2: completely understanding Kuvier's point here, but I guess this is
Speaker 2: referring to that constant chewing sound, that constant grazing sound
Speaker 2: that one hears if your head is below water with
Speaker 2: the fish. And again, this is not something that I
Speaker 2: would think actually impacts one's enjoyment of dinner. But again,
Speaker 2: 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 a
Speaker 3: kind of a gruesome way to ask for it, But
Speaker 3: people do say that. Can you say that, like, I
Speaker 3: want my parrotfish steak rare, I want it still scraping.
Speaker 2: I guess. So the fourth attribute that he mentions is
Speaker 2: quote for its salacious propensities numbers being taken by means
Speaker 2: of a female attached to a string. This, I guess
Speaker 2: alluding to a supposed method of catching them. And I
Speaker 2: suppose the Romans just like randy food, though I'm not
Speaker 2: sure it was actually considered an afrodisiac, because I didn't
Speaker 2: see it listed in another source I was looking at
Speaker 2: that had to do with various foods of the Romans
Speaker 2: did believe were aphrodisiacs.
Speaker 3: Uh huh okay.
Speaker 2: And then, fifthly for its quote remarkable sagacity and affording
Speaker 2: assistance to another when taken in the net.
Speaker 3: Huh Now what would that mean?
Speaker 2: So this is referring to something that is that that
Speaker 2: pops up in various old sources as well, and again
Speaker 2: continues to persist for centuries. May be particularly referring to
Speaker 2: a passage in Ovid. Ovid has the following passage quote,
Speaker 2: The scaris is caught by a stratagem beneath the waves,
Speaker 2: and at length dreads the bait. Fraught with treachery, it
Speaker 2: dares not strike the osres. This refers to a reed
Speaker 2: basket with an effort of its head, but turning away
Speaker 2: as it loosens the twigs with frequent blows of its tail,
Speaker 2: it makes its passage and escapes safely into the deep. Moreover,
Speaker 2: if perchance any kind scars swimming behind sees it struggling
Speaker 2: with the osures he takes hold of its tail in
Speaker 2: his mouth and it is thus turned away and so
Speaker 2: it makes its escape.
Speaker 3: So, okay, we have.
Speaker 2: This idea that these fish, these parrotfish are are essentially
Speaker 2: I don't think you social would be the term, but
Speaker 2: they are. They help each other out. They're capable of
Speaker 2: some form of altruism where if they see another one
Speaker 2: of their kind stuck in one of these wicker basket traps,
Speaker 2: they will try and help them out.
Speaker 3: Huh.
Speaker 2: And so this idea ends up sticking around for against
Speaker 2: centuries and centuries. The idea that the scarce or parrotfish
Speaker 2: is not only a cud chewing herbivore of the sea,
Speaker 2: 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 friendly behavior be based on. So the idea
Speaker 3: is they help each other avoid traps or save each
Speaker 3: other from traps. Is there any modern research on this?
Speaker 2: So the main source I found on this, and this
Speaker 2: is where I got turned onto the idea, was the
Speaker 2: blog of Fishtories. It's like histories and fish combined. That's
Speaker 2: fis ht o r I s dot net. It is
Speaker 2: a blog maintained by Via hendricks On, information scientist and
Speaker 2: historian of science. She discusses this whole weird scenario with
Speaker 2: imagery of the parrotfish, because indeed there's there's there's imagery associated.
Speaker 2: I included this illustration for here for you here Joe
Speaker 2: from a munch latter later source. But uh, but but
Speaker 2: she does point out that, based on what we can tell,
Speaker 2: the fish are actually anything but friendly to each other
Speaker 2: in these scenarios. Wicker baskets like this are still used
Speaker 2: in some places to catch fish, she points out. But
Speaker 2: she writes that the parrotfish have actually been observed too
Speaker 2: violently attacked their fellow parrotfish that become caught in the
Speaker 2: reeds of the fishing basket. So I don't I don't
Speaker 2: know that there's really much evidence to back this up.
Speaker 2: I also get to an example here in a bit
Speaker 2: involving traditional Hawaiian techniques for catching parrotfish that also uses
Speaker 2: a basket. Like the idea of being essentially that the
Speaker 2: parrotfisher roaming around the corals feeding and they kind of
Speaker 2: have these paths that they follow. They also tend to
Speaker 2: sort of group together, and you may have like what
Speaker 2: seems to be a leader of the pack, and if
Speaker 2: you set up these baskets at the right time, you
Speaker 2: can catch them, and you can end up catching a
Speaker 2: bunch of them even and you can then release the
Speaker 2: ones you don't want, make use of the ones you
Speaker 2: want to harvest. So I don't know. On one level,
Speaker 2: it seems like, Okay, you're ending up with an artificial
Speaker 2: environment scenario here, where you're dealing essentially with captive fish
Speaker 2: doing things in a captive environment and a high stakes
Speaker 2: environment for them that they might not do otherwise. And
Speaker 2: that may mean attacking each other that I guess could
Speaker 2: also mean some sort of observational behavior, especially without the
Speaker 2: aid of any kind of like snorkeling mask and so forth,
Speaker 2: it might look like ones helping the others out. I'm
Speaker 2: not sure, But still the idea becomes entrent, and the
Speaker 2: image of the parrotfish helping each other escape from fishing
Speaker 2: baskets ends up becoming a symbol of friendship. Oh yeah,
Speaker 2: So this is something that she discusses at length in
Speaker 2: another paper. This is something that published in Emblems of
Speaker 2: the Natural World from twenty fifteen Ichthyology and Emblematics in
Speaker 2: Conrad Gesner's Historia Piscium and Joham Kamarius's Kamarus the Youngers
Speaker 2: Simbola at Emblemata. She points out that Plenty was one
Speaker 2: of the key sources for this misconception, but plenty of
Speaker 2: others sources in the ancient world echoed at Plutarch chimes
Speaker 2: in on it, and so some sources identified this as
Speaker 2: a sign of intelligence in the parrotfish, while other fishes
Speaker 2: were often held up as examples of a lack of
Speaker 2: intelligence in fish, such as then Conrad Guestner's sixteenth century
Speaker 2: work Historia Animalium, the mackerel was held up as a
Speaker 2: stupid fish.
Speaker 3: How do you get that distinction as a fish? I
Speaker 3: don't know.
Speaker 2: I mean, maybe they just it's probably a little bit unfair,
Speaker 2: right in some cases the macvil looks to and you're
Speaker 2: basing everything on the human perspective and human expectations of
Speaker 2: what an animal's intelligence is, you know, whereas ultimately you
Speaker 2: can I think you can approach these scenarios by saying, well,
Speaker 2: the yeah, the parrotfish is in a way a genius.
Speaker 2: It's as smart as it needs to be to do
Speaker 2: 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 dumbfish. And I don't
Speaker 3: know if intelligence actually has anything to do with how
Speaker 3: easy they are to catch or not. You know, might
Speaker 3: just have to do with like ingrained behavioral patterns, someone
Speaker 3: responding distress or something.
Speaker 2: Yeah, yeah, And it's kind of curious because it sounds
Speaker 2: like if you have the right traps for it, catching
Speaker 2: parrotfish is generally not considered super challenging. So but you know,
Speaker 2: we have this other narrative that emerges again that they're
Speaker 2: helping each other and that they can sort of help
Speaker 2: each other escape from these traps and so forth. Now
Speaker 2: I mentioned Hawaiian traditions because again, you have parrotfish all
Speaker 2: over and you do have them in the Hawaiian Islands,
Speaker 2: and in Hawaii, the parrotfish was historically known in the
Speaker 2: Hawaiian language as uhu. The fish are prominent there and
Speaker 2: they were eaten by Hawaiians Traditionally. There's a saying in Hawaiian,
Speaker 2: according to the online Hawaiian dictionary Ulucal, that translates to
Speaker 2: my craving makes my mouth water for the parrotfish passing
Speaker 2: before my eyes. The Hawaii Coral Reef Network points out
Speaker 2: that not only were they a delicacy, but their liver
Speaker 2: was especially favored. So again, you know, you know, other
Speaker 2: side of the world you still have people eating parrotfish
Speaker 2: and also realizing that the liver is apparently really good.
Speaker 2: Interesting now, the fish itself, to the Hawaiians, had connotations
Speaker 2: of physical beauty, as in one's love interest, but also
Speaker 2: in terms of a desirable bachelor. There was also apparently
Speaker 2: a tradition that held that a fisherman could observe the
Speaker 2: behavior of a parrotfish and it would serve as a
Speaker 2: kind of portent as to what was going on back home.
Speaker 2: So like, you know, certain things the parrotfish was doing.
Speaker 2: It's like, okay, everything's cool. Back of the house. Other
Speaker 2: things the parrotfish might be doing. It's like you need
Speaker 2: to go back and check on your wife, that sort
Speaker 2: of thing. Now, the parrotfish who also factors into one
Speaker 2: of the stories of a legendary figure in Hawaiian mythology.
Speaker 2: And I could not find a like a solid pronunciation
Speaker 2: guide for this name, So I hope I'm saying it
Speaker 2: somewhere close to correctly. In my apologies if I'm not
Speaker 2: punia kaya. This is a in these stories, he's a
Speaker 2: He's a dashing young man who one day leaves his parents'
Speaker 2: house because he feels this call of the ocean. He
Speaker 2: wants to go fishing, and so he catches this young,
Speaker 2: supernatural fish the first ooh, and it makes it his pet,
Speaker 2: and then he releases it where it becomes the parent
Speaker 2: of all fish. And so afterwards he's able to go
Speaker 2: call upon the fish to deliver fellow fish to the fisherman.
Speaker 3: Hmmm.
Speaker 2: Yeah, I was reading more about this in Native Use
Speaker 2: of Fish in Hawaii by Margaret Titcomb, and the author
Speaker 2: makes a connection to the manner in which parrotfish move
Speaker 2: along in a school, often single file, seemingly led by
Speaker 2: a leader. So that, yeah, this special trap was devised
Speaker 2: by the early Hawaiians for use during a particular season.
Speaker 2: The trap allowed them to allow the fish to file
Speaker 2: into the trap led by the leader, but then they're
Speaker 2: unable to escape, and they keep the trap in use
Speaker 2: during the May June July season, collect enough fish for
Speaker 2: personal use, and then release the rest, though another source
Speaker 2: I've looked at seems to indicate that excess fish might
Speaker 2: have been harvested to feed pigs and dogs, So I
Speaker 2: don't know. There may be some variety in the practice,
Speaker 2: or there might be a misconception on one side or
Speaker 2: the other, but at any rate, this is how they
Speaker 2: caught them, and I guess by virtue of that leader
Speaker 2: fish leads into this idea that there's kind of like
Speaker 2: a fish that is a friend of the people that
Speaker 2: will help you catch more.
Speaker 3: Fish, Like it's the leader of the school is deliberately
Speaker 3: leading them into the trap for you.
Speaker 2: Yeah, though not so much that it's like a trader fish,
Speaker 2: but more than like it is this fish that a
Speaker 2: like a legendary figure made a deal that's sort of yeah.
Speaker 2: So yeah, this was a new one to me as well.
Speaker 2: I don't think i'd heard this in my previous trips
Speaker 2: to Way, so and there may be some more interesting
Speaker 2: parafish mythologies out there that I'll have to turn up
Speaker 2: 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 parrot Fishes by CRC Press twenty eighteen. And this
Speaker 3: chapter was by Peter C. Wainwright and Samantha A. Price.
Speaker 3: It's called Innovation and Diversity of the Feeding Mechanism in
Speaker 3: parrot Fishes. And I'll probably come back to this in
Speaker 3: subsequent episodes as well. But about the authors, Peter C.
Speaker 3: Wainwright is a biologist at UC Davis and Samantha A.
Speaker 3: Price is a biologist at Clemson. And so the author
Speaker 3: is here say that how parrotfishes eat. To the various
Speaker 3: species of parrotfish, how they eat is quote one of
Speaker 3: the fundamental ecological processes in coral reef ecosystems. So when
Speaker 3: you think about parrotfish, you shouldn't just think of them
Speaker 3: as something you occasionally see in a coral reef, but
Speaker 3: rather they are an integral part of how coral reef
Speaker 3: ecosystems work, and kind of the whole ecosystem doesn't really
Speaker 3: work without them. Now, as we mentioned earlier, the feeding
Speaker 3: process of parrotfish involves a lot of scraping and biting
Speaker 3: into hard stony materials. Parrotfishes swim around coral reefs using
Speaker 3: their teeth to scrape edible stuff off the outside of coral,
Speaker 3: and they break off some coral and bring it along
Speaker 3: with them in the process. Now, what is that edible
Speaker 3: stuff on the outside of the coral. The authors say
Speaker 3: that it includes primarily algae. Algae is a big part,
Speaker 3: but also detritis, and in a marine context this usually
Speaker 3: means dead organic material, so parts of dead organisms, fecal matter,
Speaker 3: all that yummy stuff. Sometimes it will include bacteria, little
Speaker 3: colonies of bacteria. And then they just say, quote a
Speaker 3: wide range of encrusting invertebrates, so all kinds of little
Speaker 3: invertebrate animals that could be found on a coral reef.
Speaker 3: This might include coral polyps themselves, and it might also
Speaker 3: include things like sponges. Now, a couple of sources I
Speaker 3: was looking at sort of classified several different types of
Speaker 3: parrotfish feeding strategies, and the main variation here seemed to
Speaker 3: be how deep the parrotfish would cut into the stony
Speaker 3: parts of the coral. So you might have some that
Speaker 3: are referred to more as browsers or grazers that tend
Speaker 3: to typically just take the soft parts off the surface
Speaker 3: of the coral. You've got scrapers which scrape the coral
Speaker 3: a little harder and get some of what underneath. And
Speaker 3: then you've got what are called excavators, which are really
Speaker 3: just taking chunks out of the hard stuff. So the
Speaker 3: parrotfishes swim along on the reef, scraping the stuff off
Speaker 3: with their outer teeth or excavating bits of it and
Speaker 3: inevitably leaving scars on the rock or the coral skeletons
Speaker 3: as they go. And then all of this mixture of
Speaker 3: both hard and soft parts goes into the mouth, where
Speaker 3: it is subjected to a second obstacle, which is the
Speaker 3: trial of the inner jaws. Because parrotfishes don't only have
Speaker 3: these fascinating outer teeth, they have a second set of
Speaker 3: teeth at the back of their mouth. Known as the
Speaker 3: phyryngeal jaw. Now you might have read about phyngeal jaws
Speaker 3: with respect to other animals that have them. A number
Speaker 3: of fish and creatures that live in the sea have them,
Speaker 3: and a well known example is the more eel.
Speaker 2: That's right, Yeah, And of course, you know, those of
Speaker 2: you who've watched any amount of science fiction, you might
Speaker 2: also note that very angel jaws from in the world
Speaker 2: of fictional monsters, we do have, of course, the alien xenomorph,
Speaker 2: at least the main morph of the creature that we
Speaker 2: see in those films where we see this inner jaw
Speaker 2: that functions as both a feeding mechanism and a puncturing weapon,
Speaker 2: while elsewhere in the alien universe we see other morphs,
Speaker 2: such as the deacon and the neo morph that boast
Speaker 2: extendable inner jaws rather than a secondary set of jaws.
Speaker 2: But yeah, the generally you often see some like comparative
Speaker 2: biology write ups, and I think I've done right up
Speaker 2: to this in this nature in the past where when
Speaker 2: you're you're comparing xenomorph physiology to the natural world. The
Speaker 2: more a eel is like a prime stopping point of comparison.
Speaker 3: Now, the exact design of the phyngeal jaw in the
Speaker 3: xenomorph is a little bit extra like. I'm not aware
Speaker 3: of any examples in the in the natural world where
Speaker 3: like the inner jaw comes out of the mouth and
Speaker 3: stabs like a spear, like bites through the torso of
Speaker 3: a prey animal. The inner jaws in the cases I'm
Speaker 3: aware of, tend to stay mostly within the outer jaws,
Speaker 3: but they do do something fascinating and perhaps to some horrifying.
Speaker 3: So in the case of the more a eel, which
Speaker 3: is a predator, the fyringial jaw helps the eel capture
Speaker 3: and 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 prey in place without allowing
Speaker 3: it to back out and escape. And then while the
Speaker 3: eel is holding the prey in place with these outer jaws,
Speaker 3: the inner jaws reach up from out of the eel's
Speaker 3: throat to bite the animal and pull it further inside
Speaker 3: the mouth and down into the esophagus. So it's a
Speaker 3: two step capture and conveyance mechanism. Now, just to stick
Speaker 3: with the morey eel in a sidebar for a second.
Speaker 3: I got interested in this. The evolutionary reasoning for this
Speaker 3: is an interesting question. Apparently, most predatory fish rely in
Speaker 3: large part on suction to capture and swallow their prey.
Speaker 3: So these other fish use their muscles to rapidly expand
Speaker 3: the mouth through the throat cavity. And so when it
Speaker 3: expands like this, it creates a negative pressure and it
Speaker 3: sucks in water from outside the mouth, including the prey
Speaker 3: in that water. And this suction mechanism can either be
Speaker 3: the action that pulls the prey into the mouth in
Speaker 3: the first place, or can also be that after a
Speaker 3: predatory fish bites the prey with its jaws, the suction
Speaker 3: mechanism then pulls the prey farther into the mouth and
Speaker 3: down into the esophagus.
Speaker 2: Yeah, scorpionfish is a great example of this, and you
Speaker 2: can find some great video footage of this where it's
Speaker 2: an ambush press down there, hidden on the floor of
Speaker 2: the sea, and then as its prey comes by, it
Speaker 2: just kind of goes wolf and just rapidly sucks it
Speaker 2: into its mouth and it's just gone like that, and
Speaker 2: the scorpion fish is of course you'll note get very
Speaker 2: robust looking, kind of frog ish looking, and that is
Speaker 2: 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 fryngial 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 2: 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 fryngial 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. Parrot fishes are again
Speaker 3: not generally going to be chasing large live prey. They're
Speaker 3: mostly herbivores, and they eat by scraping or gouging the
Speaker 3: coral and getting stuff off the outside or in the
Speaker 3: layers underneath the surface. This material that they scrape off
Speaker 3: of rocks and coral, which mostly inclin ludes, algae and
Speaker 3: other microbial organisms, but also dead organic matter and coral
Speaker 3: skeleton bits, is pulled down into the pharyngeal teeth, where,
Speaker 3: to quote Wainwright and Price, it is quote mixed with
Speaker 3: mucus and ground to a fine slurry before being passed
Speaker 3: to the intestines. And Rob I was just looking up
Speaker 3: some photos of parrotfish pharyngeal teeth, and oh boy, what
Speaker 3: what are we looking at?
Speaker 2: Here.
Speaker 3: These are some organs, like they're clearly specialized for grinding
Speaker 3: down this mixture of hard and soft substances into a mucous,
Speaker 3: lubricated slurry. But some of these pieces of parrotfish anatomy
Speaker 3: look like a car transmission gear made out of bone.
Speaker 3: Others look like a bone pine cone. It's it's interesting.
Speaker 2: Yeah, yeah, yeah, it does kind of look like interlocking
Speaker 2: gear teeth. Yeah, it's crazy.
Speaker 3: So the digestive system extracts nutrients from this lurry, and
Speaker 3: then the parrotfish excretes what is left over, which is
Speaker 3: a big part of which is sand. Because they're grinding
Speaker 3: down this coral, they bite off and scrape off pieces
Speaker 3: of coral, grind up that coral with the nightmare throat teeth,
Speaker 3: and then they poop sand. So I've read it described
Speaker 3: that if you swim around with these buddies, you will
Speaker 3: see them just like letting out kind of poofs of
Speaker 3: sand or blasting clouds of sand into the water column.
Speaker 2: Yeah. Absolutely, yeah, Like they're just they're kind of constantly
Speaker 2: doing it. I mean, it makes sense. They're grazing. They're
Speaker 2: kind of like goats, and they're kind of pooping like goats.
Speaker 2: Except it's coming out in this kind of like puff
Speaker 2: of sand, and I know you included some photos here
Speaker 2: where it's like more than a puff. It looks like
Speaker 2: 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 bioeroosion 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 2: That's right. There beach creation machines, and some of the
Speaker 2: 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 can these fish really poop? Again, it
Speaker 3: depends where you are. There are obviously other sand creation
Speaker 3: mechanisms in the sea, so this is not the only one.
Speaker 3: But in some places 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 pariet Al called linking reef ecology to island building.
Speaker 3: Parrotfish identified as major producers for island building sediment in them.
Speaker 3: And so again this is by Perry at All and
Speaker 3: so the Maldives Archipelago. This is an island chain that
Speaker 3: contains approximately twelve hundred individual reef islands, which are islands
Speaker 3: that are made entirely out of sediment that is produced
Speaker 3: from underwater coral reefs. So the primary reason these islands
Speaker 3: exist is that there are coral reef ecosystems on an
Speaker 3: underwater platform. Of course, the reefs themselves are mostly made
Speaker 3: 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. Perry 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 dec composing into
Speaker 3: sand and gravel, you may not have an island here.
Speaker 3: But the authors of this study say, before their research,
Speaker 3: how exactly that sediment is produced from the coral reef
Speaker 3: is poorly quantified, so they investigated they're looking at where
Speaker 3: does the sediment come from, and they used the example
Speaker 3: of Karu, which is an interior reef island in the Maldives.
Speaker 3: They found that the area around this island produces about
Speaker 3: six 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 called 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 authors 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 2: I know, it's it's just it's crazy. It's one of
Speaker 2: those mind blowing facts though that again, it gets pointed
Speaker 2: out a lot when you are, you know, going to
Speaker 2: these places and snorkeling, it becomes easy to sort of
Speaker 2: take for granted and you have to sort of remind yourself.
Speaker 2: Then when you're walking on the beach, it's like, no,
Speaker 2: for real, all the sand and it's still kind of
Speaker 2: you know, beggars the imagination.
Speaker 3: Yeah. Now, another thing that's interesting is that, of course
Speaker 3: we know now that parrot fishes are very important for
Speaker 3: creating the sand that in some cases makes it possible
Speaker 3: to have an island, and like these reef island environments
Speaker 3: or helps replenish the beaches. But you might think, on
Speaker 3: the other hand, well, the parrot fishes are the enemy
Speaker 3: of the coral reefs though, because they're preying on, you know,
Speaker 3: the coral, they're like scraping the coral. In fact, it
Speaker 3: is thought that parrotfishes help protect coral reefs because as
Speaker 3: they're going along taking bites out of the barrel coral reefs,
Speaker 3: they might be leaving scars in them, biting pieces off,
Speaker 3: taking chunks out. But by grazing in this way, they
Speaker 3: prevent the reefs from becoming overgrown by things like algae
Speaker 3: and other encrusting invertebrates like sponges and stuff. So they
Speaker 3: may eat some coral as they munch along, but overall
Speaker 3: they keep the coral reefs healthy.
Speaker 2: That's right. This is a very important fact concerning like
Speaker 2: necessary conservation for parrotfish because and it goes beyond that too,
Speaker 2: Like I was reading that by constantly eating algae off
Speaker 2: the coral, again, they're they're constantly in doing this cleaning
Speaker 2: the coral, creating new surfaces on the coral, and this
Speaker 2: is where baby corals can attach and grow, so that
Speaker 2: that's in play. And on top of this, yeah, they're
Speaker 2: keeping like seaweed, which remember is a microalgae. They're keeping
Speaker 2: seaweed growth in check. And this is apparently one of
Speaker 2: the prime results of parrotfish overfishing in parts of the
Speaker 2: Caribbean and the Pacific seaweed overgrowth. And I was even
Speaker 2: reading this is from Kramer at All in twenty seventeen's
Speaker 2: prehistorical and historical declines in Caribbean coral reef accretion rates
Speaker 2: driven by loss of parrotfish. The authors here say that
Speaker 2: we see this connection proven out in sediment fossils. There's
Speaker 2: a strong observable connection between declines and coral accretion rates
Speaker 2: and parrotfish abundance. So and it's more evidence that we
Speaker 2: need to conserve our parrotfish in order to help prevent
Speaker 2: coral reef environments from becoming quote, algael dominated habitats. And yeah,
Speaker 2: so this is worth keeping in mind. If you're traveling
Speaker 2: somewhere and parrotfish is on the menu, it's advisable to
Speaker 2: eat something else. And indeed, there are a number of
Speaker 2: efforts and protections in places around the world to help
Speaker 2: protect these populations like the parrotfish are a vital part
Speaker 2: of those coral environments which are already threatened in a
Speaker 2: number of ways. This is one that we can we
Speaker 2: can we can do a lot to help coral reefs,
Speaker 2: but not eating parrotfish is perhaps even more accessible than
Speaker 2: some of the things we 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 Rays Reveal the Biting Truth about Parrotfish Teeth
Speaker 3: by Glenn Roberts Jr. 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 coral
Speaker 3: skeletons are not soft. You know, they're hard Calcium carbonate
Speaker 3: and they're just these teeth are relentlessly munching. So the
Speaker 3: particular parrotfish species in question was the steep head parrotfish
Speaker 3: also known as the blunt head parrotfish scientific name Chlorurus
Speaker 3: micro rhinos. And in this analysis, the researchers found that
Speaker 3: the resilience of parrotfish teeth was due to this woven
Speaker 3: microstructure of minerals in the enameloid of the teeth. And
Speaker 3: the article compares it in fact in structure to chain mail,
Speaker 3: which I thought was interesting. So this microstructure creates a
Speaker 3: tooth the material that is incredibly hard at the biting surface.
Speaker 3: The article points out that the hardness of the biting
Speaker 3: surface is about five hundred and thirty tons of pressure
Speaker 3: per square inch and they compare this to the weight
Speaker 3: of eighty eight African elephants on a single square inch
Speaker 3: of space. Now, that microstructure of the teeth fits into
Speaker 3: a larger structure, the sort of morphology of the jaw,
Speaker 3: which is that these parrotfish have like fifteen rows of
Speaker 3: teeth totaling about one thousand teeth, all fused together, biologically
Speaker 3: glued or cemented together into this single beak like structure,
Speaker 3: and the stiffness of the underlying mineral crystals increases as
Speaker 3: it goes toward the tip the biting surface, and the
Speaker 3: article quotes one of the researchers involved named PUPA. Gilbert,
Speaker 3: who is a professor in the physics department at the
Speaker 3: University of Wisconsin Madison, who says, quote, parrotfish teeth are
Speaker 3: the coolest biominerals of all. They are the stiffest, among
Speaker 3: the hardest, and the most resistant to fracture and to
Speaker 3: abrasion ever measured. And so given the incredible material qualities
Speaker 3: of these parrotfish teeth and beaks, researchers are looking into
Speaker 3: ways that the oven crystals of parrotfish teeth might be
Speaker 3: used as an inspiration for human engineering, a design pattern
Speaker 3: that could be reproduced in synthetic materials to create a tougher,
Speaker 3: more resilient product.
Speaker 2: Now, just a couple of notes about these teeth for one.
Speaker 2: On one hand, to come back to the alien xenomorph.
Speaker 2: You know, it is interesting that they're sometimes described, at
Speaker 2: least for some of the morphs, as possessing metal teeth.
Speaker 2: And here we have the parrotfish, whose teeth are sometimes
Speaker 2: described as being stronger than many metals men metals, so
Speaker 2: it's kind of interesting comparison there. Also, you know, inevitably
Speaker 2: there is the question in the same way that we
Speaker 2: can't look at a creature that is biting coral and
Speaker 2: you know, think about our own teeth biting coral, we
Speaker 2: also can't help but look at a creature with interesting
Speaker 2: teeth and wonder what happens if I get bitten by
Speaker 2: one of these? So I mean, to be clear, you know,
Speaker 2: humans are not on the menu for the parrotfish. There
Speaker 2: are accounts of parrotfish rarely biting humans, though it does
Speaker 2: seem very rare, and the incidents I was looking at,
Speaker 2: most of them seem to be related to incidents with
Speaker 2: fishermen who were actively harvesting them or you know, engaging
Speaker 2: with a trap or something. But they have bitten humans before,
Speaker 2: so it can happen. But I mean that can be
Speaker 2: said of a lot of creatures, like you know, a
Speaker 2: horse can bite you.
Speaker 3: Oh Lord, why did I google this? But I did?
Speaker 2: Oh? Did you just google the art? You may have
Speaker 2: googled one 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 2: Yeah, there's a particular story that comes up in search
Speaker 2: involving a fisherman that is that was bitten in a
Speaker 2: delicate area by one of these parrotfish. So yeah, I
Speaker 2: you know, weighed carefully if you decide to pursue these
Speaker 2: stories for yourself. But yeah, it can't happen. It has happened,
Speaker 2: But uh, these are generally not considered you know, risky fish,
Speaker 2: and people snorkele around them almost constantly without issue.
Speaker 3: They're not looking to bite you. They're just trying to
Speaker 3: go about their business. They're scraping, they're buzzing't.
Speaker 2: Like bees, they have so much coral to scrape, like
Speaker 2: biting you takes time away from vital coral scraping time.
Speaker 2: All right, Well, we're gonna go and close up this
Speaker 2: episode now, but we actually have even more exciting content
Speaker 2: to cover about the parrotfish we didn't. We briefly mentioned
Speaker 2: their their their their sex changing ability, so we're going
Speaker 2: to get into that for sure. There's also some other
Speaker 2: stuff that will and I think in ways get us
Speaker 2: even closer to that xenomorph 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 2: Yeah yeah, so tune in for that. In the meantime,
Speaker 2: I'd love to hear from anyone else out there who
Speaker 2: has personal experience being around parrotfish. You know, we're not
Speaker 2: encouraging anyone to actively seek out and eat parrotfish, but
Speaker 2: you know, it has been a tradition of cuisines. So
Speaker 2: if you would like to write in and share your
Speaker 2: culinary experience with parrotfish, if you have tasted a parrotfish liver, yes,
Speaker 2: we would like to know what that is like that.
Speaker 2: We just would like to know. We'd like to know
Speaker 2: what the Romans were into when they were consuming their
Speaker 2: parrot fish meals. So right in, it's all fair game
Speaker 2: as always, you know, if you have when you do
Speaker 2: write into us, you can always flag something is and
Speaker 2: say hey, don't use my name on this, I want
Speaker 2: it to be anonymous. Or you can say, hey, this
Speaker 2: is information for you, but don't actually read this. That's
Speaker 2: fair as well. Just write in. We would love to
Speaker 2: hear from you. Just a reminder that stuff to blow
Speaker 2: your mind is primarily a science and culture podcast with
Speaker 2: core episodes on Tuesdays and Thursdays, listener mail on Mondays,
Speaker 2: short form episode on Wednesdays, and on Fridays. We set
Speaker 2: aside most serious concerns to just talk about a weird
Speaker 2: 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,
Speaker 3: you can email us at contact at stuff to Blow
Speaker 3: your Mind dot com.
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