Episodes
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Thanks to Eilee and Alexis for their suggestions this week, two amazing frogs!
Further reading:
Paradoxical frog: The giant tadpole that turns into a little frog
Fungus is wiping out frogs. These tiny saunas could save them.
How to build a frog sauna
The paradoxical frog [photo by Mauricio Rivera Correa - http://calphotos.berkeley.edu, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=6703905]:
The Vietnamese mossy frog [photo by H. Zell - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=81804225]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
Let’s start 2025 off right with an episode about frogs! Thanks to Alexis and Eilee for their suggestions.
Let’s start with Eilee’s suggestion, the paradoxical frog. The paradoxical frog is a type of tree frog that lives in South America. Like other frogs, it likes ponds and shallow lakes. Some individuals are green and some are brown, and a frog may have darker stripes or splotches, or might just be plain. The tadpoles eat algae and other tiny food, while the adults eat insects.
As with most frogs, the paradoxical frog hatches into a larval stage called a tadpole or pollywog, which is fully aquatic. It later metamorphoses into its adult form as a frog. Most tadpoles start out very small and grow larger, then metamorphose into a juvenile frog which then grows to fully adult size. But while the paradoxical frog’s tadpole starts out small, it can grow to as much as 11 inches long, or 28 centimeters! It’s the largest tadpole in the world as far as we know.
So how big is the adult frog if the tadpole is so enormous? About 3 inches long, or 7.5 cm, from snout to vent. That’s why it’s called the paradoxical frog, because a paradox is something that seems contradictory to expectations. Instead of the ordinary way of things, where a small tadpole grows into a bigger frog, in this case a big tadpole grows into a smaller frog. It’s sometimes called the shrinking frog.
One interesting detail is that not all of the tadpoles are that big. If a female lays her eggs in a small body of water that’s likely to dry up, or that doesn’t have a lot of food available, or if there are a lot of predators in the water, the tadpole metamorphoses quickly and doesn’t grow very big. But if the tadpole is in a better location it matures much more slowly, which allows it to reach much larger size before metamorphosing.
I should also mention that the 11-inch-long tadpole that is the largest ever measured was actually raised in captivity. In the wild, the largest paradoxical frog tadpole ever measured was 6 ½ inches long, or almost 17 cm. That’s still really big, but not that ridiculously big. But the confusing thing is that the tadpole is big and bulky, up to four times the size of the adult frog. Where does all that mass go after it transforms?
Early scientists who learned about the paradoxical frog wondered the same thing. They were so confused that they suggested that the frog actually came first and later metamorphosed into the tadpole, which then metamorphosed into a fish. But the main reason the tadpole is so long is its tail. When it metamorphoses into a frog, it absorbs the tail and therefore appears to shrink. The bulkiness of the tadpole’s body matches the bulkiness of the frog’s body. And unlike most frogs, which metamorphose into juvenile frogs that still have some growing to do, the paradoxical frog metamorphoses into a completely adult frog. It’s as big as it will ever get and fully mature, ready to mate and lay eggs.
Next, Alexis wanted to learn about the Vietnamese mossy frog. It lives in parts of Vietnam, Laos, and other nearby areas. It prefers mountainous rainforests and the female often chooses to lay her eggs in a tree hollow or even a rock cavity where water has collected. Instead of laying her eggs in the actual water, though, she lays them on rocks or branches above the water. -
Thanks to Pranav for suggesting this week's massive topic!
Further reading:
When did the Isthmus of Panama form between North and South America?
Florida fossil porcupine solves a prickly dilemma 10-million years in the making
Evidence for butchery of giant armadillo-like mammals in Argentina 21,000 years ago
Glyptodonts were big armored mammals:
The porcupine, our big pointy friend:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week, at long last, we’re going to learn about the great American interchange, also called the great American biotic interchange. Pranav suggested this topic ages ago, and I’ve been wanting to cover it ever since but never have gotten around to it until now. While this episode finishes off 2024 for us, it’s the start of a new series I have planned for 2025, where every so often we’ll learn about the animals of a particular place, either a modern country or a particular time in history for a whole continent.
These days, North and South America are linked by a narrow landmass generally referred to as Central America. At its narrowest point, Central America is only about 51 miles wide, or 82 km. That’s where the Panama Canal was built so that ships could get from the Atlantic Ocean to the Pacific and vice versa without having to go all around South America.
It wasn’t all that long ago, geologically speaking, that North and South America were completely separated, and they had been separated for millions of years. South America was part of the supercontinent Gondwana, while North America was part of the supercontinent Laurasia.
We’ve talked about continental drift before, which basically means that the land we know and love on the earth today moves very, very slowly over the years. The earth’s crust, whether it’s underwater or above water, is separated into what are called continental plates, or tectonic plates. You can think of them as gigantic pieces of a broken slab of rock, all of the pieces resting on a big pile of really dense jelly. The jelly in this case is molten rock that’s moving because of its own heat and the rotation of the earth and lots of other forces. Sometimes two pieces of the slab meet and crunch together, which forms mountains as the land is forced upward, while sometimes two pieces tear apart, which forms deep rift lakes and eventually oceans. All this movement happens incredibly slowly from a human’s point of view--like, your fingernails grow faster than most continental plates move. But even if a plate only moves 5 millimeters a year, after a million years it’s traveled 5 kilometers.
Anyway, the supercontinent Gondwana was made up of plates that are now South America, Africa, Australia, Antarctica, and a few others. You can see how the east coast of South America fits up against the west coast of Africa like two puzzle pieces. Gondwana actually formed around 800 million years ago, then became part of the even bigger supercontinent Pangaea, and when Pangaea broke apart around 200 million years ago, Gondwana and Laurasia were completely separate. North America was part of Laurasia. But Gondwana continued to break apart. Africa and Australia traveled far away from South America as molten lava filled the rift areas and helped push the plates apart, forming the South Atlantic Ocean. Antarctica settled onto the south pole and India traveled past Africa until it crashed into Eurasia. By about 30 million years ago, South America was a gigantic island.
It’s easy to think that all this happened just like taking puzzle pieces apart, but it was an incredibly long, complicated process that we don’t fully understand. To explain just how complicated it is, let’s talk for a moment about marsupials.
Marsupials are mammals that are born very early and finish developing outside of the mother’s womb, usually in a special pouch. Kangaroos, wallabies, koalas, wombats, and Tasmanian devils are all marsupials, and all from Australia. -
Episodes manquant?
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Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions this week!
Further reading:
New population of blue whales discovered in the western Indian Ocean
An Endangered Dolphin Finds an Unlikely Savior--Fisherfolk
The humpback whale:
The gigantic blue whale:
The tiny vaquita:
The Indus river dolphin:
The false killer whale:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to have a big episode about various dolphins and whales! We’ve had lots of requests for these animals lately, so let’s talk about a bunch of them. Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions.
We’ll start with a quick overview about dolphins, porpoises, and whales, which are called cetaceans. All cetaceans alive today are carnivorous, meaning they eat other animals instead of plants. This includes the big baleen whales that filter feed, even though the animals they eat are tiny. Cetaceans are mammals that are fully aquatic, meaning they spend their entire lives in the water, and they have adaptations to life in the water that are simply astounding.
All cetaceans alive today belong to either the baleen whale group, which filter feed, or the toothed whale group, which includes dolphins and porpoises. The two groups started evolving separately about 34 million years ago and are actually very different. Toothed whales are the ones that echolocate, while baleen whales are the ones that have extremely loud, often beautiful songs that they use to communicate with each other over long distances. It’s possible that baleen whales also use a limited type of echolocation to navigate, but we don’t know for sure. There’s still a lot we don’t know about cetaceans.
Now let’s talk about some specific whales. Ezra wanted to learn more about humpback and blue whales, so we’ll start with those. Both are baleen whales, specifically rorquals. Rorquals are long, slender whales with throat pleats that allow them to expand their mouths when they gulp water in. After the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth to do it again. The humpback mostly eats tiny crustaceans called krill, and little fish.
The humpback grows up to 56 feet long, or 17 meters, with females being a little larger than males on average. It’s mostly black in color, with mottled white or gray markings underneath and on its flippers. Its flippers are long and narrow, which allows it to make sharp turns.
The humpback is closely related to the blue whale, which is the largest animal ever known to have lived. It can grow up to 98 feet long, or 30 meters, and it’s probable that individuals can grow even longer. It can weigh around 200 tons, and by comparison a really big male African elephant can weigh as much as 7 tons. Estimates of the weight of various of the largest sauropod dinosaurs, the largest land animal ever known to have lived, is only about 80 tons. So the blue whale is extremely large.
The blue whale only eats krill and lots of it. To give you an example of how much water it can engulf in its enormous mouth in order to get enough krill to keep its massive body going, this is how the blue whale feeds. When it finds an area with a lot of krill floating around, it swims fast toward the krill and opens its giant mouth extremely wide. When its mouth is completely full, its weight—body and water together—has more than doubled. Its mouth can hold up to 220 tons of water. Since the whale is in the water, it doesn’t feel the weight of the water in its mouth.
Blue whales live throughout the world’s oceans, but a few years ago scientists analyzing recordings of whale song from the we... -
Thanks to David and Jayson for their suggestions this week!
Further reading:
Unveiling the lionfish invasion in the Mediterranean Sea
DeepCCZ: The Weird and Wonderful Megafauna of the Abyssal CCZ
The red lionfish is beautiful but does not look like a lion [photo by Alexander Vasenin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=25523559]:
The sea squirrel is yellow above and red underneath (pictures from article linked above):
Under side of a gummy squirrel photographed on shipboard showing its bright red feeding palps (flower-like structure) and underbelly.
Gummy squirrel (“Psychropotes longicauda”) at 5100 m depth on abyssal sediments in the western CCZ. This animal is ~60 cm long (including tail), with red feeding palps (or “lips”) visibly extended from its anterior end (right).
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to learn about two interesting marine animals suggested by Jayson and David.
Let’s start with David’s suggestion, the lionfish. The lionfish doesn’t actually look like a lion although it is a fish. It lives in shallow tropical water in the Indian Ocean and western Pacific, especially around coral reefs.
There are twelve species of lionfish known, but they’re mostly fairly similar. The lionfish is brown or dark red in color with white stripes, fan-like fins, and lots of long spines, all of which are striped black and white or red and white to make them more visible. When a fish or other animal has markings that make it stand out against the background, you can be pretty sure that it’s dangerous, and that’s the case for the lionfish.
The lionfish’s spines are venomous, especially the spines on the dorsal fin. If it feels threatened, it will point the dorsal fin at the predator and keep it pointed at it no matter which direction the predator moves. If the predator swims below the lionfish, the lionfish will turn upside-down in the water to keep the dorsal fin pointed at it. Most predators back off at that point, and I don’t blame them because that sounds really scary.
People have died from lionfish venom, but it’s rare. Mostly it’s just extremely painful and makes the person feel really sick for a day or two. Divers have to be careful when they’re around lionfish, because lionfish can be aggressive and will point that dorsal fin at the diver as a warning. You don’t want a lionfish to point at you.
The lionfish eats smaller fish, including smaller lionfish, invertebrates, and other small animals. It confuses other fish by blowing water at them. The little fish turns to face into what it thinks is a weird water current, and suddenly, there’s a lionfish that just gulps it down.
As David points out, even though the lionfish is dangerous, it’s definitely beautiful. Some people keep lionfish in saltwater aquariums, although they’re hard to care for in captivity, and unfortunately sometimes the fish escape into the wild or are released. The red lionfish is especially invasive in the Caribbean Sea, the Gulf Coast, and off the southeastern coast of the United States. Lionfish have also been introduced to parts of the Mediterranean Sea, where they’re becoming more and more invasive.
Because invasive lionfish eat so many native fish, and because it’s spreading rapidly and becoming extremely common, people have been trying to find ways to reduce the invasive population. It turns out that lionfish are good to eat if you’re careful when handling the spines during cleaning, so people in areas where it’s invasive are encouraged to catch lionfish to eat. Invasive lionfish are even served in fancy restaurants. Since the red lionfish can grow around 18 inches long, or 47 cm, there’s lot a of meat on one.
No one’s sure why it’s called a lionfish. It doesn’t look remotely like a lion. It’s also called the zebrafish because of its stripes.
Next, -
Thanks to Cosmo for suggesting this week's animal, the electric catfish!
Further reading:
The shocking truth about electric fish
Efficient high-voltage protection in the electric catfish
Gimme kiss [electric catfish photo from this site]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re finally going to talk about a fish Cosmo wanted us to learn about, the electric catfish!
Catfish are really common fish that live throughout the world, except for Antarctica. We’ve talked about various types of catfish in lots of different episodes, since there are well over 3,000 known species and they’re incredibly diverse. The electric catfish lives in freshwater in tropical areas in western and central Africa, as far north as the Nile River.
All animals generate electric fields in their nerves and the contracting of muscles. Animals that can sense these fields are called electroreceptive. An electroreceptive animal can find hidden prey without using its other senses.
Many electroreceptive animals can also generate weak electrical fields, usually less than a single volt—small electrical pulses or a sort of wave, depending on the species, that can give them information about their environment. Like a dolphin using echolocation, a fish using electro-location can sense where potential prey is, where predators, plants, and rocks are, and can even communicate with other fish of its same species. Of course, those same electric pulses can also attract electroreceptive predators.
Some fish can generate an electric shock so strong it can stun or kill other animals. The most famous is the electric eel, which we talked about way back in episode 10, but the electric catfish falls in this category too.
The electric catfish isn’t a single species but several in the family Malapteruridae. Some are very small, but one grows as much as four feet long, or 1.2 meters, and can weigh over 50 lbs, or 23 kg. That’s Malapterurus electricus, THE electric catfish.
The electric catfish is grayish-brown mottled with black spots. Like a lot of catfish, it’s a cylinder-shaped chonk, and has three pairs of barbels around its broad mouth. Barbels are the feelers that give the catfish its name, because they look sort of like a cat’s whiskers. Sort of. Not actually very much like a cat’s whiskers. The electric catfish also has what look like surprisingly kissy lips, which are often pale in color so they stand out, especially when the mouth is open, which is frankly hilarious. It doesn’t have a dorsal fin and it’s not a fast swimmer. It spends most of its time lurking in rocky areas in muddy, slow-moving water. It’s also nocturnal.
The electric catfish eats other fish, although it will also eat pretty much anything it can swallow. It likes muddy water because it doesn’t want potential prey to see it, and of course it doesn’t want any potential predators to see it either. That includes humans, who consider it a delicacy. Humans also sometimes keep electric catfish as aquarium fish, which is sort of the opposite of being killed and eaten.
Contracting a muscle causes a tiny, tiny electrical impulse, as I mentioned earlier, but in electric fish certain muscles have developed the ability to generate much stronger electrical impulses. Instead of muscles, they’re called electric organs. The interesting thing is that this is only found in fish, but that the ability evolved separately at least six times in different lineages of fish.
The electric catfish uses its ability to generate electric shocks as a defense when it needs to, but mainly it uses it to stun or outright kill other fish, which it then gulps down. It can discharge up to 300 volts of electricity in pulses that last only a few milliseconds, but since it can generate up to 500 pulses in waves, that’s a lot of electricity. That’s not enough to kill a person, but you’d definitely feel it and try to get away.
But, -
Thanks to Mary, Mila, and Riley for their suggestions this week!
Further reading:
Comfortable and dermatological effects of hot spring bathing provide demonstrative insight into improvement in the rough skin of Capybaras
Comfort of capybaras determined by SCIENCE:
An especially attractive guinea pig:
Guinea pigs come in lots of colors, patterns, and fur types [picture taken from this excellent site]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to learn about two rodents, one small and one big. Thanks to Mary and Mila who both suggested the guinea pig, and thanks to Riley who suggested the capybara.
This episode is a bit unusual because part of it comes from a Patreon episode from 2023. Like, literally a big chunk of this episode is the original audio from that one, and you’ll be able to tell the difference in audio and know just how lazy I was this week. The episode actually came together in an unusual way too. Riley’s parent emailed me last week with some new suggestions, including capybaras, but wasn’t sure if we had already covered the topic. I thought we had, but of course there’s always more to learn about an animal. Well, since this is the beginning of a new month I was on the Patreon page to upload the December episode, and while I was there I did a quick search for capybaras and discovered the episode I was thinking of. I decided to add some more information about guinea pigs to it since I already mention guinea pigs a lot in that episode, and here is the result!
The capybara is a rodent, and a very big one. It is, in fact, the biggest rodent alive today. To figure out just how big the capybara is, picture a guinea pig. The guinea pig is also a rodent, native to the Andes Mountains in South America. No one’s sure why the guinea pig is called that in English, since it doesn’t come from Guinea and doesn’t have anything to do with anything else called guinea, but as someone who had two pet guinea pigs when I was a kid, I know exactly why they’re called guinea pigs. This is what an actual pig sounds like:
[pig squealing]
And this is what a guinea pig sounds like:
[guinea pig squealing]
Also, it’s sort of shaped like a pig. The guinea pig is a chonky little animal with short legs, only a little stub of a tail, and little round ears. Its face is sort of blocky in shape and it has a big rounded rump, similar to that of a capybara. The guinea pig is actually closely related to the capybara, and is a pretty good-sized rodent in its own right. It grows about 10 inches long, or 25 cm, on average, and roughly half that size tall.
The guinea pig has been domesticated for at least 7000 years, but it wasn’t domesticated for people to keep it as a pet. In South America and many other places now, it’s a very small farm animal raised for its meat. Guinea pig has been an important source of protein for all that time, so important that it was considered sacred in many cultures.
In the early 16th century when Europeans started arriving in South America, sailors took guinea pigs with them on ships so they’d have fresh meat on the voyage. But when the cute little animals arrived in Europe, people started buying them as pets.
Guinea pigs eat plants, mostly grass, and are social animals. If you want a pet guinea pig, make sure to get at least two. Like rabbits and some other animals, including the capybara, the guinea pig excretes special pellets that aren’t poop, but are semi-digested pellets of food. The guinea pig eats the pellets so they can pass through the digestive system again and the body can extract as many nutrients as possible from it. What’s left is then excreted as a regular poop pellet.
Even in places where the guinea pig is routinely kept as livestock and eaten, people breed guinea pigs as pets too. The pet variety is smaller than the meat variety and has different markings and different colors. -
Thanks to Lydia and "warblrwatchr" for this week's suggestions!
Further reading:
Sweet tooth: Ethiopian wolves seen feeding on nectar
The African wild dog is not actually a dog and eats lots of things:
The aardwolf is not a dog at all and eats insects:
The Ethiopian wolf is not a dog (or a wolf or a fox) and eats rodents and nectar [photo by Adrien Lesaffre and taken from this page]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to talk about three dog-like animals from Africa, suggested by Lydia and “warblrwatchr,” even though none of the three animals are dogs.
We’ll start with one of Lydia’s suggestions, the African wild dog, also called the painted dog or painted wolf. Despite those names, it’s not very closely related to dogs and wolves. It’s the only species in its own genus, although it is a member of the family Canidae. Colonizers from Europe thought the animal was just a feral dog, not anything special that should be protected, and they also brought domestic dogs with them to Africa. Domestic dogs mean diseases that other canids can catch. Between introduced diseases, farmers killing the animals to keep them away from livestock, and habitat loss, the African wild dog is endangered. Luckily, these days conservation groups have been working to protect the animal, and its numbers are increasing slowly in Kenya’s national parks in particular.
The African wild dog is a tall, strong canid with great big ears and no dewclaws. It has a yellowish coat with black blotches and some white spots, including a white tail tip, although some subspecies have darker coats. Unlike most canids, its fur is bristly and doesn’t have a soft undercoat, and as the dog ages, it loses its fur until old dogs are nearly bald. It’s very social, as canids almost always are, and its varied coat pattern helps individuals recognize friends and pack-mates at a distance.
The African wild dog prefers savannas and other open areas. It hunts in packs and mostly preys on antelopes, although it will also kill zebras and other large animals, and individual dogs will sometimes catch small animals like hares and rodents.
The African wild dog pack isn’t especially hierarchical. The males of the pack are mainly led by the dominant male, while the females are mainly led by the oldest female, who is usually the most dominant. The dominant pair is usually the only pair that has babies. A mother dog has up to 16 pups at a time but only one litter a year.
In a lot of animals, as the babies grow up, the males are usually the ones who are driven out of the pack or leave on their own to find a new pack. In the African wild dog, females are the ones who leave as they grow up. Sometimes the females join a different pack and sometimes they start their own. Either way, it stops a pack from becoming inbred.
The African wild dog is extremely vocal, making lots of different sounds to communicate with its pack-mates. It sounds a lot more like a bird than a dog. This is what African wild dogs sound like:
[doggo sounds]
Next, Lydia and warblrwatchr wanted to learn about the aardwolf, which lives in eastern and southern Africa. Unlike the African wild dog, which is mostly active during the day, the aardwolf is nocturnal. It spends most of the day in a burrow, sometimes one it digs itself, but more often one that another animal dug and abandoned at some point.
The aardwolf has black stripes on a yellowish or reddish coat, a mane of long hair down its neck and back, large ears, and a bushy tail. It’s about the size of a big dog, about 20 inches tall at the shoulders, or 50 cm, but it looks like a small, slender hyena. That’s because it is actually a type of hyena, although it’s not closely related to other hyenas. Hyenas look dog-like but they aren’t canids at all. In fact, they’re more closely related to cats than to dogs, -
Thanks to Alyx for this week's suggestion, the cookie cutter shark!
Further reading:
If You Give a Shark a Cookie
The business end of the cookie cutter shark:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to learn about a little shark suggested by Alyx, but first let’s learn about something else that might be related to the shark.
In the 1970s, the U.S. Navy started having trouble with the navigation of their submarines. The Ohio-class submarine had what was called a sonar dome that was filled with oil, and the oil helped transmit sound. But repeatedly the subs would lose navigation abilities, and investigations turned up strange chunks removed from the electric cables, the oil lines, the sound probes, and the sonar dome itself—anywhere made of rubber that was soft enough for what looked like a hole saw to damage.
The Navy thought they were dealing with a state-of-the-art weapon. The United States and the former Soviet Union were bitter enemies, so the Navy thought the USSR had invented a technologically sophisticated underwater stealth drone of some kind that could damage the subs and leave no trace—nothing but circular chunks removed from the sonar dome and its components.
Thirty submarines were damaged before the Navy figured out the cause. It wasn’t a super-secret weapon at all. It was just a little fish called the cookie-cutter shark.
The cookie cutter shark doesn’t look very scary. It only grows 22 inches long at most, or 56 cm, and is brown in color. It has lots of very sharp evenly spaced teeth on its lower jaw, but compared to a great white shark, it’s nothing to worry about. But somehow it was able to disable 30 of the world’s most advanced submarines at the time.
That’s because of how the cookie cutter shark eats, which is also how it gets its name. It picks a target fish or some other animal, such as a whale or a seal, or possibly the sonar dome of an Ohio-class submarine, and sneaks up to it. It’s just a little fish and its coloration helps it blend in with its surroundings, so most animals barely notice it. It has lips that act like a suction cup, so quick as a wink it sticks itself to the animal, bites down, and spins around. In moments it’s cut a circular chunk out of the animal’s side like a horrible cookie, which it swallows, and by the time the animal even realizes it’s hurt, the cookie cutter shark is long gone.
The shark used to be called the cigar shark because of its shape. It wasn’t until 1971 that experts realized how the cookie cutter shark eats. Until then the circular wounds on fish and whales and other animals were thought to be from lamprey bites or from some kind of parasite.
The cookie cutter shark does have teeth in its upper jaw but they’re much smaller than the lower teeth. When it sheds its lower teeth to replace them, instead of shedding just one tooth, it sheds them all at once. Like most sharks, it swallows its old teeth so it can reuse the calcium to grow new teeth.
The shark also has photophores on the underside of its body that glow greenish, which is a common way that some fish escape predators from below. A big fish looking up toward the surface of the water high above it sees a lot of light shining down from the sun, so a fish with a glowing underside just blends in. But in the case of the cookie cutter shark, it has a strip of skin on its underside without photophores, and from below that strip shows up. It’s a sort of collar that’s actually darker brown than the rest of the fish. It looks, in fact, like a tiny fish silhouetted against the surface. The would-be predator fish approaches, expecting an easy meal. Instead, the cookie cutter shark darts around and takes a big bite out of the fish, then takes off. It’s a remarkably fast swimmer, but most of the time it hangs almost motionless in the water waiting for another animal to approach. -
Thanks to Riley and Dean, Elizabeth, and Leo for their suggestions this week!
Further reading:
Groundbreaking study reveals extensive leatherback turtle activity along U.S. coastline
A bearded dragon:
The tiny bog turtle:
The massive leatherback sea turtle:
The beautiful hawksbill turtle [photo by U.S. Fish and Wildlife Service]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to learn about some reptiles suggested by four different listeners: Riley and Dean, Elizabeth, and Leo.
We’ll start with the brothers Riley and Dean. Dean wants to learn more about the bearded dragon, and that may have something to do with a certain pet bearded dragon named Kippley.
“Bearded dragon” is the name given to any of eight species of lizard in the genus Pogona, also referred to as beardies. They’re native to Australia and eat plants and small animals like worms and insects. They can grow about two feet long, or 60 cm, including the tail, but some species are half that length. Females are a little smaller than males on average.
The bearded dragon gets its name because its throat is covered with pointy scales that most of the time aren’t very noticeable, but if the lizard is upset or just wants to impress another bearded dragon, it will suck air into its lungs so that its skin tightens and the spiky scales under its throat and on the rest of its body stick out. They’re not very sharp but they look impressive. Since the bearded dragon can also change color to some degree the same way a chameleon can, when it inflates its throat to show off its beard, the beard will often darken in color to be more noticeable. Both males and females have this pointy “beard.”
Bearded dragons that are sold as pets these days are more varied and brighter in color than their wild counterparts, although wild beardies can be brown, reddish-brown, yellow, orange, and even white. Australia made it illegal to catch and sell bearded dragons as pets in the late 20th century, but there were already lots of them outside of Australia by then. Pet bearded dragons are mainly descended from lizards exported during the 1970s, which means they’re quite domesticated these days and make good pets.
Like some other reptiles and amphibians, the bearded dragon has a third eye in the middle of its forehead. If you have a pet beardie and are about to say, “no way, there is definitely not a third eye anywhere, I would have noticed,” the eye doesn’t look like an eye. It’s tiny and is basically just a photoreceptor that can sense light and dark. Technically it’s called a parietal eye and researchers think it helps with thermoregulation.
Next, Riley wants to learn about turtles, AKA turbles, and especially wants everyone to know the difference between a tortoise and a turtle. It turns out that while many turtles are just fine living on land, they’re often more adapted to life in the water. Turtles have a more streamlined shell and often flipper-like legs or webbed toes. Tortoises only live on land and as a result they have shells that are more dome-shaped, and they have large, strong legs that resemble those of a tiny elephant.
You can’t always go by an animal’s common name to determine if it’s a tortoise or a turtle, but it’s also not always clear whether an animal is a tortoise or a turtle at first glance. Take the eastern box turtle, for instance, which is common in the eastern United States. It has a domed carapace, or shell, but it’s still a turtle, not a tortoise. And, I’m happy to say, it can swim quite well. This is a relief to find out because when I was about six years old, my mom visited someone who had kids a little older than me. I didn’t know them but they were nice and showed me the swampy area near their house. At one point one of the older boys found a box turtle, took it over to a little bridge over a pond, and dropped it in the water. I screamed, -
Thanks to Molly and Mila for suggesting the anteater and its relations this week!
Further reading:
How anteaters lost their teeth
The giant anteater has a long tongue and a little mouth, and adorable babies:
The giant anteater has a weird skull [photos by Museum of Veterinary Anatomy FMVZ USP CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=72183871]:
The tamandua is like a mini giant anteater that can climb trees:
The silky anteater looks like a weird teddy bear [photo by Quinten Questel - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=30287945]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to talk about some unusual mammals, suggested by Molly and Mila. It’s a topic I’ve been meaning to cover for almost two years and now we’re finally going to learn about it! It’s the anteater and its close relations, including a creepy anteater cryptid that would have fit in just fine during monster month.
A lot of animals are called anteaters because they eat ants, but the anteaters we’re talking about today belong to the suborder Vermilingua, meaning “worm tongue.” That’s because they all have long, sticky tongues that they use to lick up ants, termites, and other insects. Anteaters are native to Central and South America and are closely related to sloths, and more distantly related to armadillos.
The sloth and anteater share a common ancestor who lived around 60 million years ago, a little animal that mainly ate worms and insect larvae and probably lived in burrows. Because its food was soft and didn’t need a lot of chewing, when a mutation cropped up that caused its teeth to be weak, it didn’t matter. It wasn’t using its teeth anyway. When the first anteaters evolved from this ancestral species, they didn’t need teeth either, and gradually they lost their teeth entirely. Modern anteaters have no teeth at all.
Sloths also evolved from this weak-toothed ancestor, and sloths eat plants. Plants need a lot of chewing, and most animals that eat plants have really strong teeth, but sloths retained the genetics for weak teeth. They don’t even have an enamel coating on their teeth, and instead of grinding molars, their teeth are basically soft little pegs. Luckily for the sloth, the little peg teeth do continue to grow throughout its life, so it never wears its teeth down so far it can’t chew.
Anteaters, sloths, and their distant relation the armadillo all share the same type of vision from their shared ancestor too. They can’t see colors at all but have good vision in low light, which is why scientists think they all evolved from an animal that spent most of its time underground hunting for worms. Anteaters have strong claws that allow them to dig into termite and ant nests, and armadillos spend a lot of time in burrows they dig. We don’t actually know what the common ancestor of these related animals looked like because we haven’t found any fossils of it yet.
In the past, scientists thought that pangolins and aardvarks were related to anteaters because they all have similar adaptations to a similar diet, but that’s just another example of convergent evolution. We talked about pangolins and aardvarks back in episode 65, as well as the giant anteater.
The giant anteater is the one most people know about. It earns the name giant because it can grow almost eight feet long, or 2 1/2 meters, if you include the tail. Its fur is brown and cream with a distinctive black stripe from its chest to its back that scientists used to think acted as camouflage. Because the black fur is outlined with white, making it stand out, scientists now think it’s used as a warning to potential predators, because the giant anteater can be dangerous. If it feels threatened, it will rear up on its hind legs, using its long tail as a prop, to slash at a predator. Its claws are so big that it knuckle-walks on its for... -
Thanks to Ezra and Leo for suggesting these two sea monsters this week! Happy Halloween!
Further reading:
Legend of Chessie alive, well in Maryland
Here be sea monsters: We have met Chessie and...is it us?
Not actually a kraken, probably:
Not actually Chessie but an atmospheric photo of a toy brontosaurus:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
Just a few days remain in October, so this is our Halloween episode and the end of monster month for another year! We had so many great suggestions for Halloween episodes that I couldn’t get to them all, but I might just sprinkle some in throughout the other months too. We have two great monsters to talk about this week, suggested by Ezra and Leo, the kraken and Chessie the sea serpent.
First, as always on our Halloween episode, we have a few housekeeping details. If anyone wants a sticker, feel free to email me and I’ll send you one, or more than one if you like. That offer is good all the time, not just now. I don’t have any new stickers printed but I do have lots of the little ones with the logo and the little ones with the capybara.
I also don’t have any new books out this year, but you can still buy the Beyond Bigfoot & Nessie book if you like. I am actually working on another book about mystery animals, tentatively titled Small Mysteries since it’s going to be all about mysteries surrounding small animals like frogs and invertebrates that often get overlooked. I’m hoping to have it ready to publish in early 2026 or so. I don’t know that I’ll do another Kickstarter for it since that was a lot of work, and I just finished a Kickstarter for more enamel pins and just can’t even think about the stress of doing another crowdfunding campaign anytime soon. Also, I hate to keep asking listeners for money.
Anyway, one of the things I don’t like about Beyond Bigfoot & Nessie is that I didn’t cite my sources properly, so for the Small Mysteries book I’m being very careful to have footnotes on pretty much every page so that anyone who wants to double-check my information can do so easily.
But all that is in the future. Let’s celebrate Halloween now with a couple of sea monsters!
We’ll start with Ezra’s suggestion, the kraken. It’s a creature of folklore that has gotten confused with lots of other folklore monsters. We don’t know how old the original legend is, but the first mention of it in writing dates to 1700, when an Italian writer published a book about his travels to Scandinavia. One of the things he mentions is a giant fish with lots of horns and arms, which he called the “sciu-crak.” This seems to come from the Norwegian word meaning sea krake.
“Krake” is related to the English word crooked, and it can refer to an old dead tree with crooked branches, or tree roots, or something with a hook on the end like a boat hook, or an anchor or drag, or various similar things related to hooks or multiple prongs. That has led to people naturally assuming that the kraken had many arms and was probably a giant squid, and that may be the case. But there’s another possibility, because in many old uses of the word krake, it means something weak or misshapen, like a rotten old dead tree. In the olden days in Norway, people thought that if you spoke about an animal by name, the spirit that protected that animal would hear you. Some historians think that whale-hunters referred to whales as krake so the whale’s protective spirit wouldn’t guess that they were planning a whale-hunt. Who would refer to a huge, strong animal like a whale as weak and crooked, after all?
Whatever its origins, the kraken’s modern form is mainly due to a Danish bishop called Erik Pontoppidan. He wrote about the kraken in 1753, and embellished the story by saying the kraken could reach out of the ocean with its long arms to grab sailors or just pull an entire ship down into the water and sink it. -
Thanks to Eesa for suggesting this week's topic, the pliosaur Predator X!
Further reading:
Predator X / Pliosaurus funkei [you can find lots of interesting pictures here, some artwork and some skeletal diagrams]
Kronosaurus had a big skull with big teeth:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
We’re one week closer to Halloween, and that means the monsters are getting more monster-y, at least in name, although I wouldn’t want to meet this one in person. It’s referred to as Predator X, and thanks to Eesa for suggesting it!
Fortunately for everyone who likes to swim and boat in the ocean, Predator X has been extinct for around 145 million years. It’s a type of marine reptile called a pliosaur, Pliosaurus funkei, but there was nothing funky about it. It was huge, fast, and incredibly strong. Also, the funky part of the name comes from the couple who originally discovered the first specimen, who had the last name of Funke.
We only have two Predator X specimens right now, both of them found in the same rock formation from a Norwegian island. The remains were first discovered in 2004 but the process of recovering them took many years. Because winters in Norway are very cold, the exposed rocks were subject to freezing temperatures that had broken a lot of the fossils into fragments, and some of the fossils crumbled into pieces as they dried out. All told, 20,000 pieces were recovered and painstakingly fit back together like a gigantic jigsaw puzzle made of fossilized bones.
Neither specimen is complete but we have enough bones that scientists can estimate the animal’s size when it was alive—and it was huge! It probably grew up to 39 feet long, or 12 meters, and some individuals would certainly have been bigger. Initial estimates were even longer, up to 50 feet, or over 15 meters, but that was before the specimens were fully studied.
Like other pliosaurs, predator X had a short tail and big teeth in its long jaws. Its head was massive, around 7 feet long, or 2 meters, and its front flippers were probably about the same length. It had four flippers, and researchers think its front flippers did most of the work of swimming, with the rear flippers acting as a rudder, but it could probably use its back flippers for a little extra boost of speed when it needed to. But it was a strong, fast swimmer no matter what, probably as fast as a modern orca, and very maneuverable. It had to be, because it ate other marine reptiles like plesiosaurs that were themselves very fast swimmers. It undoubtedly also ate sea turtles and fish, and probably pretty much anything else it could catch. It didn’t eat whales because this was long, long before whales evolved.
Predator X got its nickname from reporters back when the paleontologists thought it was 50 feet long. It didn’t have a name yet so it got called Predator X because that sounded impressive (and it is), but it isn’t the only giant pliosaur known.
Kronosaurus was originally described in 1924 from fossils discovered in Australia, and current estimates of its size agree that it could probably grow to around 33 feet long, or 10 meters. This may be a low estimate, though, because the size of the biggest skull found might have been over 9 feet long, or 2.85 meters, although the skull isn’t complete so its full size is just an estimate. Pliosaurs do have big heads, but if Kronosaurus’s skull really is longer than predator X’s skull, it was probably a bigger animal overall.
Kronosaurus’s fossils have only been found in an ancient inland sea that covered most of Queensland and Central Australia until about 100 million years ago. It was probably a relatively shallow, cold sea, and although it had all the marine animals you’d expect for the time, like sharks, ammonites, ichthyosaurs, plesiosaurs, lungfish, sea turtles, and lots more, Kronosaurus was the apex predator. It was so big and deadly that a full-grown Kronosaurus didn’t have to worry ... -
Thanks to Nora and Richard from NC this week as we learn about some scary-sounding reptiles, including the hoop snake!
Further reading:
The Story of How the Giant “Terror Skink” Was Presumed Extinct, Then Rediscovered
San Diego’s Rattlesnakes and What To Do When They’re on Your Property
Snake that cartwheels away from predators described for the first time
Giant new snake species identified in the Amazon
The terror skink, AKA Bocourt's terrific skink [photo by DECOURT Théo - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=116258516]:
The hoop snake according to folklore:
The sidewinder rattlesnake [photo taken from this article]:
The dwarf reed snake [photo by Evan Quah, from page linked above]:
The green anaconda [photo by MKAMPIS - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=62039578]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
As monster month continues, we’re going to look at some weird and kind of scary, or at least scary-sounding, snakes and lizards. Thanks to Nora and Richard from NC for their suggestions this week!
We’ll start with the terror skink, whose name should inspire terror, but it’s also called Bocourt’s terrific skink, which is a name that should inspire joy. Which is it, terror or joy? I suppose it depends on your mood and how you feel about lizards in general. All skinks are lizards but not all lizards are skinks, by the way.
The terror or possibly terrific skink lives on two tiny islets, which are miniature islands. These islets are themselves off the coast of an island called the Isle of Pines, but in French, which I cannot pronounce. The Isle of Pines is only 8 miles wide and 9 miles long, or 13 by 15 km, and is itself off the coast of the bigger island of New Caledonia. All these islands lie east of Australia. Technically the islets where the skink lives are off the coast of another islet that is itself off the coast of the Isle of Pines, which is off the coast of New Caledonia, but where exactly it lives is kept a secret by the scientists studying it.
The skink was described in 1876 but only known from a single specimen captured on New Caledonia around 1870, and after that it wasn’t seen again and was presumed extinct. Colonists and explorers brought rats and other invasive animals to the New Caledonian islands, which together with habitat loss have caused many other native species to go extinct.
But in December 2003, a scientific expedition studying sea snakes around the New Caledonian islands caught a big lizard no one recognized. Once the expedition members realized it was a terror skink, alive and well, they took lots of pictures and videos of it and then released it back into the wild. Since then, more specimens have been discovered during four different expeditions, but only on the islets, not on any of the bigger islands. It’s so critically endangered that its location has to be kept secret, because if someone captures some of the lizards to sell on the illegal pet market, the species could easily be driven to extinction.
The terror skink is gray-brown with darker stripes, a long tail, and a slightly downturned mouth that makes it look grumpy. It grows about 20 inches long, or 50 cm, including its tail. This is really big for a skink, so technically it’s a giant skink.
It gets the name terror skink from its size and from its teeth, which are large and curved like fangs. It mainly eats one particular species of land crab, which is why its jaws are so strong and its teeth are so sharp, so it can bite through the crab’s exoskeleton.
Another lizard with a spooky name that has been presumed extinct is the gray ghost lizard, suggested by Richard from NC. It’s more properly called the giant Tongan ground skink, and it’s native to some more South Pacific islands—specifically, the Tongan Islands. -
Thanks to Murilo for suggesting El Gran Maja for our first monster month episode of 2024!
Further reading:
The Loch Ness Monster: If It’s Real, Could It Be an Eel?
Further watching:
Borisao Blois's YouTube channel [I have not watched very many of his videos so can't speak to how appropriate they all are for younger viewers]
El Gran Maja, YouTube star:
The European eel [photo by GerardM - http://www.digischool.nl/bi/onderwaterbiologie/, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=284678]:
A supposed 21-foot eel, a product of trick photography:
The slender giant moray eel [photo by BEDO (Thailand) - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=40262310]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
It’s monster month, where we talk about weird, mysterious, and sometimes spooky creatures! This year I’ve decided to be less spooky and more weird, so let’s kick off the month with an episode all about gigantic eels. Thanks to Murilo for suggesting our first giant eel, El Gran Maja.
El Gran Maja is an eel that is supposed to live off the coast of northern Puerto Rico, and it’s supposed to grow 675 meters long. That’s 2,215 feet, or almost half a mile. That is an excessive amount of eel.
Obviously, an eel that big couldn’t actually exist. By the time its front end noticed danger, its back end could already be eaten by a whole family of sharks. But maybe it was based on a real eel that grows really long. Let’s take a look at some eels we know exist, and then we’ll return to El Gran Maja and learn some very interesting things about it.
Eels are fish, but not every animal that’s called an eel is actually an eel. Some are just eel-shaped, meaning they’re long and slender. Electric eels aren’t actually eels, for instance, but are more closely related to catfish. Most eels live in the ocean at the beginning and end of their lives, and freshwater in between.
For example, the European eel has a life cycle that’s pretty common among eels. It hatches in the ocean into a larval stage that looks sort of like a transparent leaf. Over the next six months to three years, the larvae swim and float through the ocean currents, closer and closer to Europe, feeding on plankton and other tiny food. Toward the end of this journey, they grow into their next phase, where they resemble eels instead of leaf-shaped tadpoles, but are still mostly transparent. They’re called glass eels at this point. The glass eels make their way into rivers and slowly migrate upstream. Once a glass eel is in a good environment it metamorphoses again into an elver, which is basically a small eel. As it grows it gains more pigment until it’s called a yellow eel. Over the next decade or two it grows and matures, until it reaches its adult length—typically around 3 feet, or about a meter. When it’s fully mature, its belly turns white and its sides silver, which is why it’s called a silver eel at this stage. Silver eels migrate more than 4,000 miles, or 6500 km, back to the Sargasso Sea to spawn, lay eggs, and die.
One place where European eels live is Loch Ness in Scotland, and in the 1970s the idea that sightings of the Loch Ness Monster might actually be sightings of unusually large eels became popular. A 2018 environmental DNA study brought the idea back up, since the study discovered that there are a whole, whole lot of eels in Loch Ness. The estimate is a population of more than 8,000 eels in the loch, which is good since the European eel is actually critically endangered. But most of the eels found in Loch Ness are smaller than average, and the longest European eel ever measured was only about 4 feet long, or 1.2 meters.
An eel can’t stick its head out of the water like Nessie is supposed to do, but it does sometimes swim on its side close to the water’s surface, which could result in sightings of a string of many humps undulating through the wate... -
To donate to help victims of Hurricane Helena:
Day One Relief - direct donation link
World Central Kitchen - direct donation link
It's the big 400th episode! Let's have a good old-fashioned mystery episode! Thanks to Richard from NC for suggesting two of our animal mysteries today.
Further reading:
A 150-Year-Old Weird Ancient Animal Mystery, Solved
The Enigmatic Cinnamon Bird: A Mythical Tale of Spice and Splendor
First ever photograph of rare bird species New Britain Goshawk
Scientists stumbled onto toothy deep-sea "top predator," and named it after elite sumo wrestlers
Bryde's whales produce Biotwang calls, which occur seasonally in long-term acoustic recordings from the central and western Pacific
A stylophoran [drawing by Haplochromis - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10946202]:
A cinnamon flycatcher, looking adorable [photo by By https://www.flickr.com/photos/neilorlandodiazmartinez/ - https://www.flickr.com/photos/neilorlandodiazmartinez/9728856384, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=30338634]:
The rediscovered New Britain goshawk, and the first photo ever taken of it, by Tom Vieras:
The mystery fish photo:
The yokozuna slickhead fish:
The Biotwang maker, Bryde's whale:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
We’ve made it to the big episode 400, and also to the end of September. That means monster month is coming up fast! To celebrate our 400th episode and the start of monster month, let’s have a good old-fashioned mysteries episode.
We’ll start with an ancient animal called a stylophoran, which first appears in the fossil record around 500 million years ago. It disappears from the fossil record around 300 million years ago, so it persisted for a long time before going extinct. But until recently, no one knew what the stylophoran looked like when it was alive, and what it could possibly be related to. It was just too weird.
That’s an issue with ancient fossils, especially ones from the Cambrian period. We talked about the Cambrian explosion in episode 69, which was when tiny marine life forms began to evolve into much larger, more elaborate animals as new ecological niches became available. In the fossil record it looks like it happened practically overnight, which is why it’s called the Cambrian explosion, but it took millions of years. Many of the animals that evolved 500 million years ago look very different from all animals alive today, as organisms evolved body plans and appendages that weren’t passed down to descendants.
As for stylophorans, the first fossils were discovered about 150 years ago. They’re tiny animals, only millimeters long, and over 100 species have been identified so far. The body is flattened and shaped sort of like a rectangle, but two of the rectangle’s corners actually extend up into little points, and growing from those two points are what look like two appendages. From the other side of the rectangle, the long flat side, is another appendage that looks like a tail. The tail has plates on it and blunt spikes that stick up, while the other two appendages look like they might be flexible like starfish arms.
Naturally, the first scientists to examine a stylophoran decided the tail was a tail and the flexible appendages were arm-like structures that helped it move around and find food. But half a billion years ago, there were no animals with tails. Tails developed much later, and are mainly a trait of vertebrates.
That led to some scientists questioning whether the stylophoran was an early precursor of vertebrates, or animals with some form of spinal cord. The spikes growing from the top of the tail actually look a little bit like primitive vertebrae, made of calcite plates. That led to the calcichordate hypothesis that suggested stylophorans gave rise to vertebrates.
Then, in 2014, -
Thanks to Anbo, Murilo, Clay, and Ezra for their suggestions this week! Let's learn about some bears!
Further reading:
Snack attack: Bears munch on ants and help plants grow
Extinct vegetarian cave bear diet mystery unravelled
Ancient brown bear genomes sheds light on Ice Age losses and survival
The sloth bear has shaggy ears and floppy lips [photo from this site]:
An absolute unit of a Kodiak bear in captivity [photo by S. Taheri - zoo, own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1118252]:
A polar bear:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re revisiting a popular topic, bears! We’ll talk about some bears we’ve never covered before, with suggestions from Anbo, Clay, Ezra, and Murilo. We’ll even discuss a small bear mystery which has mostly been solved by science.
To start us off, Anbo wanted to learn about bears in general. We’ve had bear episodes before, but our last episode all about bears was way back in 2017, in episode 42. Some of our listeners weren’t even born back then, which makes me feel super old.
Bears live throughout much of the world today, but they evolved in North America around 38 million years ago. These ancestral bears were small, about the size of a raccoon, but they were successful. They spread into Asia via the land bridge Beringia, where they were even more successful than in North America, so successful that by around 30 million years ago, descendants of those earliest bear ancestors migrated from Asia back into North America. But it wasn’t until the Pleistocene around 2 ½ million years ago that bears really came into their own.
That’s because bears are megafauna, and megafauna evolved mainly as an adaptation to increasingly cold climates. As the ice ages advanced, a lot of animals grew larger so they could stay warm more easily. Predators also had to grow larger as their prey became larger, since if you want to hunt an animal the size of a bison or woolly rhinoceros, you’d better be pretty big and strong yourself.
Bears mostly weren’t hunting animals that big, though. Modern studies suggest that overall, bears are omnivores, not fully carnivorous. Bears eat a lot of plant material even if you don’t count the panda, which isn’t very closely related to other bears. Even when a bear does eat other animals, they’re not usually very big ones.
Let’s take Murilo’s suggestion as an example, the sloth bear. The sloth bear lives in India and is increasingly vulnerable due to habitat loss and poaching. It’s probably most closely related to the sun bear that we talked about in episode 234, which also lives in parts of South Asia. Both the sun bear and the sloth bear have long black hair and a white or yellowish V-shaped marking on the chest. The sloth bear’s hair is especially long on its neck and shoulders, like a mane, and its ears even have long hair.
The sloth bear stands around 3 feet high at the shoulder at most, or 91 cm, and a big male can be over 6 feet tall, or almost 2 meters, when he stands on his hind legs. This isn’t gigantic for bears in general, but it’s not small either. Scientists think the V-shaped marking on its chest warns tigers to leave the sloth bear alone, and tigers mostly do. If tigers think twice about attacking an animal, you know that animal has to be pretty tough.
The sloth bear has massive claws on big paws. The claws can measure 4 inches long, or 10 cm, although they’re not very sharp. The bear has an especially long muzzle but its teeth aren’t very large. Like most bears, it’s good at climbing trees and can run quite fast, and it swims well too. It even has webbed toes.
With all this in mind, what do you think the sloth bear eats? I’ll give you some more hints. It has loose, kind of flappy lips, especially the lower lip. It doesn’t have any teeth in the front of its upper jaw. It mainly uses its huge claws to dig. -
Thanks to Alexandra, Pranav, Eilee, Conner, and Joel for their suggestions this week!
Velella velella, or by-the-wind-sailor [photo from this page]:
Porpita porpita, or the blue button [photo from this page]:
Cricetus cricetus, or the European hamster, next to a golden hamster:
Nasua nasua, or the South American coati [photo from this page]:
Mola mola, or the ocean sunfish:
Quelea quelea, or the red-billed quelea [photo from this page]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we’re going to learn a little bit about scientific names, and along the way we’re going to learn about several animals. Thanks to Alexandra, Eilee, Conner, Joel, and Pranav for their suggestions!
Alexandra inspired this episode by suggesting two animals, the by-the-wind-sailor and the blue button. Both are marine invertebrates that look superficially like jellyfish, but they’re actually colonial organisms. That means that although they look like a single animal, they’re actually made up of lots of tiny animals that live together and function as one organism.
The blue button is closely related to the by-the-wind-sailor and both are related to siphonophores. Both the blue button and the by-the-wind-sailor spend most of the time near or on the ocean’s surface and have a gas-filled chamber that helps keep them afloat, with stinging tentacles that hang down into the water, but both are made up of a colony of tiny animals called hydroids. Different hydroids have different functions, and all work together to find tiny food that will benefit the entire colony.
The blue button gets its name because its float is round and flat like a button, and often blue or teal in color. It’s quite small, only a little over an inch across, or about 3 cm, and its tentacles are not much longer. The by-the-wind-sailor is a little larger than the blue button, with a blue sail-shaped float that’s only a few inches across, or maybe 7 cm, with stinging tentacles of about the same size. The stings of both organisms aren’t very strong and aren’t dangerous to humans, but they do hurt, so it’s a good idea not to touch one. Since both can be very common in warm ocean waters and they sometimes get blown ashore by the wind in large numbers, it can be hard to avoid them if you’re visiting the beach at the wrong time. They can still sting you if they’re dead, too.
The by-the-wind sailor has the scientific name of Velella velella while the blue button’s scientific name is Porpita porpita. The term for a scientific name that contains the same words is a repeating scientific name, also called a tautonym or tautonymous name, and that’s the subject of this episode.
A scientific name is something we mention a lot but if you’re not sure what it means, it can sound confusing. Every organism with a scientific name has been described by a scientist, meaning it’s been studied and placed somewhere in the great interconnected web of life. The system of giving organisms scientific names is called binomial nomenclature. The first word of the name indicates which genus the organism belongs to, while the second word indicates what species it is. These are called generic and specific names. Some organisms also have a third word in their scientific name which indicates its subspecies.
The reason scientists use a complicated naming system is to make it easier for other scientists to know exactly what organism is being discussed. For example, let’s say a scientist has been studying hamsters in the wild to learn more about them, and publishes a paper about her observations. If she just calls the animal a hamster, someone reading it might assume she was talking about the hamster found in their part of the world, when the paper is actually about a totally different, although closely related, hamster that lives somewhere else. And that brings us to Pranav’s suggestion, the European hamster, -
Thanks to Cosmo, William, and Silas for their fishy suggestions this week!
You have until Sept. 13, 2024 to back the enamel pin Kickstarter!
Further reading:
The Handfish Conservation Project
Researchers Look in Tank and See Promising Cluster of Near-Extinct Babies
The unique visual systems of deep sea fish
A red handfish:
Another red handfish. This one is named Hector:
The black dragon fish:
The white-edged freshwater whipray [photo by Doni Susanto]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we return to the vertebrate world, specifically some strange and colorful fishies. Thanks to William, Cosmo, and Silas for their suggestions!
We’ll start with Silas’s suggestion, the red handfish. We talked about it before back in episode 189, but it’s definitely time to revisit it. When we last discussed it, scientists estimated there were fewer than 100 red handfish left in the wild, meaning it was in imminent danger of extinction. Let’s find out how it’s doing now, four years later.
The handfish gets its name because its pectoral fins look like big flat hands. It spends most of its time on the sea floor, and it uses its hands to walk instead of swimming. It can swim, although it’s not a very strong swimmer, and anyway if you had great big hands you might choose to walk on them too. It doesn’t have a swim bladder, which helps most fish stay buoyant.
All species of handfish are small, only growing to about 6 inches long at most, or 15 cm. This is surprising considering the handfish is closely related to anglerfish, and some anglerfish can grow over 3 feet long, or about a meter.
As for the red handfish specifically, it generally only grows about 4 inches long at most, or 10 cm, and it once lived in shallow water around much of Australia. These days, it’s only found on two reefs southeast of Tasmania. Some populations are bright red while some are pink with red spots. It has a wide downturned mouth that makes it look like a grumpy red toad with big hands.
So how is the red handfish doing? Four years ago it was almost extinct in wild, with fewer than 100 individuals alive. These days the Handfish Conservation Project estimates that the wild population is probably about the same, although because the red handfish is so small and hides so well among sea grass, algae, and rocks that make up its home, it’s hard to get a good count of how many are really alive. It’s also under even more pressure than before as an overpopulation of urchins is overgrazing the plants where it lives, which may sound familiar to you if you listened to episode 395 a few weeks ago. But there is one fantastic change that gives conservationists hope that the red handfish won’t go extinct after all.
The red handfish is so endangered, and its remaining habitat is so small, that a few years ago scientists decided they needed to start a captive breeding program. But even though the fish did just fine in captivity, they didn’t breed at first. Then, in November 2023, one of the fish laid 21 eggs and all 21 hatched safely. Hopefully it won’t be long until the babies are old enough to release into the wild.
The red handfish is one of very few fish that hatch into tiny baby fish instead of into a larval form. Newly hatched babies are only about 5 mm long. Most fish colonize new habitats after they float around aimlessly as larvae, until they grow enough to metamorphose into adults. Since the red handfish doesn’t have this larval stage, and babies just walk around on the sea floor finding tiny worms and other food, it’s hard for the fish to expand its range. Hopefully, as the captive breeding program continues and more young fish are released into the wild, scientists can start releasing red handfish into areas where they used to live.
Next, William asked about the dragon fish. We’ve talked about a few dragonfish before, in episodes 193 and 231, -
Thanks to Joel and an anonymous listener for their suggestions this week!
Further reading:
Dieback and recovery in poplar and attack by hornet clearwing moth
The enormous and beautiful Atlas moth:
A male hairy tentacle moth without and with coremata extended [photos from this site]:
The hornet moth looks like a hornet but can't sting:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
Welcome to September, where we’re mere weeks away from Monster Month! Invertebrate August is over for another year, but what’s this? An episode about moths?! Hurrah for one extra invertebrate episode, because they don’t get enough attention on this podcast! Thanks to Joel and an anonymous listener for their suggestions.
First, a listener who wants to remain anonymous suggested that we talk about moths in general, and the Atlas moth in particular. I like the Atlas moth because you can catch it in Animal Crossing. It’s also beautiful and one of the largest moths in the entire world. Its wingspan can be well over 10 inches across, or about 27 cm, which is bigger than a lot of bird wingspans.
The Atlas moth’s wings are mostly cinnamon brown with darker and lighter spots. The upper wings have a curved sort of hook at the top that’s lighter in color and has an eyespot. It looks remarkably like a snake head, and in fact if a predator approaches, the moth will move its wings so that it looks like a snake is rearing its head back to strike.
Despite having such huge wings, atlas moths don’t fly very well. That’s okay because they only need to be able to fly for a few days, which they mostly do at night. They’re only looking for a mate, not food, because they don’t even have fully formed mouthparts. They don’t eat as adults. Like many moths, they mate, lay eggs, and die.
A few weeks later, the eggs hatch and the baby caterpillars emerge. The caterpillar is pale green with little spikes all over, and it eats plants until it grows to around 4 and a half inches long, or about 11 and a half cm. At that point it spins a cocoon attached to a twig, hidden from potential predators by dead leaves that the caterpillar incorporates into the cocoon’s outside.
The Atlas moth lives in forests in southern Asia, including China, India, Indonesia, and Malaysia, with a subspecies native to Japan. Its cocoons are sometimes collected to use for silk. The silk isn’t as high a quality as the domesticated silk moth’s, but it’s very strong and since the cocoons are so big, they produce lots of silk. Sometimes people will collect a cocoon after the moth has emerged and use it as a little purse.
Next, Joel suggested two interesting moths. The first is often called the hairy tentacle moth, which sounds absolutely horrifying. Its scientific name is Creatonotos gangis, and it lives in parts of Australia and southeast Asia.
The hairy tentacle moth is also called the Australian horror moth and other names that inspire fear and disgust. But why? The moth is really pretty. Its wings are pale brown and white with dark gray stripes in the middle, and it has a black spot on its head. The abdomen is usually red with black spots in a row. The wingspan is about 40 mm.
The issue comes with the way the male attracts a female. Inside his abdomen the male has four coremata, which are glands that emit pheromones. Pheromones are chemicals that other moths can detect, much like smells. When a male is ready to advertise for a mate, he perches on the edge of a leaf or somewhere similar and inflates the coremata so that they unfurl from inside the abdomen, like blowing up a balloon. Sometimes he only extends two of the coremata, sometimes all of them. Either way, the coremata are surprisingly large, sometimes longer than the entire abdomen. They’re dark gray with feathery hairs and they do actually look like hairy tentacles. They’re sometimes called hair pencils, but the term coremata is actually Greek for feath... -
Thanks to Sy and Finn for their suggestions this week!
Further reading:
Creeping Crinoids! Sea Lilies Crawl to Escape Predators, New Video Shows
New and Unusual Crinoid Discovered
Sea otters maintain remnants of healthy kelp forest amid sea urchin barrens
Sea urchins see with their feet
A sea lily [photo from this page]:
A feather star [still from a video posted on this page]:
Purple urchins [photo by James Maughn]:
Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week as we bring invertebrate August to a close, we’re going to cover some animals suggested by Finn and Sy.
We’ll start with Sy’s suggestion, crinoids, also called feather stars or sea lilies depending on what body plan a particular species has. We talked about them in episode 79 but it’s definitely time to revisit them.
Crinoids are echinoderms, a really old phylum of animals. Fossils of ancient echinoderms date back to the Cambrian half a billion years ago and they’re still incredibly common throughout the world’s oceans.
Ancient crinoids had five arms the way many starfish do, which makes sense because crinoids are related to starfish. At some point each arm developed into two, so many crinoids have ten arms or even more, and many have arms that branch. The arms are used for feeding and have feathery appendages lined with sticky mucus that traps tiny bits of food floating in the water.
There are two big divisions of crinoids today, the feather stars and the sea lilies. Feather stars are more common and can swim around as adults if they want to, although most stick to crawling along the sea floor. They swim by waving their feathery arms. Sea lilies look like flowers as adults, with a slender stem-like structure with the small body and long feathery arms at the top. I specify that sea lilies have stems as adults because a lot of feather stars also have stems as juveniles, but when they reach maturity they become free-swimming.
Even though the sea lily looks like a plant, and some species even have root-like filaments that help it anchor itself to the sea floor or to rocks, it’s still an animal. For one thing, it can uproot itself and move to a better location if it wants to, crawling with its arms and pulling its stem behind it, which is not something a plant can do except in cartoons. If a predator attacks it, the sea lily will even shed its stem completely so it can crawl away much faster. Since echinoderms in general are really good at regenerating parts of the body, losing its stem isn’t a big deal.
The biggest sea lilies today are deep-sea species, but even they only grow a stem up to about three feet long at most, or about a meter. This wasn’t the case in the ancient past, though. The longest crinoid stem fossil ever discovered was 130 feet long, or 40 meters.
Crinoids filter food particles from the water that flows through the feathery arms. Even though they look like feathers or petals, a crinoid’s arms are actually arms. They have tiny tube feet on them that act sort of like fingers to help the crinoid hold onto pieces of food, and to do a better job of holding the food, the tube feet are covered with a sticky mucus. The mouth is in the middle of the arms on the top of the body.
Crinoids absorb oxygen directly from the water. Its body contains a system of chambers and pores that are full of water, and by contracting special muscles, the crinoid moves water around in its body to transport nutrients and oxygen and to collect waste material.
Crinoids are closely related to starfish, sea cucumbers, sand dollars, and sea urchins, which brings us to Finn’s suggestion. Finn suggested urchins, which are also echinoderms. In fact, at the end of episode 79 I mentioned that one day I’d do an episode about urchins, and it only took me six years to get here!
Many urchins look like living pincushions because they’re covered in spines. That’s where the name urchin comes from, - Montre plus
