Episode 303: Weird and Mysterious Animal Sounds

Posted on November 21, 2022 by strangeanimalspodcast

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Thanks to Emory for suggesting this week’s topic, mysterious animal sounds!

Further reading/watching:

The Story of Elk in the Great Smoky Mountains

Terrifying Sounds in the Forests of the Great Smoky Mountains

Evidence found of stingrays making noise

This New AI Can Detect the Calls of Animals Swimming in an Ocean of Noise

The wapiti [pic from article linked above]:

The stingray filmed making noise [stills from video linked to above]:

The tawny owl makes some weird sounds:

The fox says all kinds of things:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Emory suggested we do a new episode about strange and mysterious animal sounds a while back, which is one of my favorite topics. The problem is, it’s hard to find good audio clips to share. It’s taken me a while, but I think I’ve found some good ones.

In late September 2018, in the Great Smoky Mountains in North Carolina, some hikers recorded a terrifying animal sound. The sound wasn’t a mystery for long, though, because they soon saw the animal making it. Here’s what it sounded like:

[elk bugle]

It’s the bugle of a male elk, which I’m going to call wapiti to avoid confusion. It’s a sound that wasn’t heard in the Smoky Mountains for at least a century. The eastern wapiti was once common throughout eastern North America but was driven to extinction in the late 19th century, although the last wapiti in North Carolina was killed almost a century earlier than that. All North American wapiti almost went extinct by about 1900, and hunters and conservationists worked to get nature preserves set aside to save it and its habitat. Starting in the 1990s, wapiti from western North American subspecies were reintroduced in the southeast, with reintroductions in the Smokies starting in 2001. There are now at least 200 wapiti living in the mountains, probably more. I’ve seen them myself and they’re beautiful animals!

The wapiti is a type of deer. We talked about it way back in episode 30 along with the moose. Various species of wapiti live throughout Europe and Asia as well as North America, although it’s been hunted to extinction in many areas. As we mentioned in episode 30, the name elk is used for the moose in parts of Europe, which causes a lot of confusion, which is why I’ve chosen to call it by its Algonquin name of wapiti.

The wapiti is a really big animal, one of the biggest deer alive today. Only the moose is bigger. It’s closely related to the red deer of Eurasia but is bigger. A male, called a bull, can stand about 5 feet tall at the shoulder, or 1.5 meters, with an antler spread some four feet wide, or 1.2 meters. Females, called cows, are smaller and don’t grow antlers. Males grow a new set of antlers every year, which they use to wrestle other males in fall during mating season. At the end of mating season the wapiti sheds its antlers.

The bugling sound males make during mating season is extremely loud. The sound tells females that the bull is strong and healthy, and it tells other bulls not to mess with it.

[elk bugle]

Our next sound is from an animal that scientists didn’t realize could even make sounds. There’ve been reports for a long time of stingrays making clicking noises when they were alarmed or distressed, but it hadn’t been documented by experts. A team of scientists recently decided to investigate, with their report released in July of 2022. They filmed stingrays of two different species off the coasts of Indonesia and Australia making clicking sounds as divers approached. They think it may be a sound warning the diver not to get too close. This is what it sounds like:

[Stingray making clicking sounds]

One exciting new technological development is being used to detect underwater sounds and hopefully help identify them. It’s called DeepSqueak, because it was originally developed to record ultrasonic calls made by mice and rats. This is an example of a mouse sound slowed down enough that humans can hear it, specifically a male mouse singing to attract a mate, which we talked about in episode 8:

[mouse song]

But DeepSqueak also works really well to detect sounds made by whales and their relatives, and researchers are currently using it to determine whether offshore wind farms cause problems for whales.

With DeepSqueak and other listening software, it turns out that a lot of animals we thought were silent actually make noise. For instance, this sound:

[Pelochelys bibron]

That’s a grunting sound made by the southern New Guinea giant softshell turtle.

And here’s a caecilian, a type of burrowing reptile that we talked about in episode 82:

[Typhlonectes compressicauda]

Let’s finish with a strange and mysterious sound heard on land. In January and February of 2021, some residents of London, England started hearing a weird sound at night.

[mystery sound]

Because the animal making the sound moved around so much, some people thought it must be a bird. One suggestion is that it was a tawny owl, especially the female tawny owl who makes a chirping sort of sound to answer the male’s hoot. This is what the male and female tawny owl sound like:

[owl sounds]

The tawny owl also sometimes makes an alarm call that sounds like this:

[tawny owl alarm call]

But the sound didn’t really match up with what residents were hearing. Here it is again:

[mystery sound]

Finally someone pointed out that red foxes make a lot of weird sounds, mostly screams and sharp barks, but occasionally this sound:

[fox sound]

That seems to be a pretty good match for what people were hearing in early 2021, although since no one got a look at the animal they heard, we can’t know for sure. So it’s still a mystery.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 296: The Hide and the Blood-Sucking Blanket

Posted on October 3, 2022 by strangeanimalspodcast

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Monster month is upon us, October, where all our episodes are about spooky things! This episode is only a little bit spooky, though. I give it one ghost out of a possible five ghosts on the spooky scale.

Happy birthday to Casey R.!

Further reading:

All you ever wanted to know about the “Cuero”

Mystery Creatures of China by David C. Xu

Freshwater stingrays chew their food just like a goat

A 1908 drawing of the hide (in the red box) [picture taken from first link above]:

The Caribbean whiptail stingray actually lives in the ocean even though it’s related to river stingrays:

The short-tailed river stingray lives in rivers in South America and is large. Look, there’s Jeremy Wade with one!

The bigtooth river stingray is awfully pretty:

Asia’s giant freshwater stingray is indeed giant:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s finally October, and you know what that means. Monster month! We have five Mondays in October this year, including Halloween itself—and, in the most amazing twist of fate, our 300th episode falls on Halloween!

I know some of our listeners don’t like the really spooky episodes because they’re too scary, especially for our younger listeners. To help people out, I’m going to rate this year’s monster month episodes on a scale of one ghost, meaning it’s only a little tiny bit spooky, to five ghosts, which means really spooky. This week’s episode is rated one ghost, so it’s interesting but won’t make you need to sleep with a night light on.

Before we get started, we have two quick announcements. Some of you may have already noticed that if you scroll all the way down in your podcast app to find the first episode of Strange Animals Podcast, it doesn’t appear. In fact, the first several episodes are missing. That’s because we actually passed the 300 episode mark several weeks ago, because of the occasional bonus episode and so forth, and podcast platforms only show the most recent 300 episodes of any podcast. That’s literally the most I can make appear. However, the early podcasts are still available for you to listen to, you’ll just have to click through to the website to find them.

Second, we have a birthday shout-out this week! A very very happy birthday to Casey R! I hope your birthday is full of all your favorite things.

Now, let’s learn about the hide of South America and the blood-sucking blanket of Asia.

The first mention of a creature called El Cuero in print comes from 1810, in a book called Essay on the Natural History of Chile by a European naturalist named Fr. Juan Ignacio Molina. In his book Molina wrote, “The locals assure that in certain Chilean lakes there is an enormous fish or dragon…which, they say, is man-eating and for this reason they abstain from swimming in the water of those lakes. But they are not in agreement the appearance that they give it: now they make it long, like a serpent with a fox head, and now almost circular, like an extended bovine hide.”

Later scholars pointed out that the reason Molina thought the locals couldn’t decide what the animal looked like was because locals were talking about two different monsters. Molina just confused them. One monster was called a fox-snake and one was the cuero, which means “cow hide” in Spanish. And it’s the hide we’re going to talk about.

During the century or so after Molina wrote his book, folklorists gathered stories and legends from the native peoples of South America, trying to record as much about the different cultures as they could before those cultures were destroyed or changed forever by European colonizers. The hide appears to be a monster primarily from the Mapuche people of Patagonia.

Most stories about the hide go something like this: a person goes into the water to wash, or maybe they have to cross the lake by swimming. The hide surfaces and folds its body around the person like a blanket, dragging them under the water, and the person is never seen again. Sometimes the monster is described as resembling a cowskin or calfskin, sometimes a goat- or sheepskin. It’s usually black or brown and sometimes is reported as having white spots, and some reports say it has hooks or thorns around its edges. It may bask at the water’s surface or in shallow water in daytime, waiting for a person or animal to come too close.

The safest way to kill a hide is to trick it into coming to the surface to catch an animal or person. When it’s close enough, people throw the branches of a cactus with really long, sharp thorns at it. The hide folds its body around the cactus pieces, which pierce it through and kill it. The least safest way to kill a hide is to make sure you’re carrying a sharp knife, and when the hide grabs you, cut your way out of its enveloping folds before you drown or are eaten.

The main suggestion, starting in 1908, was that the hide was a giant octopus that lived in freshwater and had hooks on its legs or around the edges of its mantle. The main problem with this hypothesis is that there are no known freshwater octopuses. There aren’t any freshwater squid either, another suggestion.

A much better suggestion is that the hide is actually some kind of freshwater ray. And, as it happens, there are lots of freshwater stingrays native to South America. Specifically, they’re members of the family Potamotrygonidae, river stingrays.

River stingrays are pretty much round and flat with a slender tail equipped with a venomous stinger. The round part is called a disc, and some species can grow extremely large. The largest is actually a marine species called the Caribbean whiptail stingray, which can grow about 6 1/2 feet across, or 2 meters. But the short-tailed river stingray can grow about 5 feet across, or 1.5 meters, and it lives in the Río de la Plata basin in South America. The short-tailed river stingray is dark gray or brown mottled with lighter spots, while many other river stingrays are black or dark brown with light-colored spots.

Even better for our hypothesis, river stingrays are covered with dermal denticles on their dorsal surface, more commonly called the back. Dermal denticles are also called placoid scales even though they’re not actually scales. They’re covered with enamel to make them even harder, like little teeth. If that sounds strange, consider that rays are closely related to sharks, and sharks are well known to have skin so rough that you can hurt your hand if you try to pet a shark. Please don’t try to pet a shark. Admire sharks from a safe distance like you should with any wild animal.

River stingrays don’t eat people, of course. They mostly eat fish, crustaceans, worms, insects, mollusks, and other small animals. Females are much larger than males and give birth to live young. The ray’s mouth is underneath on the bottom of the disc near the front, and it has sharp teeth. Unlike pretty much every fish known, it chews its food with little bites like a mammal, which if you think about it too much is kind of creepy.

River stingrays also don’t hunt by wrapping animals in their disc, but the disc is involved in hunting in a way. The disc is formed by the ray’s fins, which are extremely broad and encircle the center part of its body, and the disc as a whole is pretty flat. The stingray will lie on the bottom of the river until a little fish or an insect gets too close. Then it will lift the front part of its disc quickly, which sucks water under it. If you’ve ever stood up in the bathtub before the water has completely drained, you can feel the suction as your body leaves the water. Quite often, the stingray’s prey gets sucked under it with the water. The ray then drops back down, trapping the animal underneath it, and chews it up.

That doesn’t mean stingrays aren’t dangerous to humans, though. The stingray’s sting is barbed and very strong, and can cause a painful wound even without its venom. A ray often hides by burying itself in the sand or mud, and if someone steps on it by accident, the ray whips its tail up and jabs its sting into their leg.

In other words, we have a large, flat creature with little pointy denticles on its back that may be dark-colored with white spots, and it’s dangerous to people and animals. That sounds a lot like the hide. There’s just one problem with this theory.

The stingray is a tropical or temperate animal. It needs warm water to survive. Patagonia is at the extreme southern end of South America, much closer to Antarctica than to the equator. No river stingray known lives within at least 500 miles of Patagonia, or 800 km, and the Patagonian lakes where the hide is supposed to live are extremely cold even in summer.

That doesn’t mean there isn’t a stingray unknown to science living in remote areas of Patagonia, of course. Many river stingray species were only discovered in the last decade or so, some of them quite large, and there are still some undescribed species. There’s always the possibility that at least one river stingray species has become adapted to the cold but hasn’t been discovered by scientists yet. It might be endangered now or even extinct.

Or the hide might not be a real animal, just a legend inspired by the river stingrays in other parts of South America. The Mapuche people are not closely related to the other peoples of Patagonia, even though they’ve lived there for at least 2,500 years, and some archaeologists think they might have migrated to Patagonia relatively late. If they brought memories of big river stingrays from their former home north of Patagonia, the memories might have inspired stories of the hide.

On the other side of the world, in China, there’s a similar legend of a monster sometimes called the xizi. The name means “mat” but it’s also referred to as a blood-sucking blanket. It lives in rivers and other waterways, and can even slide out of the water onto land. And like the hide, it’s described as a sort of living blanket that wraps itself around people or animals that venture into the water, where it pulls them under and sucks all the blood out of them.

In the case of the blood-sucking blanket, though, it’s supposed to have sharp round suckers on its underside that it uses to stick to its victims and slurp up their blood. It varies in size, sometimes about a foot across, or 30 cm, sometimes as much as 6 1/2 feet across, or 2 meters. Sometimes it’s described as reddish, sometimes green or covered with fuzzy moss on its back.

One story is that a hunter witnessed an elephant and her calf crossing a shallow river when the calf was dragged underwater by something. The mother elephant grabbed her calf and pulled it to safety, then trampled its attacker. Once the elephants were gone, the hunter went to investigate and found a dead creature that resembled a wool blanket, with a greenish, mossy back but with big suckers underneath the size of rice bowls, sort of like an octopus’s suckers.

And there is a freshwater stingray that lives in Asia, although it isn’t closely related to the river stingrays found in South America. Most of its closest relatives live in the ocean, but the giant freshwater stingray lives in rivers in southeast Asia. It’s dark gray-brown on its back and white underneath, and it has a little pointy nose at the front of its disc. It has denticles on its back and tail just like its distant South American cousins.

It’s also enormous. A big female can grow over 7 feet across, or 2.2 meters. Its tail is long and thin with the largest spine of any stingray known, up to 15 inches long, or 38 cm. In fact, its tail is so long that if you measure the giant freshwater stingray by length including its tail, instead of by width of its disc, it can be as much as 16 feet long, or about 5 meters. Some researchers think there might be individuals out there much larger than any ever measured, possibly up to 16 feet wide. The length and thinness of the tail gives the ray its other common name, the giant freshwater whipray, because its tail looks like a whip.

Even though it’s endangered due to habitat loss and hunting, and it only lives in a few rivers in South Asia these days, the giant freshwater stingray was once much more widespread. Because stingrays have cartilaginous skeletons the same way sharks do, we don’t have very many fossils or subfossil remains except for stingray teeth and denticles, so we don’t know for sure where the giant freshwater stingray used to live. But even if it didn’t live in China, travelers who had seen one in other places might have brought stories of it to China, where it spread as a scary legend.

Or, of course, there might be another freshwater stingray in China that’s unknown to science, possibly endangered or even extinct. It might even still be around, just waiting for someone to go swimming.

Thanks for listening!

Episode 280: Lesser-Known Sharks

Posted on June 13, 2022 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 12:25 — 14.2MB)

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Thanks to Tobey and Janice this week for their suggestions of lesser-known sharks!

Further reading/watching:

CREATURE FEATURE: The Spinner Shark [this site has a great video of spinner sharks spinning up out of the water!]

Acanthorhachis, a new genus of shark from the Carboniferous (Westfalian) of Yorkshire, England

150 Year Old Fossil Mystery Solved [note: it is not actually solved]

The cartoon-eyed spurdog shark:

The spinner shark spinning out of the water:

The spinner shark not spinning (photo by Andy Murch):

A Listracanthus spine:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re going to learn about three sharks you may have never heard of before! The first was suggested by my aunt Janice and the second by listener Tobey. The third is a mystery from the fossil record.

You may have heard about the findings of a study published in November of 2021, with headlines like “Venomous sharks invade the Thames!” My aunt Janice sent me a link to an article like this. Nobody is invading anything, though. The sharks belong where they are. It was their absence for decades that was a problem, and the study discovered that they’re back.

The Thames is a big river in southern England that empties into the North Sea near London. Because it flows through such a huge city, it’s pretty badly polluted despite attempts in the last few decades to clean it up. It was so polluted by the 1950s, in fact, that it was declared biologically dead. But after a lot of effort by conservationists, fish and other animals have moved back into the river and lots of birds now visit it too. It also doesn’t smell as bad as it used to. One of the fish now found again in the Thames is a small shark called the spurdog, or spiny dogfish.

The spurdog lives in many parts of the world, mostly in shallow water just off the coast, although it’s been found in deep water too. A big female can grow almost three feet long, or 85 cm, while males are smaller. It’s a bottom dweller that eats whatever animals it finds on the sea floor, including crabs, sea cucumbers, and shrimp, and it will also eat jellyfish, squid, and fish when it can catch them. It’s even been known to hunt in packs.

It’s gray-brown in color with little white spots, and it has large eyes that kind of look like the eyes of a cartoon shark. It also has a spine in front of each of its two dorsal fins, which can inject venom into potential predators. The venom isn’t deadly to humans but would definitely hurt, so please don’t try to pet a spurdog shark. If the shark feels threatened, it curls its body around into a sort of shark donut shape, which allows it to jab its spines into whatever is trying to grab it.

The spurdog used to be really common, and was an important food for many people. But so many of them were and are caught to be ground into fertilizer or used in pet food that they’re now considered vulnerable worldwide and critically endangered around Europe, where their numbers have dropped by 95% in the last few decades. It’s now a protected species in many areas.

The female spurdog retains her fertilized eggs in her body like a lot of sharks do. The eggs hatch inside her and the babies develop further before she gives birth to them and they swim off on their own. It takes up to two years before a pup is ready to be born, and females don’t reach maturity until they’re around 16 years old, so it’s going to take a long time for the species to bounce back from nearly being wiped out. Fortunately, the spurdog can live almost 70 years and possibly longer, if it’s not killed and ground up to fertilize someone’s lawn. The sharks like to give birth in shallow water around the mouths of rivers, where the water is well oxygenated and there’s lots of small food for their babies to eat, which is why they’ve moved back into the Thames.

Next, Tobey suggested we talk about the spinner shark. It’s much bigger than the spurdog, sometimes growing as much as 10 feet long, or 3 meters. It lives in warm, shallow coastal water throughout much of the world. It has a pointy snout and is brown-gray with black tips on its tail and fins, and in fact it looks so much like the blacktip shark that it can be hard to tell the two species apart unless you get a really good look. It and the blacktip shark also share a unique feeding strategy that gives the spinner shark its name.

The shark eats a lot of fish, especially small fish that live in schools. When the spinner shark comes across a school of fish, it swims beneath it, then upward quickly through the school. As it swims it spins around and around like an American football, but unlike a football it bites and swallows fish as it goes. It can move so fast that it often shoots right out of the water, still spinning, up to 20 feet, or 6 meters, before falling back into the ocean. The blacktip shark sometimes does this too, but the spinner shark is an expert at this maneuver.

There’s a link in the show notes to a page where you can watch a video of spinner sharks spinning out of the water and flopping back down. It’s amazing and hilarious. Tobey mentioned that the spinner shark is an acrobatic shark, and it certainly is! It’s like a ballet dancer or figure skater, but with a lot more teeth. And fewer legs.

Because spinner sharks mainly eat fish, along with cephalopods, they almost never attack humans because they don’t consider humans to be food. Humans consider the spinner shark food, though, and they’re listed as vulnerable due to overhunting and habitat loss.

We’ll finish with a mystery shark. I’ve had Listracanthus on my ideas list for a couple of years, hoping that new information would come to light, but let’s go ahead and talk about it now. It’s too awesome to wait any longer.

We know very little about Listracanthus even though it was around for at least 75 million years, since it’s an early shark or shark relative with a cartilaginous skeleton. Cartilage doesn’t fossilize very well compared to bone, so we don’t have much of an idea of what the shark looked like. What we do have are spines that grew all over the fish and that probably made it look like it was covered with bristles or even weird feathers. The spines are a type of denticle that could be up to 4 inches long, or 10 cm. They weren’t just spines, though. They were spines that had smaller spines growing from their sides, sort of like a feather has a main shaft with smaller shafts growing from the sides.

The spines are fairly common in the fossil record from parts of North America, dating from about 326 million years ago to about 251 million years ago. Listracanthus was closely related to another spiny shark-like fish, Acanthorhachis, whose spines have been found in parts of Europe and who lived around 310 million years ago, but whose spines are less than 3 inches long at most, or 7 cm.

Some researchers think the spines were only present on parts of the shark, maybe just the head or down the back, but others think the sharks were covered with the spines. Many times, lots and lots of the spines are found together and probably belong to a single individual whose body didn’t fossilize, only its spines. Some researchers even think that the flattened denticles from a shark or shark relation called Petrodus, which is found in the same areas at the same times as Listracanthus, might actually be Listracanthus belly denticles.

The spines probably pointed backwards toward the tail, which would reduce drag as the fish swam, and they might have been for display or for protection from predators, or of course both. The main parts of the spine were also hollow and there’s evidence there were capillaries inside, so they might have had a chemosensory or electrosensory function too.

Modern sharks have denticles that make their skin rough, sort of like sandpaper. One modern shark, the sandy dogfish, Scyliorhinus canicula, which is common in shallow water off the coasts of western Europe and northern Africa, and in the Mediterranean, has especially rough denticles on its tail. They aren’t precisely spines, but they’re more than just little rough patches. The sandy dogfish is a small, slender shark that barely grows more than about three feet long, or about a meter, and it eats anything it can catch. Young dogfish especially like small crustaceans, and sometimes they catch an animal that’s too big to swallow whole. In that case, the shark sticks the animal on the denticles near its tail, which anchors it in place so it can tear bite-sized pieces off. Some other sharks do this too, so it’s possible that Listracanthus and its relations may have used its spines for similar behavior.

We don’t know much about these sharks because all we have are their spines. Only one probable specimen has been found, by a paleontologist named Rainer Zangerl. Dr. Zangerl found the remains of an eel-like shark in Indiana that was covered in spines, but unfortunately as the rock dried out after being uncovered, the fossil literally disintegrated into dust.

In August of 2019, a fossil hunter posted on an online forum for fossil enthusiasts to say he’d found a Listracanthus specimen. He posted pictures, although since the fossil hasn’t been prepared it isn’t much to look at. It’s just an undulating bump down a piece of shale that kind of looks like a dead snake. Fortunately, the man in question, who goes by RCFossils, knew instantly what he’d found. He also knew better than to try to clean it up himself. Instead, he’s been working on trying to find a professional interested in taking the project on. In May of 2022 he posted again to say he’d managed to get an X-ray of the fossil, which shows a backbone but no sign of a skull. He’s having trouble finding anyone who has the time and interest in studying the fossil, but hopefully he’ll find someone soon and we’ll all learn more about this mysterious pointy shark.

Thanks for listening!

Episode 278: Gender Diverse Animals

Posted on May 30, 2022 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 16:51 — 12.7MB)

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This week is Connor’s episode, and we’re going to learn about some animals that don’t conform to “typical” gender roles, one way or another.

I’ll be at ConCarolinas this week, from June 3 through 5, including recording a live crossover episode with Arcane Carolinas!

Further reading:

Species of algae with three sexes that all mate in pairs identified in Japanese river

How a microbe chooses among seven sexes

Facultative Parthenogenesis in California Condors

The sparrow with four sexes

Chinstrap penguins make good dads:

Laysan albatrosses make good moms:

Black swans make good dads:

Some rams really like other rams (photo by Henry Holdsworth):

New Mexico whiptail lizards are all females:

California condor females don’t always need a male to produce fertilized eggs:

Clownfish change sex under some circumstances:

The white-throated sparrow essentially has four sexes:

You are awesome (photo by By Eric Rolph)!

Show transcript:

“Hey y’all, this is Connor. Welcome to a very special Pride Month edition of the Strange Animals Podcast.”

This week we have Connor’s episode! We decided to make it the very last episode in our Kickstarter month so that it’s as close to the month of June as possible, because June is Pride Month and our episode is about gender-diverse animals! Don’t worry, parents of very young children, we won’t be discussing mating practices except in very general terms.

Pride month celebrates people’s differences when it comes to gender expression and sexuality. That’s why its symbol is the rainbow, because a rainbow is made up of all different colors the same way there are different kinds of people. Sometimes people get angry when they hear about Pride month because they think there are only two genders, and that those two genders should only behave in certain ways. Pffft. That’s not even true when it comes to animals, and humans are a lot more socially complicated.

For instance, let’s start by talking about a humble creature called algae. If you remember episode 129, about the blurry line between animals and plants, you may remember that algae isn’t actually a plant or an animal. Some species resemble plants more than animals, like kelp, but they’re not actually plants. In July of 2021, scientists in Japan announced that a species of freshwater algae has three sexes: male, female, and bisexual. All three sexes can pair up with any of the others to reproduce and their offspring may be male, female, or bisexual at random.

Even though the algae has been known to science for a long time, no one realized it has three sexes because most of the time, algae reproduces by cloning itself. The research team thinks that a lot of algae species may have three sexes but researchers just haven’t been looking for it.

Yes, I realize that was a weird place to start, but it’s also fascinating! It’s also not even nearly as complicated as a protozoan called Tetrahymena thermophila, which has seven sexes.

Let’s look at a bird next, the penguin. You’ve probably heard of the book And Tango Makes Three, about two male penguins who adopt an egg and raise the baby chick together. For some reason some people get so angry at those penguins! Never trust someone who doesn’t like baby penguins, and never trust someone who thinks animals should act like humans. The events in the book are based on a true story, where two male chinstrap penguins in New York’s Central Park Zoo formed a pair bond and tried to hatch a rock, although they also tried to steal eggs from the other penguins. A zookeeper gave the pair an extra penguin egg to hatch instead.

The most interesting thing about the story is that same-sex couples are common among penguins, in both captivity and in the wild, among both males and females. Since penguins sometimes lay two eggs but most species can only take care of one chick properly, zookeepers often give the extra eggs to same-sex penguin pairs. The adoptive parents are happy to raise a baby together and the baby is more likely to survive and be healthy. Occasionally a same-sex penguin couple will adopt an egg abandoned by its parents.

If you remember episode 263 a few months ago, where we talked about animals that mate for life, you may remember the Laysan albatross. In that episode we learned about a specific Laysan albatross named Wisdom, the oldest wild bird in the world as far as we know. While I was researching Wisdom, I learned something marvelous. As many as 30% of all Laysan albatross pairs are both females. Sometimes one of the females will mate with a male and lay a fertilized egg, and then both females raise the baby as a couple. Sometimes one of the females lays an unfertilized egg that doesn’t hatch. There are many more Laysan albatross females than males, which may be the reason why females form pairs, but it’s perfectly normal behavior. It’s also been a real help to conservationists. Sometimes an albatross pair will nest in an area that’s not safe, like on an airfield. Instead of leaving the egg to be smashed by an airplane, conservationists take the fertilized egg from the unsafe nest and use it to replace the unfertilized egg of a female pair. The egg is safe and the chick has adoptive parents who raise it as their own.

Many other birds develop same-sex pairs too. This is especially common in the black swan, where up to a quarter of pairs are both male. One or both of the males will mate with a female, but after she lays her eggs the males take care of them and the cygnets after they hatch. Cygnets raised by two dads are much more likely to survive than cygnets raised by one mom and one dad. The males are stronger and more aggressive, so they can defend the nest and babies more effectively.

Birds aren’t the only animals that form same-sex pair bonds. Many mammals do too. It’s been documented in the wild in lions, elephants, gorillas, bonobos, dolphins, and many more. In species that don’t typically form pair bonds, homosexual behavior is still pretty common. It’s so common among domestic sheep that shepherds have to take into account the fact that up to 10% of rams prefer to mate with other rams instead of with ewes. Some rams show attraction to both males and females. This happens in wild sheep too, where rams may court other rams the same way they court ewes. Some ewes also show homosexual behavior.

The New Mexico whiptail is a lizard that lives in parts of the southwestern United States and northern Mexico. It can grow over nine inches long, or 23 cm, and is black or brown with yellow racing stripes. It eats insects and is an active, slender lizard that’s common throughout its range. And every single New Mexico whiptail lizard is a female.

The lizards reproduce by a process called parthenogenesis. That basically means an animal reproduces asexually without needing to have its eggs fertilized. The lizards do mate, though, but not with males. Females practice mating behaviors with each other, which researchers think causes a hormone change that allows eggs to develop. Females who don’t mate don’t develop eggs.

Female birds can sometimes reproduce asexually too. It’s been documented in turkeys, chickens, pigeons, finches, and even condors. A study published in late 2021 detailed two instances of parthenogenesis in California condors in a captive breeding program. In both cases the females were housed with their male mates, and in both cases the pairs had produced offspring together before. But in both cases, for some reason the females laid eggs that hatched into chicks that were genetically identical to the mothers. It’s possible parthenogenesis is even more common in birds than researchers thought.

In many species of reptile, whether a baby is a male or female depends completely on how warm its egg gets during incubation. For example, the American alligator. The mother gator builds a nest of plant material and lays her eggs in it. As the plant material decays, it releases heat that keeps the eggs warm. How much heat is generated depends on where the mother alligator builds her nest and what plants she uses, which in turns affects the eggs. If the temperature in the nest is under 86 degrees Fahrenheit, or 30 Celsius, during the first few weeks of incubation, most or all of the eggs will hatch into females. If the temperature is 93 F or 34 C, most or all of the eggs will hatch into males. If the temperature is between the two extremes, there will be a mix of males and females, although usually more females.

Because climate change has caused an overall increase in temperatures across the world, some already vulnerable reptile populations, especially sea turtles, are hatching almost all males. Conservationists have to dig up the eggs and incubate them at a cooler temperature in captivity, then release the babies into the ocean when they hatch.

Other animals change from male to female or vice versa, depending on circumstances. The clownfish, for example. Clownfish start out life as males but as they grow up, most become females, although only the dominant pair in a colony actually reproduces. Clownfish live in colonies led by the largest, most aggressive female, with the largest, most aggressive male in the group as her mate. If something happens to her, her former mate takes her place, becoming a female in the process. The largest juvenile male then becomes her mate and remains male even though he puts on a growth spurt to mature quickly. If Finding Nemo was scientifically accurate, it would have been a much different movie.

Another group of fish that live around reefs are wrasses, which includes the famous cleaner fish that cleans parasites and dead tissue off of larger fish. Wrasses hatch into both males and females, but the males aren’t the same type of males that can breed. Those develop later. When the dominant breeding male of the group dies, the largest female or the largest non-breeding male then develops into a breeding male. But sometimes a non-breeding male will develop into a female instead.

The term for an animal that changes sex as part of its natural growth process is sequential hermaphroditism. It’s common in fish and crustaceans in particular. Other animals have the reproductive organs of both a male and a female, especially many species of snail, slug, earthworm, sea slug, and some fish. We talked about the mangrove killifish in episode 133, and in that episode I said it was the only known vertebrate hermaphrodite. That’s actually not accurate, although I was close. It’s the only known vertebrate hermaphrodite that can self-fertilize. Almost all mangrove killifish are females, although they also produce sperm to fertilize their own eggs. The eggs hatch into little clones of the mother.

We’ve talked about seahorses before too, especially in episode 130. Seahorse pairs form bonds that last throughout the breeding season. The pair participate in courtship dances and spend most of their time together. When the eggs are ready, the female deposits them in a special brood pouch in the male’s belly, where he fertilizes them. They then embed themselves in the spongy wall of the brood pouch and are nourished not only by the yolk sacs in the eggs, but by the male, who secretes nutrients in the brood pouch. So basically the male is pregnant. The female visits him every day to check on him, usually in the mornings. When the eggs hatch after a few weeks, the male expels the babies from his pouch and they swim away, because when they hatch they are perfectly formed teeny-tiny miniature seahorses.

Let’s finish with a little songbird that’s common throughout eastern North America, the white-throated sparrow. It has a white patch on its throat and a bright yellow spot between the eye and the bill. There are two color morphs, one with black and white stripes on its head, one with brown and tan stripes on its head. Both males and females have these head stripes. The male sings a pretty song that sounds like this:

[white-throated sparrow call]

A 30-year study into white-throated sparrow genetics has revealed some amazing things. The color morphs are due to a genetic difference that affects a lot more than just feather colors. Black morph males are better singers, but they don’t guard their territory as well or take care of their babies as well as brown morphs do. They also aren’t as faithful to their mates as the brown morph males, which are fully monogamous and are diligent about helping take care of their babies. Despite their differences in raising offspring, both morphs are equally successful and equally common.

All this seems to be no big deal on the surface, maybe just pointing to the possibility that the species is in the process of splitting into two species or subspecies. But that’s not the case.

Black morphs always mate with brown morphs. A black morph male will always have a brown morph mate, and vice versa. Genetically, the two morphs are incredibly different—so different, in fact, that they seem to be developing a fully different set of sex chromosomes. In other words, there are male and female black morph birds and male and female brown morph birds that are totally different genetically, but still members of the same species that only ever breed with each other. In essence, the white-throated sparrow has four sexes.

Usually I try to end episodes with something funny, but today I’m going to speak directly to you. Yes, you! If you’re listening to this or reading the transcript, my words are meant just for you. You are an amazing person and I love you. You deserve to be happy. If anyone has ever told you there’s something wrong with the way you are, or the way you wish you were or want to be, they’re wrong. They probably also don’t like penguins, so you don’t have to believe anything they say. If you’ve ever read books by Terry Pratchett, you may recognize this quote: “Be yourself, as hard as you can.”

Thanks for listening!

Episode 271: Springtime Animals

Posted on April 11, 2022 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 13:22 — 15.4MB)

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Pre-order your tiny pin friend via our Indiegogo campaign!

This week we talk about some springtime animals! Sort of! Thanks to Derek and Nikita for their suggestions!

Happy birthday to Lillian, Hannah, and Derek! What a busy birthday week! Everybody gets cake!

Further reading:

Tales from Tennessee

There’s more than one way to grow a beak

A male river chub. “It’s not funny guys, put me down guys” (photo by Bill Hubick):

Busy busy busy building a big big nest (photo from site linked to above):

Got a rock (photo from site linked to above):

One bilby:

Two bilbies:

Easter bilbies not bunnies:

Egg tooth:

The red jungle fowl is the wild ancestor of the domestic chicken:

Modern domestic chickens:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s springtime in the northern hemisphere, with spring festivals like Easter coming up fast. This week let’s look at three animals that represent springtime, sort of. Thanks to Derek and Nikita for suggesting two of the animals we’ll learn about this week!

Before we start, though, two things! One, I’m running a little crowdfunding campaign to have some enamel pins made. I won’t spam you about it like our big Kickstarter for the book last fall, but there will be a link in the show notes if you want to take a look. There are three designs, a narwhal, a capybara with a tangerine on its head, and a not-terribly-accurate thylacine. The campaign is called Tiny Pin Friends and it’s on Indiegogo.

https://www.indiegogo.com/projects/tiny-pin-friends/x/2964999#/

Two, it’s birthday shout-out time! This week we have not one, not two, but THREE birthday shout-outs! You know what that means, of course. It means we all need to be celebrating all week! A great big happy birthday to Lillian, Hannah, and Derek! And yes, birthday Derek is the same Derek who suggested one of the animals this week!

In fact, let’s start with his suggestion, a fish called the river chub. It’s a little fish that only grows a little over a foot long at most, or 33 cm, although it’s usually much smaller than that. It’s common in fast-moving streams and rivers throughout North America, especially in the Appalachian Mountains and surrounding areas.

The river chub isn’t all that exciting to look at, unless of course you’re a fish enthusiast or a river chub yourself. It’s greenish-silver above and pale underneath with orange fins. Males are larger than females and during breeding season, in late spring, the male turns purplish-red, his head enlarges, and he develops tubercles on the front part of his head that look sort of like white rhinestones.

His physical changes aren’t just to attract a mate. The male river chub builds a pebble nest by picking up little stones and moving them to just the right spots, so by having a more robust head and broad mouth, he can pick up bigger stones. And he picks up a LOT of stones, as many as 10,000 of them, which he arranges and rearranges.

Females are attracted to well-made nests. After a female lays her eggs in the nest, the male fertilizes the eggs and then spends the next week or so defending them by head-butting other males and potential predators, until the eggs hatch into larvae.

The pebble nests help other animals too. Over 30 species of fish use the nests as spawning sites once the river chub’s eggs hatch. Good job, river chub, helping out all those other fish!

Next, a while back Nikita suggested we learn about the bilby. It’s not springtime right now in Australia where the bilby lives, but the Christian holiday of Easter is still celebrated at the same time as it is in the northern hemisphere. Instead of chocolate Easter bunnies, in Australia they also have chocolate Easter bilbies.

In 1968, a nine-year-old girl named Rose-Marie Dusting wrote a story called “Billy the Aussie Easter Bilby.” When she grew up, Rose-Marie published the story as a picture book, which became popular enough that it inspired people in Australia to start talking about the Easter bilby instead of the Easter bunny. Starting in 1991 there was a big push to change from Easter bunnies to bilbies. Rabbits are an invasive species in Australia and do a lot of damage, and in fact they’ve almost driven the bilby to extinction. The lesser bilby did go extinct in the 1950s but the greater bilby is hanging on despite introduced predators like cats and foxes, rabbits and other introduced animals that eat all their food, and habitat loss.

The bilby has silky fur that’s mostly gray in color, and it has long pink ears that look sort of like a rabbit’s. It’s sometimes called the rabbit-eared bandicoot because of its ears. It has a long, pointy muzzle that’s pink and a long tail that’s black with a white tip, and it’s about the size of a cat but with shorter, thinner legs. It has a good sense of smell and good hearing, naturally, but its big ears are also useful for shedding heat. This is important since it often lives in hot, dry areas.

The bilby is nocturnal and spends the day in one of several burrows it digs in its territory. Not only are the burrows up to almost 10 feet long, or 3 meters, but they can be up to 6 feet deep, or 2 meters, with multiple exits. Digging such large, deep burrows not only keeps the bilby cool on hot days, it helps improve soil quality and provides shelter for lots of other animals that move in when the bilby isn’t home.

The bilby eats a lot of plant material, including seeds, fruit, bulbs, and tubers, along with eggs and various types of fungus, but it also eats insects, spiders, grubs, snails, and other small animals. It gets all of the moisture it needs from its diet. Its tongue is long and sticky, which helps it gather termites and other insects more easily, and its ears are so sensitive that it can hear insects moving around underground. It will actually put its ear to the ground to listen, then dig the insect up.

A mother bilby usually has one or two babies at a time that stay in her pouch for a little under three months. Her pouch is rear-facing so that sand and dirt don’t get onto her joeys when she digs a new burrow. Once her joey leaves the pouch, she hides it in one of her burrows and comes to feed and take care of it for another few weeks, until it’s ready to strike out on its own. In a lot of marsupials, the joey will come and go from the pouch as it grows older, but by the time the bilby’s joey is ready to emerge from the pouch, she already has a new baby or two ready to be born, so she needs her pouch for the new joeys.

Sales of some brands of chocolate Easter bilbies raise money to help bilby conservation efforts. And here I thought there was no way to improve on chocolate.

We’ll finish with the humble domestic chicken. Chickens are symbols of springtime because that’s when they start laying a whole lot of eggs. Most birds only lay eggs after mating, but chickens have been selectively bred so that the females, called hens, start to lay unfertilized eggs once they’re adults. The eggs you buy at the grocery store are unfertilized. Some people think those little whitish strings on either side of the yolk are embryonic baby chicks, but that’s not the case. Those strings are called chalazae [ka-LAYzee] and they help keep the yolk from moving around too much inside the egg.

Modern domestic chickens are descendants of wild birds called jungle fowl that evolved in parts of Southeast Asia some 50 million years ago. Humans domesticated the red jungle fowl at least 8,000 years ago, probably independently in different areas, and they’ve spread around the world as people migrated from place to place. The red jungle fowl is still around in the wild, too. It looks like a chicken.

Like all birds, jungle fowl descended ultimately from theropod dinosaurs. This included Tyrannosaurus rex, which means you’ll occasionally hear people say that chickens are direct descendants of T. rex. While chickens and other birds are related to T. rex, you wouldn’t find a T. rex in a chicken’s direct ancestry even if you could follow it back 66 million years, although you would find much smaller theropods. You’d have to go back farther than 66 million years, though, because paleontologists think theropods started evolving bird-like features some 160 million years ago.

You may have heard the saying, “That’s as scarce as hen’s teeth” to indicate something that’s not just rare, it’s basically non-existent. That’s because chickens, like all modern birds, don’t have teeth. Most birds and reptiles do grow what’s called an egg tooth, which actually looks like a little spike at the tip of the bill, or the nose in reptiles. It helps the baby break out of its egg, after which it either falls off or is reabsorbed. But it’s not a real tooth.

In late 2020 paleontologists announced they’d found a fossil skull on the island of Madagascar, dated to 85 million years ago, that shows an animal with a beak. The animal resembles a small theropod dinosaur in some ways and resembles an early bird in other ways, but it has features never before seen in either. Its snout is elongated but deep with a heavy bill that looks a little like a toucan’s bill. The bill doesn’t have teeth along the jaws, although other early birds found from around the same time do. That means that not only did birds stop needing teeth as early as 85 million years ago, toothlessness must have evolved repeatedly in various species. However, the new animal’s beak does have teeth at the very tip of its mouth.

Recent research suggests that birds and their ancestors evolved toothless beaks instead of toothy snouts because they had such specialized diets. There were probably also other benefits to having beaks instead of teeth. Some research suggests it might have helped speed up egg hatching. Other studies suggest the lack of teeth lightened the bird’s head and improved flight.

Occasionally a chicken embryo bears a recessive trait called talpid. It’s a lethal mutation, but talpid chick embryos do sometimes live in the egg for a couple of weeks before dying. Genetic researchers study talpid chickens for various reasons, and at one point a researcher named Matthew Harris noticed something odd on the beak of a talpid chicken embryo. It had tiny bumps along the edge that looked like teeth.

Harris took his findings to biologist John Fallon, who verified that the structures are actually teeth, not just serrations. They develop from the same tissues that form teeth in mammals, but the teeth don’t resemble mammal teeth. Instead they’re conical and pointy like a dinosaur’s teeth.

Harris eventually engineered a virus that mimicked the mutation’s molecular signals. Introducing the virus into chickens without the talpid mutations resulted in the chickens developing teeth, although they were reabsorbed into the beak after developing.

So I guess hen’s teeth are still as scarce as hen’s teeth. Also, I don’t really know how we made it here from springtime animals, but here we are.

Thanks for listening!

Episode 261: Walking Fish

Posted on January 31, 2022 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 12:14 — 14.5MB)

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Thanks to my brother Richard for suggesting one of the fish we talk about this week–fish that can walk! (Sort of.)

Further watching:

Video of a gurnard walking

Further reading:

Walking shark moves with ping-pong paddle fins

Walking sharks discovered in the tropics

The Hawaiian seamoth (the yellowy one is a larval seamoth, the brighter one with the snoot the same fish as a juvenile, both pictures by Frank Baensch from this site):

The slender seamoth (an adult, photo from this site):

A flying gurnard with its “wings” extended:

A flying gurnard with its “wings” folded, standing on its walking rays:

An eastern spiny gurnard standing on its walking rays:

A mudskipper’s frog-like face:

Mudskippers on land:

Walking sharks:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re going to look at some weird fish, specifically fish that use their fins to walk. Well, sort of walk. Thanks to my brother Richard for suggesting one of these fish.

Before we get started, let’s learn the terms for a fish’s two main pairs of fins. Different types of fish have different numbers and locations of fins, of course, but in this episode we’re focusing on the pectoral fins and the pelvic fins. Pectoral fins are the main fins in most fish, the ones near the front on each side. If a fish had arms, that’s roughly where its arms would be. The pelvic fins are near the tail on either side, roughly where its legs would be if fish had legs. If you remember that people lift weights with their arms to develop their pectoral muscles in the chest, you can remember where pectoral fins are, and if you remember that Elvis Presley was sometimes called Elvis the Pelvis because he danced by shaking his hips, you can remember where the pelvic fins are.

So, let’s start with the seamoth, which lives in shallow tropical waters of the Indo-Pacific Ocean and the Red Sea, including around Australia. We don’t know enough about it to know if it’s endangered or not, but since it’s considered a medicine in some parts of Asia, it’s caught to sell as an aquarium fish, and its habitat is increasingly impacted by bottom trawling and coastal development, it probably isn’t doing great. It’s never been especially common and doesn’t reproduce very quickly. Researchers think it may even be a social fish that forms a pair bond with its mate, since pairs are often found together.

The seamoth doesn’t even look that much like a fish at first glance. It’s covered with bony plates that act as armor, including bony rings around its tail. It even has to shed its skin as it grows larger.

The seamoth has a long, pointed snout with a tiny mouth underneath, but it can protrude its mouth out of its…mouth–okay that doesn’t make sense. Basically it’s able to extend its mouth into a tube that it uses like a straw to slurp up worms and other small animals from the sea floor.

It can change colors to match its surroundings too. If all this makes you think of seahorses and pipefish, the seamoth is related to both, but it looks very different because of its fins.

The seamoth’s pectoral fins are so large they resemble wings, and its modified pelvic fins are stiff and more fingerlike than fin-like so that it can walk across the sea floor with them. It spends most of its time walking on the sea floor, only swimming when it feels threatened and has to move faster. Sometimes a seamoth will cover itself with sand to hide from a predator. During breeding season, males develop brightly colored patterns on their pectoral fins.

The seamoth is a small fish, with the largest species growing about five inches long, or 13 cm. One species of seamoth, the little dragonfish, sheds its armor in one big piece—not just once or twice a year, but as often as every five days or so when it needs to rid itself of parasites. Its body is flattened but broad, which makes it look kind of like a piece of shell from above.

The flying gurnard is similar in some ways. It lives in warm coastal waters where it spends most of its time on the sea floor, looking for small animals to eat. We’ve talked about it before, in episode 101, but let’s go over it again in case like me you haven’t listened to episode 101 since it came out over three years ago.

The flying gurnard is a bulky fish that grows more than a foot and a half long, or 50 cm. It has a face sort of like a frog’s and can be reddish, brown, or greenish, with spots and patches of other colors. But most importantly, its pectoral fins are extremely large, looking more like fan-like wings than fins. The so-called wings are shimmery, semi-transparent, and lined with bright blue. They sort of look like butterfly wings and can be more than 8 inches long, or 20 cm. The fins actually have two parts, a smaller section in front and the larger wing-like section behind. The front section is stiff and makes the fish able to walk along the sea floor. It’s possible the flying gurnard can also use its wing-like fins to glide above the water for short distances like a flying fish, but at the moment we don’t know for sure.

The flying gurnard hasn’t traditionally been recognized as being related to the seamoth despite their similarities, but DNA studies suggest that they might actually be related after all. The flying gurnard may be related to the true gurnards, too. Both the flying gurnard and the true gurnard have a special muscle that beats against the swim bladder to make a drumming sound, and they look and act alike in many other ways too.

The gurnard is the fish my brother Richard recommended. There are actually a lot of different gurnards and they’re all kind of weird. Gurnards in the family Triglidae are bottom dwellers that grow around 16 inches long, or 40 cm. Some species have armor plates that make their heads so strong that a gurnard will occasionally ram snorkelers with its forehead if they get too close. Like the flying gurnard, the gurnard has pectoral fins that are divided into a front section and a rear section, with the rear section being larger and the front section highly modified, called walking rays, used by the fish to walk across the sea floor.

Walking rays look more like long, thin, stiff fingers than a fish’s fins, although they’re also bendy. The gurnard has three walking rays on each side of the body, and they have special muscles that allow the fish to actually use them as little legs. It’s really disturbing to watch an otherwise pretty ordinary fish crawl forward on what look like invertebrate legs.

The mudskipper is another fish that uses its fins to walk, but not like the fish we just talked about. Instead of having walking rays, its pectoral fins are muscular and allow it to climb out of the water and onto land. In fact, it can climb into low branches and can even jump.

It’s so good at living on land the mudskipper is actually considered semi-aquatic. It lives in mudflats, mangrove swamps, the mouths of rivers where they empty into the ocean, and along the coast, although it prefers water that’s less salty than the ocean but more salty than ordinary freshwater. It only lives in tropical and subtropical areas because it needs high humidity to absorb oxygen through its skin and the lining of its mouth and throat.

The mudskipper is a fish, but it looks an awful lot like a frog in some ways, due to convergent evolution. It has a wide mouth and froglike eyes at the top of its head and will often float just under the water with its eyes above water, looking for insects it can catch. The largest species grows about a foot long, or 30 cm, and while it has some scales, its body is coated with a layer of mucus to help it retain moisture. It spends most of the day on land, hunting for insects and other small animals. Not only can it absorb oxygen through its skin, it keeps water in its gill chambers to keep the gills wet too. It even has a little dimple under its eye that holds water, that helps keep its eyes moist.

The mudskipper also takes a big mouthful of water with it when it climbs on land, but not to breathe. It uses the water to hunt with. When it encounters an insect or other small animal on land, it carefully rotates its mouth–you heard me right, it can rotate its mouth–so that it’s just above the animal. Then it spits out the mouthful of water onto the insect and immediately sucks the water back into its mouth, carrying the insect with it. When it catches an animal underwater, it opens its big mouth quickly, causing suction that sucks the animal right into its mouth that way. It also has sharp teeth, so when an animal is in its mouth, it’s not getting out again.

The mudskipper’s pectoral fins look like little arms, complete with an elbow. The elbow is actually a joint between the radial bones, which in most fish are hidden within the body but which stick out of the mudskipper’s sides a short distance, and the actual fins. This helps it move around on land more easily. Its pelvic fins are also shaped in such a way that they act as little suction cups on land.

Another bottom-dwelling fish that uses its fins to walk on the sea floor is the walking shark. There are several species known but they’re not very big, only around four feet long at most, or 107 cm. It lives in shallow coastal waters, often around reefs, and spends most of the time swimming just above the sea floor or using its pectoral and pelvic fins to walk on the sea floor while it searches for small animals to eat. It doesn’t walk like gurnards do, and it doesn’t skip or climb the way mudskippers do. Instead, it wriggles like a salamander as it uses its fins to push itself along.

At least one species of walking shark can also walk on land. That’s right: land shark. Don’t worry, it’s harmless to humans. (Still: land shark.) Because the walking shark often lives in really shallow water, including in tidal pools that sometimes dry up completely between high tides, it has to be able to reach water by walking on land. The walking shark can also survive in water with low oxygen content for short periods of time. Four newly identified species of walking shark were announced in January 2020, all from around New Guinea and northern Australia.

The really interesting thing is that the walking shark’s pectoral and pelvic fins are different from other shark fins. Not only are they strongly muscled, they can rotate to make it easier for the shark to use them as legs. Researchers think that this type of locomotion may have given rise to land animals in our far, far-distant ancestors. In other words, we’re all land sharks if you think about it.

Thanks for listening!

BONUS Q&A Episode!

Posted on August 13, 2021 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 27:58 — 32.2MB)

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It’s our bonus question and answer episode, which turned out to be ridiculously long but hopefully interesting!

Further listening/watching:

The Axolotl Song

~~~Buy my books!~~~

Whiskers used to have two eyes and a nose. In the background, Dracula (left) and Poe (right):

Black squirrel!

King cobra!

Pufferfish, puffed:

Dog nose:

Show transcript:

Welcome to the bonus Q&A episode of Strange Animals Podcast! I’m your host, Kate Shaw, and this is a little extra episode where I answer listener questions. So let’s jump right into it.

To start us off, Simon and Thia wanted to know how I first became interested in animals. I really don’t know! When I was little, I didn’t want to play with dolls, I wanted to play with my stuffed animals. I actually have a toy cat named Whiskers who I’ve had since I was four. Whiskers is older than all my teeth! I especially loved horses as a kid and since my family couldn’t afford to buy me a horse, I took riding lessons and read everything I could find about horses, fiction and nonfiction. All that reading about horses led to reading about other animals, and the more I read, the more interested I became in animals of all kinds.

Next, Melissa of the awesome podcast Bewilderbeasts asked, “What was the fact or episode that really slapped you out of left field, like, ‘I didn’t see that coming AT ALL’?”

OH MY GOSH, how many times has that happened to me? The most astounding fact I can think of isn’t actually about an animal at all but about trees. While I was researching the Temnospondyl episode, which had a related Patreon episode that ran at about the same time, I came across the fact that when trees first developed, nothing could break down the tough compound called lignin that hardens a tree’s cells to make wood and bark. When a tree died, its trunk just stayed where it fell forever, and this happened for at least 50 million years and possibly 100 million years. 100 million years of tree trunks just lying all over the ground! You wouldn’t be able to walk anywhere! You’d have to climb over hundreds of millions of fallen tree trunks, although naturally as the years passed the older ones would get buried deeper and deeper in the earth. But there would always be more!

This blew my mind, and later I came back to it, determined to do more research and make sure it was accurate. I did a whole lot of research, because it just didn’t seem possible, and that information ended up in episode 214.

As for an animal that blew my mind, I still have trouble believing ice worms are real. They’re worms that live in snow and ice! We covered them last August in episode 185 and I’m still reeling.

Next, Llewelly asks what my favorite extinct animal is, or animals. Why would you make me choose? This is so hard. Okay, fine, I’ll narrow it down to hoofed Pleistocene megafauna like the giant deer and elasmotherium and so many other animals with weird horns and ossicones and things like that. What really gets me is that they lived so recently! Many of them only died out 11,000 years ago, and some were probably around much more recently in a few isolated areas. It also really reminds me to appreciate the megafauna that’s still around. We live at the same time as giraffes!

Next, Richard E. asked, “Does your job involve the study of animals and/or is the pod something that you really wanted to do?” Tracie also asked what my background is, if I’m a professor or zookeeper or something similar. Helenka also asked my background and how I got interested in strange animals.

I’m kind of embarrassed that I never have pointed out that I’m not an animal expert, to steal a phrase from the awesome podcast Varmints! I actually work as a test proctor, AKA invigilator, in a large community college, so my work doesn’t have anything to do with animals. My background is in elementary education although I didn’t teach long. Basically I got my K-8 teaching certification and M.Ed., did some substitute teaching afterwards, and ended up getting my current job instead of taking a teaching position. I still love teaching, so when I decided I wanted to start a podcast, I knew it would be nonfiction. My undergraduate degree is in English literature, and I took so many history courses that I minored in history almost by accident, so I’m really good at research and can write an essay about any topic in the world in very little time. I didn’t know it when I was in college, which was long before podcasts existed anyway, but I have the perfect background for creating a nonfiction podcast.

Liesbet has three questions about the podcast: what inspired me to start it, what motivates me to keep going without missing any episodes, and what I enjoy most about it. I’m so pleased that someone noticed I’ve never missed a single episode! Not that it would be the end of the world if I did, of course, but if I did, I’d feel bad thinking about people who were looking forward to listening to the new episode and were disappointed when there wasn’t one.

Here is the raw, honest truth about why I started Strange Animals Podcast. It was several things combined and the whole story is kind of dumb. First, my friend Kevin makes a great pop culture podcast called The Flopcast, and after I’d listened to it for a while I thought, “Hey, that sounds like fun. I think I’ll start a podcast.” About the same time, I was listening to a back episode of a podcast I will not name, and it gave some misinformation about the Irish elk, specifically the outdated theory that it went extinct because its antlers were too big. I mentioned that in episode 4 and how I kept thinking about it and got kind of angry that a large, influential podcast hadn’t bothered to do enough research about an animal that lots of people are interested in. I decided I could do better and that my podcast would be about animals. Also at the same time, I was trying to find a good podcast about mystery animals that was well researched and didn’t skate off into speculation too much. I couldn’t find one that satisfied me, so I had to make one myself.

I wasn’t exactly sure what my focus would be when I first started the podcast. You can kind of tell when you listen to the first six months or so of the podcast that I was trying out new things and figuring out what worked best and what I liked best. I’m still figuring that out, for that matter.

It’s hard to decide what I like best about making the podcast. I like the whole process, except maybe not the frustrating parts of recording and editing. I think my favorite part has to be when I uncover information I find really exciting. I get to share that information with everyone who listens! It’s fantastic!

Next, let’s get into some questions about animals.

Pranav asked if I would explain how poisons work, which is a great question and also just a tiny bit alarming. No one eat anything Pranav cooks for you unless he’s eating some too. Actually, of course, he’s just wanting to learn more about poisonous animals, and I’ll talk about venomous animals too.

A poisonous animal contains toxins somewhere in its body, like the hooded pitohui bird that we talked about in episode 222 that has poisonous feathers. The poison stops other animals from trying to eat it. In the case of the hooded pitohui, its poison causes your skin to burn when you touch it, so an animal that tries to bite it will have a burning mouth. If it actually eats any of the poison, the animal can die. Many amphibians secrete toxins through their skin, like the poison dart frog, and many other animals concentrate toxins in their muscles or internal organs.

A venomous animal has toxins that it can inject into a wound to hurt or kill another animal. Some snakes can inject venom with special fangs, but some amphibians have pointed ribs that are sharp enough to stab a potential predator. The ribs will project through the amphibian’s sides through tiny spots that are filled with toxins. The toxins coat the points of the ribs, and if the predator tries to bite down, it gets those toxins stabbed right into its mouth. Some fish have spines that are coated in toxins, and of course many insects, arachnids, and other invertebrates have stingers that inject toxins.

Generally, a poisonous animal absorbs toxins from a food it eats, often a toxic insect, and instead of getting sick, it uses those toxins to protect it from predators. A venomous animal usually produces its own toxins in its body, especially animals that use venom to kill or disable prey. It costs energy for the animal to make venom, and it doesn’t want to waste it. That’s why snakes will sometimes give what are called dry bites in self-defense, where it bites but doesn’t inject any venom. It’s hoping that the pain of the bite itself will make a potential predator retreat without the snake needing to use venom.

Different toxins have different effects, naturally, and animals produce so many different kinds of toxins that we could talk about it all day and not even cover them all. Instead, let’s quickly discuss two animals, one venomous and one poisonous.

Our venomous example is the king cobra. It can grow over 18 feet long, or 5.5 meters, and lives in southern Asia. It mostly eats other snakes and some lizards. Its venom contains numerous toxins that do different horrible things. The neurotoxins in its venom affect the central nervous system, which can cause all sorts of issues like dizziness, pain, blurred vision, sleepiness, and even paralysis. Other toxins in the venom are called cardiotoxic because they affect the heart, making it weak so that circulation of blood slows down. If a king cobra bites you and injects venom, you can die within 30 minutes as the venom basically just shuts your body down, one process at a time. If your heart stops or your diaphragm becomes paralyzed so you can’t breathe, that’s it for you. Fortunately, in ordinary situations the king cobra is shy and avoids people, so if you don’t bother it, it won’t bite you.

Our poisonous example is the pufferfish. Some species of pufferfish are incredibly poisonous. You may have heard about fugu, which is considered a delicacy even though it’s so poisonous that in Japan and some other countries, chefs have to be specially trained and licensed to prepare the fish to eat. The part of the fish that’s considered tastiest is also the part that’s most poisonous, the liver. It contains tetrodotoxin, which is a neurotoxin that stops your nerves from sending the tiny electrical signals that allow them to move. If you’re poisoned with tetrodotoxin, you start to feel dizzy and sick, then you start having difficulty speaking and moving, then you have trouble breathing, and then, ultimately, you’re paralyzed and can’t breathe, at which point you die. Since the toxin doesn’t affect your brain, you remain completely aware of what’s happening to you but there’s nothing you can do about it. There’s no antidote. Fortunately, you have the option of not eating fugu. Also, it turns out that the pufferfish’s poison comes from a type of bacteria, so fish raised in careful conditions in captivity aren’t poisonous.

Most poisonous and venomous animals are harmless to humans!

Next, Connor wrote and said, “I recently moved to Michigan from West Virginia and noticed a lot of black squirrels around. Are they a different species/sub-species or just melanistic individuals?”

I looked into this and sure enough, Michigan and other areas around the Great Lakes are known for a large population of black squirrels. I’ve never seen a black squirrel but now that I’ve looked at pictures of them, they are awesome and I wish I had some in my yard.

The eastern gray squirrel is the most common species of squirrel in eastern North America, and a black morph of that species and other squirrel species is not that unusual. The color difference is due to a small mutation in the gene that controls how much pigment the squirrel’s fur contains. Connor is right that the coloration is due to melanistic individuals.

But that doesn’t explain why there are so many black squirrels in Michigan and surrounding areas. No one’s completely sure why that is. In other animals, including the gray wolf and the leopard, melanistic individuals are more common in areas where there’s thick vegetation that blocks a lot of sunlight. A dark-colored wolf or leopard is better camouflaged in the shadows, which allows it to sneak up on prey. But the squirrel isn’t a predator, and black squirrels don’t seem to be any more common in heavily forested areas compared to more park-like areas.

One suggestion is that black squirrels find it easier to stay warm in cold weather, because dark fur absorbs more heat than gray fur. This actually does seem to have some basis in fact. Black squirrels are much more common in northern areas, including parts of Canada where the eastern gray squirrel ordinarily doesn’t live. Black squirrels are correspondingly rare in more southern areas where winters are mild, which explains why I’ve never seen one. Then again, the fox squirrel is also common in eastern North America, often living in the same areas where eastern gray squirrels live, and they also have a black morph, but black fox squirrels mostly live in the southeast. So it’s a mystery.

Black squirrels are the same as ordinary colored squirrels. They just look different. That reminds me that I have an episode about squirrels planned for some time later this year, especially unusual squirrels.

Next, Anna has a question about dogs. She says, “We have a dog named Sadie, who is a beagle mix. She is much more aware of the sounds and smells around us and often howls and barks at things that we can’t see. How do dogs have such a strong sense of smell and good hearing?”

The wild ancestors of dogs were wolves. Wolves are generally nocturnal, and as a result, dogs have sensitive hearing and smell to find prey when it’s dark. A dog can hear in the ultrasonic range, which refers to sounds higher than human hearing. Humans can hear sounds up to 20,000 hertz, while dogs can hear sounds up to 50,000 hertz. A dog also has a lot of muscles in its ears that allow it to turn its outer ear to find sounds. While some dog breeds have lapped-over ears, wolves and many dog breeds have pricked-up ears that act as little satellite dishes to gather up as many sounds as possible. If you cup your hands behind your ears, you can get a sense of how this helps. A dog also has a relatively large ear canal, which is the inside part of the ear. A large ear canal allows more sound vibrations in. Cats actually have even better hearing than dogs, but cats don’t have nearly the same ability to smell.

A dog’s sense of smell is incredible. Humans have about six million olfactory receptors in our noses. That sounds like a lot, but a dog has over 200 million olfactory receptors! It can also process all those smells incredibly well in its brain, so that with training a dog can detect unbelievably faint smells. That’s why dogs are used to sniff out dangerous items like bombs and illegal drugs, or find people who are buried in rubble after an earthquake or other disaster, or track down people who are lost. Dogs can even learn to detect the smell of some diseases, including cancer, malaria, and tuberculosis.

A dog’s nose is much different from a human nose. If you have a dog, or can borrow a friend’s dog, sit down and take a look at their nose. Ha ha, the dog just licked you in the face! That’s hilarious! The dog’s nose has nostrils in the front but if you look carefully, you’ll see that the nostril openings continue along the sides of its nose, in a little slit. There’s also a little fold of tissue inside the nose. The tissue separates the air into two streams. One stream goes into the lungs, but the other gets circulated into the nose to come in contact with all those olfactory receptors. Then, when the dog breathes out, the air goes out the side slits instead of out the main nostrils, so it doesn’t push any odors out of the nose. A dog’s nose works best when it’s damp, which is why a healthy dog has a wet nose.

When you hear a sound, you can usually tell which direction it’s coming from by turning your head, because the sound will be slightly louder in one ear than the other and your brain can make sense of this difference. Dogs can tell which direction a smell is coming from because its brain can tell which nostril is picking up more of the smell.

A dog’s sense of smell is so acute, and so important to the animal, that a dog that loses its vision can often do just fine. It can smell its way around. Naturally, some dog breeds have a better sense of smell than others, and some individuals are better at smelling than others too.

Don’t feel bad about your sense of smell, though. Humans may not be as good at smelling as dogs are, but we can train ourselves to be more sensitive to faint odors. The next time you take a walk, pay attention to what you’re smelling and I bet you’ll notice a lot more scents than you realize.

Next, Helenka also wanted to know about my writing. Thank you so much for asking! Now I can plug my books and also tell you how the strange animals podcast book is coming along!

I mostly write fantasy fiction. I have a steampunk adventure book available called Skytown, and a related collection of short stories about the same characters from the book, which is called Skyway. Sometimes I get the titles confused because they’re really similar, but Skytown is called that because there’s a city in the book that can only be reached by air, which in this fantasy world is mostly airships. The main characters are two young women named Jo and Lizzy, friends who are airship pirates. It’s a lot of fun, and the short story collection actually tells how Jo and Lizzy met and what they did together right up to the start of the novel. If that sounds interesting, I’d love it if you could pick up a copy of one or both books. They’re published by small independent publishers, who don’t make a lot of money and have trouble getting books into physical stores. There’s a link in the show notes.

Okay, so now I get to tell you all about the Strange Animals Podcast book! I’ve been working on it all year and it’s getting really close to being done. The title is Beyond Bigfoot and Nessie: Lesser-Known Mystery Animals from Around the World, and most of the material is taken directly from mystery animal episodes from the last four-plus years, BUT I’ve made sure to update the chapters as much as possible and I’ve added some new chapters.

I’ve decided to self-publish the book, so I’m planning a Kickstarter to cover the costs of hiring a cover artist and things like that. I’d like to run the Kickstarter in October, which would give me time to get it published hopefully in time for the holidays in case people want to order copies to give as gifts. We’ll see how that goes, though. There’s a ton of work that goes into running a successful Kickstarter, and although I don’t need a whole lot of funding for the book, it still worries me that maybe no one will be interested and it won’t meet its funding goal and I’ll have to pay for everything out of pocket. I’m already kind of broke this year from paying about $5,000 to the emergency vet to save my cat Poe’s life, but honestly, if the choice is between having Poe running around and playing or self-publishing a book, I will choose Poe every single time.

Anyway, one way or another I’ll make sure the Beyond Bigfoot and Nessie book is available to buy before the podcast’s fifth year anniversary in February 2022!

Finally, this wasn’t sent in as a question but I thought it would be a nice way to finish off the episode. In a really nice review, a listener who I think is named Meg said “I think she’s southern like me but not sure.” Yes, I am southern, although I don’t have much of an accent. I was born in Georgia and grew up in East Tennessee, where I live now.

Thanks to everyone who sent in questions! We’ll probably have another Q&A episode eventually, maybe next year, so feel free to send me your questions! I think I got everyone’s questions answered this time, but if I missed yours, definitely let me know. The best way to get in touch with me is through email, strangeanimalspodcast@gmail.com.

To finish us off, Richard from NC wanted me to play the Axolotl song. I won’t play the whole thing, because it’s kind of long, but here’s a clip and there’s a link in the show notes. It’s by an animator and musician called Joel Veitch. I’ve had this song stuck in my head ever since Richard sent me the link, so now you will too. Also, I promise I’ll make a whole episode about the axolotl soon.

Thanks for listening!

Episode 236: Updates 4 and a Mystery Snake!

Posted on August 9, 2021 by strangeanimalspodcast

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It’s our fourth annual updates and corrections episode! I’ve already had to make a correction to this episode!

Further reading:

Cassowary, a rare emu-like bird, attacks and kills Florida man, officials say

The dog Bunny’s Facebook page

3D printed replicas reveal swimming capabilities of ancient cephalopods

Enormous ancient fish discovered by accident

A rare observation of a vampire bat adopting an unrelated pup

Pandemic paleo: A wayward skull, at-home fossil analyses, a first for Antarctic amphibians

Neanderthals and Homo sapiens used identical Nubian technology

Entire genome from Pestera Muierii 1 sequenced

Animal Species Named from Photos

Cryptophidion, named from photos:

The sunbeam snake showing off that iridescence:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s our fourth annual updates and corrections episode, and to keep it especially interesting we’ll also learn about a mystery snake. Make sure to check the show notes for lots of links if you want to learn more about these updates.

First, we have a small correction from episode 222. G emailed with a link about a Florida man who was killed by a cassowary in 2019, so cassowaries continue to be dangerous.

We also have a correction from episode 188, about the hyena. I called hyenas canids at one point, and although they resemble canids like dogs and wolves, they’re not canids at all. In fact, they’re more closely related to cats than dogs. Thanks to Bal for the correction!

In response to the talking animals episode, Merike told about a dog who uses computer buttons to communicate. The dog is called Bunny and she’s completely adorable. I’ll link to her facebook page. I have my doubts that she’s actually communicating the way it looks like she is. She’s obviously a clever dog but I don’t think she understands the English language so well that she can choose verbs like “is” from her list of words. I think she’s probably mostly taking unconscious cues from her owner. But I would be happy to be proven wrong.

Following up from our recent deep-sea squid episode, a team of paleontologists studying ancient cephalopods 3-D printed some replicas of what the animals would have looked like while alive. Then they took the models into a swimming pool and other water sources to study how their shells affected the way they could move through the water. They discovered that a type of cephalopod with a straight shell, called an orthocone, probably mostly moved up and down in the water to find food and could have moved extremely fast in an upward or downward direction. A type of cephalopod with a spiral shaped shell, called a torticone, also spun slightly as it moved around. The same team has previously worked with 3-D models of ammonoids, which we talked about in episode 86. The models don’t just look like the living animals, they have the same center of balance and other details, worked out mathematically.

Speaking of ancient animals, a collector in London bought a fossil found in Morocco thinking it was part of a pterodactyl skull. When the collector asked a palaeontologist to identify it, it turned out to be a fossilized coelacanth lung. The collector donated the fossil for further study, and the palaeontologist, David Martill, worked with a Brazilian coelacanth expert, Paulo Brito, to examine the fossil.

The fossil dates to the Cretaceous, about 66 million years ago, and is bigger than any coelacanth lung ever found. Modern coelacanths grow a little over six feet long at most, or 2 meters, but the estimated length of this Coelacanth is some 16 ½ feet, or 5 meters. The fossil is being donated to a university in Morocco.

We talked about vampire bats way back in episode 11, and I love bats and especially vampire bats so I try to keep an eye on new findings about them. Everyone thinks vampire bats are scary and creepy, but they’re actually social, friendly animals who don’t mean to spread rabies and other diseases to the animals they bite. It just happens.

Vampire bats live in colonies and researchers have long known that if a female dies, her close relations will often take care of her surviving baby. Now we have evidence that at least sometimes, the adoptive mother isn’t necessarily related to the birth mother. It’s from a recently published article based on a study done in 2019.

A team researching how unrelated vampire bats form social bonds captured 23 common vampire bats from three different colonies and put them together in a new roost where their interactions could be recorded by surveillance cameras. One particular pair of females, nicknamed Lilith and BD, became good friends. They groomed each other frequently and shared food. If you remember from episode 11, vampire bats share food by regurgitating some of the blood they drank earlier so the other bat can lap it up. Since vampire bats can starve to death in only a few nights if they can’t find blood, having friends who will share food is important.

During the study, Lilith gave birth to a baby, but shortly afterwards she started getting sick. She had trouble getting enough food and couldn’t groom or take care of her baby as well as a mother bat should. Her friend BD helped out, grooming the baby, sharing food with Lilith, and eventually even nursing the baby when Lilith got too sick to produce milk. After Lilith died, BD adopted the baby as though it was her own. By the time the study ended, BD was still caring for the baby bat.

We talked about spiders in the Antarctic in episode 221, and mentioned that Antarctica hasn’t always been a frozen wasteland of ice and snow. In a new study of fossils found in Antarctica, published in May of 2021, the first Antarctic amphibian skull has been identified. It lived in the early Triassic, not long after the end-Permian mass extinction 252 million years ago. It’s been named Micropholis stowi and is a new species of temnospondyl that was previously only known from South Africa. The skull, along with other fossils from four individuals, was discovered in the Transantarctic Mountains in 2017 and 2018, and the research team studied them from home during the 2020 pandemic lockdowns.

In news about humans and our extinct close relations, a new finding shows that Neanderthals and humans used the same type of tools. Researchers studied a child’s tooth and some stone tools, all found in a cave in the mountains of Palestine, and determined that the tooth was from a Neanderthal child, not a human. The tooth was discovered in 1928 but was in a private collection until recently, so no one had been able to study it before now. The tools are a specific type developed in Africa that have only been found associated with humans before. Not only that, but until this finding, there was no evidence that Neandertals ever lived so far south.

The child is estimated to have been about nine or ten years old, which is the age when you’re likely to lose a baby tooth as your adult teeth start growing in. I like to think about the child sitting next to their Mom or Dad, who were either creating new tools or using ones they’d already made to do something like cut up food for that evening’s dinner. Maybe the child was supposed to be helping, and they were, but they had a loose tooth and kept giving it a twist now and then, trying to get it to come out. Then, finally, out it popped and bounced onto the cave floor, where it was lost for the next 60,000 years.

Researchers have just announced that they’ve sequenced the genetic profile of a woman who lived in what is now Romania about 35,000 years ago. Judging from her skull shape and what is known about ancient humans in Europe, the team had assumed she would be rather restricted in her genetic diversity but that she would show more Neanderthal ancestry than modern humans have. Instead, they were surprised to find that the woman had much more genetic diversity than modern humans but no more Neanderthal genes than most human populations have these days.

This was a surprise because modern humans whose prehistoric ancestors migrated out of Africa show much less genetic diversity than modern humans whose ancestors stayed in Africa until modern times. Researchers have always thought there was a genetic bottleneck at some point during or not long after groups of humans migrated out of Africa around 80,000 years ago. Lots of suggestions have been made about what might have caused the bottleneck, including disease, natural disaster, or just the general hardship of living somewhere where humans had never lived before. A genetic bottleneck happens when a limited number of individuals survive long enough to reproduce—in other words, in this case, if so many people die before they have children that there are hardly any children left to grow up and have children of their own. To show in the general population as it does, the bottleneck has to be widespread.

Now researchers think the genetic bottleneck happened much later than 80,000 years ago, probably during the last ice age. Humans living in Europe and Asia, where the ice age was severe, would have had trouble finding food and staying warm.

I’m getting close to finishing the Strange Animals Podcast book, which I’ll talk about a little more in our Q&A episode later this week. It’s a collection of the best mystery animals we’ve covered on the podcast, along with some new mystery animals, and I’m working hard to update my research. If you remember back in episode 83, about mystery big cats, we discussed the Barbary lion, which was thought to be an extinct subspecies of lion that might not actually be extinct. Well, when I looked into it to see if any new information had turned up, I found more than I expected. I rewrote those paragraphs from episode 83 and I’ll read them here as an update:

Lions live mostly in Africa these days, but were once common throughout southern Asia and even parts of southern Europe. There even used to be a species called the American lion, which once lived throughout North and South America. It only went extinct around 11,000 years ago. The American lion is the largest species of lion ever known, about a quarter larger than modern African lions. It probably stood almost 4 feet tall at the shoulder, or 1.2 meters. Rock art and pieces of skin preserved in South American caves indicate that its coat was reddish instead of golden. It lived in open grasslands like modern lions and even in cold areas.

Much more recently, the Barbary lion lived in northern Africa until it was hunted to extinction in the area. The Barbary lion was the one that battled gladiators in ancient Rome and was hunted by pharaohs in ancient Egypt. It was a big lion with a dark mane, and was thought to be a separate subspecies of lion until genetic analysis revealed in 2006 that it wasn’t actually different from Panthera leo leo.

The last wild Barbary lion was sighted in 1956, but the forest where it was seen was destroyed two years later. The lions in a few zoos, especially in Ethiopia and Morocco, are descended from Barbary lions kept in royal menageries for centuries.

Lions are well known to live on the savanna despite the term king of the jungle, but they do occasionally live in open forests and sometimes in actual jungles. In 2012 a lioness was spotted in a protected rainforest in Ethiopia, and locals say the lions pass through the reserve every year during the dry season. That rainforest is also one of the few places left in the world where wild coffee plants grow. So, you know, extra reason to keep it as safe as possible.

Finally, we’ll finish with a mystery snake. In 1968, during the Vietnam War, the United States Naval Medical Research Unit discovered a small snake in central Vietnam. It was unusual enough that they decided to save it for snake experts to look at later, but things don’t always go to plan during wartime. The specimen disappeared somewhere along the line. Fortunately, there were photographs.

The photos eventually made their way to some biologists, and in 1994 a paper describing the snake as a new species was published by Wallach and Jones. They based their description on the photos, which were good enough that they could determine details like the number of scales on the head and jaw. They named it Cryptophidion annamense and suggested it was a burrowing snake based on its characteristics.

Other biologists thought Cryptophidion wasn’t a new species of snake at all. In 1996 a pair of scientists published a paper arguing that it was just a sunbeam snake. The sunbeam snake is native to Southeast Asia, including Vietnam, and can grow over 4 feet long, or 1.3 meters. It’s chocolate-brown or purplish-brown but has iridescent scales that give it a rainbow sheen in sunshine. It’s a constricting snake, meaning it squeezes the breath out of its prey to kill it, but it only eats small animals like frogs, mice, and other snakes. It’s nocturnal and spends a lot of its time burrowing in mud to find food.

Wallach and Jones, along with other scientists, argued that there were too many differences between the sunbeam snake and Cryptophidion for them to be the same species. But without a physical specimen to examine, no one can say for sure if the snake is new to science or not. If you live in or near Vietnam and find snakes interesting, you might be the one to solve this mystery.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 231: Fish of the Twilight Zone

Posted on July 5, 2021 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 17:28 — 18.2MB)

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Let’s learn about some strange fish of the mesopelagic, or the twilight zone deep in the ocean! Thanks to Page, Joel, Anonymous Animal Lover, Brigham, and Fireburster for suggestions this week!

Further reading:

In Defense of the Blobfish

Further viewing:

Pacific viperfish (video embedded)

The Pacific viperfish, head-on (or rather teeth-on), still from video linked above:

Sloane’s viperfish, rocking those teeth:

The blobfish as it’s usually seen on the internet:

The blobfish as it looks when it’s cozy in its deep-sea environment:

The barreleye, which I have helpfully labeled for you:

Look at the bristlemouth’s sharp thin teeth! Good thing it’s only a few inches long:

An indignant bristlemouth (someone should take MS Paint away from me):

The bristlemouth is the most abundant vertebrate in the WORLD (photo by Paul Caiger):

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Where on earth does the time go? Suddenly we’re halfway through 2021 and I’m still vaguely thinking we’re only a few months in. I’m getting seriously behind on listener suggestions, so let’s have an episode about some weird fish that’s all listener suggestions. Thanks to Page, Joel, an animal lover who wants to remain anonymous, Brigham (whose name I hope I’m pronouncing correctly), and someone who calls themself Fireburster. Fireburster and Anonymous Animal Lover also both left us really nice reviews, so thank you! I picked all these suggestions at random, just grabbing fish suggestions that sounded interesting, but the great thing is they all turned out to live in a specific part of the deep sea.

Brigham and Fireburster both suggested the same fish, so let’s start with that one: the dragon fish. Neither of them specified which kind of dragon fish they’re talking about, though. It’s a popular name for weird fish of various kinds. We’ve even talked about a few before, the Pacific blackdragon of episode 193, which was coincidentally suggested by Page, and the barbeled dragonfish in that same episode. That’s the episode about William Beebe’s mystery fish, which happens to be my current favorite.

We only talked about the barbeled dragonfish briefly before, so let’s learn more about them now.

The barbeled dragonfish gets its name from the filament that hangs down from its chin, called a barbel. If you’ve ever wondered what the proper name for a catfish’s whiskers is, they’re also barbels. The dragonfish’s barbel has a photophore at the end that produces blue-green bioluminescent light, and the fish flashes the light to attract prey. Its head is large and its jaws are full of sharp teeth, so when an animal comes close, CHOMP! The barbeled dragonfish grabs it.

The dragonfish isn’t very big, with the blackdragon that we talked about in episode 193 being the largest at only 16 inches long, or 40 cm. Most species are about half that. So what happens when an animal the same size as or even bigger than the dragonfish happens along?

The dragonfish eats it, that’s what happens. It has large jaws that it can unhinge to swallow prey that’s bigger than it is, and its stomach can expand considerably to hold whatever it swallows. Mostly it just eats tiny animals like krill and amphipods, though.

We don’t know a whole lot about dragonfish. Various species live throughout most of the world’s oceans, especially in tropical and subtropical areas, and they don’t live in the deepest parts of the ocean. Instead, they’re found in what’s called the twilight zone, or more properly the mesopelagic. Only 1% of all light shining down from the surface makes it down this far, which is why so many animals produce their own bioluminescent light. The dragonfish also has photophores along its sides that it can flash to help attract prey or attract mates. On nights when the moon isn’t too bright, the dragonfish will migrate closer to the surface to find more food, but it makes sure to go back to the twilight zone before the sun rises.

[twilight zone music]

One genus of dragonfish is called the viperfish, and they’re a little different from other dragonfish. Instead of a barbel on the chin, viperfish have a light at the end of a long spine that’s a modified dorsal fin. This is similar to the anglerfish we’ve talked about many times before, even though dragonfish and anglerfish aren’t related. Convergent evolution, at it again!

The viperfish has teeth so long they don’t fit in its mouth. Instead, they stick out, which gives it its other name of fangfish. Sloane’s viperfish has the largest teeth of all the viperfish species, so long that they form a cage across its mouth to stop prey from escaping before the fish can swallow it. Unlike most dragonfish, Sloane’s viperfish sometimes swims toward its prey very quickly, slamming into it and wounding it with its fangs. It even has a sort of built-in shock absorber in its spine right behind its head. The Pacific viperfish can also be aggressive when hunting.

This is probably a good place to learn a little more about the twilight zone, AKA the mesopelagic. It’s measured not by depth but by how much light is available from the surface, in this case only 1% of light. There’s also not as much oxygen in the water here as at the surface. Many, if not most, animals that live in the mesopelagic migrate closer to the surface at night to find food, then retreat to the darkness below to avoid being seen as the sun rises and fills the upper layers of water with more light.

Lots and lots of animals live in the mesopelagic, from giant squid to oarfish, although most of the animals here are small. Below this layer of water is the bathypelagic, and below that is the real depths, the abyssopelagic where conditions are extreme and life gets really weird and scarce. The uppermost layer of the ocean is called epipelagic, if you were wondering. No plants live in the mesopelagic or below, because there’s not enough light. Obviously, the ocean isn’t always deep enough to have a bathypelagic layer or below, and quite often the mesopelagic ends at the sea floor.

It’s hard to study mesopelagic animals because many of them can’t survive at the surface. They’re built to withstand the increased water pressure at depths up to 3,300 feet, or 1000 meters, below the surface, and when they’re dragged up in nets they often die within minutes. Many marine animals have an organ called a swim bladder that’s filled with gases, which helps the animal stay neutrally buoyant in the water so it doesn’t float upward or sink downward when it’s not moving. The animal can adjust the amount of gas in its bladder as it swims upward, but when it’s pulled upward quickly in a net it can’t expel enough gas fast enough and the swim bladder can burst or expand so much that it squishes the rest of its insides, killing the animal before it even reaches the surface. Animals that don’t migrate vertically often don’t have a swim bladder since they don’t need it, and they’re just adapted for water pressure that’s as much as 120 times greater than pressure at the surface. This pressure difference is why blobfish look so blobby, so let’s talk about the blobfish next, Anonymous’s suggestion.

The blobfish lives on the sea floor in deep water near Australia and New Zealand. It grows about a foot long at most, or 30 cm, and is grayish with little spikes all over it. It has a gelatinous body with weak muscles and a weak skeleton, but it doesn’t need either since the intense pressure of the water presses in around the fish all the time and keeps it just the way it should be. It looks like a fish. Its gelatinous flesh is slightly less dense than the water around it, which means it can float just above the sea floor without much effort, just drifting along, giving its tail and broad fins a little flap every so often. It eats whatever detritus floats down from far above, although it’s also mostly on the lookout for small crustaceans that live on the sea floor.

The problem comes when a fishing net catches a blobfish and brings it to the surface. Suddenly there’s no nice firm water around the fish. Instead of being slightly less dense than the water around it, the blobfish is suddenly way more dense than the water, and it expands as a result. Then someone looks at this horrible dead pinkish blob that was once a happy live fish and thinks, “Gross! I’ll take a picture of that for the internet,” and that’s why the blobfish gets its name. Poor blobfish!

Fortunately, scientists have developed a compression chamber for the animals they study. When a deep-sea animal is put in the compression chamber and brought to the surface, the compression chamber keeps the water pressure where the animal needs it. The animal doesn’t die horribly, and that allows researchers to observe a live animal instead of a dead blobby one.

Next, let’s learn about Page’s suggestion, the barreleye fish. It lives in the North Pacific in deep water, and it has upward-pointing eyes that are very sensitive to light. It’s a small fish, only about six inches long, or 15 cm, and is mostly dark in color, as you would expect from a deep-sea fish. It’s chonky in shape with large fins that help it stay motionless in the water while it looks for tiny fish and jellyfish silhouetted against the water’s surface far above. Then the barreleye will move quickly to grab its prey.

It seems like there’s something I’m forgetting to tell you. Hmm. There’s something unusual about the barreleye fish, I just know it.

Oh yeah. The domed top of its head is transparent and its eyeballs are inside the dome. You can see the internal eyeballs and its brain through its transparent head, which is otherwise filled with liquid. It is really weird-looking. Its eyes are tubular, which gives it its name, and they can rotate around to focus on things or look straight ahead when it wants to. The eyes also have bright green lenses, which helps filter out the faint sunlight from above so the fish can better see the bioluminescent glow of other deep-sea animals.

It wasn’t until 2004 that researchers realized the barreleye’s eyes were covered by the transparent dome, because it’s fragile and would end up destroyed when a fish was dragged up by nets. The first photographs and video of the barreleye in its natural environment, taken by deep-sea remote vehicles, must have freaked the researchers out completely.

If you’re wondering why the barreleye has its eyeballs hidden inside a transparent dome, researchers have wondered that too. The best guess is that the dome protects the large, sensitive eyes from jellyfish stings, since barreleyes love to eat jellyfish.

Finally, Joel suggested the bristlemouth fish. The bristlemouth is a small, slender fish that generally grows no longer than a person’s finger, although one species grows up to 14 inches long, or 36 cm. Males are smaller than females. It lives throughout the world’s oceans and is black or dark brown to hide it in the twilight zone where it lives. Like the barbeled dragonfish, which by the way really likes to eat it, it migrates closer to the surface at night to find food, then goes deeper again in the daytime to hide in the darkness.

The bristlemouth gets its name from its teeth, as you may have guessed. It has a large mouth lined with lots of short, thin teeth. It mostly eats small crustaceans, especially copepods, but will also grab tiny fish and other animals. Its lower jaw is longer than its upper jaw and can open wide to grab animals larger than it is. Unlike the other fish we’ve talked about today, its eyes are small and it doesn’t use them to find prey. Instead, it uses its lateral line system, which allows it to detect tiny movements in the water. The male bristlemouth also has a good sense of smell to help it find a female. All bristlemouths start out life as male, but some males metamorphose into females as they age.

The bristlemouth also has rows of light-emitting photophores on its underside to help hide it from predators. Its photophores glow to match the amount of light shining down from far above, which means its silhouette is much harder to see by fish or other animals below it.

There’s still a lot we don’t know about the bristlemouth, but we do know one thing. It’s the most abundant fish in the ocean. Literally there are more bristlemouths in the world than any other vertebrate, estimated at hundreds of trillions of them, possibly as many as a quadrillion, which is a million billion. That’s a lot of fish. There are so many that Navy sonar bounces off them and looks like a false bottom of the ocean. The United States Navy calls it the Deep Scattering Layer and wasn’t sure what was causing it, but the mystery was solved in 2010 when a research vessel with fine-mesh nets kept bringing up unbelievable numbers of the tiny fish. Specifically, the abundant ones are bristlemouth fish in the genus Cyclothone, which mostly lives in tropical areas.

The first person to see a bristlemouth in its natural habitat was William Beebe in the 1930s, during a bathysphere descent into the twilight zone, which brings us right back to where we started this episode.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way, and don’t forget to join our mailing list. There’s a link in the show notes.

Thanks for listening!

Episode 223: The Elephantnose Fish and the Burmese Star Tortoise

Posted on May 10, 2021 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 12:19 — 12.7MB)

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This week let’s learn about an amazing little fish and an awesome tortoise! All the pictures here were taken by ME at the Tennessee Aquarium in Chattanooga!

Further Reading:

Star tortoise makes meteoric comeback

The astonishing elephantnose fish:

Burmese star tortoises:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. I’m fully vaccinated now so I’m able to go out and about cautiously, still wearing a mask of course, and this weekend I went to the Tennessee Aquarium in Chattanooga. I had a fantastic time and saw lots and lots of amazing fish and other animals! If you ever get a chance to visit, it’s definitely worth it.

When I got home, I kept thinking about one particular fish. I wanted to learn more about it. So I decided to make an episode about that fish and another animal I saw at the aquarium.

The fish that captivated me so much is called the elephantnose fish. I’d never seen anything like it. The one I saw was about the length of my hand, dark gray or black in color, and looked like a pretty ordinary fish except for the proboscis that gives it its name. The fish has a flexible projection from its nose that it was using to probe around in the gravel at the bottom of its river habitat.

I should mention that the Tennessee Aquarium has enormous displays, beautifully designed to mimic the animals’ natural habitat and give them plenty of room to move around. There’s one tidal animals display in the ocean side of the aquarium where the water sloshes through and around rocks to mimic the tide. It’s fascinating to watch the fish in that exhibit stay pretty much motionless despite the water’s movement, because that’s what they’re adapted for. So there’s plenty of opportunities to see an animal’s behavior.

Anyway, I took lots of pictures of the elephantnose fish and when I got home, I started researching it. It turns out that it’s way more interesting even than I thought!

It lives in rivers and other freshwater in central Africa and grows up to 9 inches long, or 23 cm. That’s according to the info display next to the exhibit. The display also said the fish was a species called Peter’s elephantnose fish, although it’s possible they have more than one species on display. There are a lot of elephantnose fish, more properly called mormyrids or freshwater elephantfish, and many of them have this interesting proboscis.

The proboscis isn’t actually a nose like an elephant’s trunk. It’s technically a modified chin and mouth, called the Schnauzenorgan. The elephantnose fish mostly eats small worms and insect larvae, and it especially loves mosquito larvae.

The elephantnose fish uses electroreception to navigate the muddy waters where it lives and find food. Its whole body, and especially its Schnauzenorgan, is covered with electrocyte cells that can detect tiny electrical pulses. If you remember way back in episode ten, about electric animals, many animals can sense the weak bioelectrical fields that other animals generate in their nerves and muscles. It’s especially common in fish since water conducts electricity much better than air does. But the elephantnose fish also generates a stronger electric field of its own, which it uses as a sort of sonar. It generates the field in special electric organs in its tail, and as it moves around in the water, the electric field comes in contact with other things—plants, rocks, other fish, and so on. It’s not strong enough to give an animal a shock, but it’s strong enough for the elephantnose fish to easily sense changes in its environment. The fish can tell what it’s near because its electrical field interacts differently with different things. A rock, for instance, doesn’t conduct electricity so the fish probably senses it as a blank spot in its electrical field, while a plant may conduct electricity even better than water and therefore changes the shape of the fish’s electrical field in a particular way. But it doesn’t generate its bioelectric field all the time. It can control when it discharges pulses of electricity the same way a dolphin can control when it sends out pulses of sound. If the fish feels threatened, maybe by another elephantnose fish nosing in on its territory, it will pulse much faster so it can keep tabs on what the other fish is doing—plus, of course, the other elephantnose fish can sense its pulses and can interpret how aggressive the first fish is. Female elephantnose fish generate a slightly different electrical field than males, which allows males and females to find each other to spawn.

You may be thinking about all this and wondering how the elephantnose fish can sense the tiny bioelectric charges of its tiny prey over its own electric field. Its electric field is much stronger than that of a teensy worm hiding in the mud, after all. It would be like trying to hear a bird chirping outside through a closed window while someone is playing music really loudly in the room you’re in. It turns out that the elephantnose fish is able to filter out its own electrical field so it can sense other things—but at the same time it’s still able to navigate using its electrical field.

The elephantnose fish needs a large brain to interpret all these complicated bioelectrical signals, and it has a brain to body size ratio equivalent to birds and possibly equivalent to primates. It’s not a social fish, and intelligence seems to develop from complex social interactions, although the fish is considered pretty intelligent. I mean, generally fish are not masterminds, so it’s not hard to be considered an intelligent fish, but the elephantnose fish has the brainpower to pull it off.

The elephantnose fish lives along the bottom of rivers and ponds, usually murky ones, and is mostly nocturnal. For a long time researchers thought it probably couldn’t see very well. It turns out, though, that it sees extremely well. Its retina is made up of cup-shaped cells that act like tiny mirrors, reflecting light and concentrating it so it can see better even in low light.

The elephantnose fish is a popular pet, but it is hard to keep. You have to really know what you’re doing and have a really big aquarium that’s set up just right. The males are aggressive toward each other and while the fish isn’t threatened in the wild, from what I could find out it has never bred in captivity.

Speaking of breeding in captivity, our other animal this week isn’t a fish but a reptile. It’s called the Burmese star tortoise and unlike the elephantnose fish, it’s critically threatened in the wild. It also doesn’t have a Schauzenorgan and instead just has a short little snub nose and lives on land in dry forests in Myanmar. It’s basically the opposite of the elephantnose fish.

It gets the name star tortoise because of its pretty shell markings that look sort of like stars. It can grow up to a foot long, or 30 cm, and eats grass, fruit, and other plant material, but will also eat mushrooms, insects, and snails. It has a steeply domed carapace, the proper name for its shell, with big bumps on it. It lives in central Myanmar in south Asia, but by the late 1990s it was almost extinct in the wild. The tortoise was eaten by locals, but mostly it was captured and sold as a pet or as a medicine ingredient even though it’s a tortoise, not a medicine. This was despite the tortoise being a protected species in the country.

Conservationists realized they had to act fast before this lovely tortoise went extinct. In 2004, authorities caught smugglers with 175 of the tortoises, so Myanmar’s conservation group created tortoise breeding facilities within three of the country’s wildlife sanctuaries. They consulted zoo veterinarians and tortoise experts from all over the world to make sure the rescued tortoises were as happy and healthy as possible. The first captive-bred Burmese star tortoise babies had only been hatched the year before, since it’s hard to breed in captivity.

Each sanctuary has guards that protect it from anyone who wants to sneak in and steal the animals to sell, and 150 of the tortoises have little radio trackers attached to their shells so conservationists can keep an eye on exactly where they are. They go out and check on the tagged tortoises every other week.

Since 2004, over 16,000 Burmese star tortoises have hatched in captivity and about a thousand have been returned to the wild. They’d release more into the wild, but the conservationists are worried that poachers would collect them to sell. The country of Myanmar is in a long-running civil war, unfortunately, and that makes it hard for the people living there to concentrate on conservation. Their main goal is just to stay safe. Hopefully things will get better soon for the people of Myanmar, and when they do, the tortoises will be waiting.

Thanks for listening!

Strange Animals Podcast

A podcast about living, extinct, and imaginary animals!

Category Archives: fish

Episode 303: Weird and Mysterious Animal Sounds

Episode 296: The Hide and the Blood-Sucking Blanket

Episode 280: Lesser-Known Sharks

Episode 278: Gender Diverse Animals

Episode 271: Springtime Animals

Episode 261: Walking Fish

BONUS Q&A Episode!

Episode 236: Updates 4 and a Mystery Snake!

Episode 231: Fish of the Twilight Zone

Episode 223: The Elephantnose Fish and the Burmese Star Tortoise