Category Archives: fish

Episode 338: Updates 6 and an Arboreal Clam!?!

Posted on by

Podcast: Play in new window | Download (Duration: 19:50 — 23.3MB)

Subscribe: RSS | More

This week we have our annual updates and corrections episode, and at the end of the episode we’ll learn about a really weird clam I didn’t even think was real at first.

Thanks to Simon and Anbo for sending in some corrections!

Further reading:

Lessons on transparency from the glass frog

Hidden, never-before-seen penguin colony spotted from space

Rare wild asses spotted near China-Mongolia border

Aye-Ayes Use Their Elongated Fingers to Pick Their Nose

Homo sapiens likely arose from multiple closely related populations

Scientists Find Earliest Evidence of Hominins Cooking with Fire

153,000-Year-Old Homo sapiens Footprint Discovered in South Africa

Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex

Earth’s First Vertebrate Superpredator Was Shorter and Stouter than Previously Thought

252-Million-Year-Old Insect-Damaged Leaves Reveal First Fossil Evidence of Foliar Nyctinasty

The other paleo diet: Rare discovery of dinosaur remains preserved with its last meal

The Mongolian wild ass:

The giant barb fish [photo from this site]:

Enigmonia aenigmatica, AKA the mangrove jingle shell, on a leaf:

Show transcript:

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

This week is our annual updates and corrections episode, but we’ll also learn about the mangrove jingle shell, a clam that lives in TREES. A quick reminder that this isn’t a comprehensive updates episode, because that would take 100 years to prepare and would be hours and hours long, and I don’t have that kind of time. It’s just whatever caught my eye during the last year that I thought was interesting.

First, we have a few corrections. Anbo emailed me recently with a correction from episode 158. No one else caught this, as far as I can remember. In that episode I said that geckos don’t have eyelids, and for the most part that’s true. But there’s one family of geckos that does have eyelids, Eublepharidae. This includes the leopard gecko, and that lines up with Anbo’s report of having a pet leopard gecko who definitely blinked its eyes. This family of geckos are sometimes even called eyelid geckos. Also, Anbo, I apologize for mispronouncing your name in last week’s episode about shrimp.

After episode 307, about the coquí and glass frogs, Simon pointed out that Hawaii doesn’t actually have any native frogs or amphibians at all. It doesn’t even have any native reptiles unless you count sea snakes and sea turtles. The coqui frog is an invasive species introduced by humans, and because it has no natural predators in Hawaii it has disrupted the native ecosystem in many places, eating all the available insects. Three of the Hawaiian islands remain free of the frogs, and conservationists are working to keep it that way while also figuring out ways to get them off of the other islands. Simon also sent me the chapter of the book he’s working on that talks about island frogs, and I hope the book is published soon because it is so much fun to read!

Speaking of frogs, one week after episode 307, an article about yet another way the glass frog is able to hide from predators was published in Science. When a glass frog is active, its blood is normal, but when it settles down to sleep, the red blood cells in its blood collect in its liver. The liver is covered with teensy guanine crystals that scatter light, which hides the red color from view. That makes the frog look even more green and leaf-like!

We’ve talked about penguins in several episodes, and emperor penguins specifically in episode 78. The emperor penguin lives in Antarctica and is threatened by climate change as the earth’s climate warms and more and more ice melts. We actually don’t know all that much about the emperor penguin because it lives in a part of the world that’s difficult for humans to explore. In December 2022, a geologist named Peter Fretwell was studying satellite photos of Antarctica to measure the loss of sea ice when he noticed something strange. Some of the ice had brown stains.

Dr Fretwell knew exactly what those stains were: emperor penguin poop. When he obtained higher-resolution photos, he was able to zoom in and see the emperor penguins themselves. But this wasn’t a colony he knew about. It was a completely undiscovered colony.

In episode 292 we talked about a mystery animal called the kunga, and in that episode we also talked a lot about domestic and wild donkeys. We didn’t cover the Mongolian wild ass in that one, but it’s very similar to wild asses in other parts of the world. It’s also called the Mongolian khulan. It used to be a lot more widespread than it is now, but these days it only lives in southern Mongolia and northern China. It’s increasingly threatened by habitat loss, climate change, and poaching, even though it’s a protected animal in both Mongolia and China.

In February of 2023, a small herd of eight Mongolian wild asses were spotted along the border of both countries, in a nature reserve. A local herdsman noticed them first and put hay out to make sure the donkeys had enough to eat. The nature reserve has a water station for wild animals to drink from, and has better grazing these days after grassland ecology measures were put into place several years ago.

In episode 233 we talked about the aye-aye of Madagascar, which has weird elongated fingers. Its middle finger is even longer and much thinner than the others, which it uses to pull invertebrates from under tree bark and other tiny crevices. Well, in October of 2022 researchers studying aye-ayes started documenting another use for this long thin finger. The aye-ayes used it to pick their noses. It wasn’t just one aye-aye that wasn’t taught good manners, it was widespread. And I hope you’re not snacking while I tell you this, the aye-aye would then lick its finger clean. Yeah. But the weirdest thing is that the aye-aye’s thin finger is so long that it can potentially reach right through the nose right down into the aye-aye’s throat.

It’s pretty funny and gross, but wondering why some animals pick their noses is a valid scientific question. A lot of apes and monkeys pick their noses, as do humans (not that we admit it most of the time), and now we know aye-ayes do too. The aye-aye is a type of lemur and therefore a primate, but it’s not very closely related to apes and monkeys. Is this just a primate habit or is it only seen in primates because we have fingers that fit into our nostrils? Would all mammals pick their nose if they had fingers that would fit up in there? Sometimes if you have a dried snot stuck in your nose, it’s uncomfortable, but picking your nose can also spread germs if your fingers are dirty. So it’s still a mystery why the aye-aye does it.

A recent article in Nature suggests that Homo sapiens, our own species, may have evolved not from a single species of early human but from the hybridization of several early human species. We already know that humans interbred with Neandertals and Denisovans, but we’re talking about hybridization that happened long before that between hominin species that were even more closely related.

The most genetically diverse population of humans alive today are the Nama people who live in southern Africa, and the reason they’re so genetically diverse is that their ancestors have lived in that part of Africa since humans evolved. Populations that migrated away from the area, whether to different parts of Africa or other parts of the world, had a smaller gene pool to draw from as they moved farther and farther away from where most humans lived.

Now, a new genetic study of modern Nama people has looked at changes in DNA that indicate the ancestry of all humans. The results suggest that before about 120,000 to 135,000 years ago, there was more than one species of human, but that they were all extremely closely related. Since these were all humans, even though they were ancient humans and slightly different genetically, it’s probable that the different groups traded with each other or hunted together, and undoubtedly people from different groups fell in love just the way people do today. Over the generations, all this interbreeding resulted in one genetically stable population of Homo sapiens that has led to modern humans that you see everywhere today. To be clear, as I always point out, no matter where people live or what they look like, all people alive today are genetically human, with only minor variations in our genetic makeup. It’s just that the Nama people still retain a lot of clues about our very distant ancestry that other populations no longer show.

To remind everyone how awesome out distant ancestors were, here’s one new finding of how ancient humans lived. We know that early humans and Neandertals were cooking their food at least 170,000 years ago, but recently archaeologists found the remains of an early hominin settlement in what is now Israel where people were cooking fish 780,000 years ago. There were different species of fish remains found along with the remains of cooking fires, and some of the fish are ones that have since gone extinct. One was a carp-like fish called the giant barb that could grow 10 feet long, or 3 meters.

In other ancient human news, the oldest human footprint was discovered recently in South Africa. You’d think that we would have lots of ancient human footprints, but that’s actually not the case when it comes to footprints more than 50,000 years old. There are only 14 human footprints older than that, although there are older footprints found made by ancestors of modern humans. The newly discovered footprint dates to 153,000 years ago.

It wouldn’t be an updates episode without mentioning Tyrannosaurus rex. In late 2022 a newly discovered tyrannosaurid was described. It lived about 76 million years ago in what is now Montana in the United States, and while it wasn’t as big as T. rex, it was still plenty big. It probably stood about seven feet high at the hip, or a little over 2 meters, and might have been 30 feet long, or 9 meters. It probably wasn’t a direct ancestor of T. rex, just a closely related cousin, although we don’t know for sure yet. It’s called Daspletosaurus wilsoni and it shows some traits that are found in older Tyrannosaur relations but some that were more modern at the time.

Dunkleosteus is one of a number of huge armored fish that lived in the Devonian period, about 360 million years ago. We talked about it way back in episode 33, back in 2017, and at that time paleontologists thought Dunkleosteus terrelli might have grown over 30 feet long, or 9 meters. It had a heavily armored head but its skeleton was made of cartilage like a shark’s, and cartilage doesn’t generally fossilize, so while we have well-preserved head plates, we don’t know much about the rest of its body.

With the publication in early 2023 of a new study about dunkleosteus’s size, we’re pretty sure that 30 feet was a huge overestimation. It was probably less than half that length, maybe up to 13 feet long, or almost 4 meters. Previous size estimates used sharks as size models, but dunkleosteus would have been shaped more like a tuna. Maybe you think of tuna as a fish that makes a yummy sandwich, but tuna are actually huge and powerful predators that can grow up to 10 feet long, or 3 meters. Tuna are also much heavier and bigger around than sharks, and that was probably true for dunkleosteus too. The study’s lead even says dunkleosteus was built like a wrecking ball, and points out that it was probably the biggest animal alive at the time. I’m also happy to report that people have started calling it chunk-a-dunk.

We talked about trace fossils in episode 103. Scientists can learn a lot from trace fossils, which is a broad term that encompasses things like footprints, burrows, poops, and even toothmarks. Recently a new study looked at insect damage on leaves dating back 252 million years and learned something really interesting. Some modern plants fold up their leaves at night, called foliar nyctinasty, which is sometimes referred to as sleeping. The plant isn’t asleep in the same way that an animal falls asleep, but “sleeping” is a lot easier to say than foliar nyctinasty. Researchers didn’t know if folding leaves at night was a modern trait or if it’s been around for a long time in some plants. Lots of fossilized leaves are folded over, but we can’t tell if that happened after the leaf fell off its plant or after the plant died.

Then a team of paleontologists from China and Sweden studying insect damage to leaves noticed that some leaves had identical damage on both sides, exactly as though the leaf had been folded and an insect had eaten right through it. That’s something that happens in modern plants when they’re asleep and the leaves are folded closed.

The team looked at fossilized leaves from a group of trees called gigantopterids, which lived between 300 and 250 million years ago. They’re extinct now but were advanced plants at the time, some of the earliest flowering plants. They also happen to have really big leaves that often show insect damage. The team determined that the trees probably did fold their leaves while sleeping.

In episode 151 we talked about fossils found with other fossils inside them. Basically it’s when a fossil is so well preserved that the contents of the dead animal’s digestive system are preserved. This is incredibly rare, naturally, but recently a new one was discovered.

Microraptor was a dinosaur that was only about the size of a modern crow, one of the smallest dinosaurs, and it probably looked a lot like a weird bird. It could fly, although probably not very well compared to modern birds, and in addition to front legs that were modified to form wings, its back legs also had long feathers to form a second set of wings.

Several exceptionally well preserved Microraptor fossils have been discovered in China, some of them with parts of their last meals in the stomach area, including a fish, a bird, and a lizard, so we knew they were generalist predators when it came to what they would eat. Now we have another Microraptor fossil with the fossilized foot of a mammal in the place where the dinosaur’s stomach once was. So we know that Microraptor ate mammals as well as anything else it could catch, although we don’t know what kind of mammal this particular leg belonged to. It may be a new species.

Let’s finish with the mangrove jingle shell. I’ve had it on the list for a long time with a lot of question marks after it. It’s a clam that lives in trees, and I actually thought it might be an animal made up for an April fool’s joke. But no, it’s a real clam that really does live in trees.

The mangrove jingle shell lives on the mangrove tree. Mangroves are adapted to live in brackish water, meaning a mixture of fresh and salt water, or even fully salt water. They mostly live in tropical or subtropical climates along coasts, and especially like to live in waterways where there’s a tide. The tide brings freshly oxygenated water to its roots. A mangrove tree needs oxygen to survive just like animals do, but it has trouble getting enough through its roots when they’re underwater. Its root system is extensive and complicated, with special types of roots that help it stay upright when the tide goes out and special roots called pneumatophores, which stick up above the water or soil and act as straws, allowing the tree to absorb plenty of oxygen from the air even when the rest of the root system is underwater. These pneumatophores are sometimes called knees, but different species of mangrove have different pneumatophore shapes and sizes.

One interesting thing about the mangrove tree is that its seeds actually sprout while they’re still attached to the parent tree. When it’s big enough, the seedling drops off its tree into the water and can float around for a long time before it finds somewhere to root. If can even survive drying out for a year or more.

The mangrove jingle shell clam lives in tropical areas of the Indo-Pacific Ocean, and is found throughout much of coastal southeast Asia all the way down to parts of Australia. It grows a little over one inch long, or 3 cm, and like other clams it finds a place to anchor itself so that water flows past it all the time and it can filter tiny food particles from the water. It especially likes intertidal areas, which happens to be the same area that mangroves especially like.

Larval jingle shells can swim, but they need to find somewhere solid to anchor themselves as they mature. When a larva finds a mangrove root, it attaches itself and grows a domed shell. If it finds a mangrove leaf, since mangrove branches often trail into the water, it attaches itself to the underside and grows a flatter shell. Clams attached to leaves are lighter in color than clams attached to roots or branches. Fortunately, the mangrove is an evergreen tree that doesn’t drop its leaves every year.

So there you have it. Arboreal clams! Not a hoax or an April fool’s joke.

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 337: Ghost Shrimp and Snapping Shrimp

Posted on by

Podcast: Play in new window | Download (Duration: 9:49 — 11.0MB)

Subscribe: RSS | More

Thanks to Zachary and Anbo for their suggestions this week! Let’s learn about some shrimp!

Further reading:

This is why the pistol shrimp is immune to its own powerful shock waves

The Symbiotic Relationship Between Gobies and Pistol Shrimp

An eastern ghost shrimp:

A snapping shrimp:

A goby fish and its snapping shrimp buddy:

Show transcript:

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

This week we’re going to have an episode about a few different types of shrimp, with suggestions from Zachary and Ambo.

Let’s start with the ghost shrimp, since Zachary recently got an aquarium and has some ghost shrimp in it.

The name ghost shrimp refers to various species of freshwater shrimp in the genus Palaemon. One of the most popular species to keep as a pet is Palaemonetes paludosus. It’s sometimes called the glass shrimp since it’s mostly transparent, or the eastern ghost shrimp.

The eastern ghost shrimp can grow up to about an inch long, or 2.5 cm. It’s native to the southeastern United States, mostly east of the Appalachian Mountains, where it lives in lakes and eats plankton.

Even though the eastern ghost shrimp is mostly transparent, it can actually change its color to blend in with its background. Only one other species of ghost shrimp is known to do this, a very similar species that is only found in the Mississippi River.

There are dozens of species of ghost shrimp, though, and they live throughout the world. Some species are freshwater, others are marine. Most are at least partially transparent and rarely grow more than two inches long, or maybe 5 cm at most. In some cases people catch them to eat, although more often they’re caught to use as bait or fish food, and of course they’re eaten by a whole lot of wild animals.

We actually don’t know a whole lot about many species of ghost shrimp. Some have only recently been discovered, and some are endangered. For instance, the Florida cave shrimp is only found in a single sinkhole near Gainesville, Florida. It’s the only known species of ghost shrimp that lives in a cave, and it’s closely related to the eastern ghost shrimp.

The Florida cave shrimp grows a little over one inch long, or about 3 cm. It has eyes but doesn’t need them, so they don’t work anymore. It’s mostly transparent with some white spots. It was discovered in 1953 during a scientific exploration of a sinkhole in the Squirrel Chimney Cave and hasn’t been seen since 1973. It may even be extinct by now, but further explorations of the sinkhole have revealed that it connects with a much larger underwater cave system. Hopefully the little shrimp lives within this cave system, but it hasn’t been found anywhere else so far and we know almost nothing about it.

That’s pretty much all there is to know about the ghost shrimp, so congratulations to Zachary for keeping a mysterious little friend in your aquarium.

Next, Anbo wanted to learn about snapping shrimp. (Anbo also wanted to learn about the mantis shrimp, but it turns out that the mantis shrimp isn’t actually a shrimp, or a mantis, and it deserves its own episode one day.) We talked about the snapping shrimp before in episode 273, but there’s definitely more to learn about it. There are a whole lot of species–like, more than a thousand. They’re especially common in coral reefs and live in colonies that communicate with each other by snapping their claws. The sound is so loud that it can sound like a gunshot, which is why it’s sometimes called the pistol shrimp.

The snapping shrimp is about the same size as the ghost shrimp, about 2 inches long at most, or 5 cm. One of its claws is ordinary, but the other claw is much bigger, and it’s the large claw that makes the snapping sound. As we discussed in episode 273, the snapping shrimp will hide in a burrow or rock crevice with its antennae sticking out, and when a small animal like a fish happens by, the shrimp will emerge from its hiding place just far enough to get a good shot at the animal. It opens its big claw and snaps it shut so fast and so forcefully that it shoots tiny bubbles out at speeds of over 60mph, or 100 km/hour. The bubbles only travel a few millimeters in distance, but the shock wave is powerful enough at this short range to stun or outright kill a small animal.

Scientists figured out how the snapping shrimp’s snap worked in 2020, but it wasn’t until 2022 that they discovered why the shrimp doesn’t damage its tiny shrimp brain when it snaps. It turns out that its brain is protected by a translucent helmet called an orbital hood. It needs to be translucent because it covers the shrimp’s eyes as well as the rest of its head. The hood is an extension of the shrimp’s exoskeleton, and it has an opening at the back. Scientists think that when the shock wave of a snap meets the hood, the change in water pressure under the hood is expelled out the opening instead of affecting the brain.

Scientists want to learn how exactly the orbital hood works to redirect pressure waves, in hopes of being able to replicate it. That way we can make really effective armor for people who work with explosives, or for military personnel.

In episode 332 we talked about mutualism, and the snapping shrimp actually has a mutualistic relationship with the goby fish. Gobies are little fish that are usually even smaller than snapping shrimp, or not much bigger. The order Gobiiformes is one of the largest fish families, and we’ve talked about at least one type of goby before. That was back in episode 189 when we learned about the lumpsucker. Not all gobies are buddies with snapping shrimp, but about 130 species are, most of which live in the Pacific Ocean.

Snapping shrimp live in burrows, and the 20 species or so of snapping shrimp that partner with gobies will dig an extra-large burrow. That’s because it’s making room for its goby friend, or even more than one goby friend. The burrow can extend as much as two feet deep, or about 61 cm, with different chambers. While the shrimp is digging the burrow, the goby watches for danger. If a predator approaches, the fish warns the shrimp by moving its fins in a specific way, which signals that the shrimp should hide. If part of the burrow collapses and buries the fish, it just waits until the shrimp digs it out of the sand.

The shrimp and the goby live together in the burrow. They leave the burrow together so they can watch out for each other. The snapping shrimp doesn’t see very well so while it’s outside of the burrow, it will keep track of the goby with its long antennae. The goby watches out for danger and warns the shrimp if it needs to hide.

Both eat small animals, but the shrimp also likes eating some types of algae that grow on rocks. The shrimp will even bring pieces of algae to its burrow to snack on later, and at least one researcher has witnessed the goby help transport algae to the burrow.

During mating season, the goby brings its mate into the burrow, where the female lays eggs in the male’s chamber. Only the male takes care of the eggs, and he spends almost all of his time guarding them and swimming around them to keep them oxygenated. When he has to leave, he blocks the entrance with sand. The eggs hatch after a little over a week and the larvae swim out of the burrow immediately. The female shrimp carries her eggs around until they hatch, which they do in the burrow, and they too leave the burrow right away and float off on their own.

Both the goby eggs and the shrimp eggs hatch at night or sometimes early in the morning, which is important because those are times when both the goby and the shrimp are not active. In other words, that’s a time when the larva can safely leave the burrow without being eaten by its parent’s roommate. Having a buddy is great, but when it comes to your kids, it’s always safety first, even among fish and snapping shrimp.

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 334: Piranha!

Posted on by

Podcast: Play in new window | Download (Duration: 9:15 — 10.3MB)

Subscribe: RSS | More

Thanks to David for this week’s suggestion, the piranha!

Further reading:

Florida wildlife officer’s fish seizure nibbles at illegal piranha sales

How Teddy Roosevelt Turned Piranhas into Ferocious Maneaters

The beautiful butterfly peacock bass (not a piranha):

The red-bellied piranha (By H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=82557603):

Chompy chompy teeth:

Show transcript:

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

This week we’re covering a type of fish that I absolutely cannot believe we haven’t talked about before. It’s the piranha! Thanks to David for telling me on Mastodon about a piranha incident that led to me realizing we don’t have an episode about it yet.

David’s incident is something that happened in Florida in 2009. In October of that year, a 14-year-old boy named Jake was fishing in a retention pond in West Palm Beach, Florida, which he did a lot. He’d caught all kinds of unusual fish in the pond, including a butterfly peacock bass, which is yellow, green, or even orange in color with three black stripes on its back. It can grow well over two feet long, or 74 cm. The peacock bass is native to tropical areas of South America but was deliberately introduced to Florida in 1984 to prey on other invasive species. This actually worked, and because the fish can’t survive if the water gets too cold, it can’t spread very far.

But on this particular October day in 2009, Jake caught a fish that no one wanted to find in Florida, a red-bellied piranha! The teenager took the fish to his dad, who called the Florida Fish and Wildlife Conservation Commission. A wildlife biologist investigated and caught another piranha in the same pond the following week.

That was enough of a problem that wildlife officials decided to poison the entire 4-acre pond rather than risk having piranhas become naturalized in Florida. The poison killed every single fish in the pond, including at least one other piranha, although it was a poison that quickly broke down into nontoxic compounds. The pond was later restocked with bluegills and other native fish.

The reason that Florida wildlife officials would rather kill all the fish in a big pond rather than let any piranhas live is that Florida is very similar to the piranha’s native habitat in South America. Florida already has enough issues with invasive species like the Burmese python, cane toad, lionfish, and giant land snail without adding another fish that’s famous for its sharp teeth and voracious appetite. If the piranha became established in Florida, it could drive all kinds of native fish and other animals to extinction very quickly.

This has actually happened in parts of China, where red-bellied piranha were first found in the wild in 1990 and have since spread throughout much of South China. In some waterways, up to half of the native fish have disappeared after piranha and other invasive species became established.

But wait, you may be thinking, what about the danger to humans? Aren’t piranhas incredibly dangerous to swimmers?

The red-bellied piranha is the species that most people think is dangerous to people. We’ve all heard the stories and maybe seen movies where a pack of piranha attack someone swimming along, and within minutes all that’s left of them is a skeleton. But it may not surprise you to learn that those stories are fake, but they’re widespread for an unusual reason.

Back in 1913, the former U.S. President Teddy Roosevelt, who we talked about in episode 284 about the teddy bear, took part in an expedition to the Amazon basin in South America. The expedition was arranged by the Brazilian government, who invited Roosevelt along.

The expedition planned to explore the headwaters of the Amazon and it did, at great peril. Three people died and almost everyone got sick from malaria or some other disease, including Roosevelt, who got a cut on his leg that became badly infected. One of the three people who died was murdered by another expedition member, and instead of taking the murderer home to face justice, they just…left him in the jungle, a looooooooong way from anywhere or anyone.

Anyway, one of the things Roosevelt saw early on in the trip was something he told everyone about later, in gruesome detail. You’ve probably heard about it too. The local dignitaries took Roosevelt and the other expedition members on a tour of their town, showing things off, as people do all over the world when they have important visitors. They also showed how ferocious the local piranhas were by driving a cow into the water. A pack of piranhas attacked the cow, and within minutes it was nothing but a skeleton, just like in the movies!

But wait, you’re probably thinking again, I just said that was all fake! Did it really happen? It did, but not the way it sounds. The whole cruel spectacle was arranged ahead of time by the local dignitaries. They had people capture piranhas from miles away and bring them to one section of the river, where they were penned in with a net and not given any food for days. By the time the cow was driven into the makeshift pen, the piranhas were starving and desperate. Under normal circumstances, they would have never attacked the cow.

The red-bellied piranha and its relations are actually mild-mannered fish who only want to eat small fish, snails, insects, and other tiny animals, along with fruit and leaves. It will also sometimes eat dead animals it finds, which has led to people assuming piranhas killed someone swimming in the water when actually the person drowned and the piranhas just, you know, cleaned things up a little.

The red-bellied piranha can grow up to 20 inches long, or 50 cm, and is usually silvery-gray in color with black markings and a reddish belly. It does have big sharp teeth, but so do lots of other fish. Most importantly, the piranha doesn’t hunt in packs. It hunts individually most of the time, but it may stay in a school with other piranhas to help it avoid predators. If a caiman or something decides it wants a piranha snack, any given individual fish in a school is likely to escape the caiman, whereas a fish by itself has a much higher chance of being grabbed and eaten.

The piranha communicates with other piranha by sound. Fish aren’t usually famous for making noise, but the piranha can use its swim bladder as a resonant chamber. It uses special muscles to make a low-pitched drumming sound, usually to warn another piranha away from whatever food it’s found.

Aquarium enthusiasts sometimes keep piranha as pets, but they need special care. A piranha won’t eat meat that’s going bad, so it has to have fresh meat or live animals it can catch, and some animals can make the piranha sick, like goldfish. It’s also a messy eater, so its water will get yucky very quickly and has to be continually changed. And, of course, in some places people aren’t allowed to own piranha at all. You know, places like Florida.

The red-bellied piranha is the largest living species, but 8 to 10 million years ago a species named Megapiranha could grow as much as four feet long, or 1.27 meters. If you’d lived back then, you might have needed to be a little more careful where you swam.

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 332: Hunting Partners and Mutualism

Posted on by

Podcast: Play in new window | Download (Duration: 10:37 — 11.9MB)

Subscribe: RSS | More

Thanks to Vaughn and Jan for their suggestions this week! We’re going to learn about mutualism of various types.

Further reading:

The odd couple: spider-frog mutualism in the Amazon rainforest

What Birds, Coyotes, and Badgers Know About Teamwork

Octopuses punch fishes during collaborative interspecific hunting events

An Emotional Support Dog Is the Only Thing That Chills Out a Cheetah

Buddies [picture from the first link above]:

The honeyguide bird:

Cheetahs and dogs can be friends:

Show transcript:

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

This week we’re going to learn about a topic that I’ve been wanting to cover for a long time, mutualism. It’s a broad topic so we won’t try to cover everything about it in this episode, just give an overview with some examples. Vaughn suggested symbiotic behavior ages ago, and Jan gave me a great example of this, also ages ago, so thanks to both of them!

Mutualism is similar to other terms, including symbiosis, often referred to as “a symbiotic relationship.” I’m using mutualism as a general term, but if you want to learn more you’ll quickly find that there are lots of terms referring to different interspecies relationships. Basically we’re talking about two unrelated organisms interacting in a way that’s beneficial to both. This is different from commensalism, where one organism benefits and the other doesn’t but also isn’t harmed, and parasitism, where one organism benefits and the other is harmed.

We’ll start with the suggestion from Jan, who alerted me to this awesome pair of animals. Many different species have developed this relationship, but we’ll take as our specific example the dotted humming frog that lives in parts of western South America.

The dotted humming frog is a tiny nocturnal frog that barely grows more than half an inch long from snout to vent, or about 2 cm. It lives in swamps and lowland forests and spends most of the day in a burrow underground. It comes out at night to hunt insects, especially ants. It really loves ants and is considered an ant specialist. That may be why the dotted humming frog has a commensal relationship with a spider, the Colombian lesserblack tarantula.

The tarantula is a lot bigger than the frog, with its body alone almost 3 inches long, or 7 cm. Its legspan can be as much as 8 and a half inches across, or 22 cm. It’s also nocturnal and spends the day in its burrow, coming out at night to hunt insects and other small animals, although not ants. It’s after bigger prey, including small frogs. But it doesn’t eat the dotted humming frog. One or even more of the frogs actually lives in the same burrow as the tarantula and they come out to hunt in the evenings at the same time as their spider roommate.

So what’s going on? Obviously the frog gains protection from predators by buddying up with a tarantula, but why doesn’t the tarantula just eat the frog? Scientists aren’t sure, but the best guess is that the frog protects the spider’s eggs from ants. Ants like to eat invertebrate eggs, but the dotted humming frog likes to eat ants, and as it happens the female Colombian lesserblack tarantula is especially maternal. She lays about 100 eggs and carries them around in an egg sac. When the babies hatch, they live with their mother for up to a year, sharing food and burrow space.

This particular tarantula also gets along with another species of frog that also eats a lot of ants. Researchers think the spiders distinguish the frogs by smell. The ant-eating frogs apparently smell like friends, or at least useful roommates, while all other frogs smell like food. Or, of course, it’s possible that the ant-eating frogs smell and taste bad to the spider. Either way, both the frogs and the tarantulas benefit from the relationship–and this pairing of tiny frogs and big spiders is one that’s actually quite common throughout the world.

Mutualism is everywhere, from insects gathering nectar to eat while pollenating flowers at the same time, to cleaner fish eating parasites from bigger fish, to birds eating fruit and pooping out seeds that then germinate with a little extra fertilizer. Many mutualistic relationships aren’t obvious to us as humans until we’ve done a lot of careful observations, which is why it’s so important to protect not just a particular species of animal but its entire ecosystem. We don’t always know what other animals and plants that animal depends on to survive, and vice versa.

Sometimes an individual animal will work together with an individual of another species to find food. This may not happen all the time, just when circumstances are right. Sometimes, for example, a coyote will pair up with a badger to hunt. The coyote is closely related to wolves and can run really fast, while the American badger can dig really fast. Both are native to North America. They also both really like to eat prairie dogs, a type of rodent that can run really fast and lives in a burrow. Some prairie dog tunnels can extend more than 30 feet, or 10 meters, with multiple exits. The badger can dig into the burrow and if the prairie dog leaves through one of the exits, the coyote chases after it. When one of the predators catches the prairie dog, they don’t share the meal but they will often continue to hunt together until both are able to eat.

Other animals hunt together too. Moray eels will sometime pair up with a fish called the grouper in a similar way as the coyote and badger. The grouper is a fast swimmer while the eel can wriggle into crevices in rocks or coral. The grouper will swim up to the eel and shake its head rapidly to initiate a hunt, and if the grouper has seen a prey item disappear into a crevice, it will lead the eel to the crevice and shake its head at it again.

Groupers also sometimes pair up with octopuses to hunt together, as will some other species of fish. Like the eel, the octopus can enter crevices to chase an animal that’s trying to hide. But the octopus isn’t always a good hunting partner, because if the grouper catches a fish, sometimes the octopus will punch the grouper and steal its fish. Not cool, octopus.

Birds have mutualistic relationships too, including the honeyguide that lives in parts of Africa and Asia. It’s a little perching bird that’s mostly gray and white or brown and white, with the males of some species having yellow markings. It eats insects, spiders, and other invertebrates, and it especially likes bee larvae. But it’s just a little bird and can’t break open wild honeybee hives by itself.

Some species of honeyguide that live in Africa have figured out that humans can break open beehives. When the honeyguide bird finds a beehive, it will fly around until it hears the local people’s hunting calls. The bird will then respond with a distinct call of its own, alerting the people, and will guide them to the beehive. This has been going on for thousands of years. The humans gather the honey, the honeyguide feasts on the bee larvae and wax, and everyone has a good day except the bees.

The honeyguide is also supposed to guide the honey badger to beehives, but there’s no definitive evidence that this actually happens. Honey badgers do like to eat honey and bee larvae, though, and when a honey badger breaks open a beehive, honeyguides and other birds will wait until it’s eaten what it wants and will then pick through the wreckage for any food the badger missed. But the honeyguide might lead the honey badger to the hive, we just don’t know for sure.

Humans sometimes even help other animals into a commensal relationship. Vaughn gave me an example of a cheetah in a zoo who became best friends with a dog. This hasn’t just happened once, it’s happened lots of times because zookeepers have found that it helps cheetahs kept in captivity. Cheetahs are social animals but sometimes a zoo doesn’t have a good companion for a cheetah cub. The cub could be in danger from older, unrelated cheetahs, but a cheetah all on its own is prone to anxiety. It’s so important for a cheetah to have a sibling that if a mother cheetah only has one cub, or if all but one cub dies, a lot of times she’ll abandon the single cub. If this happens in the wild, it’s sad, but if it happens in captivity the zoo needs to help the cub.

To do this, the zoo will pair the cub with a puppy of a sociable, large breed of dog, such as a Labrador or golden retriever. The cub and the puppy grow up together. The cheetah has a mellow friend who helps alleviate its anxiety, and the dog has a friend who’s really good at playing chase.

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 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 331: Ompax, the Mystery Fish

Posted on by

Podcast: Play in new window | Download (Duration: 10:43 — 11.9MB)

Subscribe: RSS | More

This week we have a mystery fish from Australia, the ompax!

Main source consulted:

Whitley, G. P. (1933). Ompax spatuloides Castelnau, a Mythical Australian Fish. The American Naturalist, 67(713), 563–567. http://www.jstor.org/stable/2456813

The fateful Ompax drawing:

The freshwater longtom (picture by Barry Hutchins):

Show transcript:

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

For the Patreon episode this month, we had a bird mystery from Queensland, Australia. While I was researching it I came across this mystery fish, also from Queensland.

In 1872, a man named Karl Staiger visited the town of Gayndah as part of his job. He was a chemist, but he also had an interest in nature and years later he worked for the Queensland Museum. One morning in Gayndah he went to breakfast and was served a strange-looking fish—so strange-looking that he asked what it was. He was told it was a very rare fish found in the nearby Burnett River.

Staiger was interested enough that he asked the road inspector, presumably one of his coworkers, to draw the fish for him. But the drawing wasn’t made until after Staiger ate the fish. It was his breakfast and he was hungry and, as he wrote later, he didn’t know he should have at least saved the head for study. Presumably he also didn’t want his breakfast to get cold while the drawing was being made.

The road inspector was a careful artist although he wasn’t a naturalist himself, so he did what he could to draw the fish accurately from the remains of Staiger’s meal. According to the drawing, the fish had a long, flattened rostrum that looked a little like a very long, thin duckbill, big scales on its body, and a fin that went all the way around the edges of the tail starting about halfway down the back, which appeared to be connected dorsal, caudal, and ventral fins. Its pectoral fins were small, and its eyes were also small and near the top of its head. The fish was brown in color and about 18 inches long, or 46 cm.

Staiger eventually wrote to a French naturalist and sent him the drawing. The French naturalist has about 500 names and titles, usually shortened to something like Francis de Laporte de Castelnau. I’m going to call him Francis because obviously I can’t pronounce any of those names properly.

Francis saw at a glance that the fish was unlike anything he’d ever seen before. He suspected it didn’t just deserve its own genus but its own family. Staiger had reported what he’d been told, that the fish was known from a particular part of the Burnett River, and he’d also mentioned that it lived in the same area as another strange fish, the Australian lungfish.

The Australian lungfish had only been described a few years before, in 1870, and it’s a very big fish. It can grow up to 5 feet long, or 1.5 meters, and is greenish in color. It has big overlapping scales on its body and four strong fins that look more like flippers than ordinary fish fins, which it uses to stand and walk on the bottom of the river. Its tail comes to a single rounded point and it has tooth plates instead of regular teeth, which it uses to crush the small animals it eats. It also has a single lung in addition to gills, and like other lungfish it comes to the surface every so often to replace the air in its lung. When it’s especially active it will breathe at the surface more often. The ability to breathe air allows it to survive in water with low oxygen.

Francis noted that there were some similarities between the new fish and the Australian lungfish, but he thought it was more likely to be related to the alligator gar of North America. It had the same type of scales as the alligator gar. He also noted that its duckbill rostrum resembled the rostrum of the American paddlefish, which is similarly shaped but even longer than the new fish’s, but that the rest of the new fish was very different from the paddlefish.

Francis described the new fish in 1879 and gave it the name Ompax spatuloides, but as early as 1881 some fish experts wondered if the original drawing was misleading. They pointed out that the fish wasn’t drawn by someone with a knowledge of fish and that it had already been cooked and eaten, so the details might be completely wrong.

As it happens, the details were completely wrong, but not in a way anyone expected.

There’s actually some confusion as to whether the drawing of the fish was made before or after Staiger ate it, but it doesn’t actually matter after all. In 1930, an article in the Sydney Bulletin claimed that Ompax was a hoax to fool Staiger, made up of a lungfish head, a mullet body, and an eel tail.

The 1930 article isn’t available online, but one published in 1933 is, and it quotes the 1930 article. The 1933 article appears in a periodical called The American Naturalist and discusses the history of Ompax from start to finish, which is where most of our information comes from. The article finishes by pointing out that the Ompax’s head can’t have been made from a lungfish head unless a platypus bill or something like that was added, and suggests that the head might actually have been that of a fish of the family Belonidae. These are commonly called needlefish because they have long thin rostrums lined with teeth.

Needlefish are long, slender fish that resemble gars, although gars are native to North America and mostly live in freshwater. Needlefish live throughout much of the world’s oceans although some do live in brackish or freshwater. The needlefish swims near the surface of the water and will leap out of the water at high speed to jump obstacles like floating logs or boats. Since needlefish rostrums really do have a sharp point like a needle, it sometimes badly injures or even kills people who are fishing in boats by accidentally stabbing them.

One species, the freshwater longtom, is not only found in Australian rivers, it’s found in Queensland and occasionally even in the Burnett River. Its rostrum is the right size and shape to be the Ompax’s rostrum, while the platypus’s so-called duckbill is much too large to match the drawing. The freshwater longtom can grow almost three feet long, or about 85 cm, but is usually much smaller than that.

Like most needlefish, the freshwater longtom eats small fish, insects, and crustaceans. Also like other needlefish, it has no stomach. It swallows its prey whole and instead of the food going into its stomach, it just goes directly into its intestines, which excrete an enzyme called trypsin that breaks down proteins so they can be absorbed. This isn’t as efficient as stomach acids, but it also takes less energy to digest food this way.

The freshwater longtom’s dorsal and anal fins are long but fairly low and set well back on its body. Its pectoral fins are very small. While it does have an ordinary-looking tail fin, this might easily appear different after being cooked. And the longtom is edible, although it has a lot of thin bones that make it difficult to eat. Its bones are also green in color, which can be offputting to some people. Some needlefish also have greenish meat.

Staiger didn’t recount any details about the edibility and taste and texture of the fish he ate, so we don’t know if he actually ate a mullet that had a needlefish head and an eel tail stuck to it. The sea mullet and the sand mullet are both common fish around Australia and considered excellent eating fish. But if there really was that much of an eel’s tail stuck onto the fish’s body, you’d think Staiger would have noticed the difference in meat texture. The eels found in Australia are edible and considered a delicacy, but they wouldn’t look or taste the same as the rest of the fish.

The only reason we know the Ompax fish was a hoax is because of the 1930 article written by someone who called himself Waranbini. Waranbini’s article was published 58 years after the fish was served to Staiger for his breakfast.

I think the only hoax here was the 1930 article. I think Waranbini, whoever he was, looked at the picture, thought, “That looks like someone stuck three different types of animal together,” and wrote his article.

I think Staiger was actually served a freshwater longtom, and I think the people who served it to him were sincere that it was a rare fish. It is rare in the Burnett River. Staiger wasn’t an ichthyologist, nor was the man who drew the fish. They did the best they could, and Francis did the best he could to decipher from Staiger’s notes and the drawing what the fish was.

So from this we can learn three important things: Don’t use a drawing of a cooked and possibly mostly eaten fish to describe a new species, don’t assume people in the olden days were stupid, and don’t trust anonymous newspaper articles with no sources listed.

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 316: The Blobfish and a Round Bunny

Posted on by

Podcast: Play in new window | Download (Duration: 9:23 — 10.3MB)

Subscribe: RSS | More

This week we learn more about the blobfish thanks to Matilde’s suggestion, and we’ll also learn about a primitive rabbit.

Further reading:

In Defense of the Blobfish: Why the ‘World’s Ugliest Animal’ Isn’t as Ugly as You Think It Is

A rare rabbit plays an important ecological role by spreading seeds

The Amami Rabbit: A Living Fossil in the Wilds of Amami Ōshima [amazing photos in this article!]

The blobfish as we usually see it:

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

The Amami rabbit is so so so round:

Show transcript:

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

This week we’re going to learn a little more about the blobfish, which is Matilde’s suggestion, and we’ll also talk about an unusual primitive rabbit that’s still alive today.

We talked about the blobfish briefly in episode 231. 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 has weak muscles and a weak skeleton, but it doesn’t need to be any stronger since the intense pressure of the water presses in around the fish all the time. 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 also really likes to eat small crustaceans that live on the sea floor.

But wait, you may be thinking, I’ve seen pictures of the blobfish and it looks like a pinkish blob with a cartoony frown and a droopy nose. Is that blobfish a different one from the one I just described?

No! The trouble is that the blobfish lives in really deep water, up to 4,000 feet below the surface, or 1200 meters. That means that there’s up to 4,000 feet of water above the fish, and if you’ve ever had to carry a bucket of water more than a few steps, you’ll know that water is really heavy. So the blobfish has 4,000 feet of water pressing on it from all directions. This is naturally called water pressure, and at the depths where the blobfish lives, it’s 120 times higher than water pressure in, for instance, your bathtub.

At that water pressure, you could not survive for even one second. You would be instantly crushed into a messy blob if you were suddenly transported into water that deep, because your body is adapted to live on the earth’s surface. But the opposite is true for the blobfish. If it was suddenly transported to the earth’s surface, or at least the water’s surface, without all that comfortable pressure keeping its body in place like a really big exoskeleton you can swim through, the blobfish would expand. And that’s exactly what happens when a fishing net catches a blobfish and pulls it to the surface. It just goes BLOB all over the place.

The blobfish was voted the world’s ugliest animal in 2013, which doesn’t seem fair since no one looks good when they’ve exploded into a blob.

When the blobfish is alive in its deep-sea home, it’s silvery or grayish with little spikes all over its body. It’s a member of the family Psychrolutidae, sometimes called toadfish, and it has little black eyes near the top of its head sort of like a toad. Its head is large and wide, while its body tapers to a thin little flat tail.

We know almost nothing so far about the blobfish, but we do know a bit about some of its close relatives like the blob sculpin. The blob sculpin lives in the North Pacific Ocean in even deeper water than the blobfish, up to 9200 feet deep, or 2800 meters. That’s about a mile and three-quarters deep, or almost 3 kilometers. Deep-sea animals are mostly solitary, but the blob sculpin gathers in large numbers to spawn. The females choose a nesting area and they all lay their eggs in the same place. Then the males release sperm into the water that fertilizes the eggs. Some nesting areas have been found to contain well over 100,000 eggs! Not only that, but the females guard the nesting area, and as they hover over their eggs, their slow-moving fins help keep the eggs clean of sand and sediment, which allows the eggs to absorb more oxygen. It’s the first documented case of a deep-sea fish taking care of its eggs.

Deep-sea animals often live for a long time, and it’s estimated that the blobfish might live to be as much as 130 years old.

That’s about all we know about the blobfish right now, so let’s finish with some information about a different cute round animal, although not a blobby one. It’s the Amami rabbit that only lives on two tiny islands off the southern coast of Japan.

The Amami rabbit used to live throughout Asia but as modern species of rabbit evolved, it eventually died out on the mainland. Now it only survives on these two small islands, and although it’s now a protected species, it’s still endangered. It’s especially vulnerable to habitat loss and introduced predators like dogs and cats. There are probably only about 5,000 individuals alive today, most of them on Amami Island with only a few hundred on Tokuno Island.

The Amami rabbit differs from other rabbits in a number of ways. Its eyes are smaller, its ears are smaller, and it’s shaped differently from other rabbits, with a chonky body and short legs. It also lives in forested areas instead of open grasslands. It’s nocturnal, with thick dark brown fur and long claws that it uses to dig burrows and climb steep hillsides.

A female Amami rabbit only has babies once a year, called kits or kittens, and usually only one or two kits are born at a time. In autumn the mother rabbit digs a special burrow that may be several feet deep, or up to a meter, somewhere away from her regular burrow. She brings leaves in to line the nesting chamber, where she gives birth to her kits. But she doesn’t stay with her babies all the time. In fact, she leaves them and only comes back to feed them about once a day or every other day. To keep them safe while she’s gone, she closes the entrance to the burrow so snakes and other predators can’t get in. When she returns, she digs the entrance open and spends a few minutes feeding her kits. Then she leaves again and closes the entrance behind her.

When the babies are a little over a month old, they start digging their way out of the nest on their own to explore. At that point the mother leads them to her home burrow where they stay for a few more months before they leave to find their own territories.

The Amami rabbit eats plants, especially grass and ferns, but it also eats acorns and fruit. A study published in January 2023 reported that the rabbit eats the fruit of a parasitic flowering plant called Balanophora, including swallowing the seeds whole. The seeds travel through the rabbit’s digestive system unharmed and the rabbit poops them out later, which allows them to sprout in an area far from the parent plant. Since Balanophora doesn’t produce chlorophyll and instead needs a host plant that can provide it with nutrients, having a rabbit help spread its seeds is important. This discovery was a surprise to the scientists studying the rabbit, because modern species of rabbit don’t usually eat seeds.

Who knows how many more surprises the Amami rabbit and the blobfish might hold? Hopefully scientists will continue to learn more about them so they can be better protected.

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 314: Animals Discovered in 2022

Posted on by

Podcast: Play in new window | Download (Duration: 17:28 — 20.2MB)

Subscribe: RSS | More

Let’s learn about some of the animals discovered in 2022! There are lots, so let’s go!

Further Reading:

In Japanese waters, a newly described anemone lives on the back of a hermit crab

Rare ‘fossil’ clam discovered alive

Marine Biologists Discover New Giant Isopod

Mysterious ‘blue goo’ at the bottom of the sea stumps scientists

New Species of Mossy Frog Discovered in Vietnam

A Wildlife YouTuber Discovered This New Species of Tarantula in Thailand

Meet Nepenthes pudica, Carnivorous Plant that Produces Underground Traps

Scientists discover shark graveyard at the bottom of the ocean

Further Watching:

JoCho Sippawat’s YouTube channel

A newly discovered sea anemone (photo by Akihiro Yoshikawa):

A mysterious blue blob seen by a deep-sea rover:

A newly discovered frog:

A newly discovered tarantula (photo by JoCho Sippawat):

Show transcript:

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

It’s the 2022 discoveries episode, where we learn about some of the animals discovered in 2022! Most of the time these animals were actually discovered by scientists before 2022, but the description was published in that year so that’s when we first learned about them. And, of course, a lot of these animals were already known to the local people but had never been studied by scientists before. There are lots of animals in the world but not that many scientists.

The great thing is, so many animals get discovered in any given year that I have to pick and choose the ones I think listeners will find most interesting, which in a stunning coincidence turns out to be the ones that I personally find most interesting. Funny how that works out.

We’ll start in the ocean, which is full of weird animals that no human has ever seen before. It’s about a hermit crab who carries a friend around. The hermit crab was already known to science, but until a team of scientists observed it in its natural habitat, the deep sea off the Pacific coast of Japan, no one realized it had an anemone friend.

The sea anemone is related to jellyfish and is a common animal throughout the world’s oceans. Some species float around, some anchor themselves to a hard surface. Many species have developed a symbiotic relationship with other animals, such as the clownfish, which is sometimes called the anemonefish because it relies on the anemone to survive. Anemones sting the way jellyfish do, but it doesn’t sting the clownfish. Researchers aren’t sure why not, but it may have something to do with the clownfish’s mucus coating. Specifically, the mucus may have a particular taste that the anemone recognizes as belonging to a friend. If the anemone does accidentally sting the clownfish, it’s still okay because the fish is generally immune to the anemone’s toxins.

The clownfish lives among the anemone’s tentacles, which protects it from predators, and in return its movements bring more oxygen to the anemone by circulating water through its tentacles, its droppings provide minerals to the anemone, and because the clownfish is small and brightly colored, it might even attract predators that the anemone can catch and eat.

Anemones also develop mutualistic relationships with other organisms, including a single-celled algae that lives in its body and photosynthesizes light into energy. The algae has a safe place to live while the anemone receives some of the energy from the algae’s photosynthesis. But some species of anemone have a relationship with crabs, including this newly discovered anemone.

The anemone anchors itself to the shell that the hermit crab lives in. The crab gains protection from predators, who would have to go through the stinging tentacles and the shell to get to the crab, while the anemone gets carried to new places where it can find more food. It also gathers up pieces of food that the crab scatters while eating, because crabs are messy eaters.

The problem is that hermit crabs have to move into bigger shells as they grow. Anemones can move, but incredibly slowly. Like, snails look like racecar drivers compared to anemones. The anemone moves so slowly that the human eye can’t detect the movement.

What the team of scientists witnessed was a hermit crab spending several days carefully pushing and pinching the anemone to make it move onto its new shell. If it wasn’t important, the crab wouldn’t bother. The sea anemone hasn’t yet been officially described since it’s still being studied, but it appears to be closely related to four other species of anemone that also attach themselves to the shells of other hermit crab species.

In other marine invertebrate news, a researcher named Jeff Goddard was turning rocks over at low tide at Naples Point, California a few years ago. He was looking for sea slugs, but he noticed some tiny clams. They were only about 10 mm long, but they extended a white-striped foot longer than their shells. Goddard had never seen anything quite like these clams even though he was familiar with the beach and everything that lived there, so he took pictures and sent them to a clam expert. The expert hadn’t seen these clams before either and came to look for the clams in person. But they couldn’t find the clams again. It took ten trips to the beach and an entire year before they found another of the clams.

They thought the clam might be a new species, but part of describing a new species is examining the literature to make sure the organism wasn’t already described a long time ago. Eventually the clam research team did find a paper with illustrations of a clam that matched, published in 1937, but that paper was about a fossilized clam.

They examined the 1937 fossil shell and compared it to their modern clam shell. It was a match! But why hadn’t someone else noticed these clams before? Even Goddard hadn’t seen them, and he’s a researcher that spends a lot of time along the coast looking specifically for things like little rare clams. Goddard thinks the clam has only recently started extending its range northward, especially during some marine heatwaves in 2014 through 2016. He suspects the clam’s typical range is farther south in Baja California, so hopefully a future expedition to that part of the Pacific can find lots more of the clams and we can learn more about it.

We talked about deep-sea isopods just a few weeks ago, in episode 311. They’re crustaceans related to crabs and lobsters, but also related to roly-polies that live on land. The deep-sea species often show deep-sea gigantism and are referred to as giant isopods, and that’s what this newly discovered species is. It was first found in 2017 in the Gulf of Mexico and is more slender than other giant isopods. The largest individual measured so far is just over 10 inches long, or 26 cm, which is almost exactly half the length of the longest giant isopod ever measured. It’s still pretty big, especially if you compare it to its roly-poly cousins, also called pillbugs, sow bugs, or woodlice, who typically grow around 15 mm at most.

Before we get out of the water, let’s talk about one more marine animal. This one’s a mystery that I covered in the October 2022 Patreon episode. It was suggested by my brother Richard, so thank you again, Richard!

On August 30, 2022, a research team was off the coast of Puerto Rico, collecting data about the sea floor. Since the Caribbean is an area of the ocean with high biodiversity but also high rates of fishing and trawling, the more we can learn about the animals and plants that live on the sea floor, the more we can do to help protect them.

When a remotely operated vehicle dives, it sends video to a team of scientists who can watch in real time and control where the rover goes. On this particular day, the rover descended to a little over 1,300 feet deep, or around 407 meters, when the sea floor came in view. Since this area is the site of an underwater ridge, the sea floor varies by a lot, and the rover swam along filming things and taking samples of the water, sometimes as deep as about 2,000 feet, or 611 meters.

The rover saw lots of interesting animals, including fish and corals of various types, even a fossilized coral reef. Then it filmed something the scientists had never seen before. It was a little blue blob sitting on the sea floor.

The blue blob wasn’t moving and wasn’t very big. It was shaped roughly like a ball but with little points or pimples all over it and a wider base like a skirt where it met the ground, and it was definitely pale blue in color.

Then the rover saw more of the little blue blobs, quite a few of them in various places. The scientists think it may be a species of soft coral or a type of sponge, possibly even a tunicate, which is also called a sea squirt. All these animals are invertebrates that don’t move, which matches what little we know about the blue blob.

The rover wasn’t able to take a sample from one of the blue blobs, so for now we don’t have anything to study except the video. But we know where the little blue blobs are, so researchers hope to visit them again soon and learn more about them.

It wouldn’t be a newly discovered species list without at least one new frog. Quite a few frogs were discovered in 2022, including a tree frog from Vietnam called Khoi’s mossy frog. It lives in higher elevations and is pretty big for a tree frog, with a big female growing over 2 inches long, or almost 6 cm, from snout to vent. Males are smaller. It’s mostly brown and green with little points and bumps all over that help it blend into the moss-covered branches where it lives. That’s just about all we know about it so far.

Our next discovery is an invertebrate, a spider that lives in bamboo. Specifically it lives in a particular species of Asian bamboo in Thailand, and when I say it lives in the bamboo, I mean it really does live inside the bamboo stalks. Also, when I say it’s a spider, specifically it’s a small tarantula.

It was first discovered by a YouTuber named JoCho Sippawat, who travels around his home in Thailand and films the animals he sees. I watched a couple of his videos and they’re really well done and fun, and he’s adorable even when he’s eating gross things he finds, so I recommend his videos even if you don’t speak the language he speaks. I’m not sure if it’s Mandarin or another language, and I’m not sure if I’m pronouncing his name right either, so apologies to everyone from Thailand for my ignorance.

Anyway, Sippawat found a tarantula where no tarantula should be, inside a bamboo stalk, and sent pictures to an arachnologist. That led to a team of scientists coming to look for more of the spiders, and to their excitement, they found them and determined right away that they’re new to science. It was pretty easy to determine in this case because even though there are more than 1,000 species of tarantula in many parts of the world, none of them live in bamboo stalks. The new spider was placed in a genus all to itself since it’s so different from all other known tarantulas.

It’s mostly black and dark brown with narrow white stripes on its legs, and its body is only about an inch and a half long, or 3 1/2 cm. It can’t make holes into the bamboo plants itself, so it has to find a hole made by another animal or a natural crack in the bamboo. It lines its bamboo stalk with silk to make a little home, and while there’s a lot we don’t know yet about how it lives, it probably comes out of its home to hunt insects and other small animals since tarantulas don’t build webs.

Finally, let’s wrap around to the sea anemone again, at least sort of. If you remember episode 129, we talked about the Venus flytrap sea anemone, which is an animal that looks kind of like a carnivorous plant called the Venus flytrap. We then also talked about a lot of other carnivorous plants, including the pitcher plant. Well, in 2022 a new species of pitcher plant was discovered that has underground traps.

The pitcher plant has a type of modified leaf that forms a slippery-sided pitcher filled with a nectar-like liquid. When an insect crawls down to drink the liquid, it falls in and can’t get out. It drowns and is dissolved and digested by the plant. Almost all known carnivorous plants are pretty small, but the largest are pitcher plants. The biggest pitcher plant known is from a couple of mountains in Malaysian Borneo, and its pitchers can hold over 2 ½ liters of digestive fluid. The plant itself is a messy sort of vine that can grow nearly 20 feet long, or 6 meters. Mostly pitcher plants just attract insects, especially ants, but these giant ones can also trap frogs, lizards, rats and other small mammals, and even birds.

The newly discovered pitcher plant grows in the mountainous rainforests of Indonesian Borneo and is relatively small. Unlike every other pitcher plant known, its pitchers develop underground and can grow a little over 4 inches long, or 11 cm. Sometimes they grow just under the surface, with leaf litter or moss as their only covering, but sometimes they grow deeper underground. Either way, they’re very different from other pitcher plants in other ways too. For one thing, scientists found a lot of organisms actually living in the pitchers and not getting eaten by the plant, including a new species of worm. Scientists aren’t sure why some animals are safe in the plant but some animals get eaten.

The new pitcher plant is found in parts of Indonesian Borneo that’s being turned into palm oil plantations at a devastating rate, leading to the extinction or threatened extinction of thousands of animal and plant species. The local people are also treated very badly. Every new discovery brings more attention to the plight of the area and makes it even more urgent that its ecosystems are protected from further development. The fastest way to do this would be for companies to stop using so much palm oil. Seriously, it’s in everything, just look at the ingredients list for just about anything. I try to avoid it when I’m grocery shopping but it’s just about impossible. I didn’t mean to rant, but the whole palm oil thing really infuriates me.

You know what? Let’s have one more discovery so we don’t end on a sour note.

A biodiversity survey of two of Australia’s marine parks made some really interesting discoveries in 2022. This included a new species of hornshark that hasn’t even been described yet. It’s probably related to the Port Jackson shark, which grows to around five and a half feet long, or 1.65 meters, and is a slow-moving shark that lives in shallow water off the coast of most of Australia. Instead of a big scary mouth full of sharp teeth, the Port Jackson shark has a small mouth and flattened teeth that allow it to crush mollusks and crabs. The newly discovered shark lives in much deeper water than other hornsharks, though, around 500 feet deep, or 150 meters.

Another thing they found during the survey wasn’t a new species of anything, but it’s really cool so I’ll share it anyway. It was a so-called shark graveyard over three miles below the ocean’s surface, or 5400 meters. The scientists were trawling the bottom and when they brought the net up to see what they’d found, it was full of shark teeth–over 750 shark teeth! They were fossilized but some were from modern species while some were from various extinct species of shark, including a close relative of Megalodon that grew around 39 feet long, or 12 meters. No one has any idea why so many shark teeth are gathered in that particular area of the sea floor.

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 303: Weird and Mysterious Animal Sounds

Posted on by

Podcast: Play in new window | Download (Duration: 7:48 — 8.6MB)

Subscribe: RSS | More

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 by

Podcast: Play in new window | Download (Duration: 15:18 — 16.7MB)

Subscribe: RSS | More

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.

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!