Episode 463: The Big Fish Episode

It’s an episode just absolutely full of fish! Thanks to Arthur, Yuzu, Jayson, Kabir, Nora, Siya, Joel, Elizabeth, Mac, Ryder, Alyx, Dean, and Riley for their suggestions this week!

Further reading:

Study uncovers mechanics of machete-like ‘tail-whipping’ in thresher sharks

Business end of a sawfish:

Giant freshwater stingray!

The frilled shark looks like an eel:

The frilled shark’s teeth:

The thresher shark and its whip-like tail [photo by Thomas Alexander – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50280277]:

The Halmahera epaulette shark, looking a little bit like a long skinny koi fish [photo by Mark Erdmann, California Academy of Sciences, Attribution, https://commons.wikimedia.org/w/index.php?curid=30260864]:

A mudskipper, which is a fish even though it kind of looks like a weird frog [photo by Heinonlein – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44502355]:

The red-lipped batfish wants a big kiss:

The male blue groper is very blue [photo by Andrew Harvey, some rights reserved (CC BY) – https://www.inaturalist.org/photos/62196538, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=157789928]:

The giant oarfish is very long:

Show transcript:

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

This week we have a big fish episode! I mean, it’s a big episode about a lot of different fish, not necessarily fish that are big—although some of them sure are! Thanks to Arthur, Yuzu, Jayson, Kabir, Nora, Siya, Joel, Elizabeth, Mac, Ryder, Alyx, Dean, and Riley. I told you this is a big fish episode.

Let’s jump right in with a fish suggested by Jayson, the sawfish. There are five species of sawfish alive today. The smallest can still grow over 10 feet long, or 3 meters, while the biggest species can grow over 20 feet long, or 6 meters. The largest sawfish ever reliably measured was 24 feet long, or 7.3 meters.

The sawfish lives mostly in warm, shallow ocean waters, usually where the bottom is muddy or sandy. It can also tolerate brackish and even freshwater, and will sometimes swim into rivers and live there just fine.

The sawfish is a type of ray, and rays are most closely related to sharks. Like sharks, rays have an internal skeleton made of cartilage instead of bone, but they also have bony teeth. You can definitely see the similarity between sharks and sawfish in the body shape, although the sawfish is flattened underneath, which allows it to lie on the ocean floor. There’s also another detail that helps you tell a sawfish from most sharks: the rostrum, or snout. It’s surprisingly long and studded with teeth on both sides, which makes it look like a saw.

The teeth on the sawfish’s saw are actual teeth. They’re called rostral teeth and the rostrum itself is part of the skull, not a beak or a mouth. It’s covered in skin just like the rest of the body. The sawfish’s mouth is located underneath the body quite a bit back from the rostrum’s base, and the mouth contains a lot of ordinary teeth that aren’t very sharp.

Since the sawfish has plenty of teeth in its mouth, you may be wondering how and why it also has extra teeth on both sides of its saw. It’s because the rostral teeth evolved from dermal denticles.

Dermal denticles look like scales but they’re literally teeth, they’re just not used for eating. Sharks have them too, along with some other fish. In the case of the sawfish, the rostral teeth grow much larger than an ordinary dermal denticle, and stick out sideways.

Both the rostrum and the head are packed with electroreceptors that allow the sawfish to sense tiny electrical charges that animals emit as they move. This might mean a school of fish swimming through muddy water, or it might mean a crustacean hiding in the sand. The sawfish sometimes uses its rostrum to dig prey out of the sand, but it also uses it to slash at fish or other animals. Then the sawfish can either grab the injured or dead animal with its mouth or pin it to the sea floor with its rostrum to maneuver it into its mouth. Its mouth is relatively small and it prefers to swallow its food whole, head-first, so it can only eat fish that are smaller than its mouth. That’s also why it doesn’t want to eat people. Its mouth is too small.

Yuzu wanted to learn about another shark relation, the giant freshwater stingray, which 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 also has dermal denticles on its back.

The giant freshwater stingray has a rounded, flattened body, and it’s really big. 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. 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.

While we’re talking about shark relations, let’s go ahead and talk about a few actual sharks. Kabir wanted to learn about the frilled shark, which looks and acts more like an eel than a shark. A big female can grow up to 6 and a half feet long, or 2 meters. Males are a little shorter on average. The frilled shark has the same anatomy found in ancient sharks from the fossil record, dating back at least 95 million years. It’s found a body type that works for it.

The frilled shark lives on the continental shelf in many parts of the world, and while it technically lives near the sea floor, at night it migrates closer to the ocean surface to find fish, squid and other cephalopods, and other food. There are two species known, with the southern African frilled shark only discovered in 2009.

The frilled shark is dark brown or gray, and its jaws are long and contain clusters of teeth in little rows. Each tooth has three sharp points, and there are 300 teeth, so a frilled shark has 900 points in its mouth. The points are so sharp that scientists examining dead sharks have gotten cut on the teeth, which would be really embarrassing if you’re a shark expert that was bitten by a dead shark. The frilled shark can open its jaws extremely wide to swallow fish and other animals that are up to about half the size of the shark itself. It even eats other sharks.

Next, Joel wanted to learn about the thresher shark. It’s a truly big fish that can grow up to 20 feet long, or over 6 meters. It’s a fast, slender shark with a tail fin that can be as long as its body. It eats a lot of other animals, including birds and crustaceans, but it specializes in hunting fish that travel in schools, like tuna, sardines, and mackerel. It uses its incredibly long tail as a whip, slapping a fish to stun it so the shark can eat it. When it whips its tail, its body flexes so that its head points downward in the water with the tail snapping forward over it. A 2024 study determined that the thresher shark’s vertebral column is fortified to allow it to work like a catapult. The thresher shark can also use its long tail to help it leap out of the water completely, although scientists don’t know why it wants to do that.

There are three species of thresher shark known to science, but in 1995 a genetic analysis revealed the possible presence of a fourth species. Scientists think it lives in the eastern Pacific and may look similar to the bigeye thresher, enough that it gets misidentified as that species when it’s seen. The three known species of thresher shark are hard to tell apart at a distance as it is.

And for our last shark, Siya asked about the Halmahera epaulette shark. It’s light brown with darker and lighter spots, and is a slender shark that can grow a little over 2 feet long, or 68 cm. It lives around Indonesia, and it might live in other places too. We don’t know yet, because it was only discovered in 2013 and only two specimens have ever been found.

Epaulette sharks are also called walking sharks, because they use their fins to walk along the sea floor and explore crevices in rocks. Some species can even walk short distances on land to enter tidal pools and other places where they can find food. They live in warm, shallow water, usually near reefs or islands, and they eat whatever small animals they can find. There are nine species known, but there are undoubtedly more than haven’t yet been discovered by science. You might think this is strange for a shark that can walk on land, but walking sharks are nocturnal and not very big, so it’s easy to miss them when they’re out and about.

That brings us to Arthur’s suggestion, the mudskipper. The mudskipper also uses its fins to walk. Its pectoral fins are muscular and allow it to climb out of the water and onto land, climb into low branches, and even jump. Its pectoral fins look like little arms, complete with an elbow. The elbow is actually a joint between the actual fins and the radial bones, which in most fish are hidden within the body but which stick out of the mudskipper’s sides a short distance. This helps it move around on land more easily. Its pelvic fins are also shaped in such a way that they act as little suction cups on land.

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

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

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

Alyx, Dean, and Riley suggested we talk about the red-lipped batfish, a type of anglerfish only found around the Galapagos Islands in the Pacific Ocean. It lives on the ocean floor where the water is fairly shallow, and it grows about 8 inches long, or 20 cm. It’s usually a mottled brown, green, or grey with a white stomach, but its mouth is bright red. It looks like it’s wearing lipstick. It eats fish and other small animals, which it attracts using a lure on its head, a highly modified dorsal fin called an illicium.

The weirdest thing about the red-lipped batfish is actually its fins. It prefers to walk on the bottom of the ocean instead of swim, and it has modified pectoral fins called pseudolegs. The pseudolegs make it look a little bit like a weird frog with lipstick. Researchers think the red lips may be a way to attract potential mates, presumably ones who are hoping for a big smooch. At this rate I’m wondering if there are any fish that don’t walk on their fins.

Next, Mac wanted to learn about a fish called the payara. The problem is, there are two fish with that name, so let’s learn about them both!

The first payara is a pretty, silvery fish with a couple of small dark spots on its body. It’s found in the Amazon basin in South America and can grow at least 1 foot 8 inches long, or 51 cm. It’s sometimes kept in large aquariums, and is sometimes called the vampire tetra or the vampire fish because it has a pair of long fangs that it uses to stab other fish with before eating them. Its fangs stick up from its lower jaw, though, so if it’s a vampire fish, it’s an upside-down vampire.

As for the other payara, it’s related to the first kind and is also found in South America, but it’s even larger. It can grow a little over 3 feet long, or 3.3 meters. Its teeth are also large and sharp, including two big fangs sticking up from its lower jaw. In a big individual, its fangs may be 4 inches long, or 10 cm. This is not a fish you want to get bitten by! You are probably not in any danger of being bitten by this payara, though, unless you happen to spend a lot of your time swimming along the bottom of rivers in the Amazon.

Quite a while ago, Ryder suggested we learn about the pipe cichlid. I tried to find more about it and I think it’s actually a fish called the pike cichlid. Pike cichlids are popular freshwater aquarium fish that are native to tropical and subtropical parts of eastern South America, and there are about 45 species known so far. They’re typically quite small, with most species only growing a few inches long, or around 8 cm, although some species are more than twice that length. The pike part of their name comes from their shape, like a teeny-tiny pike, a predatory fish that can grow up to 5 feet long, or 1.5 meters. Pike and pike cichlids aren’t related, but pike cichlids are predatory. It’s just that instead of eating other fish, ducks, frogs, and even reptiles and mammals that end up in the water, the pike cichlid mostly eats insects.

Elizabeth wanted to learn about the blue groper, a fish found around Australia and nowhere else in the world. It lives around reefs and rocky areas near the coast, where it can find plenty of starfish, urchins, crustaceans, and other small animals to eat. It can grow almost six feet long, or 1.75 meters, and its teeth are peg-shaped to help it pick mollusks and other animals off of rocks before crushing them.

It’s called the blue groper because males are a beautiful blue color, while females are brown or reddish-brown and young fish are green. All young blue gropers are female, and as they grow up some change to become males while most remain females. The fish grow very slowly and can live to be at least 70 years old, so the fish don’t even reach maturity until they’re 15 or 20 years old. When a fish is around 30 or 35 years old, it will change gender again, this time becoming a male. But if the male of a group dies, the group’s dominant female will change into a male and turn blue. This is common in the family of fish that the blue groper belongs to, Labridae, also called wrasses.

Let’s finish with a suggestion from Nora, the oarfish. The giant oarfish and Russell’s oarfish can both grow at least 26 feet long, or 8 meters, and possibly much longer. Most of its length is tail, which often shows damage from being bitten. Since its organs are all close to the front of its body, and it doesn’t need its tail for swimming, if a predator takes a bite out of its tail, the fish is going to be fine. The oarfish can even detach pieces of its tail if it needs to, the same way some lizards can, to distract a potential predator. Like those lizards, the tail doesn’t grow back.

The oarfish is silvery in color with a red crest on its head and a mane-like fin down its back, although it’s actually an elongated dorsal fin. It has extremely long pelvic fins too.

The giant oarfish has a short, blunt snout and no teeth because it filters krill and other tiny animals from the water. It doesn’t have scales. Instead, its skin is soft with a delicate layer called ganoine that gives it a shimmery, almost metallic appearance. The long filaments of the crest on its head and its pelvic fins are also delicate. But although it’s long and slender like an eel, it actually swims vertically with its head pointing up and its tail down. We’re not sure why, although one theory is that this minimizes its profile to predators looking up from below. It can swim quickly straight up and down to avoid predators that mostly just swim forward.

We know so little about the oarfish, and what we know is so strange, that it’s the next best thing to a sea serpent. The first living giant oarfish was only filmed in 2001. Most oarfish are only seen when they’re dead or dying. It seems to live throughout the world’s oceans, except for the Arctic and Antarctic, and is a deep-sea fish but may migrate closer to the surface at night to find more food.

A Japanese legend says the oarfish predicts earthquakes. If an oarfish is seen near the surface or washes up on a beach, an earthquake is supposed to be imminent. That seems to be a coincidence, though.

The oarfish looks like a sea serpent, and some people think it might have given rise to some sea serpent sightings. This may or may not be the case, but it’s certainly a mysterious fish.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, corrections, or suggestions, email us at strangeanimalspodcast@gmail.com.

Thanks for listening!

Episode 455: Spooky Animals

Thanks to Richard of NC, Richard my brother, Siya, Ezra, and Owen and Aksel for their suggestions this week!

Further reading:

Creature Feature: Googly-Eyed Stubby Squid

Nocturnal Spiders Use Trapped Fireflies as Glowing Bait to Attract Additional Prey

A male vampire deer:

The adorable googly eyed squid [still taken from video linked above]:

The snowy owl [photo by Bill Bouton from San Luis Obispo, CA, USA – Snowy Owl, Bubo scandiacus, male, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=19899431]:

Show transcript:

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

This week for monster month, let’s learn about some animals that are considered spooky, although in actuality they’re just regular animals who don’t even know the meaning of spooky. Thanks to Ezra, Owen and Aksel, Richard from NC, my brother Richard, and Siya for their suggestions!

We’ll start with the two Richards. Richard from NC suggested vampire deer, and my brother Richard suggested zombie salmon.

The vampire deer is more commonly called the water deer, but considering it has tusks growing down from its upper jaw that look like fangs, vampire deer is an excellent name. Females have short tusks, but in males they grow quite long, sometimes over 3 inches long, or 8 cm. Since the animal only stands about two feet tall at the shoulder, or 65 cm, that’s pretty impressive. Its hind legs are longer than its front, so that when it runs it sort of bounces like a rabbit. It has a very short tail, small rounded ears, and is golden brown in color with a lighter underside. It doesn’t have antlers. We talked about the musk deer in episode 366, which also has fangs instead of antlers, but the vampire deer isn’t closely related to the musk deer.

The vampire deer currently lives in Korea, China, and Russia although it used to be much more widespread. It mostly lives in reedy habitats near rivers, and it’s a solitary animal although females will sometimes congregate to eat. Males protect their territories by fighting with their tusks, although they don’t actually drink blood.

As for the zombie salmon, it’s not a type of fish but something that can happen to an ordinary salmon. The salmon is a fish that famously spends most of its adult life in the ocean, but travels up rivers to spawn. The eggs hatch in freshwater and the baby fish grow up in the river, and then they migrate to the ocean and live there for almost the rest of their lives. Eventually the fish is fully mature and ready to spawn, so it travels to the river where it was hatched, fights its way upstream, and the cycle starts all over with the new generation.

Almost all salmon die after spawning. This is partly because the energy requirements of swimming upstream is so high, but also because a salmon is genetically programmed to die after spawning. This is called senescence, and while it’s common in invertebrates like octopuses and some insects, it’s rare in vertebrates. Not only that, there’s not enough food for an adult salmon in the spawning area, and an adult salmon’s body is adapted for salt water, not fresh water, so it can’t live long in rivers as an adult anyway.

A small number of female Atlantic salmon are able to return to the ocean, recover and regain their strength, and spawn again a few years later, but for all other species, after spawning, that’s it. Within days all the salmon have died.

But sometimes, rarely, a salmon remains alive for weeks after spawning. It doesn’t have the energy to return to the ocean, and its body is in the process of shutting down for planned senescence, and the freshwater is causing damage to the fish’s skin. But still it survives, growing more and more raggedy, just like a zombie in a movie. But unlike movie zombies, it doesn’t want to eat brains. Eventually the zombie salmon dies, if something doesn’t catch and eat it first.

Next, Siya suggested the googly-eyed squid. Some people find squid and octopuses scary because they look so strange, but I admit I added this squid to the episode because I think its name is funny. It’s also called the stubby squid or the googly-eyed stubby squid. Its scientific name is Rossia pacifica, which gives you a hint that it lives in the northern Pacific Ocean. In the winter it likes shallow water without strong currents, but in summer it migrates to deeper water where it doesn’t get too warm.

The googly-eyed squid is small and closely related to the cuttlefish. It grows less than four and a half inches long, or 11 cm, including its eight short arms and two retractable tentacles. It’s usually reddish-brown or purplish in color, but like most squid it can change color when it needs to. It gets its name because it has large eyes that show white around the edges and have a black pupil, which makes it look like it has googly eyes.

During the day, the googly-eyed squid buries itself most of the way in sand or mud at the bottom of the sea floor, with just its googly eyes showing so it can watch for danger. At night it comes out to hunt small animals like crabs and other crustaceans, mollusks, and fish, but what it really likes is shrimp. Naturally, it has good eyesight.

Next, let’s talk about a bird that some people find spooky. Ezra, Owen, and Aksel all suggested the snowy owl.

The snowy owl is mostly snow-white although young birds have black and gray markings. Its eyes are yellow and it often hunts in the daytime, but not always. Its wingspan can be as much as six feet across, or 1.8 meters.

The snowy owl lives throughout the Arctic and nearby regions, especially in summer, but sometimes travels long distances to find food. It’s also migratory, traveling south for the winter. Snowy owls have been spotted in such far-flung places as Hawaii, Bermuda, Pakistan and India, Iran, and Japan and Korea.

The snowy owl mostly eats small animals like lemmings and mice, although it will kill and eat pretty much anything it can catch, including ducks and other water birds, fish, and even insects and frogs. It will sometimes eat carrion and even sometimes steals food from other birds. It swallows small animals whole, and a day or two later, regurgitates a compacted pellet made up of the indigestible parts, including bones and fur. A lot of predatory birds do this, not just snowy owls. Scientists who study the birds love finding these pellets, because they can dissect them and learn what the bird has been eating.

Not only does the snowy owl make its nest on the ground, sometimes it hunts on the ground too, just running along after an animal on its big feet.

This is what the snowy owl sounds like:

[owl call]

Let’s finish with an invertebrate that a lot of people are scared of, a spider! This particular spider is a species of sheet-web spider, which lives in Taiwan. It’s a nocturnal spider that was only described in 2012. Unlike a lot of spiders, which build upright webs to trap insects that are flying along between branches and twigs, the sheet-web spider builds its web horizontally just above the ground.

The webs are light-colored and reflect light. The spiders build their webs in shady areas, and scientists think that moths see the light reflecting off the webs, and think the webs are actually the ground in an area open to the sky. Moths like open areas like this, and moths also happen to be one of the spider’s favorite foods. When a group of scientists experimented by darkening some webs with charcoal dust, they determined that the darkened webs attracted considerably fewer moths.

But it turns out that the sheet-web spider does something even more extraordinary. If a firefly gets caught in the web, the spider doesn’t eat it—or at least, not right away. It lets it stay in the web, flashing its light. Scientists noticed this and were intrigued. Did the fireflies not taste good, or was something else going on?

They placed LEDs that blinked like fireflies in some webs, but not in others, and monitored the results. It turns out that three times the number of insects were attracted to the webs with fake fireflies, and most of those were other fireflies. Fireflies attract a mate by flashing. The spiders were taking advantage of having a built-in lure stuck in their webs. So even though spiders are very tiny and have tiny brains, sometimes they’re pretty darn smart.

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. 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 451: the Stellar Jay and the Gulper Eel

Thanks to Joelle, Jacob, and Anna for their suggestions this week!

Further reading/watching:

Gulper Eel Balloons Its Massive Jaws

Watch rare footage of a shapeshifting eel with ‘remarkably full tummy’ swimming in the deep sea

The beautiful stellar jay:

The maybe not quite as beautiful but really awesome gulper eel (with its mouth full of water, image taken from first video linked above):

The same eel as above but with its mouth open so you can see just how big it is!

Show transcript:

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

This week we’re going to learn about a bird suggested by Joelle, Jacob, and Anna, and a weird fish also suggested by Jacob.

Let’s start with the bird, the stellar jay, also called Steller’s jay! In the last few years there has been a push among bird enthusiasts to change the common names of birds named after people to names that are more general. While Steller’s jay hasn’t officially been renamed to the stellar jay, a lot of people are calling it that already so that’s what we’ll call it here. The word stellar means outstanding, and that’s definitely a good description of this bird.

The stellar jay is a beautiful bird that lives in western North America down into parts of Central America. It’s closely related to the blue jay found in eastern North America, and if you saw it from the middle down you might think it was a blue jay, except that it doesn’t have white markings on its tail and wings. It has a blue tail and wing feathers with dark bars, but from about the shoulders up it looks very different from the blue jay. It’s silvery-gray, brownish, or black on its head, neck, and back. Some populations have a white eyebrow marking that makes the bird look like it’s frowning. It has a crest like the blue jay, but its crest is bigger, spikier like it hasn’t brushed its hair yet, and the bird itself is bigger overall than its eastern cousin.

The stellar jay lives in forests, especially coniferous forests, where it eats pretty much anything it can find. It’s an omnivore that likes insects and other invertebrates, eggs and baby birds of other species, and even small animals like lizards and mice, but it also eats lots of nuts, berries, seeds, and other plant material. It will visit bird feeders, and especially likes sunflower seeds and raw peanuts.

The stellar jay is a corvid, distantly related to crows and magpies, and it shares the corvid trait of being intelligent, sometimes aggressive, and loud. It will imitate hawks in order to scare other birds away from food, and it will often chase smaller birds away from feeders. During nesting season, the birds get a lot quieter, and the male will sneak his way to and from the nest to feed his mate while she’s sitting on the eggs. The stellar jay prefers to build its nest in a conifer, either in a hollow in the trunk or on branches close to the trunk.

This is what the stellar jay sounds like:

[bird calls]

Jacob also suggested we learn about the gulper eel, which is sort of the opposite of the stellar jay. It’s a deep-sea fish with a lot of names, including pelican eel and my favorite, the umbrella-mouth. It’s black or sometimes dark brown and can grow up to about three feet long, or 90 cm. Much of its length consists of a long, whip-like tail.

The gulper eel’s mouth is ENORMOUS, ridiculously enormous, especially considering how slender the rest of the fish is. Its lower jaw is hinged and is extremely long, with a stretchy pouch of skin that forms its mouth and I guess you can call them cheeks. It is a very weird fish. Most of the time it keeps its jaw folded down against its sides, so that the jaws are barely visible and it looks more or less like a regular eelh. But when it wants to, the gulper eel can unfold its jaw and gulp in water to inflate its pouch, which makes it look like a black balloon with a tail. It sometimes does this if it feels threatened so that it looks bigger, but the huge jaws are actually for swallowing animals whole.

Not only can its mouth stretch to engulf animals bigger than the gulper eel is, its stomach can stretch just as much. It has tiny teeth, though, so it’s not likely that it would try to eat animals stronger than it is, because if it swallowed a big fish, that fish might thrash around inside the gulper eel and kill it. More often, the gulper eel’s stretchy mouth and stomach allow it to eat large groups of very small animals, mostly shrimp and other small crustaceans. It also helps it swallow squid and other soft-bodied animals that are larger than it is but not dangerous.

The gulper eel has a well-developed lateral line system, more properly called the octavolateralis system. All fish and some amphibians have this system, and in many species you can see it. It’s a line or a series of dots along the fish’s sides, and it’s actually a series of modified cells that are super sensitive to water motion. The lateral line system is what allows schools of fish to stay in formation while moving around as a group, and it also helps a fish know when a predator is approaching or when potential prey is nearby. It can even help the fish sense obstacles in the water that aren’t moving, like rocks. In the gulper eel, instead of the sensory cells being in a tiny canal under the skin, they’re on the surface to increase the amount of information the fish can gather from tiny water movements.

At the end of the tail, the gulper eel has a tiny organ called a caudal appendage, which is translucent. It has tiny tentacles and glows with a pinkish light, although it occasionally flashes red. Some researchers report that the lateral line also sometimes produces bioluminescence. The bioluminescence may lure small animals to the gulper eel the same way the anglerfish’s lure does. It’s possible that the gulper eel sometimes hangs in the deep water with its long tail curved up over its head, waiting for prey to approach, but for the most part it’s an active hunter of small crustaceans and other animals.

You may remember from other episodes that most deep-sea animals can’t see the color red. Some predatory fish, including a species of dragon fish, use that to their advantage by emitting red light that they can see but their prey can’t. It’s possible that the gulper eel’s tail emits red light to help it find groups of the tiny crustaceans it mostly eats. It has very small eyes and we don’t even know if it can see the color red or not. We also don’t know if its bioluminescent tail also gives off other light wavelengths that would act as a lure to small animals, or if it uses its caudal appendage to communicate with other gulper eels.

The gulper eel lives in many of the world’s oceans, especially in tropical areas, in depths up to 9,800 feet, or 3,000 meters. Sometimes it lives in shallower water too. Because it lives so deep most of the time, we don’t know a whole lot about it. Luckily, in the last few years scientists have learned a lot more about it from deep-sea rover observations.

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. 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 448: Tennessee water mysteries

While I’m at Dragon Con, here’s an old Patreon episode about Tennessee water mysteries, including some spooky sightings of what were probably bears, and some mystery fish!

Show transcript:

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

As this episode goes live, I should be at Dragon Con, so I decided to go ahead and schedule an old Patreon episode to run instead of trying to get a new episode ready in time. It’s about some water mysteries in my home state of Tennessee, although I actually just moved away from Tennessee to Georgia.

Tennessee is in the southeastern United States, a long thin state divided into three geographical sections. East Tennessee borders the southern Appalachian Mountains, Middle Tennessee is on the Cumberland Plateau, and West Tennessee borders the Mississippi River. The only natural lake in the state is Reelfoot in northwestern Tennessee, a shallow, swampy body of water formed in the early 19th century.

Before 1811, instead of a lake a small river flowed through the area, a tributary of the Mississippi. In earlier accounts, Reelfoot River is called Red Foot River. Most of the residents of the area at the time were Choctaw, although white settlers lived in the small town of New Madrid near the bank of the Mississippi.

From December 1811 through February 1812, a series of earthquakes in the New Madrid Seismic Zone changed the land radically. There were three main quakes and innumerable smaller ones, ranging from an estimated 6.7 for the smallest quake to a possible 8.8 for the largest.

In the initial quake and aftershocks on 16 December 1811, chimneys collapsed, trees fell, and fissures opened and closed, projecting water or sand high in the air. Boats on the Mississippi capsized as huge waves crashed from bank to bank.

A woman named Eliza Bryan, who lived in New Madrid, wrote an account of the quakes:

On the 16th of December, 1811, about 2 o’clock a.m., a violent shock of earthquake, accompanied by a very awful noise, resembling loud but distant thunder, but hoarse and vibrating, followed by complete saturation of the atmosphere with sulphurous vapor, causing total darkness. The screams of the inhabitants, the cries of the fowls and beasts of every species, the falling trees, and the roaring of the Mississippi, the current of which was retrograde for a few minutes, owing, as it is supposed, to an eruption in its bed, formed a scene truly horrible.

From this time on until the 4th of February the earth was in continual agitation, visibly waving as a gentle sea. On that day there was another shock…and on the 7th, at about 4 o’clock a.m., a concussion took place so much more violent than those preceding it that it is denominated the ‘hard shock.’

The Mississippi first seemed to recede from its banks, and its waters gathered up like a mountain… Then, rising 15 or 20 feet perpendicularly and expanding, as it were, at the same time, the banks overflowed with a retrograde current rapid as a torrent.

A riverboat captain reported in another account that his boat was caught in a ferocious current on the Mississippi, crashing across waves he estimated as six feet high, or 1.8 m. He also reported whirlpools that he estimated were 30 feet deep, or 9 m. He saw all the trees on either bank fall at once.

The December quake was so large it was felt across North America, from Canada to the Gulf Coast. Then, only five weeks later, it happened again, followed by the third major earthquake on 7 February. Only 15 miles, or 24 km, from the epicenter, the land dropped 20 feet, or 6 m, and created a basin that immediately filled with water. Reelfoot Lake was formed, Tennessee’s only natural lake.

Reelfoot is a state park these days, popular with boaters, fishers, hunters, and birdwatchers. The only cryptid sighting I could find took place in the Glass community near Obion, within ten miles, or 16 km, of the lake. A man who grew up in Glass reported in 2009 that a bipedal creature 8 or 9 feet tall, or 2.5-2.7 m, and covered in off-white hair was well-known to the residents of the community. They referred to it as “the white thing.” The man had seen it several times as a child and his father, who was initially a skeptic, changed his mind when he found huge tracks in the woods.

Technically, Tennessee has two natural lakes, but the “Lost Sea” is underground. It’s located in a large cave system called Craighead Caverns in the foothills of the Great Smoky Mountains. It’s one of the largest underground lakes ever found, although it hasn’t been fully explored so its actual size isn’t known. The lake doesn’t support any known animals, although scientific explorations haven’t been conducted as far as I could find. In the 1960s the cave owners stocked the lake with rainbow trout in hopes that they would discover an exit to the surface. They didn’t, and the fish have to be fed and restocked since they have no natural food sources and won’t spawn in the lake. The cave, and the lake, are a local tourist attraction.

Besides Reelfoot Lake, Tennessee is home to many man-made lakes. Most are in East Tennessee. During the Great Depression, President Roosevelt set up the New Deal plan, creating government-funded projects to employ out-of-work Americans. The Tennessee Valley Authority was founded in 1933 to improve the lives of people who lived along the Tennessee River and its tributaries. To curb seasonal flooding and stop the spread of malaria, and to bring electricity to residents, TVA built numerous hydroelectric dams.

I grew up in a town built in the 1930s to house workers on Norris Dam, which formed Norris Lake from the Clinch River. Norris Dam was TVA’s first large project, completed in 1936. This makes the lake only 85 years old, but that’s certainly long enough for local lore to grow up around it. As a kid I heard about monster catfish—as big as a VW Beetle—living at the bottom of the spillway. The largest fish ever caught in the lake, however, was a 49.5 pound, or 22.45 kg, striped bass in 1978. The largest catfish ever caught in Tennessee was a blue catfish that weighed 112 pounds, or 50.8 kg. That’s huge, but not the size of a car.

There are other strange reports from around Norris Lake. On the night of 3 March 2012, two men went to a clearing near the first man’s house, in a swampy area near the lake’s edge, to build a bonfire and talk. They noticed footsteps and the sound of a large animal moving around in the trees nearby but assumed it was a white-tailed deer, although both men did have the sensation of being watched throughout the evening. Around midnight, when the men decided to leave, they heard sticks breaking in the trees as though being stepped on. One of the men knocked on a tree with a piece of wood and heard knocking in response, and then both were frightened by a loud, deep, long growl.

Black bears do occasionally stray into the Norris area from the nearby Smoky Mountains, but black bears don’t growl—they make distinctive moaning or chuffing noises instead. They also usually stay away from humans and fire.

In the late 1980s, possibly September of 1988, a woman returning to her car after a day of fishing with her family saw a huge hairy Bigfoot-type figure cross the trail ahead of her at speed. She only caught a quick glimpse of it at dusk but estimated it was 8 or 9 feet tall, or 2.5-2.7 m, with long arms that swung oddly as it took huge strides.

Other Tennessee lakes have their share of mysteries too. The “catzilla” legend is repeated in just about every waterway, with the catfish’s size usually compared to that of a small car. There really are some enormous fish in Tennessee’s lakes, though. In January of 2021 a man caught and released an American paddlefish in Cherokee Lake that might have approached the world record weight of 151 pounds, or 68.5 kg. It was six feet long, or 1.8 m.

There’s also a 19th century mystery associated with the Tennessee River. The earliest report of it I could find is from April 1878 in the Chattanooga Daily Times, an account from an old resident about river monster sightings from earlier that century. The first sighting by a white settler is from 1822, when a man named Buck Sutton was fishing and sighted the monster. The next reported sighting was near the same area five years later, when a man named Billy Burns saw the monster while crossing the ferry. Jim Windom was fishing in 1829 when he saw it. All three men died the summer after their encounters, although subsequent sightings (including 1836 and 1839) didn’t lead to anyone’s death.

The sightings all apparently took place in a part of the Tennessee River near Chattanooga, now dammed to form Chickamauga Lake. At the time the river there was relatively sluggish and shallow, with many shoals.

The monster was described as serpent-like and about the length of a canoe, or around 20 to 25 feet long, or 6 to 7.6 m. At least one report says it had a doglike head. Billy Burns reported that its belly was yellow and its back was blue. The most interesting detail comes from at least two reports, that of a tall black fin on its back that stood at least 18 inches high, or 45 cm, or possibly two feet high, or 61 cm.

The Tennessee River has its share of unusual animals, from tiny freshwater jellyfish to the paddlefish, a filter feeder with an elongated rostrum, but nothing with such a large and prominent dorsal fin. The lake sturgeon, which can grow well over seven feet long, or 2.2 m, has bony plates on its back and an elongated snout, which doesn’t fit the description given by witnesses. The alligator gar can grow 10 feet long, or 3 m, but like the lake sturgeon, its dorsal fin is small and set far back on the body. The longnose gar can grow six feet long, or 1.8 m, but again, its dorsal fin is small and set far back on its body, and as its name implies, its jaws are elongated.

In shallow water the tail fins of any of these fish or others can show above the surface higher than the dorsal fin, but not two feet out of the water. Moreover, all these fish were much more common in the early 19th century than they are now, and locals would likely recognize all of them.

Alligators do occasionally show up in Tennessee, although not historically. Most alligator sightings are quite recent. The American alligator can grow up to 15 feet long, or 4.5 m, but even if one occasionally strayed into the Tennessee River in the 19th century, it has no structure on its back that could be mistaken for a tall fin.

On rare occasions, a bull shark could find its way into the Tennessee River. The Tennessee is a tributary of the Ohio River, which in turns flows into the Mississippi, which then empties into the Gulf of Mexico. While bull sharks do occasionally swim up the Mississippi, no genuine sighting of one in the Ohio or Tennessee rivers has ever been documented. It’s not impossible, though. An exceptionally large bull shark can grow up to 13 feet long, or 4 m, and it prefers shallow water. Tennesseans in the early 19th century would have no knowledge of sharks and might consider it a monster, not an ordinary fish.

It’s possible that the Tennessee River was once home to a large fish with a tall dorsal fin, one that was already rare in the early 19th century and which went extinct soon after. It’s also possible that the story was just a newspaper hoax, written to fill space on a slow news day. The article from 1878 was a “contribution…from an old citizen of Chattanooga” who was not named, talking about events that took place more than fifty years before. In 1885 another newspaper, the Chattanooga Daily Commercial, ran a nearly identical article—obviously taken from the 1878 one, often word-for-word—that claims the reporter heard the story “yesterday while listening attentively to the conversation of one of Chattanooga’s oldest citizens.”

We may never know what the strange Tennessee River animal was, just as we may not know whether bigfoot-type creatures live near Tennessee’s lakes. I have my doubts that there are catfish in Tennessee bigger than cars, though—but just to be on the safe side, I’m staying in the boat.

Thanks for your support, and thanks for listening!

Episode 430: The Fake and the Real Coelacanth

This week we examine two recent articles about coelacanth discoveries. Which one is real and which one is fake?!

Further reading:

Fake California Coelacanth

First record of a living coelacanth from North Maluku, Indonesia

A real coelacanth photo:

A fake coelacanth photo (or at least the article is a fake) [photo taken from the first article linked above]:

A real coelacanth photo [photo from the second article linked above]:

Show transcript:

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

I had another episode planned for this week, but then I read an article by geologist Sharon Hill and decided the topic she researched was so important we need to cover it here. No, it’s not the dire wolf—that’s next week. It’s the coelacanth.

We talked about the coelocanth way back in episode two, with updates in a few later episodes. Because episode two is so old that it’s dropped off the podcast feed, and to listen to it you have to actually go to the podcast’s website, I’m going to quote from it extensively here.

In December of 1938, a museum curator in South Africa named Marjorie Courtenay Lattimer got a message from a friend of hers, a fisherman named Hendrick Goosen, who had just arrived with a new catch. Lattimer was on the lookout for specimens for her tiny museum, and Goosen was happy to let her have anything interesting. Lattimer went down to the dock. Then she noticed THE FISH.

It was five feet long, or 1.5 meters, blueish with shimmery silvery markings, with strange lobed fins and scales like armored plates. She described it as the most beautiful fish she had ever seen. She didn’t know what it was, but she wanted it. She took the fish back to the museum in a taxi and went through her reference books to identify it.

Imagine it. She’s flipped through a couple of books but nothing looks even remotely like her fish. Then she turns a page and there’s a picture of the fish–but it’s extinct. It’s been extinct for some 66 million years. But it’s also a very recently alive fish resting on ice in the back of her museum.

Lattimer sketched the fish and sent the drawing and a description to a professor at Rhodes University, J.L.B. Smith. But Smith was on Christmas break and didn’t get her message until January 3rd. In the meantime, Lattimer’s museum director told her the fish was a grouper and not worth the ice it was lying on.

December is the middle of summer in South Africa, so to keep the fish from rotting away, she had it mounted. Then Smith sent her a near-hysterical cable that read, “MOST IMPORTANT PRESERVE SKELETON AND GILLS.” Oops.

Smith got a little obsessed about finding another coelacanth. He offered huge rewards for a specimen. But it wasn’t until December of 1952 that a pair of local fishermen on the island of Anjuan, about halfway between Tanzania and Madagascar, turned up with a fish they called the gombessa. It was a second coelacanth.

Everyone was happy. The fishermen got a huge reward—a hundred British pounds—and Smith had an intact coelacanth. He actually cried when he saw it.

Most people have heard of the coelacanth because its discovery is such a great story. But why is the fish such a big deal?

The coelacanth isn’t just a fish that was supposed to be extinct and was discovered alive and well, although that’s pretty awesome. It’s a strange fish, more closely related to mammals and reptiles than it is to ordinary ray-finned fish. The only living fish even slightly like it is the lungfish, which we talked about in episode 55.

While the coelacanth is unique in a lot of ways, it’s those lobed fins that are really exciting. It’s not a stretch to say its paired fins look like nubby legs with frills instead of digits. Until DNA sequencing in 2013, many researchers thought the coelacanth was a sort of missing link between water-dwelling animals and those that first developed the ability to walk on land. As it happens, the lungfish turns out to be closer to that stage than the coelacanth, and both the lungfish and the coelacanth had already split off from the shared ancestor of marine and terrestrial organisms when they evolved around 400 million years ago. But for scientists in the mid-20th century, studying a fish that looked like it had little legs must have been electrifying.

But this fish story isn’t over yet. In 1997, a marine biologist on honeymoon in Indonesia found a coelacanth in a local market. And it was a different species of coelacanth. Can you imagine a better wedding gift?

Coelacanths are placid fish who do a lot of drifting, although their eight marvelous fins make them very maneuverable. They stay close to the coast and prefer rocky areas. They especially love underwater caves. They hunt for smaller fish and cephalopods like squid at night and rest in caves or hidden among rocks during the day. Sometimes sharks eat them, but for the most part coelacanths lead comfortable lives, floating around eating stuff. Sometimes they float around tail up or even upside down because they just don’t care.

Coelacanths have since been discovered in the western Indian Ocean, off the coast of Madagascar, and a few other places. I finished episode two by saying, “So far, living coelacanths have mostly been found off the coast of Africa, but they’re much more widely spread in the fossil record. Rumors of coelacanths in other places, like the Gulf of Mexico or around Easter Island, keep popping up. Maybe one day another population of these awesome fish will be discovered.”

And in late April 2025, it seemed that my hope had come true. An article was released by a website called Animals Around the Globe, detailing a new discovery of a coelacanth off the coast of San Diego, California!

Now, I missed that article but Sharon Hill didn’t. She’s a geologist whose work I follow and mention here occasionally. She likes to post about cryptids and other mysteries and dig into the real science behind reports, and she suspected right away that there was something fake about the San Diego coelacanth. There’s a link in the show notes to her article, which is worth reading. For one thing, she explains how she did the research to determine whether the article was real.

Her first step was to look for other articles about the finding. Animals Around the Globe isn’t a scientific site, just a blog that posts about animals. A new species of coelacanth, especially one found in North America, would be a HUGE big deal in the scientific community, so there should be lots of articles about it. But Sharon didn’t find anything.

Her next step was to contact the two institutions referenced in the article, the Scripps Institution of Oceanography and the Monterey Bay Aquarium Research Institute. Scripps wrote back first and said the article was a fake. Sharon suspects the article was AI generated. The blog that posted it gets money from advertising, and the more people click through to read the article, the more money they make. That’s why I’m not linking to that article from the show notes.

As it happens, on the same day that that article was published, another article about the coelacanth was published, this one in Nature Scientific Reports. It’s titled “First record of a living coelacanth from North Maluku, Indonesia,” and I do link to it in the show notes because it’s a real sighting and an article written by real scientists, not AI.

In October 2024 a team of scientists were doing deep diving off the coast of North Maluku, Indonesia, on a submerged volcanic slope where they suspected coelacanths were living. It was a dangerous dive because they had to descend so deep, so it required them to use a decompression stage on the way back to the surface. A pair of divers were on their way to the decompression site when they saw a big fish hovering over a boulder. It was a coelacanth that they estimated as being about 5 feet long, or 1.5 meters!

It swam away slowly, but the next morning the divers returned and saw it again. Because coelacanths are gray with a pattern of white dots, and each dot pattern is unique, they knew it was the same fish. They were able to get more photos and video. The most important thing, though, is that while coelacanths have been found in other parts of Indonesia, they hadn’t been found in this particular area. Live individuals also hadn’t ever been seen by actual divers, just ROVs.

The more we know about these amazing fish, the better they can be protected. Fake articles only bring confusion and doubt.

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. 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 418: Animals Discovered in 2024

This week we take a look at some of the many animals that were discovered last year!

Further reading:

‘Blob-Headed’ Catfish among New Species Discovered in Peru

New Species of Dwarf Deer Discovered in Peru

Hylomys macarong, the vampire hedgehog

Hairy giant tarantula: The monster among mini tarantulas with ‘feather duster’ legs

Woods Hole Oceanographic Institution and partners discover new ocean predator in the Atacama Trench

Never-before-seen vampire squid species discovered in twilight zone of South China

The blob headed catfish [photo by Robinson Olivera/Conservation International]:

A new mini tarantula [photo by David Ortiz]:

Show transcript:

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

This week is the 8th year anniversary of this podcast, so thanks for listening! It’s also our annual discoveries episode, where we’ll learn about a few animals that were discovered last year–in this case, in 2024.

Let’s start in Peru, a country in western South America. A 2022 survey of organisms living in the Alto Mayo region was published at the very end of 2024, revealing at least 27 new species and potentially more that are still being studied. One of those new species is a fish called the blob headed catfish.

The new fish has been placed in the bristlemouth armored catfish genus, but as you can probably guess from its name, it has a big blobby head and face. Scientists have no idea why it has a blob head. It lives in mountain streams and that’s about all we know about it right now.

Another animal found in the same survey is a new mouse. It lives in swampy forests and is semi-aquatic, including having webbed toes. It’s dark gray in color and is probably closely related to the Peruvian fish-eating rat, which is mostly brown in color and was only described in 2020.

Another new species from Peru is a type of small deer, called a pudu, that has been named Pudella carlae. It’s one of those “hidden in plain sight” discoveries, because until 2024 it was thought to be the same as the northern pudu that also lives in Ecuador and Colombia. The new deer is only 15 inches tall, or 38 cm, and is dark brownish-orange in color with black legs and face. It only lives in Peru, mostly in high elevations. It’s also the first deer species discovered in the 21st century, although hopefully not the last.

While we’re talking about mammal discoveries, we have to talk about the vampire hedgehog just because of its name. It was actually described at the very end of 2023, but it’s such an interesting animal that we’ll say it’s a 2024 discovery.

The vampire hedgehog was actually discovered a whole lot earlier than 2023, but no one noticed it was new to science for a long time. A small team of researchers studying soft-furred hedgehogs decided to collect DNA samples from all the museum specimens they could find. One of the specimens was in the archives of the Smithsonian National Museum of Natural History, collected in 1961 but never studied. When the scientists compared its DNA to the other specimens they’d found, it didn’t match up. Not only that, a closer look showed that it had fangs. Naturally, they named it the vampire hedgehog and went searching for living ones.

The vampire hedgehog lives in parts of Vietnam and is a member of the soft-furred hedgehogs, also called gymnures, hairy hedgehogs, or moonrats. Instead of spines, moonrats have bristly fur and long noses that make them look like shrews, but hairless tails that make them look like rats. They’re not rodents but are closely related to other hedgehogs. They eat pretty much anything but especially like to eat meat. This includes mice and frogs, along with various invertebrates.

As for the vampire hedgehog’s fangs, both males and females have them, but males have bigger fangs. Scientists don’t know yet what the hedgehogs use their fangs for. It could be they help the animals keep a better hold on wiggly prey, but it could be the hedgehogs just think big fangs look good on other hedgehogs so they’re one way the animals decide on a mate.

Just a few weeks ago we talked about the biggest tarantula in the world, the goliath birdeater, but did you know that there are tiny tarantulas too? The genus Trichopelma contains miniature tarantulas with body lengths measured in millimeters, and a new one was described in 2024 from western Cuba. But the great thing is, this tiny tarantula is the largest of the two dozen species known. Of the four specimens found so far, the largest body length is 11.2 millimeters—a veritable giant among miniature tarantulas!

The new species has been named Trichopelma grande, and the males, at least, have been discovered in trap-door burrows in the ground. No female specimens have been observed yet. Ground-dwelling tarantulas usually have a lot less hair on their legs, while tarantulas that live in trees are the ones with especially hairy legs, but T. grande is ground-dwelling but has very hairy legs. Or at least the males do. We don’t know about females yet.

Now let’s talk about some ocean animals, and we have to go back to Peru for our first one. The Atacama Trench is also called the Peru-Chile Trench because it’s about 100 miles, or 160 km, off the coast of both countries. At this spot a continental plate in the ocean is pushing underneath the South American plate, and it’s incredibly deep as a result. It’s been measured as 26,460 feet below the ocean’s surface, or 8,065 meters. That’s five miles deep!

Not a lot of animals live near the bottom, where the water pressure is intense and there’s not much to eat, but little crustaceans called amphipods are fairly common in the trench. Amphipods are common animals throughout the world’s oceans and freshwater, with almost 10,000 species discovered so far. There’s even a terrestrial amphipod called the sandhopper. Amphipods look a little bit like tiny shrimp, although there are some giant species. Giant in this case means 13 inches long, or 34 cm, but most are like the miniature tarantulas and are measured in millimeters.

In 2023 a new amphipod was discovered near the bottom of the Atacama Trench, and it was described in 2024 as a new species in its own genus. It grows just over an inch and a half long, or almost 4 cm, and appears white because of its lack of pigment. And most interesting of all, it’s a predator that catches and eats other species of amphipod.

Our last 2024 discovery is one that I find extremely exciting. We talked about the vampire squid way way way back in episode 11, before some of my listeners were even born, and while it has the word squid in its name, it’s not exactly a squid. It’s also not exactly an octopus. It’s the last surviving member of its own order, Vampyromorphida, which shares similarities with both squids and octopuses. And as of 2024, the vampire squid is not the only member of its own order, because they’ve found a second vampire squid!

The vampire squid is a deep-sea animal that grows about a foot long, or 30 cm, and eats whatever organic material floats down from far above. That could mean part of a dead amphipod or it could mean fish poop, the vampire squid is not picky. The new species of vampire squid was found around 3,000 feet below the surface, or a little over 900 meters, in the South China Sea. A genetic study determined that it does seem to be a new species, and the scientific name Vampyroteuthis pseudoinfernalis has been proposed. The official description hasn’t yet been published, but that just means we’ll probably get to talk more about it in a future episode.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. 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 411: Lionfish and Sea Squirrel

Thanks to David and Jayson for their suggestions this week!

Further reading:

Unveiling the lionfish invasion in the Mediterranean Sea

DeepCCZ: The Weird and Wonderful Megafauna of the Abyssal CCZ

The red lionfish is beautiful but does not look like a lion [photo by Alexander Vasenin – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=25523559]:

The sea squirrel is yellow above and red underneath (pictures from article linked above):

Under side of a gummy squirrel photographed on shipboard showing its bright red feeding palps (flower-like structure) and underbelly.

Gummy squirrel (“Psychropotes longicauda”) at 5100 m depth on abyssal sediments in the western CCZ. This animal is ~60 cm long (including tail), with red feeding palps (or “lips”) visibly extended from its anterior end (right).

Show transcript:

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

This week we’re going to learn about two interesting marine animals suggested by Jayson and David.

Let’s start with David’s suggestion, the lionfish. The lionfish doesn’t actually look like a lion although it is a fish. It lives in shallow tropical water in the Indian Ocean and western Pacific, especially around coral reefs.

There are twelve species of lionfish known, but they’re mostly fairly similar. The lionfish is brown or dark red in color with white stripes, fan-like fins, and lots of long spines, all of which are striped black and white or red and white to make them more visible. When a fish or other animal has markings that make it stand out against the background, you can be pretty sure that it’s dangerous, and that’s the case for the lionfish.

The lionfish’s spines are venomous, especially the spines on the dorsal fin. If it feels threatened, it will point the dorsal fin at the predator and keep it pointed at it no matter which direction the predator moves. If the predator swims below the lionfish, the lionfish will turn upside-down in the water to keep the dorsal fin pointed at it. Most predators back off at that point, and I don’t blame them because that sounds really scary.

People have died from lionfish venom, but it’s rare. Mostly it’s just extremely painful and makes the person feel really sick for a day or two. Divers have to be careful when they’re around lionfish, because lionfish can be aggressive and will point that dorsal fin at the diver as a warning. You don’t want a lionfish to point at you.

The lionfish eats smaller fish, including smaller lionfish, invertebrates, and other small animals. It confuses other fish by blowing water at them. The little fish turns to face into what it thinks is a weird water current, and suddenly, there’s a lionfish that just gulps it down.

As David points out, even though the lionfish is dangerous, it’s definitely beautiful. Some people keep lionfish in saltwater aquariums, although they’re hard to care for in captivity, and unfortunately sometimes the fish escape into the wild or are released. The red lionfish is especially invasive in the Caribbean Sea, the Gulf Coast, and off the southeastern coast of the United States. Lionfish have also been introduced to parts of the Mediterranean Sea, where they’re becoming more and more invasive.

Because invasive lionfish eat so many native fish, and because it’s spreading rapidly and becoming extremely common, people have been trying to find ways to reduce the invasive population. It turns out that lionfish are good to eat if you’re careful when handling the spines during cleaning, so people in areas where it’s invasive are encouraged to catch lionfish to eat. Invasive lionfish are even served in fancy restaurants. Since the red lionfish can grow around 18 inches long, or 47 cm, there’s lot a of meat on one.

No one’s sure why it’s called a lionfish. It doesn’t look remotely like a lion. It’s also called the zebrafish because of its stripes.

Next, Jayson wants to learn about the sea squirrel. Despite its name, it is not a squirrel, although it does live in the sea. It’s a type of sea cucumber that lives mostly in the Atlantic and the northeastern Pacific, but it’s also a deep-sea animal so you’re not likely to see it on your next trip to the beach. It’s yellow on top and red underneath, with 18 red feeding palps. These palps look like little flower petals surrounding its mouth, which is underneath the body. Its body is flattened on the bottom like a slug’s, but it has tiny tube feet that it uses to move around slowly.

None of this sounds like a squirrel, but that’s because I forgot to mention the rear appendage, which sticks up and back and is shaped sort of like a squirrel tail. Since the sea squirrel’s body is long and slender, it does resemble a squirrel in shape very slightly.

The sea squirrel is actually quite large. If you count the “tail,” it can measure almost 3 feet long, or 80 cm. It lives on the sea floor, where it eats whatever tiny food it can find that has sunk down from above.

The deep ocean floor mostly doesn’t have strong currents, and scientists think that’s why the sea squirrel has a tail. It’s not actually a tail, it’s a sail—or at least, that’s what we think it is. Larval sea squirrels have an appendage that almost definitely acts as a sail, allowing it to travel to new parts of the ocean without needing to swim. In adults, the tail may catch any small currents in the water, which may move the animal a short distance away. Since the sea squirrel doesn’t walk very quickly and can’t swim at all, and it finds all its food underfoot, getting moved to a new part of the sea floor where it hasn’t already eaten everything is beneficial.

Sometimes people call the sea squirrel the gummy squirrel because it kind of looks like a big piece of gummy candy, but it’s probably not a good idea to eat it. For one thing, scientists think its body may contain toxins, since its bright yellowy-green color may act as a warning to potential predators. Since nothing has been found that eats the sea squirrel, the warning must be working.

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. 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 410: Electric Catfish

Thanks to Cosmo for suggesting this week’s animal, the electric catfish!

Further reading:

The shocking truth about electric fish

Efficient high-voltage protection in the electric catfish

Gimme kiss [electric catfish photo from this site]:

Show transcript:

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

This week we’re finally going to talk about a fish Cosmo wanted us to learn about, the electric catfish!

Catfish are really common fish that live throughout the world, except for Antarctica. We’ve talked about various types of catfish in lots of different episodes, since there are well over 3,000 known species and they’re incredibly diverse. The electric catfish lives in freshwater in tropical areas in western and central Africa, as far north as the Nile River.

All animals generate electric fields in their nerves and the contracting of muscles. Animals that can sense these fields are called electroreceptive. An electroreceptive animal can find hidden prey without using its other senses.

Many electroreceptive animals can also generate weak electrical fields, usually less than a single volt—small electrical pulses or a sort of wave, depending on the species, that can give them information about their environment. Like a dolphin using echolocation, a fish using electro-location can sense where potential prey is, where predators, plants, and rocks are, and can even communicate with other fish of its same species. Of course, those same electric pulses can also attract electroreceptive predators.

Some fish can generate an electric shock so strong it can stun or kill other animals. The most famous is the electric eel, which we talked about way back in episode 10, but the electric catfish falls in this category too.

The electric catfish isn’t a single species but several in the family Malapteruridae. Some are very small, but one grows as much as four feet long, or 1.2 meters, and can weigh over 50 lbs, or 23 kg. That’s Malapterurus electricus, THE electric catfish.

The electric catfish is grayish-brown mottled with black spots. Like a lot of catfish, it’s a cylinder-shaped chonk, and has three pairs of barbels around its broad mouth. Barbels are the feelers that give the catfish its name, because they look sort of like a cat’s whiskers. Sort of. Not actually very much like a cat’s whiskers. The electric catfish also has what look like surprisingly kissy lips, which are often pale in color so they stand out, especially when the mouth is open, which is frankly hilarious. It doesn’t have a dorsal fin and it’s not a fast swimmer. It spends most of its time lurking in rocky areas in muddy, slow-moving water. It’s also nocturnal.

The electric catfish eats other fish, although it will also eat pretty much anything it can swallow. It likes muddy water because it doesn’t want potential prey to see it, and of course it doesn’t want any potential predators to see it either. That includes humans, who consider it a delicacy. Humans also sometimes keep electric catfish as aquarium fish, which is sort of the opposite of being killed and eaten.

Contracting a muscle causes a tiny, tiny electrical impulse, as I mentioned earlier, but in electric fish certain muscles have developed the ability to generate much stronger electrical impulses. Instead of muscles, they’re called electric organs. The interesting thing is that this is only found in fish, but that the ability evolved separately at least six times in different lineages of fish.

The electric catfish uses its ability to generate electric shocks as a defense when it needs to, but mainly it uses it to stun or outright kill other fish, which it then gulps down. It can discharge up to 300 volts of electricity in pulses that last only a few milliseconds, but since it can generate up to 500 pulses in waves, that’s a lot of electricity. That’s not enough to kill a person, but you’d definitely feel it and try to get away.

But, you may ask, how does the electric catfish not shock itself? Water is a really good conductor of electricity, which is one reason why this ability is only found in fish. A study published in 2022 asked that question too. The scientists used a high speed digital camera to observe captive electric catfish, and got them to discharge electricity by tickling them with a paintbrush. This allowed the scientists to see if the catfish was actually affected by its electricity at all, because the main outward sign of electrocution is involuntary muscle contractions. They determined that no, the catfish didn’t show any sign of being shocked. They also weren’t shocked when the scientists were the ones generating electricity in the tank. The conclusion is that the electric catfish is shielded by a layer of fat and other tissues that resist electric shocks, which are especially dense around the animal’s heart and nervous system.

Arthritis in humans is sometimes alleviated by the application of mild electric shocks, carefully administered by doctors, but in ancient times before electricity, people figured out that handling some fish helped arthritis. Since electric fish are pretty common in different parts of the world, different cultures figured this out at different times. The ancient Greeks would put an electric ray on the arthritic body part, for instance, while the ancient Egyptians used the electric catfish. The ancient Egyptians depicted the electric catfish in carvings and paintings that are over 5,000 years old. I have arthritis in my thumbs but I don’t think I want to touch an electric catfish with my thumbs.

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. 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 407: Cookie Cutter Shark

Thanks to Alyx for this week’s suggestion, the cookie cutter shark!

Further reading:

If You Give a Shark a Cookie

The business end of the cookie cutter shark:

Show transcript:

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

This week we’re going to learn about a little shark suggested by Alyx, but first let’s learn about something else that might be related to the shark.

In the 1970s, the U.S. Navy started having trouble with the navigation of their submarines. The Ohio-class submarine had what was called a sonar dome that was filled with oil, and the oil helped transmit sound. But repeatedly the subs would lose navigation abilities, and investigations turned up strange chunks removed from the electric cables, the oil lines, the sound probes, and the sonar dome itself—anywhere made of rubber that was soft enough for what looked like a hole saw to damage.

The Navy thought they were dealing with a state-of-the-art weapon. The United States and the former Soviet Union were bitter enemies, so the Navy thought the USSR had invented a technologically sophisticated underwater stealth drone of some kind that could damage the subs and leave no trace—nothing but circular chunks removed from the sonar dome and its components.

Thirty submarines were damaged before the Navy figured out the cause. It wasn’t a super-secret weapon at all. It was just a little fish called the cookie-cutter shark.

The cookie cutter shark doesn’t look very scary. It only grows 22 inches long at most, or 56 cm, and is brown in color. It has lots of very sharp evenly spaced teeth on its lower jaw, but compared to a great white shark, it’s nothing to worry about. But somehow it was able to disable 30 of the world’s most advanced submarines at the time.

That’s because of how the cookie cutter shark eats, which is also how it gets its name. It picks a target fish or some other animal, such as a whale or a seal, or possibly the sonar dome of an Ohio-class submarine, and sneaks up to it. It’s just a little fish and its coloration helps it blend in with its surroundings, so most animals barely notice it. It has lips that act like a suction cup, so quick as a wink it sticks itself to the animal, bites down, and spins around. In moments it’s cut a circular chunk out of the animal’s side like a horrible cookie, which it swallows, and by the time the animal even realizes it’s hurt, the cookie cutter shark is long gone.

The shark used to be called the cigar shark because of its shape. It wasn’t until 1971 that experts realized how the cookie cutter shark eats. Until then the circular wounds on fish and whales and other animals were thought to be from lamprey bites or from some kind of parasite.

The cookie cutter shark does have teeth in its upper jaw but they’re much smaller than the lower teeth. When it sheds its lower teeth to replace them, instead of shedding just one tooth, it sheds them all at once. Like most sharks, it swallows its old teeth so it can reuse the calcium to grow new teeth.

The shark also has photophores on the underside of its body that glow greenish, which is a common way that some fish escape predators from below. A big fish looking up toward the surface of the water high above it sees a lot of light shining down from the sun, so a fish with a glowing underside just blends in. But in the case of the cookie cutter shark, it has a strip of skin on its underside without photophores, and from below that strip shows up. It’s a sort of collar that’s actually darker brown than the rest of the fish. It looks, in fact, like a tiny fish silhouetted against the surface. The would-be predator fish approaches, expecting an easy meal. Instead, the cookie cutter shark darts around and takes a big bite out of the fish, then takes off. It’s a remarkably fast swimmer, but most of the time it hangs almost motionless in the water waiting for another animal to approach. Its eyes are large and it has good vision.

Sometimes the cookie cutter shark will travel in schools, which attracts even more predators who think they’re looking at a bunch of little bitty fish. Then all the sharks get a bite.

That leads us to the uncomfortable question: has the cookie cutter shark ever bitten a piece out of a human? The answer is yes, but no one has ever died from a cookie cutter shark attack. The shark usually stays in deep water during the day and rises closer to the surface at night, so it’s not likely to encounter humans except at night. Occasionally a swimmer has been bitten, and shipwreck survivors have reported being bitten at night while waiting for rescue, which is just insult to injury. In 2023 a swimmer was bitten by two cookie cutter sharks, but he saw them and was able to just grab them both and throw them away before he was seriously hurt. That’s not something you can do with a great white.

As for the submarines, the Navy started putting fiberglass shields over the sonar dome and other softer parts of the sub, and that solved the problem. It only cost $2 billion each to repair the subs.

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. 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 401: El Gran Maja and Other Giant Eels

Thanks to Murilo for suggesting El Gran Maja for our first monster month episode of 2024!

Further reading:

The Loch Ness Monster: If It’s Real, Could It Be an Eel?

Further watching:

Borisao Blois’s YouTube channel [I have not watched very many of his videos so can’t speak to how appropriate they all are for younger viewers]

El Gran Maja, YouTube star:

The European eel [photo by GerardM – http://www.digischool.nl/bi/onderwaterbiologie/, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=284678]:

A supposed 21-foot eel, a product of trick photography:

The slender giant moray eel [photo by BEDO (Thailand) – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=40262310]:

Show transcript:

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

It’s monster month, where we talk about weird, mysterious, and sometimes spooky creatures! This year I’ve decided to be less spooky and more weird, so let’s kick off the month with an episode all about gigantic eels. Thanks to Murilo for suggesting our first giant eel, El Gran Maja.

El Gran Maja is an eel that is supposed to live off the coast of northern Puerto Rico, and it’s supposed to grow 675 meters long. That’s 2,215 feet, or almost half a mile. That is an excessive amount of eel.

Obviously, an eel that big couldn’t actually exist. By the time its front end noticed danger, its back end could already be eaten by a whole family of sharks. But maybe it was based on a real eel that grows really long. Let’s take a look at some eels we know exist, and then we’ll return to El Gran Maja and learn some very interesting things about it.

Eels are fish, but not every animal that’s called an eel is actually an eel. Some are just eel-shaped, meaning they’re long and slender. Electric eels aren’t actually eels, for instance, but are more closely related to catfish. Most eels live in the ocean at the beginning and end of their lives, and freshwater in between.

For example, the European eel has a life cycle that’s pretty common among eels. It hatches in the ocean into a larval stage that looks sort of like a transparent leaf. Over the next six months to three years, the larvae swim and float through the ocean currents, closer and closer to Europe, feeding on plankton and other tiny food. Toward the end of this journey, they grow into their next phase, where they resemble eels instead of leaf-shaped tadpoles, but are still mostly transparent. They’re called glass eels at this point. The glass eels make their way into rivers and slowly migrate upstream. Once a glass eel is in a good environment it metamorphoses again into an elver, which is basically a small eel. As it grows it gains more pigment until it’s called a yellow eel. Over the next decade or two it grows and matures, until it reaches its adult length—typically around 3 feet, or about a meter. When it’s fully mature, its belly turns white and its sides silver, which is why it’s called a silver eel at this stage. Silver eels migrate more than 4,000 miles, or 6500 km, back to the Sargasso Sea to spawn, lay eggs, and die.

One place where European eels live is Loch Ness in Scotland, and in the 1970s the idea that sightings of the Loch Ness Monster might actually be sightings of unusually large eels became popular. A 2018 environmental DNA study brought the idea back up, since the study discovered that there are a whole, whole lot of eels in Loch Ness. The estimate is a population of more than 8,000 eels in the loch, which is good since the European eel is actually critically endangered. But most of the eels found in Loch Ness are smaller than average, and the longest European eel ever measured was only about 4 feet long, or 1.2 meters.

An eel can’t stick its head out of the water like Nessie is supposed to do, but it does sometimes swim on its side close to the water’s surface, which could result in sightings of a string of many humps undulating through the water.

But the Loch Ness monster aside, the European eel isn’t very big compared to many species of eel. The European conger eel is the heaviest eel known, although not the longest. It lives off the coast of Europe down to northern Africa, and also in the Mediterranean Sea. An exceptionally large female might be as much as 10 feet long, or 3 meters, but it’s also chonkier than other eels. The largest conger ever measured reportedly weighed 350 lbs, or almost 159 kg, and was caught in a net off the coast of Iceland, although that report isn’t very reliable.

In 2015, a lot of newspaper reports talked about a huge eel caught off the coast of Devon, England. They printed pictures of a massively huge eel hung up in front of the fishermen who caught it. The articles said the eel was as much as 21 feet long, or 6.4 meters, and weighed 160 lbs, or just over 72 kg.

But if you think about it, there’s something fishy (sorry) about the story. If you picture a big man, say a football player who’s fit and strong, he might be about six feet tall, or 1.8 meters, and weigh a bit more than 200 lbs, or maybe 95 kg. But the eel weighed a lot less than that hypothetical man, and eels are strongly muscled even though they’re slender in shape. A 21 foot eel should weigh much more than a football player.

Most likely, reporters looked at the photo and compared it to the fishermen, and came up with the 21 foot length themselves. But it’s a trick photo, even if the trick wasn’t planned, because the eel was hung up very close to the camera while the fishermen were much farther back, which makes the eel look huge in comparison. Not only that, but when you hang a dead eel up by its head, it stretches so that it looks longer than it really was when it was alive. Other pictures of the eel make it look much shorter.

As it turns out, the fishermen who caught the eel didn’t even measure it. They thought it might have been up to 10 feet long, but it might have been closer to 7, or 2 meters. That’s still a big eel, and the weight may be close to a reliable record of heaviest eel, but it’s nowhere near the longest eel ever measured.

That record goes to the slender giant moray eel, which lives in muddy coastal water of the Pacific Ocean. It’s brown and isn’t especially exciting to look at unless you’re an eel enthusiast or an actual eel yourself, but the longest eel ever reliably measured was a slender giant moray. That was in 1927 in Queensland, Australia. The eel measured just shy of 13 feet long, or 3.94 meters.

In other words, the longest eel ever measured is approximately 2,202 feet, or 671 meters, shorter than El Gran Maja. But to learn more about El Gran Maja we have to talk about something called the bloop.

The bloop is a sound recorded in 1997 off the tip of South America by the National Oceanic and Atmospheric Administration, AKA NOAA. The sound itself came from the middle of the South Pacific Ocean, and was so loud that it was recorded by sensors 3,000 miles away, or 5,000 km. But it was also an ultra-low-frequency sound, so that humans and most other animals wouldn’t be able to hear it at all.

This is what the bloop sounds like, sped up 16 times so that people can hear it:

[bloop sound]

It turns out that the bloop was made by a big iceberg breaking into pieces, and similar sounds have been recorded since by NOAA and other researchers. But when the bloop was first made public, its source was still a mystery, and pretty much everyone on the internet lost their minds with excitement thinking it was a deep-sea creature far bigger than a blue whale. People speculated about the size of the bloop monster and estimated it had to be about 705 feet long, or 215 meters, for it to make such a loud call.

A film-maker and artist named Borisao Blois was interested in the bloop monster and wanted to animate it, but decided it needed a rival to fight—and he wanted the rival to be even bigger. He invented El Gran Maja and animated a fight between the two. Because Blois wanted his monster to be exciting to look at during his films, he gave it a huge wide mouth filled with sharp, comb-like teeth, and six all-white eyes. The first video was released in 2001 and has more than 89 million views. Many more videos followed, along with creations made by other artists who were inspired by the original.

The videos Blois has made about El Gran Maja are popular, and some people even think it might be a real monster. Considering that an eel that big would need to eat an astounding amount of food every day to survive, and it’s big enough to swallow entire ships whole, it’s probably a good thing that it’s just a made-up monster.

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. 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!