Category Archives: invertebrates

Episode 199: Carnivorous Sponges!



Thanks to Lorenzo for this week’s topic, carnivorous sponges! How can a sponge catch and eat animals? What is its connection to the mystery of the Eltanin Antenna? Let’s find out!

Further reading/watching:

New carnivorous harp sponge discovered in deep sea (this has a great video attached)

How Nature’s Deep Sea ‘Antenna’ Puzzled the World

Asbestopluma hypogea, beautiful but deadly if you’re a tiny animal:

The lyre sponge, also beautiful but deadly if you’re a tiny animal:

The ping-pong tree sponge, also beautiful but deadly if you’re a tiny animal:

The so-called Eltanin antenna:

A better photo of Chondrocladia concrescens, looking less like an antenna and more like a grape stem:

Show transcript:

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

This week we’re going to learn about carnivorous sponges, which is a suggestion from Lorenzo.

When I got Lorenzo’s email, I thought “oh, neat” and added carnivorous sponges to the giant, complicated list I keep of topic suggestions from listeners and my Aunt Janice, and also animals I want to learn more about. When I noticed carnivorous sponges on the list the other day, I thought, “Wait, sponges are filter feeders. Are there even any carnivorous ones?”

The answer is yes! Most sponges are filter feeders, sure, but there’s a family of sponges that are actually carnivorous. Caldorhizidae is the family, and it’s made up of deep-sea sponges that have only been discovered recently. We know there are lots more species out there because scientists have seen them during deep-sea rover expeditions without being able to study them closely.

We talked about sponges way back in episode 41, with some mentions of them in episodes 64 and 168 too, but only the filter feeder kind. Let’s first learn how a filter feeder sponge eats, specifically members of the class Demosponge, since that’s the class that the family Caldorhizidae belongs to.

Sponges have been around for more than half a billion years, since the Cambrian period and possibly before, and they’re still going strong. Early on, sponges evolved a simple but effective body plan and just stuck to it. Of course there are lots and lots and lots of different species with different shapes and sizes, but they almost all work the same way.

Most have a skeleton, but not the kind of skeleton that you think of as an actual skeleton. They don’t have bones. The skeleton is usually made of calcium carbonate and forms a sort of dense net that’s covered with soft body tissues. The tissues are often further strengthened with small pointy structures called spicules. If you’ve ever played a game called jacks, where you bounce a ball and pick up little metal pieces between each bounce, spicules sort of resemble jacks.

The sponge has lots of open pores in the outside of its body, which generally just resembles a sack or sometimes a tube. One end of the sack is attached to the bottom of the ocean, or a rock or something. The pores are lined with cells that each have a teensy structure called a flagellum, which is sort of like a tiny tail. The sponge pumps water through the pores by beating those flagella. Water flows into the sponge’s tissues, which are made up of lots of tiny connected chambers. Cells in the walls of these chambers filter out particles of food from the water, much of it microscopic, and release any waste material. The sponge doesn’t have a stomach or any kind of digestive tract, though. The cells process the food individually and pass on any extra nutrients to adjoining cells.

Obviously, this body plan is really effective for filter feeding, not so effective for chasing and killing small animals to eat. The sponge you may have in your kitchen is probably synthetic or manufactured from a sponge gourd, not an actual bath sponge animal, but it’s arranged the same way. Go look at that sponge, or just imagine it, and then compare it mentally to, say, a tiger. Very different.

But in 2007, an underwater rover captured something on film that astounded researchers. The rover was investigating some undersea caves in the Mediterranean, where a tiny sponge known as Asbestopluma hypogea lives. The sponge only grows about half an inch long, or 1.5 cm, and everyone assumed it was just a regular old sponge. You know, a filter feeder. It did have an unusual structure of filaments covered with hook-like spicules, but until 2007 no one realized those spicules were actually hooks and used to snag tiny animals like copepods, nematodes, and even brittle stars. Then they saw it on film and freaked out! Well, they probably freaked out. I like to think they did.

But wait, you are probably saying, or at least thinking, sponges don’t even have a digestive system! How do they eat the animals they catch?

It works like this. When a tiny animal floats or swims past and gets snagged by the hooked spicules, which by the way is a passive process, the sponge starts growing a membrane that envelops the animal within a few hours. The membrane is made up of specialized cells that contain beneficial bacteria, and the bacteria help digest the animal so that the cells can absorb the nutrients. The process can take up to ten days. It’s similar in some ways to how carnivorous plants digest animals, as we talked about in episode 129.

One interesting thing is that while A. hypogea is a deep-sea sponge, it’s also found in shallow underwater caves. Further research has suggested that underwater caves may shelter other animals that are usually deep-sea dwellers. One cave where the sponge is found is only 16 feet below the surface, or five meters, whereas it lives around 2,300 feet deep, or 700 meters, in open ocean. Since its discovery in both the caves and in deeper parts of the Mediterranean, it’s been classified as a protected species and parts of the Mediterranean where it lives have also been protected.

It wasn’t until 2012 that the harp sponge was discovered off the coast of northern California. The harp sponge lives up to 11,500 feet below the surface, or 3,500 m, and it gets its name because of its shape. Like a harp, which has strings stretched down from an arched frame, the harp sponge has a structure called a vane that consists of a horizontal branch with straight, thin branches growing up from it in a row. The harp sponge can have up to six vanes, and where they connect in the middle the sponge has root-like filaments that anchor it to the sea floor. It’s no wonder that people used to think sponges were plants.

The vanes of the harp sponge are covered with hooked spicules like the grabby half of Velcro, but pointier. At the top of the vertical branches, little balls of sperm form and are released into the water to fertilize the eggs of other harp sponges. The sponge also has egg development areas about halfway up the vertical branches, which have tiny filaments to help it catch sperm released by other sponges. When it catches sperm, the cells of the filament fuse with it and use it to fertilize the nearest eggs. You can see both the sperm packets and the egg development areas in a picture in the show notes, and both look like little bulbs.

I should mention that all these carnivorous sponges are incredibly pretty.

The harp sponge can grow up to almost 15 inches across, or 37 cm, which is pretty big for a sponge.

The ping-pong tree sponge is another newly discovered carnivorous sponge, and arguably it has the best name. It can grow up to 20 inches tall, or 50 cm, but most of its height comes from its central stalk that anchors it to the sea floor. At the top of the stalk, smaller stems branch out and at the end of the stalks, little bulbs around 3 to 5 mm in diameter grow like grapes on a grape stem. The bulbs resemble little ping-pong balls (also known as table tennis, but ping-pong is funnier and refers to the sound the little hollow ball makes as it bounces from a paddle and off the table).

We don’t know much at all about the ping-pong tree sponge. It’s been found off the coast of South America near Easter Island, around 8,800 feet deep, or 2,700 meters. So far it seems to live in areas where the sea floor is made up largely of hardened lava.

We’ll finish with a mystery related to carnivorous sponges! In 1964 a research ship called the USNS Eltanin was photographing the sea floor in the Antarctic, and on August 29th it took a photograph of something weird off the coast of Cape Horn. Cape Horn is the very southern tip of South America except for a few islands, and is considered the point where the Atlantic and Pacific Oceans meet. That’s an arbitrary distinction made by humans since obviously the world’s oceans are connected everywhere, but it’s useful for telling people where you found a weird thing in the water. The picture was taken at a depth of almost two and a half miles, or 3,904 meters.

The picture shows what looks like a stick growing straight up from the ocean floor, with cross-shaped pieces of equal lengths sticking straight out to the sides, and a little bulb at the very top. It looks for all the world like a weird radio antenna, and it’s actually been called the Eltanin antenna.

The picture appeared in a newspaper article later that year, 1964, and drew the attention of UFO enthusiasts. By 1968 many people thought the picture showed a piece of machinery left by alien visitors for unknown but probably sinister purposes, although why they left the machinery at the bottom of the ocean, no one could say. Other people thought the antenna had been planted by the Soviets for likewise unknown but probably sinister purposes, ditto no idea why it was at the bottom of the ocean. Other people pooh-poohed all that and said it was probably just something that had fallen off a ship and lodged upright in the mud.

Instead, it turns out that the so-called antenna is probably actually a carnivorous sponge, Chondrocladia concrescens, known to science since 1880 although no one knew it was carnivorous back then. Disappointingly, better pictures of the sponge show that it looks more like a grape stem than an antenna. These days even diehard UFO researchers acknowledge that the Eltanin antenna was just a sponge, although a pretty neat one. Mystery solved!

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 192: Ghostly Animals



Let’s start off October with a spooky episode about some ghost animals–real ones, and some ghost stories featuring animals!

Don’t forget to enter our book giveaway! Details here.

Further reading:

Lolo the Ghost Snake

Barn Related Ghost Stories

What big teef you have, ghost bat:

Nom nom little ghost bat got some mealworms (also, clearly this rehabilitation worker has THE BEST JOB EVER):

Ghost snake!

This is where the ghost snake lives. This photo and the one above were both taken by Sara Ruane (find a link to the article and photos in the “further reading” section):

The ghost crab is hard to see against the sand but it can see you:

Show transcript:

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

It’s finally October, which means it’s monster month on the podcast! Let’s jump right in with an episode about three animals with the word ghost in their name, and some spooky ghost stories that feature animals. (Don’t worry, they won’t be too spooky. I don’t want to scare myself.)

First up is my personal favorite, the ghost bat. That’s, like, twice the Halloween fun in one animal! Not only that, it’s a member of a family of bats called false vampires, and is sometimes called the Australian false vampire bat. I am just, I can’t, this bat is too perfect and I have died.

The ghost bat lives in parts of northern Australia and is actually pretty big for a microbat. Its wingspan is almost 20 inches wide, or 50 cm. Its color is pale gray, sometimes almost white, while babies are darker gray. It has large, long ears and a nose leaf that helps it echolocate, and it’s nocturnal like most microbats. While it doesn’t have a tail, it does have sharp teeth and a strong jaw to help it eat even the bones of small animals.

Most microbats eat insects, but the ghost bat prefers vertebrates like frogs, mice, snakes, lizards, birds, even other species of bat. It hunts by dropping down on its prey, most of which live on the ground. It folds its wings around its prey and bites it in the neck to kill it, which makes it even better as a Halloween bat. I love this bat. It eats almost all of the body of its prey, including fur, bones, teeth, and even small feathers in the case of birds. Sometimes it eats its prey immediately, but sometimes it carries it to a small cave to eat, separate from its roosting area, referred to as a midden since the floor is littered with the remains of past meals. If you’re not familiar with the word midden, it just means a trash heap. Researchers love finding a ghost bat’s midden because they can find out exactly what animals the bat has eaten lately.

Female ghost bats roost in groups during the late spring to have their babies, usually in caves or abandoned mines. A female gives birth to a single baby, and she carries it around until it’s big enough to learn how to fly on its own, in about seven weeks. Once it can fly, it accompanies its mother on hunting trips until it’s fully weaned several months later. A mother bat has two pairs of teats, one pair near her armpits that produces milk for her baby to drink, and one pair near her legs that doesn’t produce milk. The teats near her legs act as little handholds for her baby to help it keep a good grip on her, especially when it’s very young.

The ghost bat is vulnerable to many of the usual concerns, including habitat loss and introduced predators, but it also has an unusual issue with an introduced plant and a type of fencing. The ghost bat doesn’t fly very high most of the time, since it’s usually hunting for small animals that live on the ground or birds roosting in bushes. As a result, its wings frequently get snagged on the spines of a thorny plant called lantana, and on barbed wire fencing. The spines or barbs tear the wings’ delicate patagia, often so badly that the bat can’t fly and starves to death. Since there are only an estimated 8,000 of the bats left in the wild, this is especially bad.

The ghost bat has good hearing, naturally, but it also has good eyesight. It uses a combination of hearing, vision, and echolocation to navigate and find prey. It also makes some sounds within the hearing range of humans. This is what a ghost bat sounds like:

[ghost bat chattering]

That bat sounds adorable and not spooky at all. So let’s bump up the spooky factor with our first ghost story.

This one comes from one of my favorite books, The Telltale Lilac Bush by Ruth Ann Musick, which we talked about in episode 91, about spooky owls. It’s a collection of ghost stories collected by folklorists in West Virginia. This story is called “A Loyal Dog.”

“Many years ago a small boy saw a little dog floating down the river on a log. He swam out, rescued the dog, and took it home with him. After this, the boy and the dog were together at all times. The dog lived for almost twenty years, and when it died, the young man was very sad to see his good friend go.

“Sometime later the young man was walking through a field, when all at once he was pulled down by something behind him. This gave him quite a start, but when he looked around, he saw, just in front of him, a great crack in the ground. Had he not been stopped, he would probably have fallen into it and been killed.

“What saved him, he did not know. There was nothing around that could have knocked him down or that he could have stumbled over. When he examined his clothing, however, there were the marks of a dog’s teeth on his coat, and clinging to the coat some dog hair—the same color as his old dog’s.”

Next let’s talk about the ghost snake, which lives in Madagascar. Not only is it called the ghost snake, it’s a member of a group of nocturnal or crepuscular snakes called cat-eyed snakes. The cat-eyed snakes are relatively small, slender, and have large eyes with slit pupils like cats have.

The ghost snake gets its name because it’s pale gray in color, almost white, with a darker gray pattern, and because it’s elusive and hard to find. Researchers only discovered it in 2014. A team of researchers were hiking through a national park in the pouring rain hoping to find species of snake that had never had their DNA tested. The goal was to collect genetic samples to study later. After 17 miles, or 25 km, of hiking through rugged terrain in the rain, they spotted a pale snake on the path. Fortunately they were able to catch it, and genetic analysis later showed that it was indeed a new species.

We know very little about the ghost snake since it’s so hard to find. It lives in rocky areas, which is probably why it’s pale gray, since the rocks are too. The rocks are uneven pointy limestone formations known locally as tsingy, which translates to “rock you can’t walk on barefoot.” The snake doesn’t have fangs, but it does have toxins in its saliva and a pair of enlarged teeth in the rear of the mouth. We don’t know what it eats yet, but the other cat-eyed snakes in Madagascar are general predators who eat pretty much any small animal they can catch, including frogs and toads, lizards, and rodents. Other cat-eyed snakes also sometimes act like constrictors to help kill prey.

A mysterious pale snake is definitely spooky, but I have a story that’s even spookier. It’s from a 1913 book called Animal Ghosts by Elliott O’Donnell and the story is called “The Phantom Pigs of the Chiltern Hills.”

“A good many years ago there was a story current of an extraordinary haunting by a herd of pigs. The chief authority on the subject was a farmer, who was an eye-witness of the phenomena. I will call him Mr. B.

“Mr. B., as a boy, lived in a small house called the Moat Grange, which was situated in a very lonely spot near four cross-roads, connecting four towns.

“The house, deriving its name from the fact that a moat surrounded it, stood near the meeting point of the four roads, which was the site of a gibbet, the bodies of the criminals being buried in the moat.

“Well, the B——s had not been living long on the farm, before they were awakened one night by hearing the most dreadful noises, partly human and partly animal, seemingly proceeding from a neighbouring spinney, and on going to a long front window overlooking the cross-roads, they saw a number of spotted creatures like pigs, screaming, fighting and tearing up the soil on the site of the criminals’ cemetery.

“The sight was so unexpected and alarming that the B——s were appalled, and Mr. B. was about to strike a light on the tinder-box, when the most diabolical white face was pressed against the outside of the window-pane and stared in at them.

“The children shrieked with terror, and Mrs. B., falling on her knees, began to pray, whereupon the face at the window vanished, and the herd of pigs, ceasing their disturbance, tore frantically down one of the high roads, and disappeared from view.

“Similar phenomena were seen and heard so frequently afterwards, that the B——s eventually had to leave the farm, and subsequent enquiries led to their learning that the place had long borne the reputation of being haunted, the ghosts being supposed to be the earth-bound spirits of the executed criminals.”

Our last ghostly animal is the ghost crab. There are many species of ghost crab that live all over the world, especially on tropical and subtropical beaches, including the one I’m familiar with, the Atlantic ghost crab. It’s typically a fairly small crab. The Atlantic ghost crab only grows around 2 inches across, or 5 cm, not counting its legs, while some species may be twice that size.

Its body is squarish and thick, which gives it a boxy appearance, and it has long, club-shaped eyestalks that can swivel so it can see all around it. One of its claws is always larger than the other. It digs a burrow in the sand or mud to stay in during the day, but at night it comes out and scavenges along the beach to find food. It will eat small animals if it can catch them, including insects and smaller crabs, but it also eats dead animals, rotting plants, and anything else it can find. It’s a fast runner and can zoom around on the beach at up to 10 mph, or 16 km/h.

The ghost crab gets its name from its coloration, just like the other ghost animals in this episode. Most species are white, pale gray, or pale yellow, basically the color of the sand where it lives. But it’s able to change colors to match its surroundings. This change usually takes several weeks because it has to adjust the concentration of pigments in its cells. This is useful since beaches can change color over time too.

The ghost crab is semi-terrestrial. It can’t live underwater without drowning, but it also has to keep its gills wet with seawater or it dies. This is sort of the worst of both worlds if you ask me, but it works for the crab. Generally, damp sand is wet enough to keep its gills wet, and its legs also have tiny hairlike structures that help wick moisture from the sand up to its gills.

A female ghost crab will usually join a male she likes in his burrow to mate. She carries her eggs around under her body, keeping them wet by going into the water frequently. When they’re ready to hatch, she releases them into the surf, where the larvae live until they metamorphose into little bitty young crabs that then live on land.

Surprisingly, the ghost crab makes several different sounds. It can rub the ridges on its claws together, drum on the ground with its claws, and make a weird bubbling sound. Until recently scientists weren’t sure how it made this last sound, but new research reveals that it’s made by a comblike structure in the crab’s digestive system called a gastric mill that helps grind up food. It rubs the comb of the gastric mill against another structure called a medial tooth to produce the sound. The crab uses the noises it makes to intimidate potential predators, including raccoons, and making a sound with its digestive system leaves its claws free to pinch if it needs to.

This is what the ghost crab sounds like:

[ghost crab sound]

We’ll finish up with a final spooky ghost story, or actually several short ones. I found an old but fun thread on a horse forum where people were talking about their haunting experiences in and around barns. I’ve chosen a few to read here, but if you want to go read the whole thread, I’ll link to it in the show notes.

The first comes from someone who calls themself Saidapal:

“My old mare (28 years old) and my young gelding (6 years old) were best of friends since the day he arrived at my farm when he was one. Sadly I had to have the mare put down last year. Every day for the first 2 weeks after she passed the gelding would come out of his stall and go straight to hers just like he had been doing for years to wait for her to join him. Broke my heart and still does when I think about it.

“When she had been gone for about 2-3 months I started seeing shadows out of the corner of my eyes and hearing her joints pop so I knew it was her LOL, and always the gelding would be somewhere in the vicinity. After a day or two I dreamed about her, and in the dream she was young and beautiful again. The very next morning the gelding came out of his stall and went straight to hers just like he used to. It was the last time he ever did that and I haven’t seen her since.

“I swear she had come to say goodbye to both of us.”

The next story is by Darken:

“I’ve had a number of things happen in my barn. I’ve had my collar lifted up and tugged from behind. I’ve had what felt like the nose of a big dog go into the palm of my hand, so much so that I turned around expecting to see my neighbor’s German Shepard there. And the best one was when I was walking out to the barn one night in the dark and saw the ghost of a horse run left to right between me and the barn door. Since I was looking down as I was walking, I just missed seeing its head, but I clearly saw its neck, flying mane, back, croup and flagging tail. I could see nothing below its knees, and it ran about 2 feet off the ground. The edges of it were solid white, but towards the center it was so transparent, I could see the stripes of the barn door thru it.”

And our last story is by Watermark Farm:

“Years ago I boarded at a barn where all the horses spooked badly at a certain corner near the entrance to the arena. It was a real problem and several people had been dumped badly in this corner. A boarder had a pet psychic out to work with her horse. The psychic knew nothing about this spooky spot but said ‘He hates that corner, the one with the dead pig. The dead pig thinks it’s funny to run out and scare the horses.’”

Happy Halloween!

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or just tell a friend. Don’t forget to contact me if you want to enter the book giveaway which is going on through October 31, 2020! Details are on the website.

Thanks for listening!


Episode 191: Masters of Disguise!



Thanks to Nicholas and Pranav for their suggestions which led to this episode about animals that are especially good at disguising themselves!

If you’d like to listen to the original Patreon episode about animal mimics, it’s unlocked and you can listen to it on your browser!

Don’t forget to contact me in some way (email, comment, message me on Twitter or FB, etc.) if you want to enter the book giveaway! Deadline is Oct. 31, 2020.

Further watching:

An octopus changing color while asleep, possibly due to her dreams

Crows mobbing an owl!

Baby cinereous mourner and the toxic caterpillar it’s imitating:

The beautiful wood nymph is a moth that looks just like bird poop when it sits on a leaf, but not when it has its wings spread:

The leafy seadragon, just hanging out looking like seaweed:

This pygmy owl isn’t looking at you, those are false eyespots on the back of its head:

Is it a ladybug? NO IT’S A COCKROACH! Prosoplecta looks just like a (bad-tasting) ladybug:

The mimic octopus:

A flower crab spider with lunch:

Show transcript:

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

This week let’s look at some masters of disguise. This is a suggestion from Nicholas, but we’ll also learn about how octopuses and other animals change colors, which is a suggestion from Pranav. Both these suggestions are really old ones, so I’m sorry I took so long to get to them. A couple of years ago we had a Patreon episode about animal mimics, so I’ll be incorporating parts of that episode into this one, but if you want to listen to the original Patreon animal mimics episode, it’s unlocked so anyone can listen to it. I’ll put a link to it in the show notes.

Most animals are camouflaged to some degree so that they blend in with their surroundings, which is also called cryptic coloration. Think about sparrows as an example. Most sparrows are sort of brownish with streaks of black or white, which helps hide them in the grass and bushes where they forage. Disruptive coloration is a type of camouflage that breaks up the outlines of an animal’s body, making it hard for another animal to recognize it against the background. Many animals have black eye streaks or face masks that help hide the eyes, which in turn helps hide where their head is.

But some animals take camouflage to the extreme! Let’s learn about some of these masters of disguise.

We’ll start with a bird. There’s a bird that lives in parts of South America called the cinereous mourner that as an adult is a pretty ordinary-looking songbird. It’s gray with cinnamon wing bars and an orange spot on each side. It mostly lives in the tropics. In 2012, researchers in the area found a cinereous mourner nest with newly hatched chicks. The chicks were orangey-yellow with dark speckles and had long feather barbs tipped with white. While the researchers were measuring the chicks and making observations, they noticed something odd. The chicks started moving their heads back and forth slowly. If you’ve ever seen a caterpillar moving its head back and forth, you’d recognize the chicks’ movements. And, as it happens, in the same areas of South America, there’s a large toxic caterpillar that’s fluffy and orange with black and white speckles.

It’s rare that a bird will mimic an insect, but mimicry in general is common in nature. We’ve talked about some animal mimics in earlier episodes, including the orchid mantis in episode 187 that looks so much like a flower that butterflies sometimes land on it…and then get eaten. Stick insects, also known as phasmids, which we talked about in episode 93, look like sticks. Sometimes the name just fits, you know? Some species of moth actually look like bird poop.

Wait, what? Yes indeed, some moths look just like bird poop. The beautiful wood nymph (that’s its full name; I mean, it is beautiful, but it’s actually called the beautiful wood nymph) is a lovely little moth that lives in eastern North America. It has a wingspan of 1.8 inches, or 4.6 cm, and its wings are quite lovely. The front wings are mostly white with brown along the edges and a few brown and yellow spots, while the rear wings are a soft yellow-brown with a narrow brown edge. It has furry legs that are white with black tips. But when the moth folds its wings to rest, suddenly those pretty markings make it look exactly like a bird dropping. It even stretches out its front legs so they resemble a little splatter on the edge of the poop.

But it’s not just insects that mimic other things. We’ve talked about frogfish before in episode 165. It has frills and protuberances that make it look like plants, rocks, or coral, depending on the species. The leafy seadragon, which is related to seahorses and pipefish, has protrusions all over its body that look just like seaweed leaves. It lives off the coast of southern and western Australia and grows over nine inches long, or 24 cm, and it moves quite slowly so that it looks like a piece of drifting seaweed. Not only are the protuberances leaf-shaped, they’re green with little dark spots, or sometimes brown, while the body can be green or yellowish or brown like the stem of a piece of seaweed.

Many animals have false eyespots, which can serve different purposes. Sometimes, as in the eyed click beetle we talked about in episode 186, the false eye spots are intended to make it look much larger and therefore more dangerous than it really is. Sometimes an animal’s false eyespots are intended to draw attention away from the animal’s head. A lot of butterflies have false eyespots on their wings that draw attention away from the head so that a predator will attack the wings, which allows the butterfly to escape. Some fish have eyespots near the tail that can make a predator assume that the fish is going to move in the opposite direction when startled.

Even some species of birds have false eyespots, including many species of pygmy owl. The Northern pygmy owl is barely bigger than a songbird, just six inches tall, or 15 cm. It lives in parts of western North America, usually in forests although it also likes wetlands. It’s mostly gray or brown with white streaks and speckles, but it has two black spots on the back of its head, fringed with white, that look like eyes. Predators approaching from behind think they’ve been spotted and are being stared at.

But some larger birds of prey have false eyespots too, including the American kestrel and northern hawk owl. What’s going on with that?

You’ve probably seen or heard birds mobbing potential predators. For instance, where I live mockingbirds will mob crows, while crows will mob hawks. The mobbing birds make a specific type of angry screaming call while divebombing the predator, often in groups. They mostly aim for the bird’s face, especially its eyes, in an attempt to drive it away. This happens most often in spring and summer when birds are protecting their nests. Researchers think the false eyespots that some birds of prey have help deflect some of the attacks from other birds. The mobbing birds may aim for the false eyespots instead of the real eyes. Despite its small size, the northern pygmy owl will eat other birds, and it’s also a diurnal owl, meaning it’s most active during the day, and it does sometimes get mobbed by other birds.

Sometimes, instead of blending in to its surroundings, an animal’s appearance jumps out in a way that you’d think would make it easy to find and eat. But like the cinereous mourner chicks mimicking toxic caterpillars, something in the mimic’s appearance makes predators hesitate.

A genus of cockroaches from the Philippines, Prosoplecta, have evolved to look like ladybugs, because ladybugs are inedible to many predators. But cockroaches don’t look anything like ladybugs, so the modifications these roaches have evolved are extreme. Their hind wings are actually folded up and rolled under their carapace in a way that has been found in no other insect in the world. The roach’s carapace is orangey-red with black spots, just like a ladybug.

In the case of a lot of milkweed butterfly species, including the monarch butterfly, which are all toxic and which are not related to each other, researchers couldn’t figure out at first why they all look pretty much alike. Then a zoologist named Fritz Müller suggested that because all the butterflies are toxic and all the butterflies look alike, predators who eat one and get sick will afterwards avoid all the butterflies instead of sampling each variety. That’s called Mullerian mimicry.

A lot of insects have evolved to look like bees, wasps, or other insects with powerful stings. The harmless milksnake has similar coloring to the deadly coral snake. And when the mimic octopus feels threatened, it can change color and even its body shape to look like a more dangerous animal, such as a sea snake.

And that brings us to the octopus. How do octopuses change color? Is it the same in chameleons or is that a different process? Let’s find out and then we’ll come back to the mimic octopus.

We’ve talked about the octopus in many episodes, including episodes 100, 142, and 174, but while I’ve mentioned their ability to change color before, I’ve never really gone into detail. Octopuses, along with other cephalopods like squid, have specialized cells called chromatophores in their skin. A chromatophore consists of a sac filled with pigment and a nerve, and each chromatophore is surrounded by tiny muscles. When an octopus wants to change colors, its nervous system activates the tiny muscles around the correct chromatophores. That is, some chromatophores contain yellow pigment, some contain red or brown. Because the color change is controlled by the nervous system and muscles, it happens incredibly quickly, in just milliseconds.

But that’s not all, because some species of octopus also have other cells called iridophores and leucophores. Iridophores are layers of extremely thin cells that can reflect light of certain wavelengths, which results in iridescent patches of color on the skin. While the octopus can control these reflections, it takes a little longer, several seconds or sometimes several minutes.

Leucophores are cells that scatter light, sort of like a mirrored surface, which doesn’t sound very helpful except when you remember how light changes as it penetrates the water. Near the surface, with full spectrum light from sunshine, the leucophores just appear like little white spots. But water scatters and absorbs the longer wavelengths of light more quickly than the shorter wavelengths. We’ve talked about this before here and there, mostly when talking about deep-sea animals.

To make it a little simpler, think of a rainbow. A rainbow is caused when there are a lot of water droplets in the air. Light shines through the droplets and is scattered, and the colors are always in the same pattern. Red will always be on the top of the rainbow because it has the longest wavelength, while violet, or purple, will always be on the bottom because it has the shortest wavelength. The same thing happens when sunlight shines into the water, but it doesn’t form a rainbow that we can see. Red light is absorbed by the water first, which is why so many deep-sea animals are unable to perceive the color red. There’s no reason for them to see it, so there’s no need for the body to put effort into growing receptors for that color.

Blue, by the way, penetrates water the deepest. That’s why clear, deep water looks blue. Solid particles in the water also affect how light scatters, so it can get complicated. But to get back to an octopus with leucophores, the leucophores reflect the color of the light that shines on them. So if an octopus is deeper in the water and the light shining on it is mostly in the green and blue spectrum, the leucophores will reflect green and blue, helping make the octopus look sort of invisible.

But wait, it gets even more complicated, because some octopuses can also change the texture of the skin. Sometimes that just means it can make its skin bumpy to help it blend in with rocks or coral, but some species can change the shape of the skin more drastically.

We still don’t fully understand how cephalopods know what colors they should change to. While octopuses mostly have good eyesight, at least some species are colorblind. But they can still match the background colors exactly. Some preliminary research into cuttlefish skin appears to show that the cuttlefish has a type of photosensor in the skin that allows it to sense light wavelengths and brightness without needing to use its eyes. Basically the skin acts like its own eye. This is getting weirder and weirder, but that happens when we talk about cephalopods because they are peculiar and fascinating animals. In 2019, marine biologists released footage of a captive octopus changing colors in her sleep. Some researchers think she may have been dreaming, and her dream prompted the color changes.

Let’s get back to the mimic octopus now that we’ve learned the basics of how octopuses change color. The mimic octopus lives throughout much of the Indo-Pacific, especially around Indonesia, and has an armspan of about two feet across, or 60 cm. It generally lives in shallow, murky water, where it forages for small crustaceans and occasionally catches small fish. It’s usually light brown with darker brown stripes, but it’s good at changing both its color and its shape to mimic other animals.

So far, researchers have documented it mimicking 15 other animals, including a sea snake where it hides all but two of its legs, a lion fish where it holds its legs out to look like spines, jellyfish, sting rays, frogfish, starfish, sponges, tube-worms, flatfish, and even a crab. It actually imitates a crab in order to approach other crabs, which it then grabs and eats. So obviously it’s not using its mimicry ability randomly. It will imitate a sea snake if it feels threatened by an animal that is eaten by sea snakes, for instance. And it was only discovered in 1998 and hasn’t been studied very well yet.

Unfortunately, the mimic octopus is rare to start with and threatened by pollution and habitat loss. Once it was discovered, people immediately wanted to own them. But the mimic octopus doesn’t do well in captivity, usually dying within weeks or even days. Even octopus experts have trouble keeping them alive for very long. One expert reported that the mimic octopus is incredibly shy and spends most of its time hiding deep under the sand. It’s mostly active at night and doesn’t like bright light. It’s incredibly sensitive to temperature changes, water quality, and even the type of salt used in saltwater aquariums, and most importantly, he reported that in captivity, it doesn’t do any imitating.

Chameleons are also famous for their ability to change color and pattern, but not every species can do so. The ones who can use a very different process for color changing compared to octopuses. The chameleon has a layer of skin that contains pigments with a layer beneath that contains crystals of guanine, a reflective molecule that’s used in cosmetics to make things look shimmery, like nail polish. The chameleon can move the crystals to change the way light reflects off them, which affects the color, especially when combined with the pigments in the upper layer of skin. The color change takes about 20 seconds and different species are able to change into different colors and patterns.

Not all mimics use appearance. A number of moths are toxic to bats, but it’s no use evolving bright colors to advertise their toxicity to predators who use echolocation to hunt. Instead, the moths generate high-pitched clicks that the bats hear, recognize, and avoid. And naturally, some non-toxic moths also generate the same sounds to mimic the toxic moths.

Let’s finish with a tiny spider that also changes color. It’s called the white crab spider or the goldenrod crab spider or the banana crab spider, or just the flower spider. It’s a small, common spider that lives throughout the northern hemisphere. You’ve probably seen a few of them in your time, probably when you’re leaning down to sniff a flower. It hangs out on flowers and can be white or yellow in color. A big female can be 10 mm long, not counting her legs, while males are barely half that size. They’re called crab spiders because they often run sideways like a crab. The flower spider doesn’t build a web. Instead, it just sits on a flower.

The male flower spider climbs around from flower to flower, looking for a mate. The female generally stays put on a particular flower until it fades, and then she’ll find a new one. If she moves from a yellow flower to a white one, or vice versa, she can change color to match, but it’s not a quick process. It takes at least ten days and sometimes up to 25 days to change from white to yellow, since the spider has to secrete yellow pigment into its cells, while changing from yellow to white usually takes less than a week. If she’s on a flower that is another color, she’ll usually remain white. Only the female can change color, and some females may have small red or pink markings that don’t change color. The male is usually yellow or off-white in color.

The flower spider is so well camouflaged that it can be hard to spot even if you’re looking for it. It eats butterflies and moths, bees, and other insects that visit the flowers. Males will also eat pollen. Its venom is especially toxic to bees, although it’s harmless to humans. It really likes to eat bumblebees. Its first pair of legs are longest and curve forward to make it easier for the spider to grab a bumblebee and sink its fangs into it. Meanwhile, the bumblebee has black and yellow stripes to advertise to potential predators that it will sting, but that doesn’t help it when it comes to the little crab spider. Danger in the bee world!

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Don’t forget to contact me if you want to enter the book giveaway contest, which will run through October 31, 2020! If you want to enter, just let me know by any means you like.

Thanks for listening!


Episode 187: The Praying Mantis and the Cockroach



We finish off Invertebrate August in style, with great suggestions from Rosy and Kim!

Also, I was a guest on The Flopcast last week if you want to hear me talking about DragonCon and birding with my friend Kevin! Also, he actually has a few pictures of me if you want to know what I look like (I hate having my picture taken).

Further Reading:

Why Do Mantids Only Have One Ear?

Secrets of the orchid mantis revealed

In this new praying mantis group, gender dictates disguise

Male (left) and female (right) Hondurantemna chespiritoi (photos from article linked to just above):

The female Hondurantemna chespiritoi showing her leaf-like wings:

An orchid mantis:

Vespamantoida wherleyi looks like a wasp:

A Neotropical bark mantis, hiding in plain sight:

The Indian domino cockroach is actually kind of cute:

A hissing cockroach GET IT OFF YOUR HAND OMG WHY ARE YOU TOUCHING IT:

Show Transcript:

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

It’s the last week of Invertebrate August, but what a wild ride it’s been. We’ll round out the month with a few more listener suggestions, so thanks to Kim and Rosy for some awesome topics!

Before we get started, though, last week I was a guest on The Flopcast, a hilarious and family-friendly podcast about geeky stuff like old cartoons and TV shows and music from when you were a kid, unless you’re a kid now in which case music from before you were born. I talked with the host Kevin about DragonCon, so if you are interested in hearing me talk about something besides animals, I’ll put a link in the show notes so you can go listen!

But now, on to the invertebrates! First, let’s learn about the mantis, also called the praying mantis, which is Rosy’s suggestion. If you play Animal Crossing you’ll be familiar with the orchid mantis, but there are lots of species. Lots. Like, almost 2,500 species. They live throughout much of the world but are most common in tropical areas.

All mantises have elongated bodies, enlarged forelegs used for catching and holding prey, and a triangular head with big eyes. The mantis walks on its two rear pairs of legs but holds its big front legs up to use as weapons. Most species have wings and can fly, some don’t, but they are all predators. Most are ambush predators who wait for an insect or other small animal to come near, then grab it with their spiny front legs. Mantises have good vision since they primarily hunt by sight. They’re also most active during the day.

The mantis will eat, in no particular order, insects, frogs and other amphibians, lizards, snakes, small turtles, mice, small birds, spiders, other mantises, and fish. That’s right, fish. In 2017 a team researching insects in India observed a mantis catching guppies in a rooftop garden pond. To reach the guppies, it walked across the water-lilies growing on the water. The scientists observed the mantis catch and eat nine guppies over the course of several nights, and surprisingly, it hunted them in the evening and night when mantises aren’t usually active.

Mantises can and will catch and eat hummingbirds by climbing onto hummingbird feeders or into flowering bushes, and when a hummingbird comes to feed, chomp! So basically, mantises will eat anything they can catch, and they can catch a lot of things.

The eyesight of mantises is interesting, and scientists are discovering more about it all the time. A study published in 2018 reports that the stereo vision, also called 3D vision, that mantises have is very different from that in humans. Whereas human vision is in 3D all the time, the mantis’s stereo vision only kicks in when there’s movement nearby. At that point the mantis has sharp details of exactly where potential prey is, since that’s what’s most important to it. The mantis is also the only insect known to have stereo vision at all.

The mantis doesn’t have any kind of hearing organ on its head and for a long time entomologists thought it was deaf. But it turns out that the mantis does have a type of ear that’s specialized for one thing. It’s not on the head, though. Many species of mantis have a single ear, or what’s called an auditory thoracic organ, in what is sort of their chest, just in front of the middle pair of legs. Technically the organ is split in two, but it acts as a single ear. The reason they have this organ is to detect bats. That’s right, bats. The ear can hear in the ultrasonic range. Some mantis species will fly to find new territory, especially males, and they do this mostly at night to avoid birds. But then they have to avoid bats. When a flying mantis hears a bat’s echolocation calls, it will go into a dramatic dive to avoid it, sometimes just plummeting to the ground.

Most mantises have evolved camouflage to hide from both predators and prey. Some look like leaves, like a newly discovered species from the Honduras and Mexico. Hondurantemna chespiritoi lives in forests and demonstrates sexual dimorphism, where the males and females look very different. The male is light brown with darker and lighter spots, and basically looks sort of like a bundle of sticks. He’s about two inches long, or 5 cm. The female is twice his size and bright green, with forewings that resemble leaves—so much so that the wings have spots that look like blemishes on a leaf and veins that resemble veins in a leaf. The wings are also big enough to hide the body.

Flower mantises, including the orchid mantis, are camouflaged to look like flowers. You probably guessed that from the name. The orchid mantis lives in tropical forests in parts of southeast Asia and is rare and beautiful. It looks so much like a flower that butterflies will land on it thinking it’s actually a flower, at which point—you know. CHOMP. It’s white and pink with heart-shaped lobes on its legs that resemble flower petals, and it mostly eats butterflies and bees. But scientists have determined that despite its name, the orchid mantis isn’t actually trying to specifically mimic an orchid. It doesn’t perfectly resemble any particular type of flower, but seems to have evolved to look like a general flower of the kind that insects just like.

Another newly discovered mantis species, Vespamantoida wherleyi, mimics a wasp. It was discovered in Peru near the Amazon River in 2013, and is bright orangey red in color with black markings and long antennae. Not only does it look like a wasp, it even walks and acts like a wasp. Since wasps are famous for their stinging abilities, many predators avoid them.

Other mantis species are camouflaged to look like tree bark, like the 19 new species of mantis described a few years ago that live in Central and South America. They’re called Neotropical bark mantises and unlike most mantis species, they actively pursue prey. They’re extremely fast runners as a result. They have flattened bodies and are mottled to look like pieces of bark, including imitation patches of moss and lichen. Another bark mantis group lives in Australia.

New species of mantis are discovered frequently, and some entomologists think only about half of the species alive today have actually been described scientifically. Many species that are described have barely been studied. So if you were thinking of going into entomology, praying mantises are a hot field.

The smallest species of mantis is Bolbe pygmea, which only grows to about 10 mm long. It lives in Australia. The largest species is probably the Chinese mantis, which grows almost 4.5 inches long, or 11 cm. It’s native to China and other parts of Asia, but has been introduced into North America.

The female mantis lays her eggs inside a ball of froth that then hardens to make a protective shell called an ootheca [oh-a-THEK-a]. Depending on the species, the ootheca may be attached to a tree or other plant, or may just lie on the ground. In some species, the female guards her eggs by standing over the ootheca and attacking anything that comes too close. Baby mantises are called nymphs.

At least one species of mantis doesn’t have any males, just females. The females produce eggs that hatch even though they’ve never been fertilized, which is called parthenogenesis. A few other species of mantis can reproduce parthenogenetically if they can’t find a male.

That brings us to the one thing that most people know about the praying mantis, that the female cannibalizes the male after or even during mating. This does happen in some species, but not always. It tends to happen more when the female is hungry or poorly nourished, but males are typically cautious about approaching a hungry female. But yes, sometimes the female does just bite the male’s head off, literally, while the pair is in the process of mating.

The praying mantis gets its name because of the way it holds its front legs up. It sort of looks like someone saying a prayer. In this case, the prayer is probably, “Please let me find a big juicy bug to eat.”

The mantis is closely related to the cockroach, which is perfect because Kim suggested roaches as a topic! There are even more cockroach species than there are mantis species, which is saying a lot—at least 4,600 known. Of those, only about 30 are ones that want to live in your house and only six of those 30 are major pests.

A few cockroach species are actually pretty, like the Indian domino cockroach from southern India. It’s a rounded insect that lives in leaf litter in forests and eats decomposing plant material. It grows about 1.5 inches long, or 3.5 cm, although males are smaller. It’s black with seven big white spots.

Generally, though, cockroaches are nothing special to look at. Most species are plain brown with a small head, a flattened body, and wings, although not all species can fly. Most are omnivorous and nocturnal, and many are social insects that live in colonies. They’re also extremely tough. They can go a month without eating at all and some species can even survive up to 45 minutes without air.

Cockroach pests will eat human food, pet food, leather, shed hairs, skin flakes they find in dirty clothes, paper, glue, and book bindings. They can spread diseases like salmonella, although fortunately it’s not very common. Cockroach feces can cause asthmatic reactions in some people, though, and can make your home smell bad.

Cockroaches can also become resistant to pesticides. One effective way to rid your home of roaches is to release a whole bunch of praying mantis nymphs inside. The nymphs will eat each other as well as cockroach nymphs, and once the surviving mantises are adults they will happily eat up all the full-grown and young roaches they can find. Of course then you’ve got mantises in your house, but mantises don’t spread diseases that humans can catch, and of course you can name them and treat them as pets. Some people keep mantises as pets anyway.

Speaking of which, some people keep the Indian domino cockroach as a pet. Some other people keep the hissing cockroach as a pet. The hissing cockroach is native to Madagascar and mostly lives in rotting logs, where it eats rotting plant material. There are actually 20 known species and they differ from other cockroaches because they don’t have wings. Also, they make horrible noises. The hissing is a method of communication and includes different hisses to warn other roaches when a predator approaches, or to establish dominance, or to attract a mate. The largest species can grow up to 3 inches long, or 7.5 cm.

This is what a hissing cockroach sounds like.

[hissing cockroach]

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

Thanks for listening!


Episode 186: Velvet Animals



This week’s episode is about some invertebrates who look like they’re made of velvet! Thanks to Rosy and Simon for their suggestions!

Further reading:

Red Velvet Mite

Chigger Bites

Structure and pigment make the eyed elater’s eyespots black

The red velvet mite looks like a tiny red velvet cake but is NOT CAKE, NOT A SPIDER, NOT A SPIDER CAKE:

GIANT RED VELVET MITE:

Regular sized red velvet mites on a fingertip and one parasitizing a daddy long legs spider:

An eastern velvet ant female (it’s actually a wasp, not an ant):

Velvet worms on hands:

A blue velvet worm!

Look at its teeny mouf!

An eyed click beetle DO YOU SEE THE EYES(pots):

The velvet asity (maybe you notice that it’s uh not an invertebrate):

Show transcript:

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

As we continue invertebrate August, we’ve got a nicely themed episode this week, velvet invertebrates! Thanks to Simon and Rosy for their suggestions!

First, let’s talk about Rosy’s suggestion, the red velvet mite. It sounds delicious, but only because it makes me think of red velvet cake. But the red velvet mite is an arachnid, related to spiders and scorpions–but it’s not actually a spider.

In English, the word mite, spelled m-i-t-e, means a tiny thing, and mites are tiny. Most are under a millimeter long. Scientists actually group mites into two kinds, parasitic mites that are closely related to ticks, and velvet mites that are closely related to chiggers. Chiggers, my least favorite. All the many species of velvet mite and chigger are in the order Trombidiformes.

You know what? Let’s talk briefly about chiggers, because there’s a lot of bad information about them out there. The chigger lives in vegetation, especially tall weeds and shrubs. Various species live throughout the world but it’s more common in warm, humid areas. In some places it’s called a harvest mite or scrub-itch mite.

The chigger is only parasitic as a larva. The larvae only have six legs, compared to adults that have eight. A larva waits on a blade of grass or a leaf for an animal to brush past it, and when it does, the larva grabs on. The longer you stay in one place, for instance when you’re blackberry picking, the more likely it is that a chigger will crawl onto you. It’s very nearly microscopic so you can’t look for chiggers and pick them off the way you can ticks. Like velvet mites, they’re red in color but generally paler than actual velvet mites.

A chigger bite causes intense itching, swelling, redness, and takes sometimes several weeks to heal, especially if you scratch it. It also gets infected easily. Many people believe that the chigger actually burrows into the skin. The chigger does eat skin cells from the layers of skin below the outer layer, but they don’t actually have mouthparts that can bite that deeply. They certainly can’t burrow into the skin. What they do instead is give the skin a little bite and inject digestive enzymes into the wound. The enzymes break down the skin cells they touch, and also harden the tissues around the wound. The chigger slurps up the liquefied skin cells and injects more enzymes, which seep down deeper into the skin, until basically what it’s created is a tube of hardened skin cells that reaches the lower layers of skin. The tube is called a stylosome, in case you were wondering. All this takes several days, so the best way to treat chigger bites before they get bad is to take a hot shower as soon as possible after you’ve been blackberry picking or whatever, and scrub well, especially around places where your clothing was tight. You also need to wash your clothes in hot, soapy water to kill any chiggers still on them.

The best way to deal with chiggers is to wear a good insect repellent and make sure to apply it all the way from your feet up, paying special attention to ankles, the backs of your knees, and around your waist and stomach.

Okay, that’s enough of that. Let’s talk about actual red velvet mites that don’t bite and that you can see. The red velvet mite is covered with short, dense hairlike structures that may act as sensors to help the mite find its way around in the dark or underground. The hairs are orangey-red, although some species may have white spots. Adults have eight legs like spiders do, but each pair of legs grows from a different part of the cephalothorax instead of from the same place like in spiders. Adult red velvet mites generally eat insect larvae and eggs. But the red velvet mite larvae are parasites—but not chigger-type parasites. They don’t bother people or pets, and in fact they only parasitize invertebrates like insects and spiders. A red velvet mite larva will grab onto certain types of insect like grasshoppers or beetles, or some spiders like daddy long-legs. It rides around on the insect and sucks its hemolymph like eensy-beensy insect ticks.

To attract a female, the male red velvet mite leaves droplets of sperm on twigs and grass in a little area and spins an intricate trail of silk leading to the droplets. The female examines the silk trail and if she finds it well-made, she’ll gather up some of the sperm to fertilize her eggs. But if another male comes across the trail, he’ll tear it up. The female lays her eggs in the soil.

There are thousands of species of velvet mite throughout the world, with many more undoubtedly yet to be discovered. Most are teensy, but there are some bigger species called giant red velvet mites.

There are actually two totally different mites called by that name. The first one lives in southwestern North America in dry areas, and includes several species in the genus Dinothrombium. The adults eat ants and termites. Like other mites, people are most likely to see them walking around on outside walls or patios or deck railings, usually lots of them in one area and often after summer rain. That’s why they’re sometimes called rain bugs. But while most velvet mites are just little moving red dots, the giant red velvet mite can grow up to 12 mm, which is almost half an inch long. In the mite world, that really is giant.

The other species called the giant red velvet mite lives in parts of northern India in dry areas, Trombidium grandissumum, and it can grow up to two cm long, or over ¾ of an inch. Like most other red velvet mites, it mostly lives underground and eats insect larvae, many of which are harmful to crops.

So why are red velvet mites so red? Surely that would make them easier for predators to see. Well, the red velvet mite contains compounds that make them taste bad and may be toxic, so the bright red color advertises that to predators.

The red velvet mite will curl its legs in to make itself smaller if it feels threatened, which is oddly sweet. Be safe, little mites.

Next, let’s learn about the velvet ant. It’s not an ant at all but a wasp, although wasps and ants are closely related. The female has no wings although the male does, but the male doesn’t have a stinger while the female does. Sometimes it’s called the cow killer ant because its sting is so painful that people think it could practically kill a cow. It can’t kill a cow. Or a person, for that matter, but one species of velvet ant was scored for how painful its sting was and it ranks right up there with bullet ants.

Like the red velvet mite, there are thousands of species of velvet ant that live throughout the world. The females and usually the males have plush-looking hairs, some species with orange or red hairs, some with other colors and patterns like black and white. In the case of the velvet ant, the bright coloration is to warn potential predators that this is a dangerous wasp and they should steer clear! It’s also a tough insect with a thick exoskeleton.

The biggest species of velvet ant is the eastern velvet ant, which lives in the eastern United States. It can grow almost two centimeters long, or three-quarters of an inch, and is orangey-red with a black stripe on its abdomen and black legs.

If you remember way back to episode 28, about crawdads and cicadas, we talked briefly about a huge wasp called the cicada killer. The cicada killer can grow up to two inches long, or 5 cm, which is simply enormous when one gets into your house and you worry it’s going to just move in and complain that the furniture is too small. Anyway, the cicada killer does something horrible to the cicada. The female stings a cicada, which paralyzes it but doesn’t kill it. Then it carries the cicada to its burrow and lays an egg on it. When the egg hatches a day or two later, the larva eats the still-living cicada.

Well, I bring this up because velvet ants do the same thing to cicada killers! Comeuppance in the insect world! The female velvet ant searches for cicada killer burrows, and when it finds one with a larva inside, eating a cicada, it lays an egg on the larva. The egg hatches and the velvet ant larva promptly eats the cicada killer larva which is in turn eating the cicada. This is a way different circle of life than they talked about in the Lion King.

Next, let’s talk about a different kind of invertebrate, the velvet worm. It’s not a worm and it’s also not fuzzy like the animals we’ve talked about so far, but its body does have a soft, velvety texture. There are about 180 species known in two families. It lives in tropical areas in Central and South America, the Caribbean, parts of Africa and Asia, and Australia and New Zealand, but we know it used to be more widespread because we’ve found velvet worms in Baltic amber from what is now northern Europe. It has a soft, segmented body that’s covered with a very thin layer of chitin with tiny overlapping scales. This makes the velvet worm look velvety and acts as a water repellent so the body won’t dry out, but it also needs plenty of humidity in its environment to survive.

At first glance, the velvet worm looks like a caterpillar. It has a caterpillar’s stumpy bumps of legs and a long soft-looking body like a caterpillar. Various species grow to various sizes, but the largest is only about eight inches long, or 20 cm, and most are much shorter. Different species are different colors, from brown or reddish to blue, white, or even bright green like a caterpillar. But it’s not related to any animal that goes through a caterpillar-like stage of life. Scientists aren’t even completely sure what the velvet worm is actually most closely related to. It shares features with some of the strange animals that evolved during the Cambrian, and currently many researchers think it’s a descendant of a group of Cambrian animals called lobopodians, a group which includes Hallucigenia. You may remember Hallucigenia from episode 69.

Some beautifully preserved fossil ancestors of velvet worms have been found in a Canadian fossil bed dated to 425 million years ago. While modern velvet worms live exclusively on land, its 425 million years old ancestors lived in shallow coastal water.

These days, velvet worms are uncommon animals that mostly live in leaf litter or under rotting logs or similar places. Two species even live in caves. It’s mostly nocturnal, although it will come out during the day in rainy weather. During the day, or when it’s too dry or cold for its liking, it will rest in tiny crevices in its habitat. That may be just a deep crack in the earth or a rock, a tunnel originally dug by termites, or a little hidden spot inside a rotting log. It’s eaten by a lot of animals, including birds, insects, spiders, rodents, and snakes, so it’s good at hiding.

But when the velvet worm is out hunting, it is fearsome to its prey. It mostly eats small invertebrates like insects, worms, spiders, and snails, but it can kill animals its own size or even a little larger. And it doesn’t need to eat very often, maybe once a week or even just once a month.

The velvet worm has a pair of retractable antennae that act as feelers that the velvet worm uses to very lightly touch potential prey to see whether it wants to attack. It will sneak up on an animal and use these feelers to touch it so lightly that the animal has no idea the velvet worm is there or is touching it. If that doesn’t creep you out completely, you haven’t read the spooky horror stories I’ve read, that’s all I can say. At the base of the antennae the velvet worm has a pair of eyes, although some species don’t have eyes at all.

The velvet worm’s mouth contains a sharp pair of mandibles, but these are actually inside the mouth, sort of like teeth although they’re nothing like teeth, rather than external mandibles like those of insects. But it’s behind the mouth where things get really interesting, because that’s where the slime is secreted. The velvet worm has a pair of slime glands in its body that generate and hold extremely sticky slime. The velvet worm squirts it from two tiny openings on the sides of its head to form a sort of net that ensnares its prey. If the prey is large or strong, the velvet worm may squirt more slime at its legs to keep it immobilized.

The slime immediately starts to dry and harden, and as it dries it contracts. Then the velvet worm bites the animal and injects digestive saliva into the wound that liquefies the tissues it comes in contact with. Sort of like a chigger. While it’s waiting for the saliva to do its work, the velvet worm eats up the slime it discharged, because it’s made of proteins and takes several weeks to regenerate. Then the velvet worm clamps its mouth over the wound and slurps up the liquefied insides of its prey, which by the way is very dead by this point.

But the really amazing thing is that some species of velvet worm are social. It lives in family groups that hunt together, led by a dominant female. She eats first, then the other females, then the males, then any young. Females are usually larger than males.

Velvet worms have been well studied and I could go on and on about them. I might return to them eventually and give them their own episode. But let’s go on now to our last velvet animal, the velvet asity.

Simon suggested the velvet asity of Madagascar when we were talking on twitter about an insect called the eyed elater, or eyed click beetle, which lives in forests in North and Central America. It’s a slender beetle that grows about 2.5 inches long, or 4.5 cm. The larvae are sometimes called wireworms because they’re so long and skinny. They eat the grubs of other beetles that live in rotting wood, but it’s not known what the adults eat, if anything.

Like other click beetles, if it feels threatened, the eyed click beetle can suddenly launch itself away with its click mechanism. This is a spine underneath its thorax that fits into a groove between its legs. If the insect is threatened, it flexes its body to release the spine, which snaps against whatever surface the beetle is touching and catapults it sometimes several inches away.

The eyed click beetle is black and mottled gray to blend in with tree bark, but it has two large eye spots that are probably meant to frighten predators away. The eye spots are black outlined with white, and the black part contains cone-shaped microtubules made of modified setae that contain the pigment melanin. Between the pigment and the shape of the hairs and the way they’re aligned, the eyespots absorb 96.1% of light that hits them. This makes them look much larger and more conspicuous to potential predators.

Quite a few insects and some other animals have developed similar coloring that will absorb light, often called super-black. And that brings us to the velvet asity, the male of which is almost all super-black as an adult except for bright lime green wattles above the eyes.

Uh, and this is where I have to admit I made a mistake. I often take quick notes about animals people recommend, especially if the recommendation comes from a Twitter conversation that’s easily lost. Later on I transfer my notes to the big ideas spreadsheet. Well, this time I made a note that said “Velvet asity of Madagascar, Simon replied with this to a twitter post about the eyed elater, with specialized hairs in the eyespots that deaden reflection.” That’s literally what’s in my notes, and I listed it under the invertebrates tab because I forgot what the velvet asity is and just assumed it was another insect like the eyed click beetle.

But the velvet asity isn’t an invertebrate, which I only discovered after I’d started researching the other velvet animals in this episode. It’s a bird. But what a bird it is! It’s a little round bird with a very short tail, short wings, and amazing coloration! While the female is a streaky olive color, the male’s breeding plumage is striking.

The super-black coloring of the male velvet asity deadens reflections and makes its green eyebrows look even brighter, which attracts females. The velvet asity lives in the rainforests of Madagascar and mostly eats fruit, but it will also eat nectar and some insects. During breeding season, males gather in small groups called leks to show off for females with a mating dance that involves him flipping all the way around the branch he’s standing on. The female weaves a pear-shaped nest that hangs from a branch and is camouflaged because she uses materials like strips of bark, leaves, and moss to make it. She also takes care of the eggs and chicks by herself. All the male does is show off, but you can hardly blame him. If you’ve got it, flaunt it, velvet asity.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave 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 185: Ice Worms, Army Ants, and Other Strange Invertebrates!



Let’s learn about some weird insects this week! Thanks to Llewelly for suggesting army ants!

Further reading:

If you’re interested in the magazine Flying Snake, I recommend it! You can order online or print issues by emailing the editor, Richard Muirhead, at the address on the website, and there’s a collection of the first five issues on Amazon here (in the U.S.) or here (UK)!

The magnificent, tiny ice worm! The dark speckles in the snow (left) are dozens of ice worms, and the ones on the right are shown next to a penny for scale. Teeny!

ARMY ANTS! WATCH OUT. These are soldier ants from various species:

The Appalachian tiger swallowtail (dark version of the female on the right):

Tiger swallowtails compared:

The giant whip scorpion. Not baby:

Jerusalem cricket. Also not baby but more baby than whip scorpion:

PEOPLE. GET THOSE HORRIBLE THINGS OFF YOUR HANDS.

Show transcript:

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

This week we’re going to talk about a number of strange and interesting invertebrates as part of Invertebrate August. Thanks to Llewelly for a great suggestion, and we also have a mystery invertebrate that I learned about from the awesome magazine Flying Snake. Flying Snake is a small UK magazine about strange animals and weird things that happen around the world. It’s a lot of fun and I’ll put a link in the show notes if you want to learn more about it. It’s been published for years and years but I only just learned about it a few months ago, and promptly ordered paper copies of all the issues, but they’re also available online and the first five issues are collected into a book.

So, let’s start with an invertebrate I only just learned about, and which I was so fascinated by I wanted to tell you all about it immediately! It’s called the ice worm, and it’s so weird that it sounds like something totally made up! But not only is it real, there are at least 77 species that live in northern North America, specifically parts of Alaska, Washington state, Oregon, and British Columbia.

The ice worm is related to the earthworm, and in fact it looks like a dark-colored, tiny earthworm if you look closely. It’s usually black or dark brown. It likes the cold—in fact, it requires a temperature of around 32 degrees Fahrenheit, or zero Celsius, to survive. You know, freezing. But the ice worm doesn’t freeze. In fact, if it gets much warmer than freezing, it will die. Some species live in snow and among the gravel in streambeds, and some actually live in glaciers. Ice worms can survive and thrive in such cold conditions because their body contains proteins that act as a natural antifreeze. It navigates through densely packed ice crystals with the help of tiny bristles called setae [see-tee] that help it grip the crystals. Earthworms have setae too to help them move through soil.

During the day, the ice worm hides in snow or ice to avoid the sun, and comes to the surface from the late afternoon through morning. It will also come to the surface on cloudy or foggy days. It eats pollen that gets trapped in snow and algae that is specialized to live in snow and ice, as well as bacteria and other microscopic or nearly microscopic animals and plant material. In turn, lots of birds eat ice worms. Birds also occasionally carry ice worms from one glacier or mountaintop to another by accident, which is how ice worms have spread to different areas.

The glacier ice worm can grow to 15 mm long and is only half a mm thick, basically just a little thread of a worm. It only lives in glaciers. You’d think that in such an extreme environment there would only be small pockets of glacier ice worms, but researchers in 2002 estimated that the Suiattle [soo-attle] Glacier in Washington state contained 7 billion ice worms. That’s Billion with a B on one single glacier. Other ice worm species can grow longer than the glacier ice worm, including Harriman’s ice worm that can grow nearly 2.5 inches long, or 6 cm, and is 2.5 mm thick.

There are tall tales about ice worms that can grow 50 feet long, or 15 meters, but those are just stories. An ice worm that big wouldn’t be able to find enough to eat.

Next, let’s talk about a type of ant. Llewelly suggested the army ant a long time ago, and recently I got an email from Ivy whose list of favorite animals includes the army ant!

The army ant lives in parts of Africa, South America, and Asia, and although there are some 200 species in different subfamilies, recent research suggests that many of them are descended from the same species that lived in the supercontinent Gondwana more than 100 million years ago.

Army ants don’t dig permanent nests like other ants. Instead they make temporary camps, usually in a tree trunk or sometimes in a burrow the ants dig. But these camps aren’t anything like ordinary ant nests. Often they’re formed from the bodies of worker ants, who link their legs together to make a living wall. The walls form tubes that make up chambers and passages of the nest, and inside the nest the queen lays her eggs. There are also chambers where food is stored. But the nest isn’t permanent. At most, the army ant only stays in one place for a few weeks, after the larvae pupate. The colony feeds the food stores to the queen, who lays a new batch of eggs timed to hatch when the new ants emerge from their cocoons. At that point, the colony breaks camp and enters the nomadic phase of behavior until the newly hatched batch of larvae are ready to pupate.

What do they do with the larvae while they wander? Workers carry them around. As in other ant species and the honeybees we talked about recently, an army ant colony is divided into different types of ant. There’s a single queen ant, seasonally hatched males with wings who fly off as soon as they’re grown, and many worker ants. But army ants have another caste, the soldier ant. These are much larger than the worker ants and have big heads and strong, sharp mandibles. Some species of army ant forage primarily on the ground while some hunt through treetops and some underground, but they generally hunt in large, well-organized columns with soldier ants on the outside as guards. In many species, the worker ants are further divided into castes that are specialized for specific tasks.

The queen ant is an egg-laying machine. Queens of some species can lay up to 4 million eggs every month. The queen is wingless, but a new queen doesn’t need to leave the colony the way other ant species do. Instead, when new queens emerge from their cocoons as adults, the colony splits and two new colonies form from the old one, each with one of the new queens. Usually more than two queens hatch, but only two survive.

When males emerge from their cocoons, they immediately fly off and search for another colony. But a male can’t just land and mate with a queen. He has to get through her guards, and they decide whether they like him or not. If they find him adequate, they bite his wings off and bring him to the queen. After he mates, he dies. This sounds like the plot of a weird science fiction novel from the 1960s. If a colony’s queen dies, the worker ants may join another colony.

Let’s talk specifically about the Dorylus genus of army ants for a few minutes, which live in Africa and Asia. Dorylus army ants live in simply enormous colonies. When the colony goes foraging, there may be 15 million ants marching in a dense column, and they can eat half a million animals every single day.

That’s why the army ant is so feared. The column of ants is made up of worker ants in the middle with the much larger soldier ants along the edges. The columns don’t move very quickly, but the ants attack, kill, and eat any living animal they encounter that can’t run away. This includes insects, spiders, scorpions, and lots of worms, but also eggs and baby birds, other baby animals, frogs and toads, and even larger animals. What isn’t eaten on the spot is carried back to the camp to feed larvae and the queen.

Army ants are also beneficial to the ecosystem and to humans specifically in many ways. A column of army ants that marches through a village will eat so many insects that they act like a really high quality exterminating service for homes and gardens. They also scare insects and other animals that flee from the ant columns, and a lot of animals benefit from the general chaos. Birds of many species will follow army ants in flocks, grabbing insects as they flee the ants. Some birds even make special calls to alert others that army ants are on the move, so that everybody gets a chance for easy food. Even more animal species will follow the column to clean up what they leave behind, including partially eaten carcasses, animals that were killed but rejected as food, and even the feces of the birds that follow the ants.

And, of course, a lot of animals just eat the army ants. Chimpanzees make different types of tools to help them safely harvest army ants. Most commonly, a chimp will use a stick it’s modified to the right length and shape, referred to as an ant-dipping probe. It will put one end of the stick down in the column of army ants and wait until ants start climbing up the stick. When there are enough ants on the stick, it will remove the stick and eat the ants off of it. It’s an ant-kebob!

If you’re wondering why the chimps aren’t attacked by the ants, or why the ants don’t figure out they’re climbing a stick to nowhere, Dorylus army ants, like most army ant species, are all blind. They communicate by releasing pheromones, which are chemicals with specific signatures that other ants can sense, something like smells. Some species that mostly live aboveground have re-evolved sight to a limited degree.

The mandibles of Dorylus army ant soldiers are so strong, and the ant is so tenacious about holding on, that people in some East African tribes traditionally use them to stitch up wounds. The soldier ant is held so that it bites with one mandible on each side of a wound, holding the edges of skin together. Then the person severs the ant’s body from its head, killing it—but the jaws are so strong that they will continue to stay in place for several days while the wound heals.

In Central and South America, the army ant genus Eciton [ess-ih-tahn] is very similar to Dorylus. Some species can cross obstacles like streams by building a living bridge out of individuals to allow the rest of the column to cross.

Whew, okay, I should probably have made the army ant its own episode, because there’s so much cool research about it that I could just go on forever. But let’s move on to a much different insect next, a butterfly that lives in the eastern United States, especially in the Appalachian Mountains. This is the Appalachian tiger swallowtail, which has yellow wings with black stripes and a black border, and a black body. Some females have all-black wings with orange spots. When the genetic makeup of the butterfly was examined, it turns out that the species originated as a hybrid of the Eastern tiger swallowtail and the Canadian tiger swallowtail. This kind of hybridization is rare in the wild. The Appalachian tiger swallowtail lives in the mountains, usually in high elevations, and while its range overlaps with both parent species, it almost never hybridizes with either. It has inherited the Canadian butterfly’s tolerance for cold but is twice its size. Researchers estimate that the hybridization occurred around 100,000 years ago.

I learned that interesting fact about the Appalachian tiger swallowtails from the May 2018 Flying Snake issue, and let’s go ahead and learn about a mystery invertebrate I also read about in that issue of Flying Snake.

The mystery is from The Desert Magazine, which was published between 1937 and 1985. It was a monthly magazine that focused on the southwestern United States, with article titles like “Rock Hunter in the Sawange Range” and “Ghost City of the White Hills.” Both those headlines are from the January 1947 issue, which is also where the first mention of the Baby of the Desert shows up in the letters section. Flying Snake excerpts the relevant letters from that issue and a few later issues, but I got curious and found the originals online.

I’ll quote part of the original letter because it’s really weird and interesting:

“Gentlemen: Would like to ask if there is such a thing as a very poisonous desert resident called ‘Baby of the Desert,’ so named because of the resemblance of its face to that of a human baby. Whether this so-called ‘Baby of the Desert’ is supposed to be insect, reptile or rodent, I could not find out. …[I]t was considerably smaller than the Gila monster.”

The letter was signed William M. Weldon from South Pasadena, California.

The editor responded, “The question of the Baby of the Desert, Baby-face, or Niño de la Tierra, as it is variously called, came up for discussion on the Letters page of the magazine two years ago. A reader sent in a description of the fearsome beast as it had been pictured to him and asked for confirmation from someone who had seen it.”

Because of the mention of another letter asking about the Baby of the Desert, two years before, I went through the letters sections of all the 1945 issues to find the original. I couldn’t find it in 1945, but I did find a nice letter from James Mayberry in California, who found a desert tortoise with blue paint on its shell. He thought someone had brought the tortoise back from a visit to the desert. James named the tortoise Mojave but knew it needed to go home, so he sent it to the Desert Magazine. I’m delighted to say that the editor took it out to a lonely desert hill where there were other tortoises and let Mojave go. Tortoises live a long time so Mojave might still be stumping around out there, the blue paint on his shell faded in the sun.

Then I went back through the 1944 issues and found the letter in the July issue. It was from Albert Lloyd of Tulsa, Oklahoma, who wrote, “Perhaps some reader can supply authentic information about a small denizen of the deserts and mesas of the Southwest, which the Mexicans call Niño de la Tierra, or Child of the Earth. During four years of roaming around New Mexico and Arizona I was never fortunate enough to see one. But I have talked with several who claim to have seen it. They describe it as a doll-like animal, about three or four inches in length, walking on all fours, with head and face like that of an infant. They claim it will not attack you unless molested and that its bite is more deadly than a rattlesnake’s.”

The editor of the Desert Magazine suggested that the Baby of the Desert was an insect. “[I]t appears that the Baby-face is actually our old friend the yellow and black striped Jerusalem cricket or Sand-cricket, who is nocturnal and usually found under boards or stones.”

But responses in the letters section in following issues, February and April 1947, don’t agree. S.G. Chamberlin of San Fernando, California wrote, “Some years ago…we uncovered what we first thought to be a Jerusalem Cricket. The coloring was the same and it was a little more than two inches long. Later in the day a ranch hand brought us a Jerusalem Cricket and then we noticed quite a difference in the bodies and heads of the two insects. The round face of the first one did attract our attention although we didn’t think of a baby at the time. The ranch foreman placed them in different bottles to show them to a man in the Farm Bureau office who was versed in such things. He reported back that the first insect was called Vinegarones or Sun Spider and supposed to be harmless.

“At the ranch we were told that on the Mexican border there was a similar insect that is supposed to be poisonous.”

And Coila Harris of South Laguna, California wrote, “I was interested in the recent letters about ‘Baby Face.’ This is not the Jerusalem cricket or potato bug, as many believe, but could be mistaken for one of these insects. Baby-face lives down Mexico way. When we were living in El Paso, one of the weird looking bugs was found under our house. It had a body of a large Tarantula, the head was white as a bleached bone and looked like a bald headed baby, a dreadful thing. I was told at the time that Mexicans consider them so poisonous, that if bitten on the finger by one, they chop off the finger.”

Unfortunately for me, the second I saw the mention of a vinegarone, I had a good idea of what this animal might be. And I really don’t want to look at pictures of vinegaroons.

I do try very hard not to be biased against gross-looking insects, because for one thing, they aren’t hurting me and gross is in the eye of the beholder. One person’s “ooh gross” is the other person’s “Oh, that is so neat!” Spiders don’t bother me and as long as I don’t have to look closely at an invertebrate’s mouthparts and things, I’m usually okay. But I get a big case of the nopes when it comes to the vinegaroon.

The vinegaroon is an arachnid, related to spiders and scorpions. It sort of looks like a mixture of the two, although there are lots of species and they vary quite a lot. It’s also called the whip scorpion. The name vinegaroon comes from the acidic liquid it squirts from the base of its whip-like tail if it feels threatened, which smells like vinegar. It lives in tropical and subtropical parts of the Americas and Asia, with one species known from Africa. Most species prefer dark, humid areas and live in burrows in rotting wood or under rocks and leaf litter, but the giant whip scorpion lives in more arid areas in the southwestern United States and Mexico.

The giant whip scorpion grows to around 2.5 inches long, or 6 cm, not counting the long whip-like tail. Like all vinegaroons, it eats insects, slugs, and other small animals. But no one could look at it and think “baby.” It has big claw-like pedipalps in addition to six walking legs and a pair of front legs that are extremely long and thin, that it uses to feel around with. It has eyes—in fact, like spiders it has eight eyes—but it doesn’t see very well and mostly navigates by touch. It’s dark brown or black with some lighter brown markings on its abdomen.

The Jerusalem cricket looks superficially similar to the vinegaroon although it’s not an arachnid. It’s also not a cricket, and it doesn’t have anything to do with Jerusalem since it’s native to the western United States and Mexico. In fact, it’s related to the weta of New Zealand. It lives in the same sort of places that vinegaroons like, burrowing in moist soil and rotting wood, but it mostly eats decaying plant material although it will sometimes eat small insects. It can bite, although it’s not venomous or poisonous, but it can give off a horrible smell if it’s disturbed. It’s yellowish to dark reddish-brown with a black-striped abdomen and a rounded head. It also does not look anything like a baby.

BUT, while it’s known by a couple of Navajo names that translate to variations on “red skull bug,” in Spanish it’s called cara de niño, which means child’s face, or niño de la tierra.

So I think the Desert Magazine editor was right. The Baby of the Desert is the Jerusalem cricket. But I wouldn’t be a bit surprised if the Jerusalem cricket is sometimes confused with the giant whip scorpion. They’re both large nocturnal creatures with a similar body shape and coloring, that live in the same areas and occupy the same habitat. And they’re both horrifically creepy-looking. You know what? I bet you anything that “Baby of the Desert” and “baby-face” are ironic names. BAD BABY.

The Jerusalem cricket doesn’t have any kind of hearing organs akin to ears but it can sense vibrations. Instead of chirping, it drums its abdomen on the ground to attract a mate. This is what the drumming sounds like.

[Jerusalem cricket drumming]

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave 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 184: The Mosquito!



Thanks to Kaiden who suggested we learn about mosquitoes this week! You know what eats a lot of mosquitoes? Bats! If you don’t already listen to the excellent podcast Varmints!, jump on over to it to listen to last week’s episode about bats! I cohosted with Paul and had a great time, and I know you’ll like the episode and the podcast in general. It’s family friendly and lots of fun!

Further reading:

The Paleobiologist Who Inspired the Science in ‘Jurassic Park’

SMACK SMACK SMACK SMACK:

Mosquito larvae:

An elephant mosquito in amber:

Show transcript:

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

This week we have a great listener suggestion from Kaiden, who wants to learn about mosquitoes! This is especially great because last week I was a guest co-host on the awesome podcast Varmints!, and we talked about bats! As you may know, bats eat a LOT of mosquitoes. I’ll put a link to the Varmints! page in the show notes in case you don’t already subscribe. I think you’d like it.

The mosquito is a common insect that lives all over the world, except for Antarctica and Iceland. There are something like 3,500 species of mosquito known. In areas where it gets cold in winter some species of mosquito may hibernate, but most enter a state called diapause. This basically means that any eggs and larvae delay their development until it warms up, then develop into adults normally.

The mosquito is a type of fly, and like other flies it only has one pair of wings. Most mosquito species are only 3-6 millimeters long, gray or black in color, with long, extremely thin legs and narrow wings. The largest known species of mosquito is called the elephant mosquito, which can grow up to 18mm long. That’s almost three-quarters of an inch. Its wingspan is even larger, 24 mm, which is just shy of a full inch across.

The mosquito eats nectar. Oh, sorry, that’s the male mosquito. The female mosquito is the one who drinks blood, and she needs the blood to develop her eggs. But in fact, the female mosquito also eats nectar too, and mosquitoes even help pollinate some flowers. Some species of mosquito can develop eggs without blood, but most need the extra protein and nutrients that blood provides. In some species, the female can produce one clutch of eggs without blood, but she has to have blood to develop more eggs.

The female mosquito has a long, thin proboscis that she uses to pierce the skin of an animal and suck its blood, although the process is a lot more complicated than it sounds. The proboscis is made up of a sheath that protects the other mouthparts, including a pair of mandibles and a pair of maxillae. The mandibles and maxillae are actually the parts that cause the bite. If you look at a mosquito that has landed on your arm and is biting you, it looks like the proboscis must be stuck in your skin like a teensy hypodermic needle, but what you’re seeing is the proboscis sheath. The mosquito touches the sheath to your skin and bends it back slightly, which exposes the mouthparts and acts as a guide as the mouthparts bite you. The mandibles are the pointy ones and the maxillae have flattened ends. The mosquito moves her head slightly back and forth to lever them all into your skin, and the only reason this doesn’t hurt like crazy is because they’re so incredibly tiny, plus it happens very quickly.

Once the mouthparts have pierced the skin, the mosquito injects saliva, which contains proteins that act as an anticoagulant so the blood continues to flow without clotting. The itching and swelling associated with a mosquito bite are due to this saliva, which your body reacts to as a foreign substance, which of course it is.

This biting and saliva injecting process actually takes place very quickly, and then the mosquito sucks the blood up. She can hold up to three times her weight in blood. Not only that, but if she’s not disturbed, she will start digesting the blood quickly and will eject as much of the liquid as possible to make room for more blood, since she doesn’t need the liquid part of the blood.

Vampire bats do this too, if you’ve listened to our vampire bats episode or the new Varmints! episode about bats. They digest the blood they drink quickly, then pee out the excess liquid so they’re light enough to fly. But in the case of the mosquito, she just needs as many nutrients from the blood as possible to develop her eggs. That’s why a single mosquito may bite you numerous times. She needs to fill her stomach with the nutritious solids in the blood while excreting as much extra liquid as she can.

Once she has all the blood she needs, the mosquito will hide somewhere for a few days while her eggs develop. Then she’ll fly out to find a good place to lay them.

Mosquitoes lay their eggs in water, usually stagnant water like small ponds. The larvae stay in the water after they hatch. You may have seen mosquito larvae, since they’re distinctive. They’re only a few millimeters long and skinny, with a bristly-looking head. The larvae come to the surface to breathe through a siphon in the abdomen, so they will hang head downward just under the water’s surface. If something startles them, the larvae will curl up and sort of jerk their way through the water. Mosquito larvae eat algae and other tiny food.

Even after a larva pupates, it can still move around in the water. It doesn’t eat, but it needs to breathe, so it will hang just under the water with the breathing siphon in its abdomen at the surface, just as it did as a larva. After a few days, the pupa splits open and the adult mosquito emerges. Females fly off but the males stay in a group, and female mosquitoes join the group to find a mate.

The mosquito’s feet are adapted to allow it to stand wherever it likes. Its feet have microscopic hairy pads like those found on gecko toes that allow it to stick to smooth surfaces, and it also has microscopic hooks that help it stay in place on skin. And it also has feathery scales on its feet that are only a few microns across that allow it to stand on water. Since some species of female mosquitoes lay their eggs directly into water, being able to stand on the water’s surface is useful.

Mosquitoes spread a lot of diseases, which get injected along with the anticoagulant saliva. These include malaria, West Nile virus, zika, yellow fever, dengue fever, and many others. An estimated two million people die of mosquito-spread diseases every year, which makes the mosquito the deadliest animal in the world.

Because mosquitoes are such disease spreaders, people keep trying to figure out better ways to kill them off or at least stop them from spreading disease. One way to stop mosquitoes from spreading is to make sure there is no stagnant water around your house to breed new mosquitoes. A female mosquito will lay her eggs in even small amounts of water, such as an empty drink can that has collected rainwater, so getting rid of trash helps. In the past, people tried poisoning water or spraying insecticides, but this isn’t always very effective against mosquitoes and also kills other insects that may be beneficial.

But as genetic engineering becomes more sophisticated, scientists have discovered new ways to help stop mosquitoes from spreading disease.

For example, let’s talk briefly about dengue fever. I won’t go into symptoms or anything like that, don’t worry. It’s mostly a tropical disease found primarily in parts of Asia, Africa, and Central and South America, and it’s spread by the yellow fever mosquito, which also spreads many other diseases. People do die from dengue fever but most recover and are fine, but of course no one wants to get sick. There’s a vaccine as of 2016, but it’s not fully effective and has some side effects.

To help stop the spread of dengue fever, people have tried releasing animals into standing water that eat mosquito larvae, such as guppies native to the area. This has actually helped. In northern Vietnam, copepods that eat mosquito larvae were introduced into water storage tanks and did such a good job that the yellow fever mosquito was actually eliminated in the area for years. Some species of elephant mosquitoes, which you may remember from a few minutes ago are the largest mosquitoes in the world, don’t drink blood at all. Its larvae eat the eggs and larvae of other mosquito species, which gives it enough nutrients as an adult to lay plenty of eggs. One species of elephant mosquito specializes in eating the larvae of the yellow fever mosquito and has been introduced into some areas to help control its population.

Genetically modified male yellow fever mosquitoes have been introduced into the wild to mate with ordinary female mosquitoes in many places. The males contain a gene that causes larvae to die before reaching adulthood, and it has helped quite a bit. The yellow fever mosquito population has been reduced by over 90% in the places where the males were released, but it doesn’t affect other mosquito species that don’t carry the diseases. The problem is that genetically modified males have to be continuously bred and released in order for the program to keep working.

Very recently, as of January of 2020, scientists have engineered an antibody for the yellow fever mosquito. It basically stops the dengue virus from replicating in the mosquito, which means it can’t be passed to a human. There have been attempts to do this before, but it was only effective for one or another strain of the dengue virus. This new antibody is effective against all strains of the virus. This will help people while not killing the mosquitoes. The team is also working to engineer an antibody for other mosquito-borne viruses.

So, is it true that some people get targeted by mosquitoes more than others? As someone who seems to be a mosquito magnet when I go outside in the evening when mosquitoes are most active, I would say yes–and science agrees with me. Mosquitoes are attracted to some people more than others. The mosquito has a good sense of smell and can track animals by smelling their sweat and the carbon dioxide they exhale. They also tend to prefer people with type O blood and high body heat, but how attractive a person is to a mosquito depends on genetic traits too.

Some species of mosquito prefer some types of animals over others too. Some feed almost exclusively on birds, for instance. But in a pinch, a female mosquito will bite just about any animal, and it doesn’t even need to be warm-blooded. Mosquitoes will bite reptiles, amphibians, and even fish if they’re partly out of water. Some mosquitoes will even bite caterpillars. Caterpillars don’t have blood, but they do have hemolymph, which is just as nutritious to the mosquito.

Occasionally mosquitoes are found in amber, which as you may recall from episode 108 is fossilized tree resin. The oldest known was found in 79-million-year-old amber, so that means that yes, it could have bitten a dinosaur. But even if it still contained genetic material from dinosaur blood, and even if scientists were able to extract the dinosaur genetic material, it would be damaged DNA. Without a full genome of that particular dinosaur to compare against, we wouldn’t be able to repair the DNA sufficiently to actually clone a dinosaur. But we might be able to clone the actual mosquito and compare it to modern mosquitoes to learn more about them! It’s not as exciting as a dinosaur, but on the other hand there’s not a lot of danger of being stomped on or eaten by a mosquito.

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

Thanks for listening!

 


Episode 183: BEES! AKA honey and “honey”



Thanks to Linnea for suggesting bees! Obviously we can’t learn about ALL 20,000 bee species in this episode, but we’ll learn about the honeybee and some other interesting bees!

Further reading:

Bee friendly? Pollinating California’s almond crop

The vulture bee

Western honeybees on a honeycomb:

A vulture bee thinking about “honey”:

The wholesome, solitary ivy bee:

Show transcript:

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

It’s August and we’re kicking off a full month of our spineless friends! That’s right, it’s Invertebrate August, and to get us started, we’re going to learn about some really interesting bees. Thanks to Lynnea for the topic suggestion and some great links!

Bees live all over the world and there are thousands of species, something like 20,000 of them. The only place in the world that doesn’t have any bees is Antarctica, which doesn’t have much of anything.

When most of us think of bees, we think of the honeybee. The honeybee is one of the few invertebrates that are domesticated. People really like honey, and at some point humans realized that if they made pets of the bees that make honey, getting at the honey was a lot easier on both the people and the bees. We know that ancient Egyptians had already domesticated the western honeybee because there are tomb paintings of beekeepers and hives.

The honeybee is native to Europe and Asia, and there are about 30 species. The western honeybee is the most widespread. It lives in a structured colony with a queen, worker bees, and a few drones. The worker bees are all females but they don’t mate and lay eggs. Only the queen is fertile, and the drones are males who mate with the queen. Different worker bees have different roles in the hive. Some gather nectar and pollen from flowers, while some take care of the queen’s eggs and babies or build new honeycombs. All worker bees have stingers, which they use to defend the hive. Honeybees are striped yellow and black to warn other animals that they’re dangerous.

Worker bees make honey by partially digesting nectar, then spreading it in empty honeycomb cells to partially dry. When it’s the right consistency, the workers cap the cells. Honey is antibacterial and anti-fungal and will last pretty much forever in the hive. Eventually it will crystallize, though, and the bees will remove crystallized honey from the hive since they can’t eat it that way. Bees make honey to eat, and they need lots of it so they have extra for wintertime and bad weather when the bees stay inside.

In the wild, the honeybee builds its nest in crevices, such as a hollow tree or the rafters of your attic. Worker bees secrete wax from glands on the abdomen and use it to build honeycomb, which is a sheet of hexagonal cells. Hexagonal means six-sided, and each cell does have six sides. A hexagonal shape is the most efficient use of materials, since each side of the hexagon is shared with another cell instead of the bees having to make six sides for each cell. When they finish making one cell, they’ve already got one side made for six other cells that will adjoin that first cell, sort of like the walls separating rooms in your home.

The queen bee lays her eggs in honeycomb cells. An egg hatches into a larva and is fed by worker bees. All bee larvae get fed a secretion called royal jelly for the first three days after hatching. Royal jelly is high in protein. After three days, most larvae will only get fed a mixture of pollen and nectar called bee bread. The only exception is if the colony has eggs that are intended to grow into new queens. Queen bee larvae continue to get fed royal jelly, since they need the extra protein. The established queen bee of the hive also eats royal jelly.

Honeybees who live in an area with lots of flowers can produce so much honey that they completely fill up their hive. In domesticated bees, that’s when the beekeeper harvests the honey, and will usually return the emptied honeycombs to the hive for the bees to reuse. In bees living wild, if the colony stores so much honey that it’s running out of room for eggs, this will trigger a swarm. The queen leaves with about half the worker bees to find a new home. The workers who remain will continue to feed royal jelly to the newly hatched larvae, which means they develop into new queen bees. The workers have to modify the honeycomb cells for queen bees, which are bigger than other bees and don’t fit in an ordinary-sized cell.

The queen bee larvae pupate and metamorphose into mature bees. New queens chew an opening in their cells, which the worker bees have sealed shut, and each immediately fights all the other new queen bees. If one queen emerges before the others, she will kill the others before they have even finished metamorphosing.

The surviving queen takes over, but she can’t lay eggs that will develop into worker bees yet. She has to mate first. If you listened to episode 175 where we talked about flying ants, you’ll remember that in some species of ant, new queens have a nuptial flight where they mate with males, then store the sperm they collect to use for the rest of their life. Honeybees do this too. When weather conditions are right, the new queen will leave the hive and release pheromones that attract males from various hives in the area. A queen may have several nuptial flights before she has collected enough sperm, which she keeps in a special organ in her body. Then she returns to her hive to start laying eggs that will develop into new worker bees.

Bees are important as domesticated animals not just because we all like honey, but because bees are really good pollinators. The honeybee, and some other bees, have a structure often referred to as a pollen basket on the rearmost legs. It’s a sort of divot in the leg, like a built-in pocket, surrounded by hairs. As the bee crawls around on a flower collecting nectar, pollen sticks to its fuzzy body. The bee gives its front legs a lick and uses them to brush the pollen from its body, then presses the pollen into its pollen baskets. But, of course, it can’t get every grain of pollen off, and some of it rubs off onto the next flower’s stigma, pollinating it.

Some crops, like almonds, depend on beekeepers who bring hives of bees to each orchard in spring. The bees pollinate the almond flowers so they can develop into delicious almonds, which makes the orchard owners happy, and they collect lots of nutritious pollen, which makes the bees and beekeepers happy. Some beekeepers move their bee hives from place to place every spring to help farmers pollinate various crops, but the almond crop is a big deal since the California orchards produce more than 80% of the world’s almonds every year. Beekeepers depend on the money they receive from orchard owners to bring their bees to the orchards, and the orchard owners depend on those bees to make sure there are lots of almonds to harvest later in the year.

But increasingly, there aren’t enough honeybees to pollinate the expanding almond orchards. Colony Collapse Disorder has been known for over a century under various names, but it’s been on the increase since around 2006. A colony will be fine, and then suddenly almost all of the worker bees will just leave and never return. The queen and a few worker bees stay behind. It’s like the opposite of a swarm. It was once known as disappearing disease, but it doesn’t appear to be an actual disease that bees can catch.

Researchers still don’t know what precisely causes colony collapse. The bees left behind are healthy and the hive contains plenty of food. And the disorder doesn’t just happen in one place or one country, it’s happening all over, especially in North America, Europe, and Asia, where the western honeybee is most commonly kept by beekeepers.

It’s probable that a number of factors contribute to colony collapse, from pesticide use and climate change to declining biodiversity and known honeybee parasites and diseases. Researchers suggest that a colony that’s already under stress due to one or more of these factors is less healthy to start with, and the addition of another stress factor can cause worker bees to abandon the hive. Pesticides, herbicides, and fungicides seem to be major contributing factors.

Entomologists, beekeepers, almond farmers, and many others are working to learn more about what causes colony collapse disorder. In the meantime, they’re trying lots of things to improve bee health in general. Many almond farmers have stopped spraying insecticides on their trees until after the bees have finished pollinating the almond flowers, and those who do have to use insecticides make sure they use kinds that are minimally harmful to bees and then they only spray at night when the bees are safely in their hives. Some farmers have started growing weeds and other flowering plants near the almond trees to attract wild bees, which reduces their dependence on domesticated honeybees.

So do other species of bee produce honey? Nope, only honeybees produce honey. Oh, and the honey wasp. That’s right, there are a few species of wasp that produce honey that’s very similar to that made by honeybees. The wasps are native to Central and South America, with one species living in parts of southwestern North America. They prefer humid forests, including rainforests, and they make paper nests in trees the same way many other wasps do. They eat the honey but they also eat nectar and other insects. They’re actually beneficial to farmers since they eat lots of crop pests like boll weevils and leaf miners. They also help pollinate plants. But they are definitely not domesticated and they will sting you like whoa, and they also don’t produce very much honey compared to honeybees.

Most bees eat nectar and pollen, but will sometimes also eat juice from fruit they might happen to find. But the vulture bee eats meat from dead animals, just like a tiny vulture with six legs. It’s a tropical bee that lives in parts of North America, and not only is it related to the honeybee, it actually makes honey. Sort of. It’s not vegetarian honey, let’s put it that way.

There are three species of vulture bee, all of which have been known to science for centuries, but no one realized they ate meat until 1982. The vulture bee has also lost its pollen baskets, since it lives in areas where pollen is hard to come by. That’s why it eats meat instead, since it supplies the bees with protein in the absence of nutritious pollen.

If a vulture bee can’t find a dead animal to eat, it will sometimes sneak into wasp nests and eat young wasps. Since wasps often do the same thing to bees, that seems fair. Oh, and the vulture bee doesn’t have a sting.

The vulture bee’s mandibles have sharp tooth-like points that help them cut into meat. When a bee finds a dead animal, it will actually burrow into the carcass through its eyes. It also releases pheromones that help the other bees from its colony find the carcass. The bees can strip a carcass the size of, say, a big frog, in a few hours and will even chase flies away.

But the vulture bee can’t digest the meat, not as it is. It uses saliva mixed with nectar it’s eaten to break the meat down into a liquid, which it slurps up and brings back to the hive. Like honeybees partially digesting nectar, the vulture bee partially digests the liquefied meat, which mixes it with enzymes from the bee’s body. Then it regurgitates the liquid to dry in honeycomb cells until it has the consistency of honey, which it is. But I would not eat it.

It turns out that when a bee larva pupates, it spins a cocoon. Even honeybees and other social bees do this, despite the fact that they pupate in cozy little hexagonal cells. And it turns out that the silk that social bees and ants spin to make the cocoon is very different from spider and moth silk. The proteins that make up the silk consist of coiled strands that are also coiled around each other, making the silk incredibly strong but still light-weight. Spider and moth silk is much smoother since it’s made up of a larger protein that is sort of a sheetlike structure.

Since there are so many species of bee in the world, there’s simply no way I can do more than scratch the surface of knowledge and this episode is already getting long. We haven’t even talked about mason bees, and I’d planned to focus on them this time but got sidetracked by honeybees! We’ll save mason bees for another time, but let’s finish up with a solitary bee—that is, a type of bee that doesn’t live in colonies.

The ivy bee lives throughout much of Europe, including the UK, and is a fairly large bee. The female grows to around 13 millimeters long on average although males are smaller. At first glance it looks like a big honeybee but has more vivid black and yellow-orange stripes on its abdomen. If you remember episode 160, where we talked about the Osima avosetta bee that makes her nest out of flower petals, the ivy bee will seem familiar to you. The female digs little nests in the ground to lay her eggs in, one egg per nest, and she leaves nectar and pollen for the babies to eat when they hatch. Then the larvae pupate and emerge as adults in late summer.

The ivy bee gets its name because it mostly eats the pollen and nectar of the ivy plant, which flowers in autumn. Hundreds of ivy bees may swarm over a bank of ivy but they’re not dangerous at all. The bees help pollinate the ivy flowers, which in turn means that there will be plenty of ivy berries in winter for birds to eat. The birds eat the berries but poop out the seeds, which means more ivy will grow. Teamwork!

Quite often you’ll hear people talk about saving the bees, and that’s important. Wild bees of all kinds are declining in number due to habitat loss and pesticides. The best thing you can do to help is to plant flowers, especially flowers native to your area. Even if you can only plant a small flower garden, you will definitely be helping your local wild bees—and butterflies, moths, and other beneficial insects. Teamwork again! You can be part of the bee team!

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

Thanks for listening!


Episode 182: The Coconut Crab and Friends



Join us this week for some interesting crabs! Thanks to Charles for suggesting the aethra crab!

Aethra crabs look like little rocks, although some people (who must be REALLY hungry) think they look like potato chips:

A hermit crab using a light bulb bottom as an inadequate shell:

The tiniest hermit crab:

Gimme shell pls:

THE BIGGEST HERMIT CRAB, the coconut crab. It really is this big:

Show transcript:

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

We have a bunch of crustaceans this week! I’m sorry I’ve taken so long to get to Charles’s suggestion of aethra crabs, so we’ll start with those.

There are four species of aethra crabs alive today, and they live in warm, shallow coastal waters. They like areas with lots of rocks on the sea floor, because the crabs look like small flattened rocks. They can tuck their legs under their carapace so that they don’t show at all, and often algae and other marine animals like barnacles will attach to the carapace, increasing the crab’s resemblance to a little rock. What eats rocks? Nothing eats rocks! So the aethra crab is safe as long as it stays put with its legs hidden. It lives throughout much of the world’s tropical oceans, especially around islands and reefs in South Asia, but also around Australia, Mexico, and Hawaii.

We don’t know a whole lot about aethra crabs, not even how many species there really are. There are probably undiscovered species that no one has studied yet, but we do know they used to be even more widespread than they are today. Twelve million years ago, for instance, a species of aethra crab lived in what is now Ukraine, with fossil remains only described in 2018.

Most aethra crabs only grow a few inches across, or maybe 6 cm, but the walking rock crab of Mexico can grow to 6.3 inches across, or 16 cm across. It’s light brown with lighter and darker speckles that give it a mottled appearance like a small rock.

Because they’re so flattened with rounded edges, and because some species are pale in color, aethra crabs are sometimes called potato chip crabs. I don’t like that name because it makes them sound tasty and not like little rocks. I think we have established that they really look like little rocks.

That’s just about all I can find out about the aethra crab, so if you’re thinking of going into biology and aren’t sure what subject to study, may I suggest you focus your attention on the aethra crab and bring knowledge about them to the world.

So let’s move on to a different type of crab, the hermit crab. A big part of being a crab is evolving ways to not be eaten. I mean, that’s what every animal wants but crabs have some novel ways of accomplishing it. Some crabs look like tiny rocks, some crabs hide in shells discarded by other animals.

There are hundreds of hermit crab species, which are generally grouped as marine hermit crabs and land hermit crabs. There’s also a single freshwater hermit crab that lives on a single island, Espiritu Santo, in the south Pacific, and in fact only in a single pool on that island. It was only described in 1990 and is small, less than an inch long, or about two and a half cm. It uses the discarded shells of a snail that also lives in its pool.

That’s the big thing about a hermit crab: it uses the shells of other animals as a temporary home. Like all crabs, the hermit crab is an invertebrate with an exoskeleton. But unlike most crabs, its abdomen isn’t armored. Instead it’s soft and vulnerable, but that’s okay because most of the time it’s protected by a shell that the crab wears. In most species the abdomen is actually curved in a spiral shape to better fit into most shells.

When a hermit crab finds an empty shell, it may quickly slip out of its current shell and into the new shell to see if it’s a good fit. Ideally the shell is big enough for the crab to hide in completely, but not so big that it’s awkward for the crab to carry around. If it likes the new shell it will abandon the old shell, but if it doesn’t like the new shell it will just go back to its old one. But the important thing is that it has a shell, so it spends as little time without a shell as possible. In fact, if it can’t find a shell of the right size, a hermit crab will make do with anything it can find, such as a plastic bottle, an old tin can, or other trash. But it’s safest inside a real shell. Sometimes two hermit crabs of about the same size will fight over a shell. You wouldn’t think that the ability of a hermit crab to find a good shell would be something humans can affect, but in some areas, so many shells are collected to sell as souvenirs that hermit crabs really don’t have very many left to choose from and have to use trash or pieces of driftwood instead.

Other than the freshwater hermit crab, marine hermit crabs all live in the ocean. Some species live in shallow water, others in deep water, and often around reefs. There are even a few species that are specialized to live in permanent structures on the sea floor, such as sponges or the abandoned burrows of various worms. Land hermit crabs spend most of their time on land, although they have to keep their gills wet.

People sometimes keep hermit crabs as pets, either in an aquarium for marine species, or a special terrarium for land species. Some species can live for decades if given proper care. Because a pet hermit crab is safe, it doesn’t really matter what kind of shell it wears as long as it’s comfortable, so people will sometimes give their pets imitation shells that are clear so they can see the crab’s interesting-shaped abdomen. You can also get fake shells that are shaped like skulls or tiny houses. There’s a picture that goes around sometimes online of a hermit crab using a real human skull as a shell, but that’s actually fake. Not only is the skull not real, the hermit crab isn’t real. It’s a sculpture.

The biggest species of hermit crab is the coconut crab, also sometimes called the robber crab since when it finds something that might be food, it will carry it away to investigate it. It’s not just the biggest hermit crab, it’s the biggest arthropod that lives on land. An arthropod is any invertebrate with an exoskeleton and segmented body. That includes all insects and crustaceans and arachnids, and so on.

The coconut crab has a legspan over three feet across, or about a meter. It can weigh up to nine pounds, or 4 kg. Researchers think it’s literally as big as an arthropod can grow these days and continue to live on land. It’s a bulky, strong crab that ranges in color from reddish-orange or brown to blue-gray, sometimes with white markings.

The coconut crab uses shells as protection when it’s young, but as it grows larger, it outgrows most shells available. Instead, it develops a tough exoskeleton on its abdomen. It also develops lungs, so an adult coconut crab can actually drown if it gets trapped underwater for long enough—generally about an hour. It still has gills, but they’re tiny and not very efficient.

Its lungs aren’t like those of most other arthropods. In fact it only has one lung, called a branchiostegal lung, that has traits of true lungs but also traits of gills. It doesn’t breathe like vertebrates do; instead, its lung absorbs oxygen from the air passively. To do this properly, though, the lung tissue needs to be moist. A coconut crab uses its hindmost pair of legs to dip water up and wipe it over the lung tissue, which is inside a cavity in the cephalothorax. This is the main part of the body as opposed to the abdomen. This last pair of legs is tiny compared to the other eight legs, and female coconut crabs also use these legs to tend their eggs. Usually the last pair of legs aren’t even visible, since the crab usually keeps them tucked in the lung cavity. The other legs are much larger, and the first pair of legs ends in claws like other crabs.

The coconut crab lives on lots of islands in the Indian and Pacific Oceans and used to live in Australia and on many more islands. But it’s a big crab and that means it provides a lot of food, so humans have hunted it to extinction in many areas. It’s increasingly rare in many places as a result of hunting and habitat loss. But the coconut crab isn’t helpless. If a coconut crab snaps its pincers on, for instance, a person’s thumb, it will hold on tenaciously, probably while the person flails around in panic and pain. Not only that, but sometimes a population of coconut crabs will feed on plants that contain toxins, such as the sea mango, and will retain the toxins in its body. If a person eats a toxic crab, they may get sick from the poison.

It’s called the coconut crab because it eats coconuts, but it actually doesn’t prefer coconuts. It especially likes bananas. It also eats seeds, nuts, and other plant material, but it’s an omnivore and will eat carrion, other crabs, baby turtles, and even birds. Its antennae have evolved to detect chemicals in the air instead of in the water, which means it has a good sense of smell and can track the smell of rotting fruit or meat from a long distance away.

Even the biggest crabs can climb well and will climb trees, sometimes to get away from potential predators, but sometimes to catch birds. The quickest way to get out of a tree after climbing it is just by falling, and the coconut crab often does this on purpose. Its exoskeleton is so tough that it can fall some 15 feet, or 4.5 meters, without injury. And yes, sometimes a coconut crab will use their claws to break into a coconut to eat it, but it takes a long time—sometimes days. The coconut crab is mostly nocturnal, but it will come out during the day if it’s hungry, especially if it’s raining or foggy out.

A female coconut crab glues her fertilized eggs under her abdomen and carries them around for a few months as they develop. When they’re ready to hatch, she releases them into the ocean. After they hatch, the larvae drift around for several weeks, eating tiny specks of food. As a baby coconut crab grows and develops through its juvenile stages, which generally takes several weeks, it finally settles to the sea floor and finds a shell to hide in, just like other hermit crabs do. If it can’t make it to shore on its own, it will climb onto a floating log or bunch of floating seaweed or a floating coconut, which eventually carries it to shore. It needs to be on shore because only the larvae can swim, and once it reaches its adult stage it has to breathe air.

Like other arthropods, the coconut crab has to molt its exoskeleton periodically as it grows, since the exoskeleton can’t grow. After it molts, it takes up to three weeks for the new exoskeleton to harden. During this time the crab hides in a burrow it digs, because even a gigantic coconut crab is soft and vulnerable without its exoskeleton. It lines its burrow with coconut fibers, which absorb water and helps keep the crab’s lung tissue moist while it rests. The crab will also stop up the entrance to its burrow with one of its claws, to help keep it safe and reduce the loss of moisture from the burrow. The coconut crab continues to grow throughout its life, which can be extremely long—more than sixty years. A big coconut crab’s only predator is people, and frankly I would not want to tangle with one.

Let’s finish the episode with a mystery crab. Wallowa Lake in Oregon, in the United States, is about three and a half miles long, or 5.6 km, and three-quarters of a mile across, or 1.2 km, and is 300 feet at its deepest point, or 91 meters. After gold was found in the area in the late 19th century, the Wallowa band of the Nez Perce was forced out of their ancestral home by the U.S. government, despite the treaties in place to stop that kind of thing happening. Funny how often that happens. Anyway, the gold rushers who moved in spread stories about giant crabs that lived in the lake, which would crawl out at night to grab cattle and pull them into the water to eat.

But the lake was created from melting glaciers near the end of the Pleistocene ice ages, around 11,000 years ago. It’s never been connected to the ocean and is in fact 4,300 feet above sea level, or 1,300 m. It’s also in a part of the world that experiences bitterly cold winters. All freshwater crabs are tropical or subtropical and can’t survive in cold water. Plus, of course, even the biggest coconut crab isn’t big enough to drag a cow into the water.

So the Wallowa Lake crabs are probably just tall tales. But, you know, maybe be careful if you go swimming in the lake at night, just in case.

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

Thanks for listening!


Episode 181: Updates 3 and a lake monster!



It’s our annual updates and corrections episode, with a fun mystery animal at the end!

Thanks to everyone who contributed, including Bob, Richard J. who is my brother, Richard J. who isn’t my brother, Connor, Simon, Sam, Llewelly, Andrew Gable of the excellent Forgotten Darkness Podcast, and probably many others whose names I didn’t write down!

Further reading:

Northern bald ibis (Akh-bird)

Researchers learn more about teen-age T. rex

A squid fossil offers a rare record of pterosaur feeding behavior

The mysterious, legendary giant squid’s genome is revealed

Why giant squid are still mystifying scientists 150 years after they were discovered (excellent photos but you have to turn off your ad-blocker)

We now know the real range of the extinct Carolina parakeet

Platypus on brink of extinction

Discovery at ‘flower burial’ site could unravel mystery of Neanderthal death rites

A Neanderthal woman from Chagyrskyra Cave

The Iraqi Afa – a Middle Eastern mystery lizard

Further watching/listening:

Richard J. sent me a link to the Axolotl song and it’s EPIC

Bob sent me some more rat songs after I mentioned the song “Ben” in the rats episode, including The Naked Mole Rap and Rats in My Room (from 1957!)

The 2012 video purportedly of the Lagarfljótsormurinn monster

A squid fossil with a pterosaur tooth embedded:

A giant squid (not fossilized):

White-throated magpie-jay:

An updated map of the Carolina parakeet’s range:

A still from the video taken of a supposed Lagarfljót worm in 2012:

An even clearer photo of the Lagarfljót worm:

Show transcript:

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

This is our third annual updates and corrections episode, where I bring us up to date about some topics we’ve covered in the past. We’ll also talk about an interesting mystery animal at the end. There are lots of links in the show notes to articles I used in the episode’s research and to some videos you might find interesting.

While I was putting this episode together, I went through all the emails I received in the last year and discovered a few suggestions that never made it onto the list. I’m getting really backed up on suggestions again, with a bunch that are a year old or more, so the next few months will be all suggestion episodes! If you’re waiting to hear an episode about your suggestion, hopefully I’ll get to it soon.

Anyway, let’s start the updates episode with some corrections. In episode 173 about the forest raven, I mentioned that the northern bald ibis was considered sacred by ancient Egyptians. Simon asked me if that was actually the case or if only the sacred ibis was considered sacred. I mean, it’s right there in the name, sacred ibis.

I did a little digging and it turns out that while the sacred ibis was associated with the god Thoth, along with the baboon, the northern bald ibis was often depicted on temple walls. It was associated with the ankh, which ancient Egyptians considered part of the soul. That’s a really simplistic way to put it, but you’ll have to find an ancient history podcast to really do the subject justice. So the northern bald ibis was important to the ancient Egyptians and sort of considered sacred, but in a different way from the actual sacred ibis.

In episode 146 while I was talking about the archerfish, I said something about how I didn’t fully understand how the archerfish actually spits water so that it forms a bullet-like blob. Bob wrote and kindly explained in a very clear way what goes on: “Basically, the fish spits a stream of water, but squeezes it so that the back end of the stream is moving faster than the front. So it bunches up as it flies and hits the target with one big smack. Beyond that, the water bullet would fall apart as the back part moves through the front part of the stream, but the fish can apparently judge the distance just right.” That is really awesome.

In another correction, Sam told me ages ago that the official pronouns for Sue the T rex are they/them, because that’s what Sue has requested on their Twitter profile. I forgot to mention this last time, sorry.

While we’re talking about Tyrannosaurus rex, researchers have IDed two teenaged T rex specimens found in Montana. Originally paleontologists thought the specimens might be a related species that grew to a much smaller size, Nanotyrannus, but the team studying them have determined that they were juvenile T rexes. To learn how old the specimens were and how fast they grew, they cut extremely thin slices from the leg bones and examined them under high magnification.

The study of fossil bone microstructure is called paleohistology and it’s a new field that’s helped us learn a lot about long-extinct animals like dinosaurs. We know from this study that T rex grew as fast as modern warm-blooded animals like birds and mammals, and we know that the specimens were 13 and 15 years old when they died. T rex didn’t reach its adult size until it was about twenty, and there are definite differences in the morphology of the juvenile specimens compared to an adult. The young T rexes were built for speed and had sharper teeth to cut meat instead of crush through heavy bones the way adults could. This suggests that juvenile T rexes needed to outrun both predators and smaller prey.

In other fossil news, Llewelly sent me a link about a pterosaur tooth caught in a squid fossil. We know pterosaurs ate fish because paleontologists have found fossilized fish bones and scales in the stomach area of pterosaur remains, but now we know they also ate squid. The fossil was discovered in Bavaria in 2012 and is remarkably well preserved, especially considering how few squid fossils we have. One of the things preserved in the fossil is a sharp, slender tooth that matches that of a pterosaur. Researchers think the pterosaur misjudged the squid’s size and swooped down to grab it from the water, but the squid was about a foot long, or 30 cm, and would have been too heavy for the pterosaur to pick up. One of its teeth broke off and remained embedded in the squid’s mantle, where it remains to this day 150 million years later.

And speaking of squid, the giant squid’s genome has been sequenced. Researchers want to see if they can pinpoint how the giant squid became so large compared to most other cephalopods, but so far they haven’t figured this out. They’re also looking at ways that the giant squid differs from other cephalopods and from vertebrates, including humans, to better understand how vertebrates evolved. They have discovered a gene that seems to be unique to cephalopods that helps it produce iridescence.

The Richard J. who is my brother sent me an article about giant squid a while back. There’s a link in the show notes. It has some up-to-date photos from the last few years as well as some of the oldest ones known, and lots of interesting information about the discovery of giant squid.

The Richard J. who is not my brother also followed up after the magpies episode and asked about the magpie jay. He said that the white-throated magpie jay is his favorite bird, and now that I’ve looked at pictures of it, I see why.

There are two species of magpie jay, the black-throated and the white-throated, which are so closely related that they sometimes interbreed where their ranges overlap. They live in parts of Mexico and nearby countries. They look a little like blue jays, with blue feathers on the back and tail, white face and belly, and black markings. Both species also have a floofy crest of curved feathers that looks like something a parrot would wear. A stylish parrot. Like other corvids, it’s omnivorous. It’s also a big bird, almost two feet long including the long tail, or 56 cm.

In other bird news, Connor sent me an article about the range of the Carolina parakeet before it was driven to extinction. Researchers have narrowed down and refined the bird’s range by researching diaries, newspaper reports, and other sightings of the bird well back into the 16th century. It turns out that the two subspecies didn’t overlap much at all, and the ranges of both were much smaller than have been assumed. I put a copy of the map in the show notes, along with a link to the article.

One update about an insect comes from Lynnea, who wrote in after episode 160, about a couple of unusual bee species. Lynnea said that some bees do indeed spin cocoons. I’d go into more detail, but I have an entire episode planned about strange and interesting bees. My goal is to release it in August, so it won’t be long!

In mammal news, the platypus is on the brink of extinction now more than ever. Australia’s drought, which caused the horrible wildfires we talked about in January, is also causing problems for the platypus. The platypus is adapted to hunt underwater, and the drought has reduced the amount of water available in streams and rivers. Not only that, damming of waterways, introduced predators like foxes, fish traps that drown platypuses, and farming practices that destroy platypus burrows are making things even worse. If serious conservation efforts aren’t put into place quickly, it could go extinct sooner than estimated. Conservationists are working to get the platypus put on the endangered species list throughout Australia so it can be saved.

A Neandertal skeleton found in a cave in the foothills of Iraqi Kurdistan appears to be a deliberate burial in an area where many other burials were found in the 1950s. The new skeleton is probably more than 70,000 years old and is an older adult. It was overlooked during the 1950s excavation due to its location deep inside a fissure in the cave. The research team is studying the remains and the area where they were found to learn more about how Neandertals buried their dead. They also hope to recover DNA from the specimen.

Another Neandertal skeleton, this one from a woman who died between 60,000 and 80,000 years ago in what is now Siberia, has had her DNA sequenced and compared to other Neandertal DNA. From the genetic differences found, researchers think the Neandertals of the area lived in small groups of less than 60 individuals each. She was also more closely related to Neandertal remains found in Croatia than other remains found in Siberia, which suggests that the local population was replaced by populations that migrated into the area at some point.

Also, I have discovered that I’ve been pronouncing Denisovan wrong all this time. I know, shocker that I’d ever mispronounce a word.

Now for a lizard and a couple of corrections and additions to the recent Sirrush episode. Last year, Richard J. and I wrote back and forth about a few things regarding one of my older episodes. Specifically he asked for details about two lizards that I mentioned in episode 21. I promised to get back to him about them and then TOTALLY FORGOT. I found the email exchange while researching this episode and feel really bad now. But then I updated the episode 21 show notes with links to information about both of those lizards so now I feel slightly less guilty.

Richard specifically mentioned that the word sirrush, or rather mush-khush-shu, may mean something like “the splendor serpent.” I totally forgot to mention this in the episode even though it’s awesome and I love it.

One of the lizards Richard asked about was the afa lizard, which I talked about briefly in episode 21. Reportedly the lizard once lived in the marshes near the Tigris and Euphrates rivers in what is now Iraq. Richard wanted to know more about that lizard because he wondered if it might be related to the sirrush legend, which is how we got to talking about the sirrush in the first place and which led to the sirrush episode. Well, Richard followed up with some information he had learned from a coworker who speaks Arabic. Afa apparently just means snake in Arabic, although of course there are different words for snake, and the word has different pronunciations in different dialects. He also mentioned that it’s not just the water monitor lizard that’s known to swim; other monitors do too, including the Nile monitor. I chased down the original article I used to research the afa and found it on Karl Shuker’s blog, and Shuker suggests also that the mysterious afa might be a species of monitor lizard, possibly one unknown to science. We can’t know for certain if the afa influenced the sirrush legend, but it’s neat to think about.

Next up, in cryptid news, Andrew Gable of the excellent Forgotten Darkness podcast suggested that some sightings of the White River Monster, which we talked about in episode 153, might have been an alligator—especially the discovery of tracks and crushed plants on the bank of a small island. This isn’t something I’d thought about or seen suggested anywhere, but it definitely makes sense. I highly recommend the Forgotten Darkness podcast and put a link in the show notes if you want to check it out.

And that leads us to a lake monster to finish up the episode. The Lagarfljót [LAH-gar-flote] worm is a monster from Iceland, which is said to live in the lake that gives it its name. The lake is a pretty big one, 16 miles long, or 25 km, and about a mile and a half wide at its widest, or 2.5 km. It’s 367 feet deep at its deepest spot, or 112 m. It’s fed by a river with the same name and by other rivers filled with runoff from glaciers, and the water is murky because it’s full of silt.

Sightings of the monster go back centuries, with the first sighting generally thought to be from 1345. Iceland kept a sort of yearbook of important events for centuries, which is pretty neat, so we have a lot of information about events from the 14th century on. An entry in the year 1345 talks about the sighting of a strange thing in the water. The thing looked like small islands or humps, but each hump was separated by hundreds of feet, or uh let’s say at least 60 meters. The same event was recorded in later years too.

There’s an old folktale about how the monster came to be, and I’m going to quote directly from an English translation of the story that was collected in 1862 and published in 1866. “A woman living on the banks of the Lagarfljót [River] once gave her daughter a gold ring; the girl would fain see herself in possession of more gold than this one ring, and asked her mother how she could turn the ornament to the best account. The other answered, ‘Put it under a heath-worm.’ This the damsel forthwith did, placing both worm and ring in her linen-basket, and keeping them there some days. But when she looked at the worm next, she found him so wonderfully grown and swollen out, that her basket was beginning to split to pieces. This frightened her so much that, catching up the basket, worm and ring, she flung them all into the river. After a long time this worm waxed wondrous large, and began to kill men and beasts that forded the river. Sometimes he stretched his head up on to the bank, and spouted forth a filthy and deadly poison from his mouth. No one knew how to put a stop to this calamity, until at last two Finns were induced to try to slay the snake. They flung themselves into the water, but soon came forth again, declaring that they had here a mighty fiend to deal with, and that neither could they kill the snake nor get the gold, for under the latter was a second monster twice as hard to vanquish as the first. But they contrived, however, to bind the snake with two fetters, one behind his breast-fin, the other at his tail; therefore the monster has no further power to do harm to man or beast; but it sometimes happens that he stretches his curved body above the water, which is always a sign of some coming distress, hunger, or hard times.”

The heath worm is a type of black slug, not a worm or snake at all, and it certainly won’t grow into a dragon no matter how much gold you give it. But obviously there’s something going on in the lake because there have been strange sightings right up to the present day. There’s even a video taken of what surely does look like a slow-moving serpentine creature just under the water’s surface. There’s a link in the show notes if you want to watch the video.

So let’s talk about the video. It was taken in February of 2012 by a farmer who lives in the area. Unlike a lot of monster videos it really does look like there’s something swimming under the water. It looks like a slow-moving snake with a bulbous head, but it’s not clear how big it is. A researcher in Finland analyzed the video frame by frame and determined that although the serpentine figure under the water looks like it’s moving forward, it’s actually not. The appearance of forward movement is an optical illusion, and the researcher suggested there was a fish net or rope caught under the water and coated with ice, which was being moved by the current.

So in a way I guess a Finn finally slayed the monster after all.

But, of course, the video isn’t the only evidence of something in the lake. If those widely spaced humps in the water aren’t a monstrous lake serpent of some kind, what could they be?

One suggestion is that huge bubbles of methane occasionally rise from the lake’s bottom and get trapped under the surface ice in winter. The methane pushes against the ice until it breaks through, and since methane refracts light differently from ordinary air, it’s possible that it could cause an optical illusion from shore that makes it appear as though humps were rising out of the water. This actually fits with stories about the monster, which is supposed to spew poison and make the ground shake. Iceland is volcanically and geologically highly active, so earthquakes that cause poisonous methane to bubble up from below the lake are not uncommon.

Unfortunately, if something huge did once live in the lake, it would have died by now. In the early 2000s, several rivers in the area were dammed to produce hydroelectricity, and two glacial rivers were diverted to run into the lake. This initially made the lake deeper than it used to be, but has also increased how silty the water is. As a result, not as much light can penetrate deep into the water, which means not as many plants can live in the water, which means not as many small animals can survive by eating the plants, which means larger animals like fish don’t have enough small animals to eat. Therefore the ecosystem in the lake is starting to collapse. Some conservationists warn that the lake will silt up entirely within a century at the rate sand and dirt is being carried into it by the diverted rivers. I think the takeaway from this and episode 179 is that diverting rivers to flow into established lakes is probably not a good idea.

At the moment, though, the lake does look beautiful on the surface, so if you get a chance to visit, definitely go and take lots of pictures. You probably won’t see the Lagarfljót worm, but you never know.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!