Category Archives: invertebrates

Episode 359: The Antarctic Death Star(fish)!

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Thanks to Morgan for suggesting this week’s topic, the Antarctic Death Star!

Further reading:

Giant Monster Starfish ALERT

Echinoderm Tube Feet Don’t Suck! They Stick!

Bodies of Starfish and Other Echinoderms Are Really Just Heads, New Research Suggests

The Antarctic death star [from first link listed above]:

The “beartrap” structures, magnified [from first link listed above]:

Show transcript:

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

It’s been way too long since we talked about an invertebrate, so this week we’ll look at one suggested by Morgan, the Antarctic death star.

It has a lot of other names too, including the Antarctic sun starfish and the wolftrap or beartrap starfish. Its scientific name is Labidiaster annulatus. I’m going to call it the death star because I think that’s hilarious.

As you may have guessed from its common names, the Antarctic death star is a starfish that lives in cold ocean waters near the Antarctic, AKA the south pole. But its common names also hint at how it gets its food, and this would be a good time to take a moment and be glad you’re not a copepod that also lives in the Antarctic Ocean.

The death star is reddish-brown on its dorsal side, white underneath. It’s a large starfish, up to two feet across, or 60 cm, and it also has a lot of legs, more properly called rays—up to 50 of them. The rays are long, narrow, and very flexible, and the undersides have rows of little structures called tube feet. All echinoderms, including starfish, have these tube feet and they’re used for several purposes. One important purpose is helping the animal stick to a hard surface, which allows it to climb around more easily and right itself if it gets flipped over.

For over 150 years scientists thought the tube feet acted like little suction cups, but that didn’t explain how a starfish or other echinoderm could stick to porous surfaces. It wasn’t until 2012 that a study was published explaining how the tube feet actually work. The tube feet exude tiny amounts of a sticky chemical that acts like glue.

The death star’s body also has little spines and bumps all over it, but it also has some structures that give the animal its other names, the wolftrap or beartrap starfish. The structures are called pedicellariae [PED-uh-suh-LAIR-ee-aye], which are also common in echinoderms. Most echinoderms seem to use them to keep algae and other organisms from settling on the body, although scientists aren’t completely sure. Pedicellariae have muscles and sensory receptors, and when something touches them, they snap shut like a trap. In the case of the Antarctic death star, its pedicellariae are extra big and really sharp. When a krill or other tiny animal brushes against one of these little traps, it grabs the animal and then the death star can eat it.

But that’s just part of what’s going on when the death star goes hunting, so let’s discuss it in more detail.

Most starfish spend almost all their time on the ocean floor, walking around looking for food. The death star does this too, but not all the time. Quite often a death star will climb on top of a rock or other large structure, and then it will extend some of its rays up and out into the water. It waves its rays around and if it touches a small animal, it will wrap the rays around it. The pedicellariae also snap shut. Then the death star can eat whatever it caught. Usually this is krill or amphipods, but it’s not a picky eater. Since it will eat animals it finds already dead, researchers aren’t completely sure if the death star ever catches fish. They’ve certainly found dead fish in death star stomachs, but the water it lives in is so cold that not many fish live there anyway. Fish don’t make up a big part of the death star’s diet, whether or not it’s catching them itself. The death star also eats other starfish, including smaller death stars.

Like other starfish, the death star can eat surprisingly large pieces of food because it can evert its stomach. This means it can actually push its stomach out through its mouth and engulf whatever large food it’s found or caught. The digestion process starts right away, which allows the starfish to eat food that can’t actually fit through its mouth. It doesn’t chew its food because it doesn’t have any kind of teeth or jaws, but who needs teeth and jaws if your stomach can just reach out and grab food?

While I was researching the death star, I came across a study published in November 2023 about echinoderms, so let’s learn something surprising about starfish and their relations in general.

Echinoderms demonstrate radial symmetry instead of bilateral symmetry. That’s why you can’t tell when a starfish or other echinoderm is facing forward, because it doesn’t actually have a forward. But it’s actually more complicated than it sounds, because the distant ancestor of echinoderms, which lived during the Cambrian almost half a billion years ago, did demonstrate bilateral symmetry, and the larvae of modern echinoderms do too. When a modern echinoderm larva develops into an adult, the left side of its body is the only part that grows. The right side of its body is absorbed and from then on the body develops radially. It actually shows pentaradial symmetry, with five sections around the central part of the body. That’s why so many starfish have five rays, although obviously not all of them. The death star starts out with five rays but adds more and more as it grows.

For a long time scientists have wondered if echinoderms technically have heads or if they’re just bodies. They don’t have eyes or nostrils or most other body parts that we associate with the head, just an oral opening in the middle of the underside of the disc. Starfish do have cells at the ends of their rays that act as eyespots, which are sensitive to light and dark but can’t actually see anything else. Instead of a brain, it has a nerve ring around its mouth and connected nerve nets in its rays, and its digestive system extends into its rays.

In other words, it sure seems like an echinoderm has no head and is basically just a weird body. But the new study came to a surprising conclusion. The study examined starfish genetics and discovered that the genes associated with head development were there. It was the genes associated with the development of a body and tail that were missing. In other words, the starfish, and echinoderms in general, are just really complicated heads.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 343: Mystery Jellyfish

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This week we finish out Invertebrate August with some mysterious jellyfish, including a suggestion by Siya!

Further reading:

Mystery giant jellyfish washes up in Australia

New jellyfish named after curious Australian schoolboy

Mysterious jellyfish found off the coast of Papua New Guinea intrigues researchers

Newly discovered jellyfish is a 24-eyed weirdo related to the world’s most venomous marine creature

Rare jellyfish with three tentacles spotted in Pacific Ocean

The Immortal Jellyfish

A mystery jellyfish washed up on an Australian beach [photo by Josie Lim]:

The tiny box jellyfish found in a pond in Hong Kong:

The very rare Chirodectes:

The mystery jelly that may be Chirodectes or a close relation:

A mystery deep-sea jelly with only three tentacles:

Bathykorus, a possible relation of the three-tentacled mystery jelly:

Show transcript:

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

It’s hard to believe Invertebrate August is already ending, so let’s finish the month out with some mystery jellyfish, including a recent suggestion from Siya!

When you visit the beach, it’s pretty common to find jellyfish washed ashore. They’re usually pretty small and obviously you don’t want to touch them, because many jellies can sting and the stings can activate even if the jelly is dead. Well, in February 2014, a family visiting the beach in Tasmania found a jelly washed ashore that was a little bit larger than normal. Okay, a lot larger than normal.

The jellyfish they found measured almost five feet across, or 1.5 meters. It had flattened out under its own weight but it was still impressive. The family was so surprised at how big it was that they sent pictures to the state’s wildlife organization, who sent scientists to look at it. The scientists had heard reports of a big pink and white jellyfish for years, and now they had one to examine. Dr. Lisa-ann Gershwin thought it might even be a new species of lion’s mane jelly.

New species of jellyfish are discovered all the time. Dr. Gershwin has described over 200 new species herself. One example is a jellyfish discovered by a nine-year-old.

In 2013, a nine-year-old boy in Queensland, Australia was fishing in a canal with his dad and a friend, when he noticed a jellyfish and scooped it up with a net. Its bell was only about an inch long, or 2.5 cm, and the boy thought it was really cute and interesting. He wanted to know what kind of jellyfish it was, so after some pestering on his part, his dad helped him send it to the Queensland Museum for identification.

Dr. Gershwin was the jellyfish expert at the museum at the time, and she was as surprised as the boy’s dad to discover that the jellyfish was new to science! The boy’s name was Saxon Thomas, and to thank him for being so persistent about getting his jellyfish looked at by a scientist, the jellyfish was named Chiropsella saxoni. It’s a type of box jellyfish, which can be deadly, but this one is so small that it’s probably not that dangerous to humans. You still wouldn’t want to be stung by one, though, I bet.

In 2022, a diver visiting Papua New Guinea got video of several really pretty jellyfish. He sent the video to Dr. Gershwin, who realized the jelly was either a very rare jelly called Chirodectes, or it was new to science.

Chirodectes was only discovered in 1997 and described in 2005. It’s a type of box jellyfish and only one specimen has ever been collected, caught off the coast of Queensland, Australia near the Great Barrier Reef after a cyclone. Its bell was about 6 inches long, or 15 cm, but if you include the tentacles it was almost 4 feet long, or 1.2 meters. It’s pale in color with darker rings and speckles on its bell.

The 2022 video appears to show a jellyfish without speckles or other markings, and it’s also larger than the single known Chirodectes specimen. Its bell appears to be about the size of a soccer ball, or a football if you live in most of the world. However, Dr. Gershwin and other experts who have studied the video say that it’s similar in many ways to Chirodectes and may be a close relation. Since all we have is the video, there’s no way to tell for sure if it’s a species new to science.

Most box jellies live around Australia and New Guinea, but in 2020 scientists in Hong Kong studying organisms living in an intertidal shrimp pond noticed a jellyfish they didn’t recognize. It was tiny, even smaller than Saxon’s little box jelly, with a bell barely half an inch long, or about 15 mm. There were hundreds of the little jellies in the pond, which connects to the ocean with a narrow tidal channel, and they appeared to be eating the tiny shrimp living in the pond. Close study of the jelly determined that it was indeed a new species.

The box jelly gets its name from its bell shape, which is shaped sort of like a cube. Most species are transparent to some degree, with tentacles that hang down from the corners of its cube-shaped bell. Most box jellies are fast swimmers, able to use jet propulsion to move around. Some species, including the newly discovered Tripedalia maipoensis from Hong Kong, even have paddle-like structures at the end of their tentacles to help them swim. Tripedalia probably isn’t dangerous to humans, but the scientists who studied it don’t know for sure because no one wanted to volunteer to be stung by it.

In 2015, the Ocean Exploration Trust was conducting an expedition in the Pacific Ocean, pretty much as far away from land as it’s possible to get, when they saw a mysterious little jellyfish. It was brown in color, but it only had three tentacles—and those tentacles emerge from the top of its bell, not from underneath. Then, in June 2023, another Ocean Exploration Trust expedition spotted the same type of jelly. It’s only the second time it’s been seen, and we know almost nothing about it.

The mystery jelly swims with its tentacles pointing forward, and scientists think that it hunts other jellies and small animals. When its tentacles touch an animal, it grabs it. But that’s pretty much all we know about it so far. Researchers think it might be related to the deep-sea hydrozoan Bathykorus, which was only described in 2010.

Bathykorus is sometimes called the Darth Vader jellyfish, because the shape of its bell kind of resembles Darth Vader’s helmet. Unlike Darth Vader, though, Bathykorus is mostly transparent and has eight tentacles. Four grow from the top of its bell, four grow from the bottom, and it holds the top tentacles up while it swims. It’s been found as deep as 8,200 feet below the surface of the Arctic Ocean, or 2,500 meters. And that’s pretty much all we know about this jelly, even though scientists have been able to carefully capture a few specimens and keep them alive for a few days in specially constructed tanks that mimic conditions found in the deep sea.

Let’s finish with a suggestion from Siya, the immortal jellyfish. It’s tiny, barely more than 4 mm across as an adult, and lives throughout much of the world’s oceans, especially where it’s warm. It eats tiny food, including plankton and fish eggs, which it grabs with its tiny tentacles. Small as it is, the immortal jellyfish has stinging cells in its tentacles. It’s mostly transparent, although its stomach is red and an adult jelly has up to 90 white tentacles.

The immortal jellyfish starts life as a larva called a planula, which can swim, but when it finds a place it likes, it sticks itself to a rock or shell, or just the sea floor. There it develops into a polyp colony, and this colony buds new polyps that are clones of the original. These polyps swim away and grow into jellyfish, which spawn and develop eggs, and those eggs hatch into new planulae.

Polyps can live for years, while adult jellies, called medusae, usually only live a few months. But if an adult immortal jellyfish is injured, starving, sick, or otherwise under stress, it can transform back into a polyp. It forms a new polyp colony and buds clones of itself that then grow into adult jellies.

This is all really interesting, and scientists are studying the immortal jellyfish to learn more about how it manages this incredible feat. It’s the only organism known that can revert to an earlier stage of life after reaching sexual maturity. But only an individual at the adult stage, called the medusa stage, can revert to an earlier stage of development, and an individual can only achieve the medusa stage once after it buds from the polyp colony. If it reverts to the polyp stage, it will remain a polyp until it eventually dies. However, it will bud off clones of itself that develop into medusae.

In other words, an immortal jellyfish isn’t technically immortal, but it can certainly prolong its life in an extraordinary way. It’s also really cute.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 342: Giant Snails and Giant Crabs

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Thanks to Tobey and Anbo for their suggestions this week! We’re going to learn about some giant invertebrates!

Further reading:

The Invasive Giant African Land Snail Has Been Spotted in Florida

A very big shell:

The giant African snail is pretty darn giant [photo from article linked above]:

The largest giant spider crab ever measured, and a person:

Show transcript:

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

This week we’re going to learn about some giant invertebrates, suggested by Tobey and Anbo. Maybe they’re not as big as dinosaurs or whales, but they’re surprisingly big compared to most invertebrates.

Let’s start with Tobey’s suggestion, about a big gastropod. Gastropods include slugs and snails, and while Tobey suggested the African trumpet snail specifically, I couldn’t figure out which species of snail it is. But it did lead me to learning a lot about some really big snails.

The very biggest snail known to be alive today is called the Australian trumpet snail, Syrinx aruanus. This isn’t the kind of snail you’d find in your garden, though. It’s a sea snail that lives in shallow water off the coast of northern Australia, around Papua New Guinea, and other nearby areas. It has a coiled shell that’s referred to as spindle-shaped, because the coils form a point like the spindle of a tower. It’s a pretty common shape for sea snails and you’ve undoubtedly seen this kind of seashell before if you’ve spent any time on the beach. But unless you live in the places where the Australian trumpet lives, you probably haven’t seen a seashell this size. The Australian trumpet’s shell can grow up to three feet long, or 91 cm. Not only is this a huge shell, the snail itself is really heavy. It can weigh as much as 31 lbs, or 14 kg, which is as heavy as a good-sized dog.

The snail eats worms, but not just any old worms. If you remember episode 289, you might remember that Australia is home to the giant beach worm, a polychaete worm that burrows in the sand between high and low tide marks. It can grow as much as 8 feet long, or 2.4 meters, and probably longer. Well, that’s the type of worm the Australian trumpet likes to eat, along with other worms. The snail extends a proboscis into the worm’s burrow to reach the worm, but although I’ve tried to find out how it actually captures the worm in order to eat it, this seems to be a mystery. Like other gastropods, the Australian trumpet eats by scraping pieces of food into its mouth using a radula. That’s a tongue-like structure studded with tiny sharp teeth, and the Australian trumpet has a formidable radula. Some other sea snails, especially cone snails, are able to paralyze or outright kill prey by injecting it with venom via a proboscis, so it’s possible the Australian trumpet does too. The Australian trumpet is related to cone snails, although not very closely.

Obviously, we know very little about the Australian trumpet, even though it’s not hard to find. The trouble is that its an edible snail to humans and humans also really like those big shells and will pay a lot for them. In some areas people have hunted the snail to extinction, but we don’t even know how common it is overall to know if it’s endangered or not.

Tobey may have been referring to the giant African snail, which is probably the largest living land snail known. There are several snails that share the name “giant African snail,” and they’re all big, but the biggest is Lissachatina fulica. It can grow more than 8 inches long, or 20 cm, and its conical shell is usually brown and white with pretty banding in some of the whorls. It looks more like the shell of a sea snail than a land snail, but the shell is incredibly tough.

The giant African snail is an invasive species in many areas. Not only will it eat plants down to nothing, it will also eat stucco and concrete for the minerals they contain. It even eats sand, cardboard, certain rocks, bones, and sometimes other African giant snails, presumably when it runs out of trees and houses to eat. It can spread diseases to plants, animals, and humans, which is a problem since it’s also edible.

Like many snails, the African giant snail is a simultaneous hermaphrodite, meaning it can produce both sperm and eggs. It can’t self-fertilize its own eggs, but after mating a snail can keep any unused sperm alive in its body for up to two years, using it to fertilize eggs during that whole time, and it can lay up to 200 eggs five or six times a year. In other words, it only takes a single snail to produce a wasteland of invasive snails in a very short amount of time.

In June 2023, some African giant snails were found near Miami, Florida and officials placed the whole area under agricultural quarantine. That means no one can move any soil or plants out of the area without permission, since that could cause the snails to spread to other places. Meanwhile, officials are working to eradicate the snails. Other parts of Florida are also under the same quarantine after the snails were found the year before. Sometimes when people go on vacation in the Caribbean they bring back garden plants, without realizing that the soil in the pot contains giant African snail eggs, because the giant African snail is also an invasive species throughout the Caribbean.

Next, Anbo wanted to learn about the giant spider crab, also called the Japanese spider crab because it lives in the Pacific Ocean around Japan. It is indeed a type of crab, which is a crustacean, which is an arthropod, and it has the largest legspan of any arthropod known. Its body can grow 16 inches across, or 40 cm, and it can weigh as much as 42 pounds, or 19 kg, which is almost as big as the biggest lobster. But its legs are really really really long. Really long! It can have a legspan of 12 feet across, or 3.7 meters! That includes the claws at the end of its front legs. Most individual crabs are much smaller, but since crustaceans continue to grow throughout their lives, and the giant spider crab can probably live to be 100 years old, there’s no reason why some crabs couldn’t be even bigger than 12 feet across. Its long legs are delicate, though, and it’s rare to find an old crab that hasn’t had an injury to at least one leg.

The giant spider crab is orange with white spots, sort of like a koi fish but in crab form. Its carapace is also bumpy and spiky. You wouldn’t think a crab this size would need to worry about predators, but it’s actually eaten by large octopuses. The crab sticks small organisms like sponges and kelp to its carapace to help camouflage it.

The giant spider crab is considered a delicacy in some places, which has led to overfishing. It’s now protected in Japan, where people are only allowed to catch the crabs during part of the year. This allows the crabs to safely mate and lay eggs.

There’s another species called the European spider crab that has long legs, but it’s nowhere near the size of the giant spider crab. Its carapace width is barely 8 ½ inches across, or 22 cm, and its legs are about the same length. Remember that the giant spider crab’s legs can be up to six feet long each, or 1.8 meters. While the European spider crab does resemble the giant spider crab in many ways, it’s actually not closely related to it. They two species belong to separate families.

The giant spider crab spends most of its time in deep water, although in mating season it will come into shallower water. It uses its long legs to walk around on the sea floor, searching for food. It’s an omnivore that eats pretty much anything it can find, including plants, dead animals, and algae, but it will also use its claws to open mollusk shells and eat the animals inside. It prefers rocky areas of the sea floor, since its bumpy carapace blends in well among rocks.

Scientists report that the giant spider crab is mostly good-natured, even though it looks scary. Some big aquariums keep giant spider crabs, and the aquarium workers say the same thing. But it does have strong claws, and if it feels threatened it can seriously injure divers. I shouldn’t need to remind you not to pester a crab with a 12-foot legspan.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 341: The Leaf Sheep and the Mold Pig

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Thanks to Murilo and an anonymous listener for their suggestions this week!

Further reading:

The ‘sheep’ that can photosynthesize

Meet the ‘mold pigs,’ a new group of invertebrates from 30 million years ago

A leaf sheep:

Shaun the sheep:

A mold pig:

Show transcript:

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

This week let’s learn about two animals that sound like you’d find them on a farm, but they’re much different than their names imply. Thanks to Murilo for suggesting the leaf sheep, which is where we’ll start.

The leaf sheep isn’t a sheep or a leaf. It’s actually a type of sea slug that lives in tropical waters near Japan and throughout much of coastal south Asia. The reason it’s called a leaf sheep is because it actually looks a lot like a tiny cartoon sheep covered with green leaves instead of wool.

Back in episode 215 we talked about the sea bunny, which is another type of sea slug although it’s not closely related to the leaf sheep. The leaf sheep is even smaller than the sea bunny, which can grow up to an inch long, or about 25 mm. The leaf sheep only grows about 10 mm long at most, which explains why it wasn’t discovered until 1993. No one noticed it.

The leaf sheep’s face is white or pale yellow with two tiny black dots for eyes set close together, which kind of makes it look like Shaun the Sheep. It also has two black-tipped protuberances that look like ears, although they’re actually chemoreceptors called rhinophores. The rest of its body is covered with leaf-shaped spines called cerata, which are green and often tipped with pink, white, or black. This helps disguise it as a plant, but there’s another reason why it’s green.

The leaf sheep eats a particular kind of algae called Avrainvillea, which looks like moss or fuzzy carpet. While algae aren’t exactly plants or animals, many do photosynthesize like plants. In other words, they transform sunlight into energy to keep them alive. In order to photosynthesize, a plant or algae uses a special pigment called chlorophyll that makes up part of a chloroplast in its cells, which happens to be green.

The leaf sheep eats the algae, but it doesn’t digest the chloroplasts. Instead, it absorbs them into its own body and uses them for photosynthesis. That way it gets nutrients from eating and digesting algae and it gets extra energy from sunlight. This is a trait shared by other sea slugs in the superorder Sacoglossa. Because they need sunlight for photosynthesis, they live in shallow water, often near coral reefs.

When the leaf sheep’s eggs hatch, the larvae have shells, but as they mature they shed their shells.

This is a good place to talk about cyanobacteria, which was requested ages ago by an anonymous listener. Cyanobacteria mostly live in water and are also called blue-green algae, even though they’re not actually classified as algae. They’re considered bacteria, although not every scientist agrees. Some are unicellular, meaning they just consist of one cell, while others are multicellular like plants and animals, which means they have multiple cells specialized for different functions. Some other cyanobacteria group together in colonies. So basically, cyanobacteria looked at the chart of possible life forms and said, “yes, thanks, we’ll take some of everything.” That’s why it’s so hard to classify them.

Cyanobacteria photosynthesize, and they’ve been doing so for far longer than plants–possibly as much as 2.7 billion years, although scientists think cyanobacteria originally evolved around 3.5 billion years ago. The earth is about 4.5 billion years old and plants didn’t evolve until about 700 million years ago.

Like most plants also do, cyanobacteria produce oxygen as part of the photosynthetic process, and when they started doing so around 2.7 billion years ago, they changed the entire world. Before then, earth’s atmosphere hardly contained any oxygen. If you had a time machine and went back to more than two billion years ago, and you forgot to bring an oxygen tank, you’d instantly suffocate trying to breathe the air. But back then, even though animals and plants didn’t yet exist, the world contained a whole lot of microbial life, and none of it wanted anything to do with oxygen. Oxygen was toxic to the lifeforms that lived then, but cyanobacteria just kept producing it.

Cyanobacteria are tiny, but there were a lot of them. Over the course of about 700 million years, the oxygen added up until other lifeforms started to go extinct, poisoned by all that oxygen in the oceans and air. By two billion years ago, pretty much every lifeform that couldn’t evolve to use or at least tolerate oxygen had gone extinct. So take a deep breath of life-giving oxygen and thank cyanobacteria, which by the way are still around and still producing oxygen. However, they’re still up to their old tricks because they also produce what are called cyanotoxins, which can be deadly.

That brings us to another animal in our imaginary farm, the mold pig. It’s not a pig or a mold, and unlike the leaf sheep and cyanobacteria, it’s extinct. At least, we think it’s extinct.

The mold pig is a microinvertebrate only discovered in 2019. The only reason we know about it at all is because of amber found in the Dominican Republic, on an island in the Caribbean Sea. As we’ve discussed in past episodes, especially episode 108, amber is the fossilized resin of certain types of tree, and sometimes the remains of small animals are found inside. Often these animals are insects, but sometimes even tinier creatures are preserved that we would otherwise probably never know about.

The mold pig was about 100 micrometers long, or .1 millimeter. You’ve probably heard of the tardigrade, or water bear, which we talked about in episode 234, and if so you might think the mold pig was a type of tardigrade just from looking at it, since it looks similar. It had four pairs of legs like tardigrades do, but while scientists think they were related, and that the mold pig was probably also related to mites, it was different enough that it’s been classified in its own genus and may need to belong to its own phylum. Its official name is Sialomorpha.

The mold pig probably ate mold, fungus, and microscopic invertebrates. It lived around 30 million years ago, and right now that’s about all we know about it. There’s a good chance that it still survives somewhere in the world, but it’s so tiny that it’s even easier to overlook than the leaf sheep. Maybe you will be the person who rediscovers its living descendants.

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

Thanks for listening!

Episode 340: Whale Lice and Sea Lice

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Thanks to Eilee for suggesting the sea louse this week!

Further reading:

Secrets of the Whale Riders: Crablike ‘Whale Lice’ Show How Endangered Cetaceans Evolved

Parasite of the Day: Neocyamus physeteris

A whale louse [By © Hans Hillewaert, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=19259257]:

The salmon sea louse [By Thomas Bjørkan – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7524020]:

Show transcript:

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

It’s now officially August, so we’re officially kicking off Invertebrate August with two invertebrates with the word louse in their names, even though neither of them are technically lice. Thanks to Eilee for suggesting sea lice, and thanks to our patrons because I used some information from an old Patreon episode for the first part of this episode.

That would be the whale louse. The whale louse isn’t actually a louse, although it is a parasite. Lice are insects adapted for a parasitic lifestyle on the bodies of their hosts, but whale lice are crustaceans—specifically, amphipods specialized to live on whales, dolphins, and porpoises.

There are many species of whale louse, with some only living on a particular species of whale. In the case of the sperm whale, one species of whale louse lives on the male sperm whale while a totally different species of whale louse lives on the female sperm whale and on calves. This was a fact I found on Wikipedia and included in the Patreon episode, but at the time I couldn’t find out more. It’s puzzled me ever since, which is one of the reasons I wanted to revisit this topic. I couldn’t figure out how the male calves ended up with male sperm whale lice, and I couldn’t figure out why males and females would have different species of lice. I’m happy to report that I now know the answers to both questions, or at least I can report what experts hypothesize.

Male sperm whales spend more time in polar waters while females spend more time in warmer waters to raise their calves. Sperm whales are actually host to three different whale lice species, but one species prefers colder water and is much more likely to live on males, while another species prefers warmer water and is much more likely to live on females and calves. Any sperm whale might have lice from any of the three species, though, and whale lice are spread when whales rub against each other. This happens when the whales mate, but it also happens when males fight or when whales are just being friendly.

The whale louse has a flattened body and legs that end in claws that help it cling to the whale. Different species are different sizes, from only five millimeters up to an inch long, or about 25 mm. Typically the lice cling to areas where water currents won’t sweep them away, including around the eyes and genital folds, ventral pleats, blowholes, and in wounds. Barnacles also grow on some whales and the lice live around the barnacles. But even though all that sounds horrible, the lice don’t actually harm the whales. They eat dead skin cells and algae, which helps keep wounds clean and reduces the risk of infection.

The right whale is a baleen whale that can grow up to 65 feet long, or almost 20 meters. Right whales have callosities on their heads, which are raised patches of thickened, bumpy skin. Every whale has a different pattern of callosities. Right whales are dark in color, but while the callosities are generally paler than the surrounding skin, they appear white because that’s where the whale lice live, and the lice are white. This allows whales to identify other whales by sight. It’s gross but it works for the whales. Right whales also usually host one or two other species of louse that don’t live on the callosities.

Dolphins typically have very few lice, since most dolphins are much faster and more streamlined than whales and the lice have a harder time not getting washed off. Some dolphins studied have no lice at all, and others have less than a dozen. Almost all whales have lice.

Scientists study whale lice to learn more about whales, including how populations of whales overlap during migration. Studies of the lice on right whales helped researchers determine when the whales split into three species. But sometimes what researchers learn from the lice is puzzling. In 2004 researchers found a dead southern right whale calf and examined it, and were surprised to find it had humpback whale lice, not southern right whale lice. Researchers hypothesize that something had happened to the calf’s birth mother and it was adopted by a humpback whale mother. Another study determined that a single southern right whale crossed the equator between one and two million years ago and joined up with right whales in the North Pacific. Ordinarily right whales can’t cross the equator, since their blubber is too thick and they overheat in warm water. Researchers suggest that the right whale in question was an adventurous juvenile who crossed in an unusually cool year. The lice that whale carried interbred with lice the North Pacific whales carried, leaving a genetic marker to tell us about the whale’s successful adventure.

Some animals do eat whale lice, including a little fish called topsmelt. Topsmelt live in shallow water along the Pacific coast of North America. It grows up to around 14 inches long, or 37 cm, and has tiny sharp teeth that it uses to eat zooplankton. But in mid-winter through spring, gray whales arrive in the warm, shallow waters where the topsmelt live to give birth. Then schools of topsmelt will gather around the whales, eating lice and barnacles from the whale’s skin. Good for those little fish. That makes me feel better for the whales.

Eilee suggested the sea louse a while back, and when I looked it up initially I was horrified. Sea lice is another name for a skin condition called seabather’s eruption that consists of intense itching and welts on the skin, that occurs after someone has been swimming in some parts of the world. That includes around parts of New Zealand, off the coast of Queensland, Australia, off the eastern coast of Africa, parts of south Asia, the Caribbean and Gulf of Mexico, and many other places. It usually shows up a few hours after a swimmer gets out of the water, and since it almost always shows up in people who keep wearing their bathing suit for a while after swimming, or wear their suit into a shower to rinse off, people used to think the itching was due to a type of louse that got caught in the suit. They were half-right, because it is due to a microscopic animal that gets trapped against a person’s skin by their bathing suit. It isn’t a louse, though, but the larvae of some species of jellyfish. The larvae aren’t dangerous to humans or anything else, but they do each have a single undeveloped nematocyst. That’s a stinging cell, the same kind that adult jellyfish have. In the case of the larvae, the sting only activates when a larva dies, and it dies if it dries out or gets soaked in fresh water. Fortunately, seabather’s eruption isn’t a very common occurrence and while it’s uncomfortable for a few days, it’s not dangerous and can be treated with anti-itch cream.

There is a type of animal called the sea louse, of course, but it doesn’t want anything to do with humans and wouldn’t bite a human even if it could. It’s a parasitic crustacean like the whale louse, but it only lives on fish. It’s also not related to the whale louse and doesn’t look anything like the whale louse. The whale louse looks kind of like a flattened shrimp without a tail, while the sea louse is hard to describe. It has a flattened shield at the front, with a thinner tail-like section behind, although it’s actually not a tail but the louse’s abdomen. Its legs are underneath its body and are short and hooked so it can keep hold of its host fish, although the shape of its shield acts as a sort of suction cup that also helps it remain attached.

Like the whale louse, different species of sea louse live on different species of fish. It’s usually quite small, less than 10 mm long, although at least one species can grow twice that length. Males are much smaller than females. It eats the mucus, skin, and blood of its host fish, and its mouthparts form a sharp cone that it uses to stab the fish and suck fluids out. Naturally, this isn’t good for the fish.

Most of the time a fish only has a few sea lice, if any, but sometimes when conditions are right a fish can have a much heavier infestation. This can lead to the fish dying in really bad cases, sometimes due to diseases spread by the lice, infected wounds caused by the lice, or just from anemia if the lice drink too much of the fish’s blood.

Conditions are right to spread sea lice when fish are crowded in a small space, and this happens a lot in farmed fish. It’s especially bad in salmon, so while we don’t know a lot about most sea lice, we know a whole lot about the species of sea louse that parasitizes salmon. It’s called Lepeophtheirus salmonis and it’s the sea louse that grows bigger than most others. Salmon are big fish, with the largest growing over 6 ½ feet long, or 2 meters.

The salmon sea louse has a complicated life cycle and only lives on fish part of the time, which is probably true of all sea lice. The female louse develops a pair of egg strings that hang down from the rear of her body, and each string has around 150 eggs. The eggs hatch into tiny larvae that mostly just drift along through the water, although they can swim. A larva molts its exoskeleton every few days as it transforms into new stages of development, and all the time it’s looking for a host fish.

Once it finds a salmon, the sea louse grabs hold and stays put until it molts again and reaches the next stage of its development, which doesn’t take long. Then it’s able to walk around on the fish and it can swim too if it needs to.

The sea louse can’t survive very long in fresh water, but that’s weird if you know anything about salmon. Salmon are famous for migrating from the ocean into rivers to spawn, and after spawning, most adult salmon die. Some Atlantic salmon will survive and return to the ocean, but most salmon die within a few days or weeks of spawning. Because all the sea lice die once the salmon enter fresh water, the new generation of salmon don’t get sea lice until they make their way into the ocean.

That’s a natural way that sea lice populations are kept under control. The salmon sea louse will also live on a few other species of fish, including the sea trout. But people like eating salmon, and farming salmon is an important industry. Unfortunately, as I mentioned earlier, having lots of fish in one place means the sea louse can also increase in numbers easily.

Salmon farmers have tried all kinds of things to get rid of sea lice, from underwater lasers that zap the lice to kill them, to putting cleaner fish among the salmon to eat the lice. Scientists are even trying to breed a variety of salmon that’s much more resistant to sea lice infestation, although this is controversial since it makes use of genetic modification. Not all countries allow genetically modified fish to be sold as human food.

For the most part, though, wild fish generally don’t have a lot of sea lice—and if they do, they can just visit a cleaner fish. Thank goodness for cleaner fish!

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

Thanks for listening!

Episode 339: The Tully Monster!

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Is it an invertebrate? Is it a vertebrate? It’s the Tully monster!

Further reading:

3D Tully monster probably not related to vertebrates

Has the “Tully monster” mystery finally been solved after 65 years?

Possibly what the Tully monster looked like while alive:

Show transcript:

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

This week we’re going to learn about an ancient creature surrounded by mystery. When I was working on last week’s updates episode, I found some new information about it and intended to include it as an update. Then I realized I was referencing a Patreon episode, which I also reworked into a chapter of the Beyond Bigfoot & Nessie book. So instead, I included the new information in this episode all about the Tully monster.

In 1955, an amateur fossil collector named Francis Tully discovered a really weird fossil. This was in one particular area of Illinois in the United States, roughly in the middle of North America. The fossil was about six inches long, or 15 cm, and Tully thought it resembled a tiny torpedo.

He took the fossil to the Field Museum of Natural History in Chicago in hopes that somebody could tell him what his fossil was. The paleontologists he showed it to had no idea what it was or even what it might be related to. It was described in 1966 and given the name Tullimonstrum, which means Mr. Tully’s monster, which is pretty much what everyone was calling it already.

300 million years ago, in what is now the state of Illinois, a strange animal lived in the shallow sea that covered part of the area. The land that bordered this sea was swampy, with many rivers emptying into the ocean. These river waters carried dead plant materials and mud, which settled to the bottom of the ocean. When an animal died, assuming it wasn’t eaten by something else, its body sank into this soft muddy mess. The bacteria in the mud produced carbon dioxide that combined with iron that was also present in the mud, which formed a mineral called siderite that encased the dead animal. This slowed decay long enough that an impression of the body formed in the mud, and as the centuries passed and the mud became stone, the fossilized body impression was surrounded by a protective ironstone nodule. That’s why we know about the soft-bodied animals from this area, even though soft-bodied animals rarely leave fossil evidence.

So what did this weird animal look like?

The Tully monster was shaped sort of like a slug or a leech, and it had a segmented body. Its eyes were on stalks that jutted out sideways, although the stalks were more of a horizontal bar that grew across the top of the head. The tail end had two vertical fins, which argues that the Tully monster was probably a good swimmer. But at the front of its body it had a long, thin, jointed proboscis that ended in claws or pincers lined with eight tiny tooth-like structures.

It’s easy to assume that the pincers acted as jaws and therefore the proboscis was a mouth on a jointed stalk, but we really don’t know. The Tully monster may have used its proboscis to probe for food in the mud at the bottom of the sea, but because the proboscis had a joint, it probably couldn’t act as a sort of straw. The pincers may have grabbed tiny prey and conveyed it to a mouth that hasn’t been preserved on the specimens we have.

The Tully monster resembles nothing else known, and is so bizarre that researchers aren’t sure where to place it taxonomically. And it wasn’t rare. Paleontologists have since found lots of Tully monster fossils in the Illinois fossil beds, known as the Mazon Creek formation. The Mazon Creek formation is also the source of highly detailed fossils of hundreds of other plant and animal species, including some that have never been found anywhere else.

Scientists have suggested any number of animal groups that the Tully monster might belong to. It might be a type of arthropod, a mollusk, a segmented worm…or it might be a vertebrate. The tiny tooth-like structures in the pincers have been analyzed and some researchers think they were more similar to keratin than chitin. Keratin is a vertebrate protein while chitin is an invertebrate protein.

In 2016 a study argued that pigments in the eyes are arranged the same way as they are in vertebrates, which meant the Tully monster might have been a vertebrate. The problem is that some invertebrates also have these same pigment arrangements, notably cephalopods like octopuses. A 2019 study also looked at the chemical makeup of the fossil eyes, this time with even more advanced equipment—specifically, a synchrotron radiation lightsource, which is a type of particle accelerator. It sounds so science-y. This study suggested that the Tully monster’s eyes had a different chemical makeup than the vertebrates found in the same fossil beds, which means the Tully monster probably wasn’t a vertebrate after all. But it also didn’t match up with known invertebrates from the same fossil beds.

Of course, it might be a deuterostome. The animals in this superphylum develop a nerve cord at some stage of life, usually as an embryo, but may not retain it into adulthood. This includes echinoderms such as sea stars and sea urchins, tunicates like sea squirts, and possibly acorn worms although some scientists disagree. All vertebrates are also members of the superphylum too.

One suggestion is that the Tully monster is related to a type of animal called a conodont. Technically the term conodont refers to its teeth, with the animal itself known as conodontophora, but conodont is easier to say. We know very little about the conodont, since almost the only fossils we have of it are the tiny teeth. We also have eleven body impressions, so we know it was long and skinny like an eel and grew up to 20 inches long, or 50 cm. We also know it had large eyes, a notochord (or primitive spine), and fins on the tail end.

Conodont teeth first appear in the fossil record during the Cambrian, some 525 million years ago. They disappear entirely from the fossil record about 200 million years ago during the Triassic-Jurassic extinction event. But during those 300-some million years they were around, they left a whole lot of tiny fossil teeth, so many that they’re considered an index fossil, which helps scientists determine how old a particular strata of rock is.

When I say tiny teeth, I mean tiny—they’re microfossils usually measured in micrometers, although some of the larger ones were as much as 6 mm long. But they weren’t teeth like modern animal teeth, and the mouth wasn’t like anything we know today.

The conodont’s mouth is called a feeding apparatus by scientists, and it’s very different from what most of us think of as a mouth. This was long before jawed animals evolved some 400 million years ago, and the conodont’s teeth are technically known as conodont elements since they’re not really teeth. There were three types of the conodont elements, meaning they had different shapes and probably different functions.

Some species of conodont may have used the elements to crush prey, but they probably weren’t very strong swimmers so may have mostly eaten very small animals. Some researchers even suggest the conodont used the elements to filter plankton from the water, while others think the conodont might have been parasitic on larger animals, like the sea lamprey is. Conodonts were probably related to hagfish and lampreys and may have looked similar, although not everyone agrees with this classification. Some researchers even think conodonts might have been invertebrates.

Another possibility is that the Tully monster was related to Anomalocarids, which you may remember from the Cambrian explosion episode. Anomalocaris and its relations were arthropods that resemble nothing else alive. It had eyes on stalks, clawed appendages that grew from its front near the mouth, and the rear of its body was segmented with tail fins. Another Cambrian arthropod, Opabinia, had a single flexible feeding proboscis with claws at the end, five eyes on stalks, and a segmented body, so the Tully monster may have been related to it. But we don’t have anything definitive yet one way or another as to what it was related to.

The most recent study on whether the Tully monster was an invertebrate or a vertebrate was published in early 2023 in the journal Nature. The study used high-resolution 3D scanning to examine 153 Tully monster specimens. The scientists determined that the tooth-like structures at the end of the proboscis don’t appear to be keratin, and the Tully monster has segmentation in its head, which is not something found in vertebrates. These and other findings mean that as of now, it looks like the Tully monster was an invertebrate.

However, we still have no idea what kind of invertebrate it might have been. The 2023 study suggests it was either a non-vertebrate chordate or a protostome. Non-vertebrate chordates include hagfish and tunicates, while protostomes include a whole lot of invertebrates, including insects, worms, and mollusks.

The reason all this is important is because there’s a whole lot we don’t know yet about how jawed animals evolved from jawless fish. If the Tully monster really was a vertebrate, it would give us new information about jawless animals. But part of the reason it’s hard to determine where the Tully monster should be placed taxonomically is because of how incredibly weird it is, and that’s exciting too.

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

Thanks for listening!

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

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

Thanks to Simon and Anbo for sending in some corrections!

Further reading:

Lessons on transparency from the glass frog

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

Rare wild asses spotted near China-Mongolia border

Aye-Ayes Use Their Elongated Fingers to Pick Their Nose

Homo sapiens likely arose from multiple closely related populations

Scientists Find Earliest Evidence of Hominins Cooking with Fire

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

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

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

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

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

The Mongolian wild ass:

The giant barb fish [photo from this site]:

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 337: Ghost Shrimp and Snapping Shrimp

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

Further reading:

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

The Symbiotic Relationship Between Gobies and Pistol Shrimp

An eastern ghost shrimp:

A snapping shrimp:

A goby fish and its snapping shrimp buddy:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 336: The Turtle Ant and the Alien Butt Spider

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Thanks to Kari for suggesting this week’s topics! Definitely check out her book Butt or Face?, which is funny and has lots of animal information!

Further reading:

Butt or Face? by Kari Lavelle

GBIF: Araneus praesignis [the spider pictures below come from this site]

The turtle ant’s body is flattened and the soldier caste ants have specialized head shapes to block the nest entrances:

The alien butt spider has a butt that looks like an alien’s face!

The alien butt spider hides during the day in its leaf fort:

Show transcript:

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

This week we’re going to learn about two really weird invertebrates suggested by Kari. One of these two animals is her favorite and the other is a weird ant from a book she wrote. Kari’s full name is Kari Lavelle and her book is for kids, called Butt or Face? It actually releases tomorrow as this episode goes live, so if you’re listening to this episode on Monday, July 10, 2023, you still have time to preorder the book, or you can just wait a day and run out to your local bookstore or library to get a copy.

Kari was nice enough to send me a copy of the book and it’s really funny and interesting. It’s partly a game where you look at a picture and decide whether it shows an animal’s butt or its face. It’s a lot harder than you’d think! You make your guess and turn the page to find out if you’re right and learn about the animal. It’s very fun and I actually guessed wrong on one animal, but I’m not telling you which one. There’s a link in the show notes if you want to learn more about the book and maybe order a copy for yourself.

Anyway, let’s talk about the ant first, because it’s actually one I’ve had on the list to talk about for a while. I was really excited to see it in Kari’s book. It’s called the turtle ant, sometimes called the “door head” ant. That gives you a clue as to whether its picture in the book features its butt or its face.

The turtle ant is any of the well over 100 species of ant in the genus Cephalotes, which are native to the Americas. Most live in Central and South America, especially in tropical and subtropical areas. Almost all species live in trees, nesting in cavities originally made by beetle larvae.

For the most part, turtle ants are pretty typical compared to other ant species. They have a generalized diet, eating pretty much anything they find. This includes plant material, dead insects and other animals they find, bird poop, nectar, and even pollen in some species. Each colony has a single queen that mates with multiple males and lays all the eggs for the colony. Worker ants tend the eggs and larvae, gather food, and keep the colony clean. But as in some other ants, many species of turtle ant have a soldier caste. These are worker ants who are specialized to defend the nest. We talked about army ants recently, in episode 328, and also back in episode 185, and army ant soldiers have massive sharp mandibles that can inflict painful bites. But the turtle ant soldiers don’t have sharp mandibles and aren’t aggressive. They have one job, and that job is to stand at the nest’s entrances and stop them up with their heads, only moving when another ant needs to get through.

As a result, turtle ant soldiers have weird-shaped heads. The head shape varies from species to species, with some looking more normal and some being heavily armored and strangely shaped. Well, they’re not strangely shaped except in comparison to an ordinary ant head. They’re shaped exactly right to do the job they’ve evolved to do, be a door. In some species, the top of the soldier’s head is completely round and flattened, just the right size and shape to block the entrance.

Turtle ants have another ability that they share with some other ants. If an ant falls from the twig or branch it’s climbing on, instead of just falling to the ground, it can glide back to the tree trunk. Turtle ants have flattened bodies, which helps catch the air like a tiny ant-shaped parachute. Unlike other ants that do this, which glide head-first, the turtle ant glides abdomen-first. It uses its legs and head to adjust which way it’s gliding, and most of the time it lands safely on the tree trunk.

There are undoubtedly more turtle ant species than we know about so far, and we actually don’t know very much about most of the species we have discovered. Most turtle ants live in trees, and that makes them hard to study.

There’s actually a spider called the ant-mimicking crab spider that eats turtle ants. It looks so much like a turtle ant worker that it can get close to the actual ants before it’s recognized as a predator, at which point it has a good chance of grabbing an ant to eat before the ant can run away. But that’s not actually the type of spider we’re talking about next.

The other animal we’re talking about today isn’t one from the book, it just happens to be one of Kari’s favorite animals *cough*sequel*cough*. It’s called the alien butt spider and it is completely awesome, as you can tell from the name.

The alien butt spider lives in Queensland, Australia, and it gets its name because—maybe you should just guess. I’ll wait.

Yes, you’re right! The abdomen of the spider has black or dark blue-green markings that look for all the world like the face of a tiny space alien from a movie. The spider itself is mostly green and very small, with a big female only growing about 8 mm long, although its legspan can be 20 mm across. Males are smaller, mostly because the male has a much smaller abdomen.

Its scientific name is Bijoaraneus praesignis, changed in December 2021 from Araneus praesignis. It’s also called the outstanding orbweaver or green orbweaver. Like many spiders, especially orbweavers, it’s mostly active at night. It spins a big round web that looks like the kind you see on Halloween decorations, because that’s the kind of web most orbweavers make, and at night it waits on or near the web for an insect to get stuck in it. During the day, though, the alien butt spider needs to hide. It makes what’s called a retreat in a leaf that’s partially closed or curled. The spider spins a thick layer of silk across the edges of the leaf that turns it into basically a little leaf fort, then crawls inside. The underside of the spider is plain greenish-yellow with no markings, so it’s hard to see against the leaf, especially through the layer of silk.

The spider’s abdomen is green with a yellow or white pattern on top, with black eye spots visible from the rear. The eye spots show up really well against the yellow or white pattern. But the spider also has black markings at the front of its abdomen, which also look like eyespots from some angles. The rest of its body is green, greeny-yellow, and brown, which helps it blend into leafy backgrounds.

Naturally, the alien butt spider is not actually trying to look like an alien. That’s something humans have decided it looks like because it’s green and the eyespots are so large. The spider just wants potential predators to see the eyespots and think, “Darn, that animal already saw me so I can’t sneak up on it. I won’t waste my energy trying to grab it.” Or maybe, “Uh oh, look at the size of that animal’s eyes! I must be looking at the head of a very large animal that might eat me, plus it’s looking right at me. I’d better run.”

Even though it looks kind of spooky, the alien butt spider is completely harmless to humans. We also don’t know much about it, so while it seems to be a common spider within its range, we don’t know for sure if it’s potentially endangered. It’s best to leave this little alien alone no matter how cute it is (and it is very cute).

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

Thanks for listening!

Episode 335: Large Blue Butterfly vs Ants

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We’re kicking off July with a beautiful butterfly that does horrible things to ants!

Further reading:

UK Butterflies – Large Blue

The large blue butterfly (picture taken from page linked above):

Show transcript:

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

I recently realized that I have so many weird and interesting invertebrates saved up to feature for invertebrate August that I can’t fit them all into one month, so let’s kick off invertebrate August in July!

This week we’re going to learn about a beautiful butterfly called the large blue, because it is both large and blue. Well, sort of large. The butterfly has a wingspan of up to two inches, or about 5 cm. Its wings are a dusty blue with black spots, although there are a lot of regional differences. Some populations are almost black, some are more tan than blue, and some don’t have spots.

The large blue lives throughout much of Eurasia, although its numbers have decreased in many places in the last 50 years or so. In some places it’s even gone extinct, mainly due to habitat loss. It needs specific host plants for the caterpillars to eat, and it also needs a particular type of ant in order for the caterpillars to survive–because the large blue caterpillar is a brood parasite!

We’ve talked about brood parasites before in birds, where a bird will lay an egg in the nest of a different species of bird. In the case of the large blue butterfly, in summertime the female lays her eggs on wild thyme or marjoram plants near a colony of red ants in the genus Myrmica [meer-mee-kuh]. She usually only lays one egg on any given plant.

When the eggs hatch, the newly emerged caterpillars feed on plants at first, just like any other caterpillar, especially the flowers of the plant. If more than one large blue caterpillar is on a plant and they encounter each other, one of them will grab the other and eat it. Drama among the thyme plants! The caterpillar goes through three growth stages, called instars, as an ordinary caterpillar (except for the cannibalism thing), but once it reaches the fourth instar it starts acting very different.

The caterpillar drops to the ground and releases a chemical that mimics the smell of the Myrmica ant larvae. When an ant finds a caterpillar, the caterpillar will rear up so that it resembles an ant larva. The ant usually takes it back to its nest at this point, but sometimes the caterpillar will just follow an ant trail and enter the nest on its own. Either way, the ants will assume it’s a lost baby and take it to the nesting chamber, where they feed and take care of it.

The caterpillar is bigger than a usual ant larva, but it uses this to its advantage. It mimics the sounds made by a queen ant, which means the ants take extra good care of it. If the ants run out of regular food to feed the caterpillar, they will even start feeding it real ant larvae. But sometimes the caterpillar gets impatient, or maybe just hungry, and will just start eating the other pupating ant larvae.

The system isn’t perfect, because a lot of times the ants figure out that the caterpillar is an intruder and will kill and eat it. If the queen ant encounters the caterpillar, she recognizes that it isn’t an ant larva and will attack it. Sometimes the ants just up and abandon the nest, leaving the caterpillar behind. In that case, the caterpillar will either leave the nest itself and find another one, or it will wait for a new ant colony to find the nest and move in. This can actually happen repeatedly during the nine months or so that the caterpillar requires to finish growing, although during the winter the caterpillar is more or less dormant.

Around the end of spring, the caterpillar spins a cocoon and pupates right there in the ant nest. The ants continue to take care of it, making sure the pupa is clean. When it emerges as a new butterfly after a few weeks, it has to find its way out of the ant nest and to the surface, where it climbs a plant stem and rests while its wings inflate and dry. The adult butterflies only live for a few weeks, eating flower nectar, especially of the thyme plant.

One of the places where the large blue butterfly went extinct was in the British Isles, where it was last seen in 1979. Before that, though, scientists already recognized that the species was in danger in Britain. They knew that the butterflies needed wild thyme and Myrmica ants, and made sure to plant lots of the thyme in areas with lots of Myrmica ant colonies. But the butterflies still declined until none were left in Britain. It turns out that the large blue butterfly requires a particular species of Myrmica ant, Myrmica sabuleti, and if the caterpillars are adopted by other ant species, they aren’t usually successful in surviving to grow up.

Fortunately, a few years later, scientists re-introduced large blue butterflies to Britain from Sweden, and this time it worked. Not only are there still large blue butterflies in Britain again, they’re now more common in Britain than anywhere else throughout its range.

Other butterflies closely related to the large blue also act as brood parasites to Myrmica ants, but to different species. There are probably more butterflies that do this than we know, since it takes a lot of very careful observation of the butterflies, caterpillars, and ants to determine what exactly is going on. Considering that even the ants don’t really know what’s going on, it’s no surprise that scientists have trouble figuring it out too.

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

Thanks for listening!