Episode 337: Ghost Shrimp and Snapping Shrimp

Posted on July 17, 2023 by strangeanimalspodcast

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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

Posted on July 10, 2023 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 9:43 — 10.8MB)

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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).

Thanks for listening!

Episode 335: Large Blue Butterfly vs Ants

Posted on July 3, 2023 by strangeanimalspodcast

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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.

Thanks for listening!

Episode 332: Hunting Partners and Mutualism

Posted on June 12, 2023 by strangeanimalspodcast

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

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

Further reading:

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

What Birds, Coyotes, and Badgers Know About Teamwork

Octopuses punch fishes during collaborative interspecific hunting events

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

Buddies [picture from the first link above]:

The honeyguide bird:

Cheetahs and dogs can be friends:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 328: Giant Ants

Posted on May 15, 2023 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 6:48 — 7.7MB)

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Thanks to Richard from NC for suggesting Titanomyrma!

Further reading:

‘Giant’ ant fossil raises questions about ancient Arctic migrations

A fossilized queen Titanomyrma ant with a rufous hummingbird (stuffed) for scale:

Show transcript:

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

This week we have a suggestion from Richard from North Carolina, who sent me an article about an extinct giant ant called Titanomyrma. This episode is short, but I think you’ll find it interesting.

We’ve talked about ants in previous episodes, most recently episode 185. Most ant colonies consist of a single queen ant who lays all the eggs for her colony, seasonally hatched males with wings who fly off as soon as they’re grown, and worker ants. The worker ants are all female but don’t lay eggs. Army ants have another caste, the soldier ant, which are much larger than the worker ants and have big heads and strong, sharp mandibles. In many species of ant, the worker ants are further divided into castes that are specialized for specific tasks.

The biggest species of ant alive today is probably the giant Amazonian ant. The workers can grow over 1.2 inches long, or more than 3 cm, which is huge for an ant. It lives in South America in small colonies, usually containing less than 100 workers, and unlike most ants it doesn’t have a queen. Instead, one of the workers mates with a male and lays eggs for the colony. The giant Amazonian ant can sting and its sting contains venom that causes intense pain for up to two days. Fortunately, you will probably never encounter these giant ants, and even if you do they’re not very aggressive.

Another contender for the biggest species of ant alive today is the Dorylus genus of army ants, also called driver ants, which we talked about in episode 185. It lives in Africa in colonies that have millions of members, and the queen is the largest ant known. A queen army ant can measure 2.4 inches long, or 63 millimeters, but worker ants are much smaller.

Around 50 million years ago, giant ants related to modern driver ants lived in both Europe and North America. The genus is Titanomyrma and three species are known so far, found in Germany, England, Canada, and the American states of Tennessee and Wyoming.

The Wyoming ant fossil was discovered years ago and donated to the Denver Museum of Nature and Science, where it was stored in a drawer and forgotten about. In 2011 a curator found it and showed it to a paleoentomologist named Bruce Archibald. Dr. Archibald recognized it immediately as a fossilized queen ant even though it was the size of a hummingbird. He also realized it was very similar to a type of giant ant that once lived in Germany.

The German discovery was the first Titanomyrma species discovered, and it’s also the biggest known so far. The queen Titanomyrma gigantea grew up to 2.8 inches long, or 7 centimeters. Males grew up to 1.2 inches long, or 3 cm. The fossilized queen ants found have wings, with a wingspan of over 6 inches, or 16 cm. The other two known species are generally smaller, although still pretty darn big for ants.While they’re not that much bigger than the living Dorylus queens, most of the size of a queen Dorylus ant comes from her enlarged abdomen. Titanomyrma ants were just plain big all over.

Titanomyrma didn’t have a stinger, so it’s possible it used its mandibles to inflict bites, the way modern army ants do. It might also have sprayed formic acid at potential predators, as some ants do today.

The biggest ants alive today all live in tropical areas, so researchers thought Titanomyrma probably did too. During the Eocene, the world was overall quite warm and parts of Europe were tropical. The northern hemisphere supercontinent Laurasia was in the process of breaking up, but Europe and North America were still connected by the Arctic. Even though the Arctic was a lot warmer 50 million years ago than it is now, it was still too cold for a tropical ant. If Titanomyrma couldn’t survive in cold weather, how did it spread from one continent to another when it had to go through the Arctic?

There were warming periods during the Eocene that lasted a few hundred thousand years at a time, so researchers thought the ants probably migrated through the Arctic while it was warmer than usual. Then, in early 2023, a fossilized Titanomyrma queen ant was discovered in Canada. Because the rock it was preserved in has been distorted over the years, we can’t be certain how big the ant actually was. What we do know, though, is that the ant lived in a mountainous area that could get quite chilly, very different from the tropical climate scientists thought the giant ants needed.

As a result of the new finding, researchers are reconsidering whether the giant ants that lived 50 million years ago were really all that similar to modern giant ants. Just because the biggest ants alive today require tropical climates doesn’t mean that ancient giant ants did.

Hopefully more giant ant fossils will turn up soon, so we can learn more about where they lived, how they lived, and precisely how big they could get.

Thanks for listening!

Episode 314: Animals Discovered in 2022

Posted on February 6, 2023 by strangeanimalspodcast

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

Further Reading:

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

Rare ‘fossil’ clam discovered alive

Marine Biologists Discover New Giant Isopod

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

New Species of Mossy Frog Discovered in Vietnam

A Wildlife YouTuber Discovered This New Species of Tarantula in Thailand

Meet Nepenthes pudica, Carnivorous Plant that Produces Underground Traps

Scientists discover shark graveyard at the bottom of the ocean

Further Watching:

JoCho Sippawat’s YouTube channel

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

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

A newly discovered frog:

A newly discovered tarantula (photo by JoCho Sippawat):

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 311: The Mystery Deep-Sea Spider

Posted on January 16, 2023 by strangeanimalspodcast

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Thanks to Llewelly for this suggestion, and thanks to Dr. Thomas A. Hegna for providing me with the two papers I reference in this episode!

Images are taken from the papers.

The mystery “spider”:

Long-legged isopods:

Show transcript:

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

My carefully planned out episode schedule has already gotten messed up, but I got excited about this topic and couldn’t wait to share it! It’s a mystery invertebrate from the deep sea that has been solved! Thanks to Llewelly for bringing this to my attention, and thanks to arthropod paleontologist Dr. Thomas A. Hegna for posting this information on Mastodon in the first place, and for providing the relevant papers to me. People are pretty great.

I knew about this topic from the book The Search for the Last Undiscovered Animals by Karl Shuker, but I hadn’t been able to find out more. Until now.

In the late 1980s, a program called DISCOL 1 was launched to study disturbances on the sea floor due to underwater mining. It focused on the deep sea in the South Pacific. One of the things the expedition did was drop underwater cameras with bait tied to them. When an animal came to investigate the bait, the camera took pictures. I have a birdfeeder like this now although I don’t have to drop it anywhere.

In February 1989, the camera descended to about 13,600 feet, or 4,150 meters, in the Peru basin. When it was hauled up a few days later and the pictures retrieved, the scientists saw something they didn’t recognize on 20 of the photos. It looked like a spider.

The scientists were able to get a good idea of the animal’s size because they knew how big the bait was and how big the metal rod was that the bait was tied to. The animal’s body was about 2 and a half inches long, or 6 cm, and about half that width, not counting its long, jointed legs. It had five pairs of appendages, including three pairs of walking legs. The other two pairs of appendages were longer and might be feelers of some kind, with the front pair possibly used to manipulate food. The estimated legspan was almost 8 inches across, or more than 20 cm.

The scientists published a short article about the finding later in 1989 and proposed that the animal be tentatively placed in the phylum Arachnida with spiders and their relations. But this placement is a big deal, because there are no known spider relations that live in deep water. Some spiders have evolved to live in water at least part of the time, but they always have to have access to the air.

For a long time that’s all anyone knew. Most scientists thought the animal was probably a pycnogonid [pik-NA-gunid], an arthropod commonly called a sea spider although it’s not actually an arachnid. We talked about sea spiders in episode 105, so I’ll revisit some of the information from that episode.

Sea spiders live throughout the world’s oceans and there are well over a thousand known species. Most are small and live in shallow water, but a few live in water up to 23,000 feet deep, or 7,000 meters. The biggest species live in the cold waters around Antarctica, with the very largest individual ever found having a legspan of about 27 inches across, or 70 cm.

The sea spider has four pairs of legs, although a few species have five or six pairs of legs instead. Some species have one or two pairs of simple eyes, but other species have no eyes at all. The body is quite small in relation to the legs, which are extremely long, which means the digestive tract is actually partly in the legs, because the body is too small for it. It walks along the bottom of the ocean or may swim by pulsing its long legs like a jellyfish with legs instead of a bell. In species that swim, the legs may be lined with long bristles.

Some species have mouthparts, but most eat using a proboscis that it uses to suck fluids out of its prey. Some species have spines at the tip of the proboscis. It sticks its proboscis into a sponge, worm, jelly, sea anemone, or other invertebrate, injects digestive fluids that liquefy the surrounding tissues, and slurps the fluids up. Sometimes this kills the prey animal, sometimes it doesn’t.

All this does sound a lot like the spider-like animal photographed in 1989. But in 2004 a new paper was published about the animal, where the original scientists teamed with some other experts to re-examine the photographs. Their conclusion is that the mystery animal wasn’t a spider or a sea spider but something else: a munnopsidid isopod.

Isopods are crustaceans that have been around for at least 300 million years. They live all over the world, on land and in both fresh water and in the ocean. The animal sometimes called the woodlouse or pill bug or roly-poly or sow bug are actually isopods. All isopods have segmented exoskeletons, as you may have seen in roly-polies or whatever you call those little guys, and all have two pairs of antennae and seven pairs of jointed legs.

Isopods are very common animals in the ocean and the most common isopods are members of the family Munnopsidae. Most have short legs but some have long legs, including some species in the subfamily Bathyopsurinae.

While Munnopsids are common, there are only four species in two genera in Bathyopsurinae. The biggest isopods live in the deep sea and while these four species are pretty big, up to 2 and a half inches long, or 6 cm, they’re nowhere near the size of the largest isopods known. That would be the giant isopod that can grow up to 20 inches long, or 50 cm, but it’s not closely related to these four species.

As to which species the mystery isopod belongs to, the photographs aren’t close enough or clear enough for a definite identification. It’s possible the mystery isopod belongs to a species unknown to science.

Thanks for listening!

Episode 294: Updates 5 and a New Zealand Parrot!

Posted on September 19, 2022 by strangeanimalspodcast

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It’s our fifth updates and corrections episode, with some fun information about a New Zealand parrot, suggested by Pranav! Thanks also to Llewelly, Zachary, Nicholas, and Simon who sent in corrections.

Episode 291: The Ediacaran Biota

Posted on August 29, 2022 by strangeanimalspodcast

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This week let’s find out what lived before the Cambrian explosion!

A very happy birthday to Isaac!

Further reading:

Some of Earth’s first animals–including a mysterious, alien-looking creature–are spilling out of Canadian rocks

Say Hello to Dickinsonia, the Animal Kingdom’s Newest (and Oldest) Member

Charnia looks like a leaf or feather:

Kimberella looks like a lost earring:

Dickinsonia looks like one of those astronaut footprints on the moon:

Spriggina looks like a centipede no a trilobite no a polychaete worm no a

Glide reflection is hard to describe unless you look at pictures:

Trilobozoans look like the Manx flag or a cloverleaf roll:

Cochleatina looked like a snail:

Show transcript:

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

It’s the last week of August 2022, so let’s close out invertebrate August with a whole slew of mystery fossils, all invertebrates.

But first, we have a birthday shoutout! A humongous happy birthday to Isaac! Whatever your favorite thing is, I hope it happens on your birthday, unless your favorite thing is a kaiju attack.

We’ve talked about the Cambrian explosion before, especially in episode 69 about some of the Burgess shale animals. “Cambrian explosion” is the term for a time starting around 540 million years ago, when diverse and often bizarre-looking animals suddenly appear in the fossil record. But we haven’t talked much about what lived before the Cambrian explosion, so let’s talk specifically about the Ediacaran (eedee-ACK-eron) biota!

I was halfway through researching this episode when I remembered I’d done a Patreon episode about it in 2021. Patrons may recognize that I used part of the Patreon episode in this one. You’d think that would save me time but surprise, it did not.

The word Ediacara comes from a range of hills in South Australia, where in 1946 a geologist noticed what he thought were fossilized impressions of jellyfish in the rocks. At the time the rocks were dated to the early Cambrian period, and this was long before the Cambrian explosion was recognized as a thing at all, much less such an important thing. But since then, geologists and paleontologists have reevaluated the hills and determined that they’re much older than the Cambrian, dating to between 635 to 539 million years ago. That’s as much as 100 million years before the Cambrian. The Ediacaran period was formally designated in 2004 to mark this entire period of time, although fossils of Ediacaran animals generally start appearing about 580 million years ago.

Here’s something interesting, by the way. During the Ediacaran period, every day was only 22 hours long instead of 24, and there were about 400 days in a year instead of 365. The moon was closer to the earth too. And life on earth was still sorting out the details.

Fossils from the Ediacaran period have been discovered in other places besides Australia, including Namibia in southern Africa, Newfoundland in eastern Canada, England, northwestern Russia, and southern China. Once the first well-preserved fossils started being found, in Newfoundland in 1967, paleontologists started to really take notice, because they turned out to be extremely weird. The fossils, not the paleontologists.

Many organisms that lived during this time lived on, in, or under microbial mats on the sea floor or at the bottoms of rivers. Microbial mats are colonies of microorganisms like bacteria that grow on surfaces that are either submerged or just tend to stay damp. Microbial mats are still around today, usually growing in extreme environments like hot springs and hypersaline lakes. But 580 million years ago, they were everywhere.

One problem with the Ediacaran biota, and I should explain that biota just means all the animals and plants that live in a particular place, is that it’s not always clear if a fossil is actually an animal. Many Ediacaran fossils look sort of plant-like. At this stage, the blurry line between animals and plants was even more blurry than it is now, with the added confusion that sometimes non-organic materials can resemble fossils, and vice versa.

For instance, the fossil Charnia, named after Charnwood Forest in England where it was first discovered. In 1957, a boy named Roger, who was rock-climbing in the forest, found a fossil that looked like a leaf or feather. He took a rubbing of the fossil and showed his father, who showed it to a geologist. The year before, in 1956, a 15-year-old girl named Tina saw the same fossil and told her teacher, who said those rocks dated to before the Cambrian and no animals lived before the Cambrian, so obviously what she’d found wasn’t a fossil.

Tina’s teacher was wrong about that, of course, although he was correct that the rocks dated to before the Cambrian, specifically to about 560 million years ago. But while Charnia looks like a leaf, it’s not a plant. This was about 200 million years before plants evolved leaves, and anyway Charnia lived in water too deep for plants to survive. It anchored itself to the sea floor on one end while the rest of the body stuck up into the water, and some specimens have been found that were over two feet long, or 66 cm. Some researchers think it was a filter feeder, but we have very little evidence one way or another.

One common animal found in Australia and Russia is called Kimberella, which lived around 555 million years ago and might have been related to modern mollusks or to gastropods like slugs. It might have looked kind of like a slug, at least superficially. It grew up to 6 inches long, or 15 cm, 3 inches wide, or 7 cm, and an inch and a half high, or 4 cm, which was actually quite large for most animals that lived back then. It was shaped roughly like an oval, with one thin end that stuck out, potentially showing where its front end was, although it didn’t have a head the way we think of it today. The upper surface of its body was protected by a shell, but not the type of shell you’d find on the seashore today. This was a flexible, non-mineralized shell, basically just thick, toughened tissue with what may be mineralized nodules called sclerites embedded in it. All around its body was a frill that might have acted as a gill. The underside of Kimberella was a flat foot like that of a slug.

We know Kimberella lived on microbial mats on the sea floor, and it might have had a feeding structure similar to a radula. That’s because it’s often found associated with little scratches on its microbial mat that resemble the scratches made by a radula when a slug or related animal is feeding on a surface. The radula is a tongue-like organ studded with hard, sharp structures that the animal uses to scrape tiny food particles from a surface.

Kimberella displays bilateralism, meaning it’s the same side to side. That’s the case with a lot of modern animals, including all vertebrates and a lot of invertebrates too, like insects and arachnids. But other Ediacarans showed radically different body plans. Charnia, for instance, exhibits glide reflection, where both sides are the same as in bilateralism, but the sides aren’t exactly opposite each other. If you walk along a beach and make footprints in the sand, your trail of footprints actually demonstrates glide reflection. If you stand on the sand and jump forward with both feet together, your footprints demonstrate bilateralism since the prints are side by side. (This is confusing to describe, sorry.) Pretty much the only living animals with this body pattern are some sea pens, which get their name because they resemble old-fashioned quill pens. Many sea pens look like plants, and for a long time researchers thought Charnia might be an ancient relation to the sea pen. These days most researchers are less certain about the relationship.

A similar-looking animal that lived around the same time as Charnia was Dickinsonia. It looks sort of like a leaf too, but a more broad oval-shaped leaf instead of a long thin one like Charnia. It’s also not a leaf. Some are only a few millimeters long, but some are over 4 1/2 feet long, or 1.4 meters.

Dickinsonia may be related to modern placozoans, a simple squishy creature only about one millimeter across. It travels very slowly across the sea floor and absorbs nutrients from whatever organic materials it encounters. But we don’t know if Dickinsonia was like that or if it was something radically different. Until a few years ago a lot of paleontologists thought Dickinsonia might be some kind of early plant or algae. Then, in 2016, a graduate student discovered some Dickinsonia fossils that were so well preserved that researchers were able to identify molecular information from them. They found cholesteroids in the preserved cells, and since only animals produce cholesteroids, Dickinsonia was definitely an animal. But that’s still about all we know about it so far.

Spriggina is another animal that at first glance looks like a leaf or feather. Then it sort of resembles a trilobite, or a segmented worm, or a possible relation to Dickinsonia. It looks like all sorts of animals but doesn’t really fit with anything known. It grew up to two inches long, or 5 cm, and had what’s referred to as a head shield although we don’t know for sure if it was actually its head. The head shield might have had eyes and might have had some kind of antennae, and some fossils seem to show a round mouth in the middle of the head, but it’s hard to tell. The rest of its body was segmented in rings. What Spriggina didn’t have was legs, or at least none of the fossils found so far show any kind of legs. Some species of Spriggina show a glide reflection body plan, while others appear to show a more ordinary bilateral body plan.

Three Ediacaran animals have such a weird body plan that they’ve been placed in their own phylum, Trilobozoa, meaning three-lobed animals. They show tri-radial symmetry, meaning that they have three sections that are identical radiating out from the center. They lived on microbial mats and were only about 40 mm across at most, which is about an inch and a half. Tribrachidium was roughly round in shape although its relations looked more like tiny cloverleaf rolls. Cloverleaf rolls are made by putting three little round pieces of dough together and baking them so that the roll has three lobes, although Trilobozoans probably didn’t taste as good. Also, Trilobozoans were covered with little grooves from center to edge and had three curved ridges, one on each lobe. The ridges were originally interpreted as arms or tentacles, but they seem to have just been ridges. Researchers think the little grooves directed water over the body’s surface and the ridges acted as tiny dams that slowed the water down just enough that particles of food carried in the water would fall onto the body so that the animal could absorb the nutrients, although we don’t know how that worked.

Many other Ediacaran animals had radial symmetry like modern echinoderms and jellyfish, including the ancestors of jellyfish. Some Ediacaran animals even had shells of various kinds, and they’re generally referred to as small shelly fossils. They were rarely more than a few millimeters across at most and are sometimes found mixed in with microbial mats. Cochleatina, for instance, is less than a millimeter across and all we know about it is that it had a ribbon-like spiral shell like a really simple snail’s shell. It wasn’t a snail, though. We don’t even know if it was an animal. It might have been some kind of algae or it might have been something else. Unlike most small shelly fossils, Cochleatina survived into the Cambrian period.

We’re also not sure why most Ediacaran organisms went extinct at the beginning of the Cambrian, but it’s probable that most were outcompeted by newly evolved animals. There may also have been a change in the chemical makeup of the ocean and atmosphere that caused an extinction event of old forms and allowed the rapid expansion of new animal forms that we call the Cambrian explosion.

We can also learn a lot about what we don’t find in the Ediacaran rocks. Pre-Cambrian animals didn’t appear to burrow into the sea floor, or at least we haven’t found any burrows, just tracks on the surface. Most Ediacaran animals also didn’t have armored bodies or claws or so forth. Researchers think that predation was actually pretty rare back then, with most animals acting as passive filter feeders to gather nutrients from the water, or they ate the microbial mats. It wasn’t until the Cambrian explosion that we see evidence that some animals evolved to kill and eat other animals exclusively.

With every new Ediacaran fossil that’s found and studied, we learn more about this long-ago time when multi-cellular life was brand new.

Thanks for listening!

Episode 290: Lobsters!

Posted on August 22, 2022 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 13:35 — 15.1MB)

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Thanks to Pranav for this week’s suggestion, lobsters!

Happy birthday to Jake!!

Visit Dr. Oné R. Pagán’s site for links to his podcast and his free book Arrow: The Lucky Planarian! You can also order his other books from your favorite book store. Here’s the direct link to his interview with me!

Further reading:

Don’t Listen to the Buzz: Lobsters Aren’t Actually Immortal

An ordinary lobster:

A blue lobster!

The scampi looks more like a prawn/shrimp than a lobster, but it’s a lobster:

The rosy lobsterette is naturally red because it lives in the deep sea:

The deep-sea lobster Dinochelus ausubeli was only discovered in 2007 and described in 2010:

Show transcript:

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

As invertebrate August continues, this week we’re going to talk about lobsters. Thanks to Pranav for the suggestion!

But first, we have a birthday shout-out! A great big happy birthday this week to Jake! I hope your birthday is epic fun!

I’d also like to let you know that Dr. Oné R Pagán interviewed me recently about my book, Beyond Bigfoot & Nessie: Lesser-Known Mystery Animals from Around the World, and you can hear that interview on his podcast, the Baldscientist Podcast. Baldscientist is all one word. I’ll put a link in the show notes. While you’re at it, you should definitely buy his books, including his latest one, Drunk Flies and Stoned Dolphins: A Trip Through the World of Animal Intoxication, which just came out this year and is a lot of fun, as well as being full of interesting science! He also has a free children’s story called Arrow, the Lucky Planarian that you can download and read. It’s completely charming and you’ll learn a lot about planarians, which are also called flatworms, which are invertebrates, so this is all coming together!

This week’s episode isn’t about planarians, though, but about lobsters. I don’t think we’ve ever discussed lobsters on the podcast before, oddly enough, but it’s been on my ideas list for a long time. When Pranav emailed me recently to suggest we do a lobster episode, I realized it was time! Time for lobsters!

The lobster is a crustacean, and while there are plenty of different lobsters in the world, we’re going to focus on the clawed lobsters this time. There are lots of them, all grouped in the family Nephropidae.

The lobster has eight legs that it walks on, and two more legs with pincers. That’s why it’s in the order Decapoda. Deca means ten and poda means feet. Ten feet. Some of which can pinch you if you’re not careful.

The lobster uses its claws to defend itself from potential predators, and uses them to grab and kill small animals. It eats pretty much anything it can find, from fish and squid to sea stars and mollusks, to dead animals and some plant material. But its claws are too big and clumsy to use to eat with, which is why it has much smaller pincers on its next pairs of legs. These pincers are equipped with chemoreceptors that allow the lobster to taste its food before it actually eats it, which is a neat trick.

The lobster uses these small claws to pull its food into smaller pieces and convey it to the mouthparts, which are under its head. Some mouthparts have sensory hairs that can taste food, some have sharp spines that act as teeth to tear food into smaller pieces, and others are small and just flutter to help keep pieces of food from floating away. The stomach is only about an inch away from the mouth, or about 2.5 cm, no matter the size of the lobster. The stomach itself, and the short esophagus leading to the stomach, are lined with chitin spines that act like teeth to grind food up while enzymes break it down to fully digest it. This seems like a really complicated way to eat, but it’s actually not all that different from the way we eat, it’s just that instead of mouthparts and stomach teeth, we do all our grinding up of food in the mouth with just one set of teeth.

The lobster’s body is protected by an exoskeleton made of chitin, but the trouble with exoskeletons is that they don’t grow. The lobster has to shed its exoskeleton every so often and grow a new one that fits better, and until the new exoskeleton has hardened, the lobster is vulnerable and will usually hide. This can take several weeks. When a lobster is young and growing rapidly, it may molt its exoskeleton every few months or even more often, while an adult lobster typically only molts once every year or two.

Molting takes energy, though, and the bigger a lobster is, the more energy it takes to molt. It’s not like taking off a shirt. The lobster has to wriggle carefully out of its exoskeleton through a split between its tail and abdomen, making sure not to hurt its soft body in the process, and it even molts its stomach teeth, more properly called a gastric mill.

It’s a long, difficult process, during which time the lobster is mostly helpless. Some studies indicate that something like 10% of all lobsters actually die during the molting process. A lobster usually eats its shed exoskeleton in order to extract calcium from it, which helps its new exoskeleton harden faster.

Unlike many animals, lobsters keep growing throughout their lives. Since they can live a long time, that means sometimes people catch really big lobsters. The biggest ever reliably measured was an American lobster caught in 1977 off the coast of Nova Scotia, Canada in North America. It weighed 44 lbs, 6 oz, or 20.14 kg and was 3.5 feet long, or 106 cm. A more ordinary weight of a good-sized lobster is about 2 lbs, or 910 grams.

The lobster can definitely live at least 50 years, and some researchers suggest it can live much longer than that. But it’s really hard to tell the age of a lobster. You can’t go by size since individual lobsters grow at different rates depending on how much food they can find and other factors. A study published in September 2021 reports that a DNA test of genetic modifications that lobsters and other animals accumulate during their lives can determine a lobster’s age with a good degree of accuracy. This is important since it will help conservationists learn more about lobster populations, many of which are under increasing pressure from commercial fishing.

There’s a lot of talk online about how the lobster is actually immortal, and that if nothing kills it, it will just live forever. This rumor got started when scientists reported that lobsters express an enzyme called telomerase that repairs damage to DNA sequences at the ends of chromosomes. Most adult animals lose the ability to express telomerase, but the lobster doesn’t.

But lobsters aren’t immortal. A really old lobster stops shedding its exoskeleton, which slowly becomes more and more battered. The exoskeleton is part of the lobster’s body and can contract bacterial infections when it’s injured. Sometimes the infections are bad enough that it fuses the exoskeleton to the body permanently, so if the lobster does eventually get to the point where it can molt, it gets stuck trying to and dies. Sometimes the exoskeleton just rots away, which leads to the lobster’s death.

Still, the telomerase probably helps the lobster live for such a long time. Now that scientists have a way to determine a lobster’s actual age without harming it, hopefully soon we’ll learn more about how old they really get. We might be surprised, who knows?

Most species of lobster are brown, black, or greenish, which helps them hide on the sea floor. When a lobster is cooked by boiling, chemicals in its exoskeleton react with the hot water and turn it bright red. But sometimes—like, once every 10 million lobsters—a live lobster is found that is red. Researchers aren’t sure what causes this coloration.

Sometimes lobsters can be blue too. It’s still rare but not as rare as red coloration, estimated at about one every two million lobsters. While some species of lobster are naturally dark blue or even dark purple, a blue lobster is a really pretty shade of bright blue. It’s caused by a genetic mutation that results in it producing more of a protein that reacts with the pigments in its body, turning it blue. Since blue lobsters are so striking and attractive, lobster fishers usually either throw blue lobsters back or donate them to local aquariums. People sometimes assume blue lobsters are poisonous even though they’re not, so mostly no one wants to eat them anyway.

Lobsters are closely related to crabs and shrimp, and some clawed lobsters look a lot like their close relatives. This includes the scampi, which is the pinkish and silvery-white coloration of a prawn or shrimp, and only grows about 10 inches long at most, or 25 cm. It lives in parts of the northeastern Atlantic and parts of the Mediterranean Sea, where it digs a burrow in the muddy sea floor and spends most of its time hiding. It eats worms, small fish, jellyfish, and anything else it can catch. There are other species of scampi that live in other parts of the world’s oceans too.

Another lobster that looks even more like a shrimp is the rosy lobsterette, which only grows about 5 inches long, or 13 cm, and which is naturally red. This isn’t a rare coloration but an adaptation to its habitat. Unlike most lobsters, which live in shallow coastal waters, the rosy lobsterette lives in much deeper water where there’s very little light. As we’ve talked about before, the wavelength of light that is red can’t penetrate very far into water, so a red animal in the deep sea is basically invisible. A lot of deep-sea animals can’t even perceive the color red. The rosy lobsterette lives in the Gulf of Mexico, around the Caribbean, and in the western Atlantic Ocean.

There are actually quite a few species of lobster that live in the deep sea, with more being discovered every so often. In 2010 a new species of deep-sea lobster was described, Dinochelus ausubeli, which lives near the Philippines in South Asia. It was discovered during the ten-year Census of Marine Life, which sponsored 540 expeditions by thousands of scientists all over the world. It only grows a few inches long, or about 5 cm, and is mostly transparent with some pinkish coloring. It has one really long, thin, spiny claw with a bulbous base, while the other claw is much smaller.

There are a whole lot of other clawed lobster species, some of them known from only a few specimens. The Cape lobster, for instance, lives off the coast of South Africa in rocky areas, and even though it’s been known to science since the late 18th century, we don’t know much about it. It’s small, only growing about 4 inches long, or 10 cm, and ranges in coloration from greenish to yellowish to brown, even sometimes red, and it looks like a miniature version of the European or American lobsters although it’s not very closely related. In 1992 someone found one, which was such a rare occurrence that it was reported in the news. It was only the 14th specimen ever found at the time, although the publicity it received got other people out looking for the little lobster and more have been found since.

In other words, there are undoubtedly lots more species of lobster than we know about, just waiting to be discovered.

Thanks for listening!

Strange Animals Podcast

A podcast about living, extinct, and imaginary animals!

Category Archives: invertebrates

Episode 337: Ghost Shrimp and Snapping Shrimp

Episode 336: The Turtle Ant and the Alien Butt Spider

Episode 335: Large Blue Butterfly vs Ants

Episode 332: Hunting Partners and Mutualism

Episode 328: Giant Ants

Episode 314: Animals Discovered in 2022

Episode 311: The Mystery Deep-Sea Spider

Episode 294: Updates 5 and a New Zealand Parrot!

Episode 291: The Ediacaran Biota

Episode 290: Lobsters!