Monthly Archives: September 2024

Episode 398: Repeating Scientific Names

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Thanks to Alexandra, Pranav, Eilee, Conner, and Joel for their suggestions this week!

Velella velella, or by-the-wind-sailor [photo from this page]:

Porpita porpita, or the blue button [photo from this page]:

Cricetus cricetus, or the European hamster, next to a golden hamster:

Nasua nasua, or the South American coati [photo from this page]:

Mola mola, or the ocean sunfish:

Quelea quelea, or the red-billed quelea [photo from this page]:

Show transcript:

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

This week we’re going to learn a little bit about scientific names, and along the way we’re going to learn about several animals. Thanks to Alexandra, Eilee, Conner, Joel, and Pranav for their suggestions!

Alexandra inspired this episode by suggesting two animals, the by-the-wind-sailor and the blue button. Both are marine invertebrates that look superficially like jellyfish, but they’re actually colonial organisms. That means that although they look like a single animal, they’re actually made up of lots of tiny animals that live together and function as one organism.

The blue button is closely related to the by-the-wind-sailor and both are related to siphonophores. Both the blue button and the by-the-wind-sailor spend most of the time near or on the ocean’s surface and have a gas-filled chamber that helps keep them afloat, with stinging tentacles that hang down into the water, but both are made up of a colony of tiny animals called hydroids. Different hydroids have different functions, and all work together to find tiny food that will benefit the entire colony.

The blue button gets its name because its float is round and flat like a button, and often blue or teal in color. It’s quite small, only a little over an inch across, or about 3 cm, and its tentacles are not much longer. The by-the-wind-sailor is a little larger than the blue button, with a blue sail-shaped float that’s only a few inches across, or maybe 7 cm, with stinging tentacles of about the same size. The stings of both organisms aren’t very strong and aren’t dangerous to humans, but they do hurt, so it’s a good idea not to touch one. Since both can be very common in warm ocean waters and they sometimes get blown ashore by the wind in large numbers, it can be hard to avoid them if you’re visiting the beach at the wrong time. They can still sting you if they’re dead, too.

The by-the-wind sailor has the scientific name of Velella velella while the blue button’s scientific name is Porpita porpita. The term for a scientific name that contains the same words is a repeating scientific name, also called a tautonym or tautonymous name, and that’s the subject of this episode.

A scientific name is something we mention a lot but if you’re not sure what it means, it can sound confusing. Every organism with a scientific name has been described by a scientist, meaning it’s been studied and placed somewhere in the great interconnected web of life. The system of giving organisms scientific names is called binomial nomenclature. The first word of the name indicates which genus the organism belongs to, while the second word indicates what species it is. These are called generic and specific names. Some organisms also have a third word in their scientific name which indicates its subspecies.

The reason scientists use a complicated naming system is to make it easier for other scientists to know exactly what organism is being discussed. For example, let’s say a scientist has been studying hamsters in the wild to learn more about them, and publishes a paper about her observations. If she just calls the animal a hamster, someone reading it might assume she was talking about the hamster found in their part of the world, when the paper is actually about a totally different, although closely related, hamster that lives somewhere else. And that brings us to Pranav’s suggestion, the European hamster, whose scientific name is Cricetus cricetus [cry-SEE-tus].

The hamster most of us are familiar with is actually the golden hamster, also called the Syrian hamster, more properly called Mesocricetus auratus. That’s the most common species kept as a pet. We can learn from the different scientific names that the European hamster is in a different genus from the golden hamster, which usually means it’s pretty different in some significant ways.

The European hamster lives throughout parts of Eurasia, especially eastern Europe through central Asia, and used to be extremely common. It’s also called the black-bellied hamster because the fur on its underside is black, while the fur on its upper side is tan or brown with white markings. These days it’s critically endangered due to habitat loss and being killed by farmers who think it hurts their crops. It does eat seeds, vegetables, and some roots, but it also eats grass and many other plants that are considered weeds, as well as insects, including insects that farmers also don’t want in their gardens.

In many respects, the European hamster is a lot like the golden hamster. It carries food home to its burrow in its cheek pouches and stores food in a larder. It hibernates in cold weather but wakes up around once a week to have a snack from its larder, which honestly sounds like the best way to spend the winter. But the European hamster is larger than the golden hamster. Like, a lot larger. The golden hamster is maybe 5 inches long, or 13 cm, which is small enough that you can easily hold it in your hand. The European hamster grows up to 14 inches long, or 35 cm. That’s the size of a small domestic cat, but with a short little hamster tail and short little hamster legs.

Even though an organism’s scientific name only designates genus and species, and subspecies when applicable, it allows scientists to look up a more detailed family tree. Every genus is classified in a family and every family is classified in an order, and every order in a class, and every class in a phylum, and every phylum in a kingdom, and every kingdom in a domain. Almost all of the organisms we talk about in this podcast belong to the kingdom Animalia. The more of these categories an organism shares with another organism, the more closely related they are.

Conner suggested we learn more about the coati, which we talked about in episode 302. The South American coati’s scientific name is Nasua nasua [NAH-sue-uh]. It grows almost four feet long, or 113 cm, which makes it sound enormous, but half of its length is its long ringed tail. It lives in much of South America, especially the northern part of the continent.

The coati is related to the raccoon of North America, and the two animals’ scientific names can help us determine how closely they’re related. The common raccoon’s scientific name is Procyon [PROSE-eon] lotor, so we already know it belongs to a different genus than the coati. But both the genus Procyon and the genus Nasua are classified in the family Procyonidae. So we know they’re closely related, because they belong to the same family, but not as closely related as they’d be if they belonged to the same genus, so we can expect to see some fairly significant differences between the two animals.

The South American coati is diurnal, unlike the nocturnal raccoon. While female raccoons often live in small groups of a few animals that share the same territory, female coatis live in groups of up to 30 animals who forage for food together and are very social. The coati also doesn’t have a set territory. The male coati is completely solitary, while the male raccoon will also live in small groups of three or four animals. Both are omnivorous but the coati eats more fruit and insects than the raccoon does, and the coati doesn’t dunk its food in water the way the raccoon famously does.

The system of binomial nomenclature that we use today was developed by the Swedish botanist Carolus Linnaeus in 1735. We talked about some of his mistakes in episode 123. Linnaeus built on a system developed by a zoologist almost a century before him, but streamlined it and made it easier to use. In the 300 years since Linnaeus came up with his system, many other scientists have made changes to reflect increased knowledge about the natural world and how best to denote it.

I keep saying “organism” instead of “animal,” and that’s because all living organisms may be given a scientific name as they are described. This includes everything from humans to maple trees, from earthworms to harpy eagles, from bumblebees to mushrooms. Linnaeus originally included minerals in his classification system, but minerals don’t evolve the way living organisms do. One group that wasn’t given scientific names until 2021 are viruses. There’s still a lot of controversy as to whether viruses are technically alive or not, but giving them scientific names helps organize what we know about them.

Eilee suggested the ocean sunfish, which has the scientific name Mola mola. Because its scientific name is easy to say, and because there’s also a freshwater sunfish that isn’t related to the ocean sunfish, a lot of people just call it the mola-mola, or just the mola. We talked about it way back in episode 96, so we’re definitely due to revisit it.

The ocean sunfish doesn’t look like a regular fish. It looks like the head of a fish that had something humongous bite off its tail end. It has one tall dorsal fin and one long anal fin, and a little short rounded tail fin that’s not much more than a fringe along its back end. This isn’t even a real tail but part of the dorsal and anal fins. The sunfish uses the tail fin as a rudder and progresses through the water by waving its dorsal and anal fins the same way manta rays swim with their pectoral fins. Pectoral fins are the ones on the sides, while the dorsal fin is the fin on a fish’s back and an anal fin is a fin right in front of a fish’s tail. Usually dorsal and anal fins are only used for stability in the water, not propulsion. The ocean sunfish does have pectoral fins, but they’re tiny.

The ocean sunfish lives mostly in warm oceans around the world, and it eats jellies, small fish, squid, crustaceans, plankton, and even some plants. It has a small round mouth that it can’t close and four teeth that are fused to form a sort of beak. It also has teeth in its throat, called pharyngeal teeth. Its skin is thick and rough like sandpaper with a covering of mucus, and its bones are mostly cartilaginous. It likes to sun itself at the water’s surface, and it will float on its side like a massive fish pancake and let sea birds stand on it and pick parasites from its skin. This also helps it absorb heat from sunlight after it’s been hunting in deeper water.

The female ocean sunfish can lay up to 300 million eggs at a time. That is the most eggs known to be laid by any vertebrate. When the eggs hatch, the larval sunfish are only 2 ½ mm long. Once they develop into their juvenile form, they have little spines all around their thin end, which kind of make them look like tiny stars. If that seems weird, consider that the ocean sunfish is actually related to the pufferfish, although not very closely. The largest adult ocean sunfish ever reliably measured was 14 feet tall, or 4.3 meters, including the long fins, which is a whole lot bigger than 2 ½ mm.

Sometimes after an organism is initially described and named, later scientists learn more about it and determine that it doesn’t actually belong in the genus or family where it was initially placed. If it gets moved to a different genus, its scientific name also needs to change. Some organisms get moved a lot and their scientific names change a lot. But typically, the species name doesn’t change. That’s the case for a little bird from Africa.

Joel suggested a bird called the red-billed quelea [QUEE-lee-ya], whose scientific name is Quelea quelea. When Linnaeus described it in 1758, he thought it was a type of bunting, so he named it Emberiza quelea. Another scientist moved it into a new genus, Quelea, in 1850.

I’d never heard of the red-billed quelea, which is native to sub-Sarahan Africa, but it may actually be the world’s most numerous non-domesticated bird, with an estimated 1.5 billion birds alive at any given moment.

The red-billed quelea mainly eats grass seeds, and unlike the European hamster, it is actually a problem to farmers. The bird doesn’t know the difference between yummy grass seeds and yummy wheat, barley, milt, oats, sunflowers, and other food that humans eat. In fact, some researchers suggest that the bird has become incredibly numerous because it has all this great food to eat that was planted by people.

A flock of red-billed quelea birds can number in the millions. The flock flies until they find grassland or fields with food they like. The first birds land, the birds behind them land a little bit farther along, and so on until all the birds have landed and are eating. But by the time the last birds of the flock land, the first ones have eaten everything they can find, so they fly up and over the rest of the birds until they find fresh grass to land in again. This is happening constantly with the entire flock of millions of birds, so that from a distance the flock’s movement looks like a cloud of smoke rolling across a field.

The red-billed quelea also eats insects, mostly during nesting season. Insects and other small invertebrates like spiders are especially nutritious for nestlings.

The quelea is about the size of a sparrow, which it resembles in many ways, although it’s actually a member of the weaver bird family, Ploceidae. It grows less than five inches long, or about 12 cm, including its tail, and it’s mostly brown and gray. Its beak and legs are orangey-red, and during breeding season the male has a rusty-red head with a black mask on his face.

One subspecies of red-billed quelea is native to western and central Africa. Since it’s a subspecies, it has three words in its scientific name: Quelea quelea quelea.

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 397: Some Colorful Fishies

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Thanks to Cosmo, William, and Silas for their fishy suggestions this week!

You have until Sept. 13, 2024 to back the enamel pin Kickstarter!

Further reading:

The Handfish Conservation Project

Researchers Look in Tank and See Promising Cluster of Near-Extinct Babies

The unique visual systems of deep sea fish

A red handfish:

Another red handfish. This one is named Hector:

The black dragon fish:

The white-edged freshwater whipray [photo by Doni Susanto]:

Show transcript:

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

This week we return to the vertebrate world, specifically some strange and colorful fishies. Thanks to William, Cosmo, and Silas for their suggestions!

We’ll start with Silas’s suggestion, the red handfish. We talked about it before back in episode 189, but it’s definitely time to revisit it. When we last discussed it, scientists estimated there were fewer than 100 red handfish left in the wild, meaning it was in imminent danger of extinction. Let’s find out how it’s doing now, four years later.

The handfish gets its name because its pectoral fins look like big flat hands. It spends most of its time on the sea floor, and it uses its hands to walk instead of swimming. It can swim, although it’s not a very strong swimmer, and anyway if you had great big hands you might choose to walk on them too. It doesn’t have a swim bladder, which helps most fish stay buoyant.

All species of handfish are small, only growing to about 6 inches long at most, or 15 cm. This is surprising considering the handfish is closely related to anglerfish, and some anglerfish can grow over 3 feet long, or about a meter.

As for the red handfish specifically, it generally only grows about 4 inches long at most, or 10 cm, and it once lived in shallow water around much of Australia. These days, it’s only found on two reefs southeast of Tasmania. Some populations are bright red while some are pink with red spots. It has a wide downturned mouth that makes it look like a grumpy red toad with big hands.

So how is the red handfish doing? Four years ago it was almost extinct in wild, with fewer than 100 individuals alive. These days the Handfish Conservation Project estimates that the wild population is probably about the same, although because the red handfish is so small and hides so well among sea grass, algae, and rocks that make up its home, it’s hard to get a good count of how many are really alive. It’s also under even more pressure than before as an overpopulation of urchins is overgrazing the plants where it lives, which may sound familiar to you if you listened to episode 395 a few weeks ago. But there is one fantastic change that gives conservationists hope that the red handfish won’t go extinct after all.

The red handfish is so endangered, and its remaining habitat is so small, that a few years ago scientists decided they needed to start a captive breeding program. But even though the fish did just fine in captivity, they didn’t breed at first. Then, in November 2023, one of the fish laid 21 eggs and all 21 hatched safely. Hopefully it won’t be long until the babies are old enough to release into the wild.

The red handfish is one of very few fish that hatch into tiny baby fish instead of into a larval form. Newly hatched babies are only about 5 mm long. Most fish colonize new habitats after they float around aimlessly as larvae, until they grow enough to metamorphose into adults. Since the red handfish doesn’t have this larval stage, and babies just walk around on the sea floor finding tiny worms and other food, it’s hard for the fish to expand its range. Hopefully, as the captive breeding program continues and more young fish are released into the wild, scientists can start releasing red handfish into areas where they used to live.

Next, William asked about the dragon fish. We’ve talked about a few dragonfish before, in episodes 193 and 231, but there are lots of species in many genera in the family Stomiidae. Many have barbels with photophores at the end that lure prey, and most have long needle-like teeth and jaws that can open incredibly wide. They also have stretchy stomachs so they can hold whatever they manage to catch. As you may have guessed from these traits, the dragon fish lives in the deep sea where there’s little or no light from the surface.

You may wonder why deep-sea fish even have eyes if there’s no light. Fish that live in cave systems eventually evolve to be eyeless, since they don’t need their eyes to see and growing eyes is just a waste of their energy. It’s because even though there’s no sunlight in the deep sea, there is light from lots of different organisms. Many, many deep-sea animals produce bioluminescent light to attract mates or trick smaller animals into coming closer.

Any sunlight that does find its way to the depths of the ocean is blue, because blue has the shortest wavelength and can travel farther. Red wavelengths are longest so that red is the first color lost when you start descending into the water. One article that I’ve linked to in the show notes mentions that if a diver gets a cut, the blood looks brown or even black if the water is deep enough. That’s creepy.

As a result, deep-sea fish are most sensitive to the color blue. Most of them can’t perceive red at all because there just isn’t any red in their environment. And that’s where the dragon fish comes in, because some species of dragon fish can not only see red, they produce red light that illuminates everything around them. A fish or other animal swimming along has no idea that it’s lit up like it’s under a red spotlight because it can’t even see that color.

At least one species, the black dragon fish, perceives red light very differently from the way other animals do. As far as we know it’s unique among all animals. Its eyes contain a photosensitizer derived from chlorophyll, which allows it to see shorter lightwaves. Chlorophyll is found in plants and some bacteria, and it’s actually a specialized pigment that absorbs energy from light. It’s the reason why plants are green. But the black dragonfish uses the chlorophyll it digests to perceive red light.

But remember how dragon fish have giant sharp fangs and will eat pretty much anything they can swallow? Where does the black dragon fish get the chlorophyll it needs? There aren’t any plants in the deep sea anyway.

The answer seems to be that the black dragon fish eats a whole lot of copepods, tiny crustaceans that live throughout the world. The particular species of copepods that the black dragon fish prefers contain a type of chlorophyll.

Finally, Cosmo wanted to learn about the freshwater stingray. We talked about it in episode 296, but mostly we concentrated on the South American fish in that episode. There are freshwater stingrays that live in other parts of the world, such as Asia. This includes the white-edge freshwater whipray, which is extremely rare and only found in four rivers in Southeast Asia.

The white-edge freshwater whipray grows up to two feet across, or 60 cm, with a thin tail about two and a half times longer than the body itself so that technically it can grow around 6 and a half feet long, or 2 meters. Most of that length is tail, though. It’s mostly brown so it can hide in the sandy mud at the bottom of the river, with black dermal denticles down the middle of its back. The tail is mostly white, though, and has two long stinging spines that can be over 3 inches long, or 8 cm.

While the white-edged whipray lives in rivers, it can also tolerate brackish water where the ocean and the river waters mix. It eats small animals it finds on the bottom of the river, including crustaceans and mollusks. It’s endangered due to habitat loss, overfishing, and pollution.

The white-edged whipray is so rare these days that it’s unlikely that anyone would accidentally step on one in the water. But if they did, the ray would whip its long tail up and jab the spines into the person’s leg or foot. The spines can do a lot of damage on their own, but the venom they inject makes the wound incredibly painful and can even potentially kill the person.

If you plan to do some wading in a South Asian river anytime soon, make sure to shuffle your feet as you walk to scare away any potential whiprays before you step right on it.

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 396: Moths!

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

Further reading:

Dieback and recovery in poplar and attack by hornet clearwing moth

The enormous and beautiful Atlas moth:

A male hairy tentacle moth without and with coremata extended [photos from this site]:

The hornet moth looks like a hornet but can’t sting:

Show transcript:

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

Welcome to September, where we’re mere weeks away from Monster Month! Invertebrate August is over for another year, but what’s this? An episode about moths?! Hurrah for one extra invertebrate episode, because they don’t get enough attention on this podcast! Thanks to Joel and an anonymous listener for their suggestions.

First, a listener who wants to remain anonymous suggested that we talk about moths in general, and the Atlas moth in particular. I like the Atlas moth because you can catch it in Animal Crossing. It’s also beautiful and one of the largest moths in the entire world. Its wingspan can be well over 10 inches across, or about 27 cm, which is bigger than a lot of bird wingspans.

The Atlas moth’s wings are mostly cinnamon brown with darker and lighter spots. The upper wings have a curved sort of hook at the top that’s lighter in color and has an eyespot. It looks remarkably like a snake head, and in fact if a predator approaches, the moth will move its wings so that it looks like a snake is rearing its head back to strike.

Despite having such huge wings, atlas moths don’t fly very well. That’s okay because they only need to be able to fly for a few days, which they mostly do at night. They’re only looking for a mate, not food, because they don’t even have fully formed mouthparts. They don’t eat as adults. Like many moths, they mate, lay eggs, and die.

A few weeks later, the eggs hatch and the baby caterpillars emerge. The caterpillar is pale green with little spikes all over, and it eats plants until it grows to around 4 and a half inches long, or about 11 and a half cm. At that point it spins a cocoon attached to a twig, hidden from potential predators by dead leaves that the caterpillar incorporates into the cocoon’s outside.

The Atlas moth lives in forests in southern Asia, including China, India, Indonesia, and Malaysia, with a subspecies native to Japan. Its cocoons are sometimes collected to use for silk. The silk isn’t as high a quality as the domesticated silk moth’s, but it’s very strong and since the cocoons are so big, they produce lots of silk. Sometimes people will collect a cocoon after the moth has emerged and use it as a little purse.

Next, Joel suggested two interesting moths. The first is often called the hairy tentacle moth, which sounds absolutely horrifying. Its scientific name is Creatonotos gangis, and it lives in parts of Australia and southeast Asia.

The hairy tentacle moth is also called the Australian horror moth and other names that inspire fear and disgust. But why? The moth is really pretty. Its wings are pale brown and white with dark gray stripes in the middle, and it has a black spot on its head. The abdomen is usually red with black spots in a row. The wingspan is about 40 mm.

The issue comes with the way the male attracts a female. Inside his abdomen the male has four coremata, which are glands that emit pheromones. Pheromones are chemicals that other moths can detect, much like smells. When a male is ready to advertise for a mate, he perches on the edge of a leaf or somewhere similar and inflates the coremata so that they unfurl from inside the abdomen, like blowing up a balloon. Sometimes he only extends two of the coremata, sometimes all of them. Either way, the coremata are surprisingly large, sometimes longer than the entire abdomen. They’re dark gray with feathery hairs and they do actually look like hairy tentacles. They’re sometimes called hair pencils, but the term coremata is actually Greek for feather dusters.

If you don’t know what they are, the coremata really do look weird and unpleasant. But the moth is just doing his best to get his pheromones picked up on the breeze so a female will find him. The pheromone also repels other males.

The hairy tentacle moth can only develop his coremata and the pheromones he needs if he eats enough of plants that contain pyrrolizidine alkaloids. These are intensely bitter compounds that are also toxic to many animals. When he’s a caterpillar, the male eats plants that contain these alkaloids and retains them in his body, chemically modifying them later into pheromones, but if he doesn’t eat enough of them, he’s not able to grow coremata either.

Finally, Joel also suggested the hornet moth, which lives in Europe and the Middle East. It’s a moth, but it genuinely looks exactly like a yellow and black striped hornet. It even has clear wings like a hornet or wasp and flies like one too, and it’s about the size of a hornet. Even though it’s harmless, it looks like it would give you a bad sting, which protects it from potential predators who know better than to mess with a hornet. It’s a great example of what’s called Batesian mimicry, but it has one big drawback. The moth lives in some areas where there aren’t any hornets, and in those areas birds and other animals soon learn that those brightly striped insects are yummy and easy to catch.

The female hornet moth lays her eggs in the plants around the base of a tree or on its bark, especially the poplar tree. When the eggs hatch, the larvae spend the next two or three years in and around the tree, mostly around its roots. It eats the wood of the roots, and when it’s ready to pupate it burrows into the tree trunk and spins its cocoon in the burrow. The problem is that it needs the cocoon to be protected inside the tree, not near the entrance of the burrow, but when it emerges from the cocoon it needs to be near the entrance or its newly metamorphosed body will be too large for it to crawl out. To solve the problem, when it’s getting close to emerging, the moth will wriggle around in its cocoon so energetically that it manages to push the pupa up the burrow to the entrance. You can imitate this action by zipping yourself into a sleeping bag and trying to crawl across a room.

For a long time people thought the hornet moth was damaging poplar trees by this behavior, causing them to die. It turns out that the moths aren’t hurting the trees, they’re just more noticeable when poplars are already injured by drought.

There’s also an American hornet moth that lives in some parts of the Midwest and western areas of North America. It’s closely related to the hornet moth of Europe and adults look an awful lot like hornets, but they don’t sting. So the next time you’re about to run from a hornet, take a moment to determine if the hornet is actually a harmless moth. Or at least don’t run, just walk away quickly and safely. Just in case.

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!