Category Archives: fish

Episode 140: Rains of Fish and Frogs (and other things)

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We’re starting off October (you know, MONSTER MONTH) with accounts of animals that fall from the sky like rain, mostly fish and frogs! Is this a real thing that actually happens, and if so, what causes it?

Further reading:

Raining Frogs

Recent observations of “mystery star jelly” in Scotland appear to confirm one origin as spawn jelly from frogs or toads

Not a real photo of an octopus falling in a storm:

This photo is probably real, two shrimp/prawns on a windshield in the same storm as above (in 2018):

A photo of people picking up fish in the street but I have no idea where it was taken:

An arctic lamprey found in someone’s yard:

Some of the stuff called star jelly, star rot, or star snot:

A walking catfish:

Show transcript:

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

It’s finally October, and that means monsters and other spooky stuff! I have lots of fun episodes planned this month, but first, an important announcement!

A few weeks ago I got a message from someone on Podbean, and I feel terrible because I can’t reply or even see the whole message or who it’s from! Podbean does not like me. I get an email with the first couple of lines of the message but when I click through and log in to Podbean to see the whole message and respond, Podbean goes, “Message? What message? You don’t have any messages.” So please, person who messaged me with a suggestion I can’t see, I’d love it if you email me at strangeanimalspodcast@gmail.com! And if anyone else has ever messaged me somewhere but never received a reply, email is the best way to get hold of me. I always reply, so if you don’t get an answer it means I never saw your message and you should totally send it again. Thanks!

So, back to the October fun! Let’s start off the month right with a strange phenomenon that’s been reported for untold centuries all over the world. Do fish and frogs and other animals actually sometimes fall from the sky like rain?

It seems pretty certain that while this is a rare event, and not all reports are of animals that actually fell from the sky, it does sometimes happen. In fact, lots of weird stuff falls from the sky from time to time. For instance, after a heavy rain over Punta Gorda, Florida at the end of August 1969, the streets were full of golf balls, dozens of them if not hundreds. But there wasn’t a golf course near the town.

Sometimes colored rain falls instead of ordinary clear water. This happens because raindrops form around tiny specks of dust or pollen in the air. When the dust is colored, the rain will be too. Red rains come from dust blown into the atmosphere from the Sahara while yellow rain results from dust from the Gobi Desert. Volcanic eruptions, soot, and other pollutants in the air can cause black rain. And a red rain that fell in Kerala, India in July 2001 was analyzed and the color found to be due to fungal spores. Snow is occasionally colored too, just like rain.

But sometimes frogs, fish, or other small animals do apparently fall from the sky, with or without rain. Here’s a typical report of a rain of frogs. It comes from the book The Unexplained by zoologist Karl Shuker, whose honesty and scholarship I trust. Not only that, it’s something that happened to his own grandmother, Gertrude Timmins. In 1902, Gertrude was only eight years old. She and her mother were walking across a field in the West Midlands in England when it started to rain. They opened their umbrellas, but a moment later Gertrude noticed that amid the regular pattering of rain on an umbrella there were some heavier thumps. Then she noticed that the thumps were caused by small frogs falling onto her umbrella and bouncing off onto the ground. Gertrude was frightened at first, naturally, because that’s just a weird thing to happen to anyone. But her mother told her not to be scared, it was just a rain of frogs.

Remember, Gertrude and her mother were walking across a field. There weren’t any trees or buildings around that the frogs might have fallen from. So where did they come from?

The main hypothesis is that the animals are picked up by a water spout or small tornado and carried on the wind until they’re dropped elsewhere, miles away. When I was a kid I thought this was a dumb suggestion. If a dissipating water spout dropped everything it had picked up out of a pond, why do people just report one kind of frog falling from the sky or one kind of fish? Where’s the algae, water plants, turtles, mud, and other stuff presumably also picked up and carried out of a pond?

The answer may be pretty simple. When the wind velocity is high, the tornado or water spout can carry heavy objects, but as the wind slows and loses energy, it starts to drop the heaviest items. But the wind is still moving, so as it moves across the land and slowly loses more and more energy, it drops the heaviest items first, then the next heaviest items, then the next heaviest, and so on.

It might not even be a tornado or water spout. A powerful updraft, which is often associated with storms, can lift light items like sticks, leaves, and pool toys and drop them miles away. Small frogs often weigh no more than a penny does and during breeding season can be incredibly common in a small area, hopping everywhere. It’s reasonable to assume that sometimes these little frogs get lifted from one area by a strong updraft and dropped elsewhere, astonishing anyone who happens to see it. If you doubt the strength of an updraft, keep in mind that storms can also generate downdrafts and they can be so powerful they destroy or uproot trees.

No one has witnessed frogs or other animals get sucked up into the air and dropped elsewhere, so we don’t know if it actually happens this way. But the animals are obviously getting into the air somehow.

Frogs aren’t the only animals witnessed to fall from the sky. Fish are actually probably the most common animals that fall with rain. It doesn’t even have to be raining.

On October 23, 1947 fish fell over Marksville, Louisiana in the United States. A biologist was having breakfast with his wife in a local restaurant when the server said that fish were falling from the sky. Naturally he went to look. He identified the fish as several different freshwater species common in the area, including two species of sunfish, a type of bass, and a few others, all ranging from 2 to 9 inches long, or 5 to 23 cm. It was a foggy but calm morning with no reports of tornados or strong winds in the area.

It’s possible that a small waterspout formed over one of the many nearby lakes, sucked up whatever fish happened to be in the wrong place at the wrong time, and deposited them a few miles away. Waterspouts form the same way tornados do except that it happens over water. The inside of a waterspout, like the inside of a tornado, is a low-pressure tunnel inside a high-pressure cone of air. It acts like a vacuum cleaner, sucking up water as it moves, and anything that’s in the water near the surface gets sucked up too.

There are two types of waterspouts. Tornadic waterspouts are tornados that happen to touch down over water instead of land. They can be dangerous and are usually reported in the local news and weather if they’re spotted. But fair-weather waterspouts aren’t associated with storms, although they do form ahead of developing storm systems. They’re typically smaller, much less dangerous, and much less likely to be reported to the news. So it’s possible that the 1947 fish fall was the result of a fair-weather waterspout.

This phenomenon isn’t something that used to happen in the olden days and doesn’t happen now. In June of 2009, there were tadpole rains in parts of Japan on two different days in slightly different areas. One man saw over a hundred dead tadpoles on car windshields in one parking lot after a rain shower.

On June 13, 2018, shrimp and possibly other sea creatures fell on the coastal city of Qingdao [zhing-daugh], China during a storm. The media reported it as a “seafood rain” since people posted photos of octopus, squid, starfish, mollusks, and shrimp that they claimed had fallen during the storm. Some of the photos are hoaxes, especially the ones of octopuses flying through the air, but at least some of them are real. Some people speculate that the source of the animals may have actually been a market stall, but since the city is on the coast of the Yellow Sea and the storm’s winds were measured at 77 mph, or 125 km per hour, it’s just as likely that the animals were lifted into the air from shallow water as from a market stall.

Sometimes we can figure out what the cause is of falling animals. In 2015 the Alaska Department of Fish and Game received four separate calls from people who’d found arctic lampreys on their property, including the parking lot of a store and someone’s front yard. If you remember from waaaaay back in episode 3, where we talked about the sea lamprey, lampreys are jawless fish with suckerlike mouths. They latch onto a fish and use their rasping teeth to parasitize it. The arctic lamprey grows to about a foot long on average, or 30 cm, but occasionally one will grow twice that long. It lives in cold freshwater lakes and rivers in the arctic, although it’s found as far south as Japan. An investigation revealed that all four lampreys found on land had cut marks and bruises in a specific pattern, which indicated that they’d been picked up in the beak of a seagull and then dropped, probably by accident when the lamprey wriggled too much. In 2015 there were an unusually high number of arctic lampreys in the Chera River, near where the four lampreys were reported on land.

A substance often referred to as star jelly or star rot has been seen in various parts of the world for centuries, usually connected in folklore with comets and shooting stars. In late 2008 through February 2009 the BBC’s Scotland Outdoors website collected photos and accounts of star jelly people had encountered in Scotland and other places. People reported finding lumps of the usually clear or white, jelly-like substance in their gardens, on walkways, on fence posts, stumps lawns, on the side of the road, in pastures, on rocks, and so on. One person found a lump of it on his tractor, another on a 3rd floor balcony.

Even hundreds of years ago some people suspected star jelly had something to do with frogs. At least some of it looks like the jelly-like matrix that surrounds the eggs of many frog and toad species. This is backed up by the presence of small black eggs in some star jelly that look like frog eggs. But it’s clearly not exactly frog spawn and is often found in places where a frog would never lay its eggs, even if it could for instance get up onto a third floor apartment balcony.

Many samples of star jelly have been examined by scientists and found to be the spawn jelly of frogs and toads, which is produced by the female to surround the eggs and keep them damp. As the female lays her eggs, each one is coated with a layer of spawn jelly, which absorbs water in the environment and increases in volume. Sometimes when a predator tears a frog or toad into pieces to eat it, the reproductive tract is torn open and its contents falls to the ground. When the spawn jelly is exposed to the air, it starts to absorb moisture from whatever it’s touching. This will make it swell up and become much more noticeable to people, especially if it’s rained and the spawn jelly has absorbed a lot of water.

Often an animal will eat a frog or toad, then later regurgitate the less digestible parts. This includes spawn jelly and some parts of the reproductive tract, specifically the oviducts since they contain the spawn jelly. Sometimes eggs are mixed in too. Star jelly has been examined and tested frequently, although most DNA testing has been inconclusive since samples are contaminated with bacteria. But a 2015 DNA test determined that the star jelly was from a frog. The test also found traces of magpie DNA, so we can probably guess what ate the frog.

Some star jelly doesn’t have anything to do with amphibians, though. Instead, some are slime molds or a type of freshwater algae-like bacteria known as nostoc. Neither slime molds nor nostoc fall from the sky but they can appear suddenly, so people may assume that’s what happened. Many birds that eat frogs and toads will eat them in midair, and may also regurgitate the indigestible portions while flying, so at least some star jelly does fall from the sky.

Sometimes people assume an animal has fallen from the sky when it actually hasn’t. For instance, the walking catfish will wriggle across dry land to find water when its pond dries up. It can grow up to 1 ½ feet long, or half a meter, and is usually grayish-brown with little white spots. Its skin is covered with mucus that helps keep it from drying out when it’s out of water. It’s native to parts of Southeast Asia, but it’s been introduced to other places, including southern Florida. In places where it’s not native, people may not be familiar with its ability to breathe air and move around out of the water, so when they see the walking catfish on land they may assume it fell from the sky.

The walking catfish is an invasive species in many areas. It’s an omnivore and can tolerate all kinds of habitats, including stagnant water where other fish can’t survive, since it can breathe air. Fish farmers in areas where the walking catfish lives have to put fences up around their ponds to keep walking catfish out. And if you see one, don’t pick it up. Its fins have spines that help stiffen them so it can use them to move more effectively on land, but that make them sharp.

We obviously don’t know everything about animals that fall from the sky, so let’s finish with a real mystery. It’s called the Kentucky Meat Shower and it happened on March 3, 1876 in a tiny community called Olympia Springs, Kentucky.

Olympia Springs is east of Lexington, Kentucky, in the southeastern United States. These days it’s in the Daniel Boone National Forest and just outside of the Olympia State Forest, so there’s not much in the area except wilderness. This was probably also the case in 1876 except that in 1876 there probably wasn’t a Dairy Queen restaurant a ten minute drive away. Wikipedia says it happened in a community named Rankin in the same county, but most other sources say Olympia Springs. Either way, it was an isolated, remote area at the time.

On this particular day, a woman only identified as Mrs. Crouch was in the yard, making soap. It was a perfectly clear day, not a cloud in the sky, when suddenly it started raining meat. She said it fell like big snowflakes all around her, but presumably not as pretty as snow, and lasted for several minutes. It was fresh meat, looked like beef or other red meat, and the pieces were irregularly shaped and gristly. Some were as big as 4 inches across, or 10 cm, but most about half that size. The meat landed all around, including on fences, in an area estimated to be about 100 yards across and 50 yards wide, or 91 by 46 meters.

Mrs. Crouch and her husband were understandably shaken by this event, and records don’t report whether the soap got finished that day but I suspect not. The next morning, the meat was still lying around, but it had dried out overnight and was starting to spoil. A couple of men stopped by and actually tasted it—ugh, I hope they at least cooked it first—and said they thought it might be venison or mutton. That’s meat from deer and sheep, respectively.

Samples of the meat were sent to various experts who examined it. Keep in mind that this was 1876 so they couldn’t do much more than look at it under an old-timey microscope. Two samples were identified as lung tissue, two as cartilage, and three as muscle.

As soon as the story hit the newspapers, people were quick to offer solutions that didn’t actually fit the reported facts. One person suggested that it was just nostoc that hadn’t actually fallen from the sky, it had been on the ground all along but that rain had made it swell up, which is something nostoc does. Never mind that nostoc is a slimy bacteria that looks nothing like meat—remember, it’s sometimes identified as star jelly—and that it wasn’t raining at the time and that Mrs. Crouch actually saw it fall and that pieces of it were found draped over fences. Plus, nostoc doesn’t taste like venison or mutton. Plus, samples were identified as actual meat.

The main suggestion is that some vultures were flying overhead and had disgorged some meat they had eaten, which had been caught by the wind and fell across a wide area. But while even nowadays people claim that is what must have happened, it has one big flaw. Vultures don’t disgorge meat while they’re flying. They disgorge it as a way to deter predators approaching their nest, and they may disgorge if a predator approaches while they’re feeding so they can get into the air quickly, but not while flying. Not only that, but any meat disgorged by a vulture would smell and taste horrible, since it would have already been rotting before the vulture ate it, and it would then be coated with caustic vulture digestive juices.

So what might have caused the Kentucky Meat Shower? If it wasn’t a newspaper hoax, which were really common in the late 19th century, it might have been the result of some poor animal that was swept up by a tornado, torn apart, and the smallest pieces dropped over the Crouch’s farm after the winds had dissipated. Presumably the heavier pieces, like bones, fell earlier and probably landed in the forest where no one saw them fall. I looked for a weather report for Kentucky for that day, but couldn’t find one. Eastern Kentucky is not too far north from where I live in East Tennessee, so I can verify that March can be a very warm month with unsettled weather. It wouldn’t be at all unusual to have a storm strong enough to generate a small but powerful tornado in March, although this usually happens at night after a hot day.

I don’t know if I believe the Kentucky Meat Shower really happened or if it was a hoax. But either way, we can stop blaming vultures.

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

Thanks for listening!

Episode 136: Smallest of the Small

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Last week we learned about the smallest species of animals not typically thought of as small, like snakes and cetaceans. This week let’s look at some of the tiniest animals in the world, the smallest of the small!

Further watching:

A short video about jerboas. Really interesting and well-made!

A button quail:

Baby button quails are the size of BEES:

Kinglets are teeny birds even when grown up. Left, the golden-crowned kinglet. Right, the goldcrest. These birds MAY BE RELATED, you think?

The pale-billed flowerpecker, also teeny and with a cute name:

Moving on from birds, the pygmy jerboa is one of the smallest rodents in the world:

The Etruscan pygmy shrew is even tinier, probably the smallest known mammal alive today. Shown here with friend/lunch:

The Western pygmy blue butterfly is probably the smallest butterfly known:

But the pygmy sorrel moth is even smaller. Right: red marks left behind on a sorrel leaf eaten by its larvae:

One of the world’s teeniest frogs:

Show transcript:

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

Last week we learned about the smallest species of animals that aren’t typically thought of as small. But this week let’s learn about the smallest of the small animals. It’s like saying they’re the cutest of the cute animals. We’ll start with the bigger ones and get smaller and smaller as we go.

Let’s start with a bird. The smallest bird is the bee hummingbird, which we’ve talked about before. But there’s another bird that’s really small, the button quail. It’s about the size of a sparrow.

The button quail isn’t actually a quail, but it looks like one due to convergent evolution. There are a number of species in parts of Asia and Africa and throughout Australia. It generally lives in grasslands and is actually more closely related to shore and ocean birds like sandpipers and gulls than to actual quails, but it’s not very closely related to any other living birds. It can fly but it mostly doesn’t. Instead it depends on its coloring to hide it in the grass where it lives. It’s mostly brown with darker and lighter speckled markings, relatively large feet, and a little stubby nothing of a tail. It mostly eats seeds and other plant parts as well as insects and other invertebrates.

The button quail is especially interesting because the female is more brightly colored than the male, although not by much. In some species the female may have bright white markings, in some their speckled markings are crisper than the males. The female is the one who calls to attract a male and who defends her territory from other females. The female even has a special bulb in her throat that she can inflate with air to make a loud booming call.

The male incubates the eggs and takes care of the chicks when they hatch. Baby button quails are fuzzy and active like domestic chicken babies but they’re only about the size of a bumblebee. In many species, as soon as the female has laid her eggs, she leaves them and the male and goes on to attract another male for her next clutch of eggs.

People sometimes keep button quails as pets, specifically a species called the painted buttonquail or the Chinese painted quail. It’s about five inches long, or 12 cm. The female has black and white stripes on her face and throat. The birds can become quite tame and can live several years.

Button quails make a lot of different noises. This is what a button quail sounds like:

[button quail calls]

One of the smallest birds in the world that isn’t a hummingbird is the kinglet, with several species that live in North America and Eurasia. The goldcrest is a type of kinglet and the smallest European bird. It’s only 3.3 inches long, or 8.5 cm, although some individuals are larger. It looks a lot like the North American bird the golden-crowned kinglet, which is just a shade smaller at 3.1 inches, or 8 cm. Both species have a golden patch on the top of the head. The male also has an orangey spot in the middle of the golden patch. Both live in coniferous forests and eat insects and spiders.

Because kinglets are so small and active, they can starve to death quickly—in only an hour in some cases. Females lay up to 12 eggs at a time. TWELVE EGGS. That is a lot of eggs. The nest is too small to hold a dozen eggs in one layer so they end up in a pile. The female keeps all of them warm by pushing her legs down into the pile of eggs. Since her legs have a lot of blood vessels near the surface, they’re much warmer than most birds’ legs.

When the babies hatch, they stay in a pile. The ones on the top of the pile get fed first, naturally, but then they burrow down into the pile and push their siblings up toward the top. They’re not just being nice, though, since birds in the bottom of the pile stay warmer.

This is what a golden-crowned kinglet sounds like:

[bird call]

The pale-billed flowerpecker is even smaller than the kinglets and are among the smallest birds in Asia. It lives in parts of India and nearby areas and mostly eats berries, although it also eats flower nectar. It grows to only 3 inches long, or 8 cm, and is plain brownish-green in color with a short tail and shiny black eyes. It lives in forests but often visits gardens. It doesn’t lay a dozen eggs at a time, just an ordinary two or three.

This is what a pale-billed flowerpecker sounds like. These are some teeny sounds from teeny birds:

[bird call]

There are several rodents that are considered the smallest rodent, but we’re only going to learn about one of them today, the pygmy jerboa. On average it’s only 1.7 inches long, or 4.4 cm, not counting its extremely long tail.

The pygmy jerboa lives in the deserts of Pakistan and possibly in nearby areas too. It has very long hind legs and very short front legs so it hops like a tiny kangaroo, using its long tail as a way to balance and maneuver at high speeds. Its tail is twice as long as its body. Its large hind feet and the end of its tail are very furry to give it more surface area so it can easily maneuver through loose sand.

It mostly eats seeds and leaves, and it gets all the moisture it needs from the food it eats. It’s nocturnal and spends its days in the burrow it usually digs under bushes. Like many other tiny animals, when it rests it slows its metabolism drastically so it won’t starve to death while it’s asleep. Life is rough for tiny animals.

We don’t know a whole lot about the pygmy jerboa except that it’s endangered due to habitat loss, so let’s move on to an even smaller mammal.

The Etruscan shrew grows to about 1.6 inches long, or 4 cm, on average, not counting its short tail. The tail is about a third of the length of its body. It lives in southern Europe, parts of Asia, parts of the Arabian Peninsula, and northern Africa and prefers warm, moist climates. It’s the same size and weight as the bumblebee bat we talked about last week, so it’s one of the smallest mammals known.

The Etruscan pygmy shrew is pale brown with a lighter colored belly, a long nose, and short whiskers around its mouth that it uses to help it find its prey. It’s incredibly active and makes clicking noises almost constantly, as a way to alert other shrews that it’s there and is willing to defend its territory. It makes its nest among rocks and in the abandoned burrows of other animals.

Like the kinglets and other highly active, tiny animals, it has to eat a lot to keep its metabolism going—up to twice its own weight in food every day. It can also enter a torpid state where it reduces its body temperature and metabolism the same way the pygmy jerboa does, in order to not starve while it sleeps. But the Etruscan shrew doesn’t rest very often.

It mostly eats insects and other invertebrates like earthworms, but it will eat anything it can kill. This includes lizards, small rodents, and frogs. It especially likes grasshoppers and crickets, which are often as large as it is. In order to kill prey its own size, the shrew is incredibly fast. If you remember episode 82 where we talked about the star-nosed mole, the Etruscan shrew primarily hunts by touch and can react in barely 25 milliseconds when it touches something it wants to eat. It takes something like 300 milliseconds for a human to blink their eyes, if that gives you an idea of how fast the shrew is. It can touch a cricket and kill it in less time than it takes to blink.

So that’s as small as mammals get, as far as we know. What’s the smallest amphibian?

Well, it’s really, really small. The smallest known frog is only 7.7 mm long. Paedophryne amauensis isn’t just the smallest frog, it’s the smallest vertebrate known. It was only discovered in 2009 in Papua New Guinea.

It sounds like an insect and lives in the damp leaf litter on the forest floor, and it’s dark brown and black in color to blend in with dead leaves, so it was hard to find. Researchers only found it by using sensitive microphones to triangulate on its call, then quickly scooping up lots of leaf litter and stuffing it into plastic bags so anything living in the leaves couldn’t escape. Its eggs hatch into tiny froglets instead of tadpoles.

The tiniest frog is just about the same length as the tiniest fish, the stout infantfish that lives in a few coral reefs near Australia, including the Great Barrier Reef. It also grows 7.7 mm long on average, although females are typically longer and it can grow as much as 10 mm long. But the smallest known fish is the male of an anglerfish species that only grow 6.2 mm long. This doesn’t really count, though, since females grow up to two inches long, or 50 mm. Like other deep-sea anglerfish species, when a male of Photocorynus spiniceps finds a female, he bites her and stays there. Eventually his mouth actually fuses to her body and he lives the rest of his life as a sort of parasitic extension of the female. He supplies her with sperm to fertilize her eggs before she lays them, and she supplies him with nutrition and oxygen since he’s basically part of her body at that point. A female can have more than one male fused to her.

So, we seem to have reached the smallest vertebrates. What about the smallest insects and other invertebrates?

Butterflies are generally pretty small, but the smallest butterfly known is really, really small. The Western pygmy blue butterfly only has a wingspan of 20 mm at most but usually more like 12 mm across. That’s less than an inch. It lives in western North America and parts of the middle east, and has even been found on Hawaii. Its wings are a pretty coppery brown color with rows of black and white spots. It likes deserts and waste places where you wouldn’t expect to find anything as delicate as a tiny butterfly. Its caterpillars eat various types of weed plants.

That is pretty much it. There’s not much to this tiny butterfly. The real mystery is why it’s called the western pygmy blue when it’s not actually blue.

Compared to the smallest moth known, the western pygmy blue butterfly is a giant. The smallest moth is the pygmy sorrel moth and its wingspan is barely four millimeters. Its wings shade from silvery with a metallic bronze tint to purply with a white stripe, and gray along the ends. It’s really pretty but so tiny that it’s hard to spot. It lives in much of Europe and its larvae leave distinctive spiral shapes on sorrel leaves as it eats.

We’ll come back to insects in a minute or two, but let’s look at a few snails first. The smallest land snail is the Borneo snail. Its shell is only .7 of a mm high. It was only discovered in 2015. We don’t know a lot of about it yet, but it probably eats bacterial film growing on limestone in caves. So far researchers haven’t even found a living Borneo snail, though, just its shells.

The smallest water snail is even smaller than the Borneo snail. It’s from North America and its shell is only half a millimeter across at the most. Some individuals are only .3 mm across. Ammonicera minortalis lives in shallow water off the coast of southern Florida and around Cuba and other islands in that area. And that’s pretty much all we know about it. It’s a lot easier to study bigger animals just because they’re easier to find.

Small as that is, on average the smallest beetle is smaller than the smallest snail. It’s a type of featherwing beetle only described in 1999, and on average it’s .338 mm long. So far it’s only been found in Central America and it eats fungus. It’s yellowish-brown in color but that doesn’t really matter because it’s so small that you need a magnifying glass to really see it.

Once you start dividing millimeters, you’re getting into ridiculously tiny territory. But the smallest insect is a type of wasp known as a fairyfly. Kikiki huna is so small it’s measured in micrometers, sometimes called microns, and is smaller than some single-celled organisms. It’s only 150 micrometers long, which is shorter than an ordinary piece of printer paper is thick. It’s been found on Hawaii, Costa Rica, and Trinidad but it probably lives in other places but just hasn’t been found yet. Some researchers suspect that it’s as small as a flying animal can become without losing the ability to fly under its own power instead of just floating on the wind.

At this point anything smaller than Kikiki huna and its close relatives are made up largely of bacteria, which are frankly not as cute or as interesting as, say, button quail. So let’s finish with what may be the very smallest living organism ever found. Or it may not be. Because researchers are literally not even sure if the nanobe is even alive.

In 1996 researchers found what looked like filiments growing among rock samples collected from wells off the Australian coast. Some of them were only 20 nanometers in diameter. To put that into perspective, a nanometer is one billionth of a meter. That’s billion with a B. It’s one thousandth of a micrometer. A nanobe is a tenth of the size of the smallest known bacteria.

The researchers weren’t sure what they’d found so they did a lot of tests. They thought they might have discovered a new kind of crystal, but when they stained the nanobes with a type of dye that binds to DNA, the results indicated the nanobes might be living organisms. But no DNA has been successfully recovered from nanobes.

There’s still a lot of research to be done to determine what they are and if they’re actually alive, though. The main problem is that nanobes appear to be too small to contain all the things that living organisms need. But they do resemble fungi in some ways, just much, much smaller. If nanobes are alive, they’re extremely different from any living animal ever known and presumably live and reproduce in ways completely unlike all other life.

But here’s an interesting note. In 1996 researchers found structures inside a meteorite from Mars that look a lot like nanobes.

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

Thanks for listening!

Episode 133: The mangrove killifish and the unicorn pig

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This week’s (short) episode is about two animals that should have been in the strangest small fish and weird pigs episodes, respectively. I left them out by accident but they’re so interesting that they deserve an episode all to themselves anyway. Thanks to Adam for suggesting the mangrove killifish!

Further reading:

25 Years in the Mud: How a Quirky Little Fish Changed My Life

The mangrove killifish just looks normal:

Not a unicorn pig (okay yes technically a unicorn pig):

Unicorn pig skull:

Show transcript:

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

A few weeks ago we had an episode about strange small fish. Shortly after that episode released, I was going through my disorganized ideas and suggestions file and realized I’d left out one of the best weird small fish ever, a suggestion by Adam. I also discovered I’d missed an extinct pig I’d planned to include in the recent weird pigs episode. So let’s play catch up in a short episode and learn about both this week.

The fish Adam suggests is called the mangrove killifish, also called the mangrove rivulus, which lives in parts of Florida and Mexico, down to Central and South America. It’s technically a marine fish, meaning it lives in salt-water, but it also likes brackish water, that’s less salty than the ocean, and occasionally it even lives in freshwater. It especially likes mangrove swamps. It grows up to 3 inches long, or 7.5 cm and is a mottled brown in color with an eye spot on its tail. It doesn’t look like anything special.

But the mangrove killifish has a lot in common with amphibians, especially the lungless salamanders. Many types of salamander absorb air through the skin instead of through lungs or gills. The mangrove killifish does this too. It often lives in abandoned crab holes, which may not have very high quality water. But that’s okay, because it can absorb air through its skin and can live out of the water for well over a month as long as its skin stays damp. It’s sometimes found in places where you wouldn’t expect to find a fish, like the inside of rotting logs or buried in damp dead leaves.

So how does the killifish get into the rotting logs or the leaf litter or the crab burrows that aren’t connected to waterways? It actually uses its tail to flip itself out of the water and onto land, and then it continues to flip here and there until it finds a place where it wants to live for a while. It can direct this jumping, not just flop around like most fish out of water, and can jump several times its own length.

A lot of times when the tide goes out, fish get trapped in crab holes, dimples in the sand or mud, and other shallow water. That’s okay if the tide comes back in far enough to re-submerge the holes, but if the water doesn’t quite reach, it’s not long before fish start to suffocate as all the oxygen in the water is used up. But the killifish doesn’t have that problem. It just flips itself out of the water. It can also leave the water if it gets too hot.

The killifish is also territorial in water, which requires a lot of energy. When it’s out of the water, or in a little temporary pool or a crab burrow where it doesn’t have to worry about other killifish, it can relax. On the other hand, it loses a lot of weight while it’s out of the water since it doesn’t eat as much. So there are trade-offs.

Even the killifish’s eggs can survive out of water. The fish usually lays its eggs in shallow water, sometimes even on land that’s just near water. The eggs continue to develop just fine, in or out of water, but they delay hatching until they’re submerged.

And that leads us to the most astonishing thing about the mangrove killifish. In most populations, almost all killifish are females, and most of the time they don’t need a male fish to fertilize their eggs. Females produce eggs but they also produce sperm that fertilize the eggs before they’re even laid. The eggs hatch into genetic duplicates of the parent—clones, basically. The term for an organism that produces both eggs and sperm is hermaphrodite, and while it’s common in some invertebrates, the killifish is the only known vertebrate hermaphrodite. Vertebrate, of course, is an animal with a backbone.

But while most killifish are females, there are occasionally males. Male killifish are orangey in color. When a male is around, females suppress their ability to self-fertilize eggs and they lay the eggs for the male to fertilize, just like any other fish. This helps keep the species genetically diverse and able to adapt to external pressures like increased numbers of parasites.

Next, let’s talk about the unicorn pig. Or pigicorn, if you like. It’s called Kubanochoerus [koo-ban-oh-ko-rus] and there were several species. It was related to modern pigs and lived throughout most of Eurasia and parts of Africa around 10 million years ago.

It was big, up to four feet tall at the shoulder, or 1.2 meters, and had tusks like other pigs. It probably looked a lot like a wild boar. But its skull is longer than modern pig skulls and it had horns. Three horns, specifically. Two of the horns were small and grew above the eyes, while a bigger horn grew forward from its forehead. The forehead horn wasn’t very long and was probably blunt. Researchers used to think males used these forehead horns to fight each other, but females had them too so they may also have been used for defense from predators.

That is literally all I can find out about this fascinating animal. I can’t even speculate about the horns since literally no other pig has horns, at least that I can find. Presumably the warty protrusions that many modern pig species have are similar to the horns that Kubanochoerus had. The eyebrow horns might have had the same purpose as the facial protrusions on warthogs and other pigs, as a way to protect the eyes when the pigs fight. The forehead horn, though…well, that’s just weird. It probably wasn’t covered with keratin, but we don’t know. My own guess is that it was something more like an ossicone and was covered with skin and hair. But again, we don’t know. Not until we invent a working time machine and go back to look at one.

That’s it, a very short episode. I’m actually in Dublin, Ireland right now attending WorldCon, so while I’m here I will keep an eye out for leprechauns, fairies, and pigicorns, just in case.

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

Thanks for listening!

Episode 130: Strangest Small Fish

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This week we’re going to revisit a suggestion from Damian and follow up on episode 96, our strangest big fish episode. This time let’s find out about some weird small fish!

The teeny, newly-discovered American pocket shark:

The brownsnout spookfish wears its mirror sunglasses on the INSIDE:

The goblinfish with a dangerous head and basically a dangerous everything else too:

Two teeny pygmy seahorses. Can you spot them? Hint: they’re the ones with eyes.

The razorfish. Just another sea urchin spine, no fish to see here:

The much-maligned candiru:

The red-lipped batfish:

Gimme kiss:

Show transcript:

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

Ages ago, Damian suggested an episode about weird fish. We covered some weird big fish in episode 96, but now it’s time for some weird little fish.

So, think about sharks for a second. Big, scary, sharp teeth, fast swimmers, black eyes of a pitiless killer of the deep.

But have you perhaps considered that maybe the world needs a very small shark? One that actually kind of looks like a tiny whale? Like, a tiny shark, only about 5 ½ inches long, or 14 cm. Almost, you know, pocket sized. Oh, and it should glow in the dark.

That’s the American pocket shark, a real animal that was only discovered in 2010! It’s called a pocket shark not because it’s pocket sized, although it is, but because it has a sort of pocket on each side near its gills that produces luminous fluid. Researchers aren’t sure whether the shark uses the fluid for attracting prey or avoiding predators. Maybe both. Its head is bulbous and rounded, which kind of makes it look like a tiny whale.

The American pocket shark was discovered in the Gulf of Mexico while scientists were observing sperm whales and tracking them with sonar. When a whale surfaced from a dive, the research team dropped nets to the depth the whale had dived to, hoping to catch the same kind of prey the whales were eating. And one of the things they found in the net was a tiny shark new to science, found at a depth of 3,000 feet, or 914 meters.

In 2013 the tiny shark, which had been frozen for later study, was finally examined. The expert who looked at it had only seen one other shark like it before, a shark discovered in the eastern Pacific in 1979. But this tiny shark had some differences from that tiny shark, and after examining both specimens carefully, they’ve been classified as different species.

So that’s a cute start, but it’s still just a rare little shark that glows. Not really that unusual, right? Let’s look at a really weird fish next. Like, seriously weird.

It’s called the brownsnout spookfish, which is a really terrible name, but it’s not a terrible fish. I mean, it couldn’t hurt you. It grows about 7 inches long, or 18 cm, and eats copepods and other tiny crustaceans. Its snout is long and kind of pointy, its body is slender, and it has elongated pelvic fins. Because it lives in the deep sea, it has eyes that point upward, which help it see predators and prey that might be silhouetted against the far-distant surface of the ocean. But it also has something only one other fish is known to have, an extra structure to the side of the eyeball. It’s called a diverticulum and it does two things. First, it allows the fish to see downward in addition to upward, and second, it allows it to see across a really wide angle. The diverticulum does this because it contains a mirror that reflects light from the main eyeball onto the retina of the diverticulum. A MIRROR IN ITS EYEBALLS. The mirror is made up of tiny crystalline plates.

Some invertebrates like clams and crustaceans contain reflectors in their eyes, but except for the brownsnout spookfish, the only other vertebrate known to have mirrored eyeballs is the glasshead barreleye. Also a terrible name. The glasshead barreleye is a little smaller than the brownsnout spookfish, and not surprisingly, they’re related. But surprisingly, they’re not that closely related and the mirrored diverticulum appears to have evolved independently in each species.

Although the fish has been known to science for over a century, no one realized it had mirrors in its eyes until 2008 when a live one was caught by a deep-sea scientific expedition off the island of Tonga in the Pacific Ocean. Researchers took pictures of the brownsnout spookfish and got a shock when they looked at the photos. The upward-pointing parts of the eye reflected light normally, the typical eyeshine you get when you use a flash to photograph most animals. But the lower parts of the eyes reflected bright light. Researchers think the fish uses its downward-pointing eyes to see the faint bioluminescent flashes of its prey, while the upward-pointing eyes watch for predators approaching from above.

Oh, and I forgot to mention. The brownsnout spookfish is mostly transparent. You can see right through it. Yeah.

After that, the goblinfish that lives around reefs off the southern coast of Australia seems practically normal. It grows up to 8 inches long, or 20 cm, and spends most of its time resting among rocks on the seabed. It hunts at night, eating small crustaceans, and instead of swimming it usually walks along the sea floor with its large pectoral fins.

The goblinfish gets its name from its appearance, which is frankly ugly unless you are another goblinfish. Its head looks sort of turtle-like, including a dip in its body behind its eyes and in front of its dorsal fin that looks like a turtle’s neck. Its eyes are large and orange in color. Its dorsal fin is spiny and runs most of the length of its back. It also has broad pectoral fins that it sometimes spreads like fans. It can change color to blend in with the rocks around it, which makes it hard for divers to see, which is too bad because it’s also venomous.

It’s a type of waspfish, related to scorpionfish and stonefish, all of which are venomous. Like many of those other fish, the goblinfish has venomous spines on its fins, but it also has a spine on each side of its head, underneath its eyes. Only these spines are hidden inside the fish’s head. The spine is called a lachrymal saber, and it acts like a switchblade that the fish can extend with its cheek muscles. The lachrymal saber isn’t venomous, but if you’ve just picked one up by the head and those switchblades come out, you probably aren’t going to be happy anyway. Also, why did you just pick that fish up by its head? What is wrong with you?

Next, let’s talk about the seahorse. It’s a fish although it doesn’t look like an ordinary fish. And in fact nothing about the seahorse is ordinary.

Unlike most fish, the seahorse has a flexible neck. Also unlike almost all other fish it swims vertically, with its head up and its tail down. It has a prehensile tail made up of 36 bony segments, and each segments is made of four pieces connected by tiny joints. The joints make the segments incredibly strong and able to withstand considerable pressure without breaking. The seahorse uses its tail to hold onto seaweed or other items to keep from being swept away in currents, since it isn’t a strong swimmer. It propels itself through the water by fluttering its dorsal fin, using its pectoral fins to steer. Males also fight each other by tail-wrestling and bopping their heads together. The seahorse’s body is protected with an external skeleton of bony plates, which take the place of ribs. The seahorse doesn’t have ribs. It also doesn’t have scales, just the bony plates with thin skin over them.

The seahorse lives in warm, shallow oceans throughout the world, especially in coral reefs and seagrass beds where there’s plenty of cover. The largest seahorse species grow to about 14 inches long, or 35 cm. The smallest species are barely more than half an inch long, or 15 mm. The smallest species are mostly new to science since they’re so hard to find and identify. Seahorses are well camouflaged to blend in with the plants and coral they live in.

The seahorse’s mouth is at the end of a long, tubelike snout, and it actually sucks its prey into its snout like a straw. It eats small crustaceans, larval fish, and other small animals. Oh, and its eyes can move independently of each other.

Seahorses don’t mate for life, but they do form bonds that last throughout the breeding season, and it has a long courtship period while the female develops her eggs. The pair participate in courtship dances and spend most of their time together. When the eggs are ready, the female deposits them in a special brood pouch in the male’s belly, where he fertilizes them. They then embed themselves in the spongy wall of the brood pouch and are nourished not only by the yolk sacs in the eggs, but by the male, who secretes nutrients in the brood pouch. So basically the male is pregnant. The female visits him every day to check on him, usually in the mornings. When the eggs hatch after a few weeks, the male expels the babies from his pouch and they swim away, because when they hatch they are perfectly formed teeny-tiny miniature seahorses.

If you’re wondering why I said the seahorse is almost the only fish that swims vertically, there’s some evidence that the oarfish does this too. We talked about the oarfish way back in episode 6, about sea monsters. But there’s another fish that swims vertically, the razorfish—but it swims with its head pointed down and its tail pointed up. It’s a slender fish that grows about six inches long, or 15 cm, with a pointy nose and tiny fins. Its back is protected by bony plates that extend past the tail fin in a spine. It eats tiny animals, including brine shrimp, AKA sea monkeys. When it feels threatened, the razorfish swims to the nearest sea urchin and hides among its spines, blending in with them. Schools of razorfish will swim around together, all of them head-down, because that’s just what they do.

Not all weird fish live in the ocean. A lot of freshwater fish are weird too. For instance, the candiru [kan-DEE-roo]. You’ve probably heard of this one although you may not know what it’s called. It’s native to the Amazon and Orinoco Rivers in South America and it’s actually a type of catfish. Some species grow over a foot long, or around 40 cm, but the species we’re talking about today, Vandellia cirrhosa, grows less than two inches long, or 5 cm. Like the brownsnout spookfish, it’s mostly translucent so it’s hard to see in the water. It has short spines on its gill covers that point backwards.

Unlike other catfish, the candiru eats blood, which gives it its other name of the vampire fish. It parasitizes other fish by lodging itself in their gills and sucking their blood. But the candiru is supposed to do something else, something that happens by accident. The story goes that if someone pees while in the water and a candiru is around, it’ll swim up the stream of urine, attracted by the smell, and lodge itself in the urethra of the person peeing. It’s supposed to do this thinking it’s entering the gills of a fish. Its spines keep it locked in place, causing intense pain to the person, followed by infection and, if the fish isn’t surgically removed, death.

At least, that’s the story. There’s even a 1997 video of a man who had to have a candiru removed from his penis after he peed while wading in a river in Brazil. The doctor filmed the surgery and even kept the fish he removed, preserved in formaldehyde. So it must be true, right?

Maybe not. One study determined that the candiru isn’t interested in the chemicals present in urine and in fact it hunts by sight, not smell. And a study of medical reports throughout South America only found a single instance of anyone reporting a candiru attack. That instance is the same one from 1997 where the surgery to remove the fish was filmed.

But a further study of the surgery, photos, and preserved candiru specimen tell a different story. The human urethra is extremely narrow and the preserved fish was much too large to enter without squishing itself to death, not to mention that the candiru is just not strong enough to muscle its way into anything but a larger fish’s gills. The doctor also said he’d had to cut off the candiru’s spines before removing it, but the specimen is fully intact, spines and all. It sounds like the video may be a hoax of some kind.

Reports of candiru attacks are common in parts of South America today and have been common as far back as recorded history, but they seem to be more of a legend than something that happens a lot or maybe even at all. Still, probably better not to pee into the Amazon River, just in case.

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

The weirdest thing about the red-lipped batfish is actually its fins. It prefers to walk on the bottom of the ocean instead of swim, and it has modified pectoral fins called pseudolegs. The pseudolegs make it look a little bit like a weird frog with a tail, a unicorn horn, and lipstick. It’s like something out of a fever dream, honestly.

Researchers think the red lips may be a way to attract potential mates, presumably ones who are hoping for a big smooch.

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

Thanks for listening!

Episode 122: Strange Shark Ancestors

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This week let’s learn about some ancestors of sharks and shark relatives that looked very strange compared to most sharks today!

Stethacanthus fossil and what the living fish might have looked like:

Two Falcatus fossils, female above, male below with his dorsal spine visible:

Xenacanthus looked more like an eel than a shark:

Ptychodus was really big, but not as big as the things that ate it:

A Helicoprion tooth whorl and what a living Helicoprion might have looked like:

Show transcript:

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

This week we’re going back in time again to learn about some animals that are long-extinct…but they’re not land animals. Yes, it’s a weird fish episode, but this one is about shark relatives!

The first shark ancestor is found in the fossil record around 420 million years ago, although since all we have are scales, we don’t know exactly what those fish looked like. The first true shark was called Cladoselache [clay-dough-sell-a-kee] and lived around 370 million years ago, at the same time as dunkleosteus and other massive armored fish. We covered dunkleosteus and other placoderms back in episode 33. Cladoselache grew up to four feet long, or 1.2 meters, and was a fast swimmer. We know Cladoselache ate fish because we have some fossils of Cladoselache with fish fossils in the digestive system—whole fish fossils, which suggests that cladoselache swallowed its prey whole. Cladoselache also had fin spines in front of its dorsal fins that made the fins stronger, but unlike its descendants, it didn’t have denticles in its skin. It didn’t have scales at all.

The denticles in shark skin aren’t just protection for the shark, they also strengthen the skin to allow for the attachment of stronger muscles. That’s why sharks are such fast swimmers.

[Jaws theme]

Stethacanthidae was a family of fish that went extinct around 300 million years ago. It was related to ratfish and their relatives, including sharks. Stethacanthus is the most well-known of the stethacanthidae. It grew a little over 2 feet long, or 70 cm, and was probably a bottom-dwelling fish that lived in shallow waters. It ate crustaceans, small fish, cephalopods, and other small animals.

We have some good fossils of various species of Stethacanthidae and they show one feature that didn’t get passed down to modern ratfish or sharks. That’s the shape of its first dorsal fin, the one that in shark movies cuts through the water just before something awful happens.

[Jaws theme again]

Stethacanthidae’s dorsal fin was really weird. It was shaped sort of like a scrub brush on a pedestal, with the bristles sticking upwards, which is sometimes referred to as a spine-brush complex. Researchers aren’t sure why its fin was shaped in such a way, but since it appears that only males had the oddly shaped fin, it was probably for display. It also had a patch of the same kind of short bristly denticles on its head. Males also had a long spine that grew from each pectoral fin that was probably also for display. Some researchers think the males fought each other by pushing head to head, possibly helped by the odd-shaped dorsal fin.

In the past, before researchers figured out that only the males had the strange dorsal fin, some people suggested that the fish may have used the fin as a sucker pad to attach to other, larger fish and hitch a ride. This is what remoras do. Remoras have a modified dorsal fin that is oval-shaped and acts like a sucker. The oval contains flexible membranes that the remora can raise or lower to create suction. The remora attaches to a larger animal like a shark, a whale, or a turtle and lets the animal carry it around. In return, the remora eats parasites from the host animal’s skin. But remoras aren’t related to sharks.

Other shark relatives had dorsal spines. Falcatus falcatus lived about the same time as Stethacanthus, around 325 million years ago. It grew up to a foot long, or 30 cm, and ate shrimp, fish, and other small animals. We have so many fossils of falcatus from the Bear Gulch Limestone deposits in Montana that we know quite a bit about it. It probably detected prey with electroreceptors on its snout like many modern sharks do, and it was probably a fast swimmer that could dive deeply. Its eyes are unusually large for a shark too. Females would have looked like a small, slender sharklike fish, but males had a spine that grew forward from just behind its head, sort of like a single bull’s horn. It’s called a dorsal spine and is actually a modified dorsal fin. It was probably for display, although males may have also used it to fight each other. We have a well preserved fossil of a pair of falcatus together, a male and female, where it looks like the female may be biting the male’s dorsal spine. Some researchers suggest the spine was used in a pre-mating ritual, but it’s probable that the fish just happened to die next to each other and no one was actually biting anyone.

Another shark relative with a dorsal spine is Hybodus, which grew up to 6 ½ feet long, or 2 meters. Hybodus was a successful genus of cartilaginous fish that lived from around 260 million years ago up to 66 million years ago. Researchers think its dorsal spine was used for defense since both males and females had the spine. Hybodus would have looked like a shark but its mouth was relatively small. It probably ate small fish and squid, catching them with the sharp teeth in the front of its mouth, but it also probably ate a lot of crustaceans and shellfish, which it crushed with the flatter teeth in the rear of its mouth.

Xenacanthus had a dorsal spine too, but it was a much different shark ancestor from the ones we’ve talked about so far. It lived until about 208 million years ago in fresh water. It grew to about three feet long, or one meter, and would have looked more like an eel than a shark. It was slender with an elongated body, and its dorsal fin was short but extended along the back down to the pointed tail. This suggests it probably swam like an eel, since eels have a similar fin structure. It probably ate crustaceans and other small animals.

Xenacanthus’s spine grew from the back of the skull and, unusually for a shark relation, it was made of bone instead of cartilage. Both males and females had the spine and some researchers suggest that it may have been venomous like a sting ray’s tail spine.

Rays are closely related to sharks, and if you want to see a fish that makes every single weird extinct shark look normal, just look at a sawfish. The sawfish is a type of ray and it’s alive today, although it’s endangered. I’m going to do a whole episode on rays pretty soon so I won’t go into detail, but the sawfish isn’t the only fish alive today with a long snout with teeth that stick out on either side. The sawshark is related to the sawfish but is actually a shark, not a ray. And there’s a third type of fish with a saw, related to both sawfish and sawsharks, called the Sclerorhynchidae. Sclerorhynchids went extinct around 55 million years ago and are considered part of the ray family, although they’re not ancestors of living rays. Sclerorhynchids grew around three feet long, or about a meter, and probably looked a lot like modern sawfish although with a rostrum, or snout, that was more pointed and less broad than most sawfish rostrums. The teeth that stuck out to either side were also relatively small. Researchers think Sclerorhynchids used their saws the same way modern sawfish and sawsharks do, to find small animals living on or near the bottom in shallow water and slash them to death before eating the pieces.

[Jaws theme again]

Most of the shark relatives we’ve talked about so far were pretty small, certainly compared to sharks like the great white or megalodon, which by the way we covered in episode 15 along with the hammerhead shark. But a shark called Ptychodus grew up to 33 feet long, or ten meters. It went extinct about 85 million years ago. Its dorsal fin had serrated spines and its mouth had lots and lots of really big teeth–up to 550 teeth, but they weren’t sharp. Instead, they were flattened with riblike folds that helped Ptychodus crush the mollusks it ate. It probably also ate squid and crustaceans, along with any carrion it might come across. It lived at the bottom of the ocean, but in relatively shallow areas where there were plenty of mollusks but not too many mosasaurs or other sharks that might treat Ptychodus as a nice big meal.

In episode 33, the one about dunkleosteus, we also talked about helicoprion and some of its relations. Helicoprion looked like a shark but was actually less closely related to true sharks than to ratfish. Helicoprion lived until about 250 million years ago and some researchers estimate it could grow up to 24 feet long, or 7.5 meters.

Instead of a weird dorsal fin, helicoprion had weird teeth. Weird, weird teeth. It had a tooth whorl instead of the regular arrangement of teeth, where its teeth grew in a spiral that seems to have been situated in the lower jaw. It looked like the blade of a circular saw. Now, this is bizarre but it’s not really all that much more bizarre than sawfish teeth, which aren’t even inside the mouth and stick out sideways. But the frustrating thing for researchers is that we still don’t have any helicoprion fossils except for the teeth whorls and part of one skull. Like most sharks and shark relatives, almost all of helicoprion’s skeleton was made of cartilage, not bone, and cartilage doesn’t fossilize very well. So even though helicoprion was widespread and even survived the Permian-Triassic extinction event, we don’t know what it looked like or what it ate or how exactly its tooth whorl worked. But I think it’s safe to say that it would not be good to be bitten by helicoprion.

[stop playing the Jaws theme omg]

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

[Jaws theme again]

Episode 121: Cave Dwelling Animals

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This week let’s learn about some animals that live in caves!

The dipluran Haplocampa:

Oilbirds and their big black eyes:

A swiftlet:

The angel cave fish that can walk on its fins like a salamander walks on its feet:

Leptodirus, carrying around some air in its abdomen in case it needs some air:

The cave robber spider and its teeny hooked feet:

The devils hole pupfish:

Show transcript:

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

Way back in episode 27 we learned about some animals that live deep in caves. Cave dwelling animals are always interesting because of the way they’ve adapted to an unusual environment, so let’s learn about some of them!

We’ll start with an invertebrate. Diplurans are common animals that are related to insects but aren’t insects. They live all over the world, with hundreds of species known to science, but most people have never seen one because of where they live. They like moist, dark areas like soil, dead leaves, and caves. They’re also small, usually only a few millimeters long, although a few species grow larger, up to two inches long, or five cm.

Diplurans have long bodies with a number of segments, six legs, long antennae, and a pair of tail appendages called cerci. Depending on the species, the cerci may just be a pair of straight filaments like an extra pair of antennae, or they may look like pincers. Diplurans with pincer-like cerci use them to help capture prey, while ones with antennae-like cerci eat fungi and plant material.

Diplurans also don’t have eyes. They don’t need eyes because they live underground where there’s little or no light. A lot of species are pale in color or lack pigment completely.

Diplurans have been around for something like 350 million years, although we don’t have very many fossil diplurans. But recently, a new species of dipluran was discovered in North America that has raised some interesting questions.

Vancouver Island is a large island on the west coast of Canada, near the city of Vancouver. It’s prone to earthquakes and contains a lot of caves, and last summer, in June of 2018, a party of cavers and scientists explored two of the caves and found a new dipluran, which has been named Haplocampa wagnelli. This dipluran is chunkier than most other known diplurans, with shorter antennae, which researchers think points to a more primitive body plan. Since the dipluran is so different from most other diplurans known, and because the caves where it was found were under a thick ice sheet until around 18,000 years ago, researchers are trying to figure out if it found its way into the caves after the ice sheet melted or if it survived in the caves while they were buried under ice.

Haplocampa seems to be most closely related to a few diplurans found in Asia. Asia was connected to western North America during the Pleistocene when sea levels were much lower, since so much of the world’s water was frozen, so it’s possible the ancestors of Haplocampa migrated from Asia after the ice sheets started to melt but before the Bering Land Bridge was completely submerged. Possibly its eggs were accidentally transported by birds who foraged in leaf litter where its ancestor lived.

A lot of animals that live in caves are only found in one particular cave system. This happens when a species of animal that lives near a cave moves into the cave, either full-time or part-time. As its descendants grow up, they become more and more adapted to cave life, until eventually they couldn’t live outside of the cave. Since there’s no way for them to travel from one cave system to another, they are confined to that single cave. And since caves are largely difficult for humans to explore, that means there are lots and lots and lots of animals unknown to science living out their quiet lives deep within caves where humans have never visited. Every so often a group of adventurous and brave scientists explore a cave and discover new animals, usually with the help of experienced cavers.

Animals that are endemic to a specific cave system are rare to start with and vulnerable to any changes in the cave environment. The Tumbling Creek cave snail is only found in a single stream in Tumbling Creek Cave in Missouri, in the United States. It lives its whole life in the water and is only about 2 millimeters in size, with a pale yellowish shell. When it was first discovered in 1971 it was common. Thirty years later, researchers could only find about forty of the snails due to water pollution.

Caves aren’t very friendly environments. Most of the animals that live in caves are very small as a result. Lots of insects and spiders live in caves, some snails, lots of fish, lots of crustaceans that live in fresh water, like crawdads and amphipods, and some salamanders. But the only mammals and birds that live in caves leave the cave to hunt or forage outside of it, like bats. There just isn’t enough food inside a typical cave to sustain a population of larger animals.

So what do cave animals eat? Obviously they eat each other, but without plants a cave system is definitely lacking in organic matter that can sustain populations of animals. Nutrients enter a cave primarily in two ways. Water flowing into a cave brings nutrients from outside, and animals that mainly live outside but sleep in caves also bring nutrients in. In the case of animals, their poop is a major source of organic material, with dead animals also contributing to the cave’s ecosystem. Bats in particular support a lot of cave animals with their poop, which is called guano, but bears, hyenas, and various other animals, birds, and insects also spend time in caves, either to sleep or to hibernate, and bring nutrients in from outside in one way or another.

There are two birds that spend time in caves, and I’m going to talk about both of them briefly even though technically they don’t live in caves, because they’re so interesting. Both birds are nocturnal and can echolocate like bats. The oilbird lives in parts of northern South America and is related to nightjars. I have a whole episode planned about nightjars and their relatives, but the oilbird is the only one that echolocates (as far as we know). The other bird that echolocates is the swiftlet.

The oilbird nests in caves and also roosts in caves during the day, then flies out at night and eats fruit. Some oilbirds roost in trees during the day instead. Its wings have evolved to allow it to hover and to navigate through tight areas, which helps it fly through caves. It sees well in darkness, with eyes that are arranged more like those of deep-sea fish rather than typical bird eyes.

Several species of swiflet echolocate. These are the birds that make their nests from saliva, and which humans gather to make bird’s nest soup from. They mostly live in Asia. They nest in caves and roost in caves at night, then fly out during the day to catch insects.

Researchers don’t know a lot yet about either bird’s echolocation. It’s audible to human ears, unlike most bat echolocating, and some researchers think it’s less sophisticated than bats’. It’s always possible there are other birds that echolocate, but we don’t know about them yet because maybe we can’t hear their echolocating.

This is what oilbirds sound like. The clicking noises are the echolocation calls.

[oilbird calls]

Cave fish are especially interesting. There isn’t one kind of cave fish but hundreds, mostly evolved from ordinary fish species that ended up in a cave’s water system and stayed. Sometimes the species of fish that gave rise to cave fish are still around, living outside the cave, but most cave fish species have evolved so much that they’re no longer very closely related to their outside ancestors.

Cave fish are considered extremophiles and they tend to have similar characteristics. They usually have no pigment, no scales, and often have no eyes at all, or tiny eyes that no longer function. They’re usually only a few inches long, or maybe 10 cm, and have low metabolic rates. They typically eat anything they can find.

Some cave fish have evolved in unusual ways to better fit their specific habitats. The cave angel fish lives in a single large cave system in Thailand, in fast-moving water. It’s about an inch long, or not quite 3 cm, and gets its name from its four broad fins, which look feathery like angel wings.

It was discovered in 1985 but it wasn’t until 2016 that researchers verified a persistent rumor about the fish, which is that it can WALK on its fins. It has a robust pelvis and vertebral column, and strong fin muscles that allow it to climb rocks to navigate waterfalls.

Other fish navigate waterfalls and other obstacles by squirming and wriggling, using their fins to push them along. But the cave angel fish walks like a salamander. Scientists are studying the way it walks to learn more about how the ancestors of four-legged animals evolved.

The largest cave dwelling animal is the blind cave eel, which grows up to 16 inches long, or 40 cm, although it’s very slender. Since it appears pink due to a lack of pigment in its skin and it has no eyes or fins, it looks a lot like a really long worm. But it’s actually a fish. Not much is known about it, but it’s widespread throughout western Australia and is sometimes found in wells. It lives in caves or underground waterways that are connected to the ocean.

The first insect that was recognized as living only in caves is a beetle called Leptodirus hochenwartii. It was discovered in 1831 deep in a cave in Slovenia, and researchers of the time found it so intriguing that they invented a whole new discipline to study it and other cave animals, known as biospeleology.

Leptodirus has some interesting adaptations to cave living. It has no wings and no eyes, its antennae and legs are long, but the real surprise is its body. Its head is small and the thorax, the middle section of an insect, is slender. But the abdomen is relatively large and round, and the insect uses it to store moist air. Caves tend to be humid environments and Leptodirus has evolved to need plenty of moisture in the air it breathes. But some parts of a cave can be dry, so not only does Leptodirus keep a supply of breathable air in its abdomen, its antennae can sense humidity levels with a receptor called the Hamann organ.

Some spiders live in caves and like other cave dwellers, they’ve evolved to look strange compared to ordinary spiders. The cave robber spider was only discovered in 2010 in a few caves in Oregon. Researchers suspect there are more species of cave robber spider in other cave systems that haven’t been explored yet by scientists.

The cave robber spider is so different from other spiders that it’s been placed in its own family, Trogloraptoridae, which means cave robber. It has hook-like claws on the ends of its legs which it probably uses to capture prey. It spins small, simple webs on the roofs of caves and researchers think it probably hangs upside down from its web and grabs its prey as it passes by. But since no one knows what the cave robber spider eats, it’s anyone’s guess. Researchers have even tried raising the spider in captivity to learn more about it, but it wouldn’t eat any of the insects or other small invertebrates it was offered as food. It starved to death without ever eating anything, so it’s possible it only eats specific prey. It’s a yellowish-brown spider with two rows of teeth, called serrula in spiders, which researchers say is unique among spiders.

It’s also pretty big for a cave dweller. Its body is up to 10 millimeters long, or about a third of an inch, and it has a legspan of about 3 inches, or 7.6 cm. But it’s very shy and rare, and of course it’s not going to hurt you. It literally wouldn’t even hurt a fly to keep itself from starving.

One of the scientists who discovered the spider and is studying it, Charles Griswold, points out that there are stories in the area of giant spiders living in caves. He suggests the cave robber spider might be the source of the stories, since a three inch spider looks much bigger when it’s hanging down from the roof of a cave right in your face, with hooked claws.

Let’s finish with a remarkable cave fish known as the devil’s hole pupfish. Devil’s hole is a geothermal pool inside a cavern in the Amargosa Desert in Nevada, which is in the southwestern United States. It’s not far from Death Valley. The cavern is more than 500 feet deep, or 150 meters, with water that stays at about 92 degrees Fahrenheit, or 33 degrees Celsius. There’s a single small opening into the cavern at the surface, which geologists estimate opened about 60,000 years ago. The cavern and cave system are more than half a million years old.

The geothermal pool is home to the devils hole pupfish, which is barely an inch long, or 25 millimeters, and looks pretty ordinary. It mostly stays around the opening to the surface, where there’s a limestone shelf just below the water’s surface that measures about 6 ½ by 13 feet, or 2 by 4 meters. While the pupfish does swim deeper into the cavern at times, it mostly eats algae that live on and around the shelf, and tiny animals that live within the algae. It also depends on the shelf for laying eggs and spawning.

So the shelf is really important. But it’s also really small and close to the surface. It can only support so many pupfish, so the average devil’s hole pupfish population is about 200 or 300 fish, although this fluctuates naturally depending on many factors. In the 1960s, a farming corporation drilled wells in the area and pumped water out for irrigation, and the water in devil’s hole started to drop and drop. Devil’s hole is part of Death Valley National Monument, and conservationists were well aware of how fragile the pupfish’s environment was. As the water level dropped, threatening to expose the limestone shelf that the pupfish depended on for their entire lives, conservation groups sued to stop the pumping of groundwater in the area. After a series of court cases that went all the way up to the Supreme Court, the water rights were acknowledged to be part of the national monument status. Pumping of groundwater was limited and the pupfish was saved.

The water level in devil’s hole is monitored daily, which has led to a lot of information about how the water is affected by seismic events. Earthquakes as far away as Alaska, Japan, and South America have all affected the water level.

Researchers aren’t sure how long the pupfish have lived in devil’s hole. Some researchers think they’ve been there for 20,000 years, others think it’s more like a few hundred. Researchers aren’t sure how such a small population of fish has stayed healthy for so long, since such a restricted number of individuals should be so inbred they’re no longer viable. The most recent genetic analysis of the pupfish suggests they became isolated from other pupfish species in the area less than a thousand years ago. But if that’s the case, no one’s sure how they got into devil’s hole in the first place. Flooding of the area hasn’t happened in the last thousand years.

Because the pupfish’s habitat is so fragile, the U.S. Fish and Wildlife Service has moved some of the fish into captive populations that mimic the fish’s original habitat. It’s nice to think that these tiny silvery-blue fish with big eyes have so many people working to keep them safe.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 114: The Depths of the Sea of Cortez

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The Gulf of California, AKA the Sea of Cortez, is home to thousands upon thousands of animals, many of them not found anywhere else in the world. New research expeditions in its deep-sea fissures and trenches have turned up some amazing new animals too. Let’s take a look at a few of them!

Thanks to Hally for this week’s topic suggestion!

The lollipop catshark sounds cuter than it is:

The black brotula:

A super creepy grenadier fish. Look at those EYES:

A type of batfish. It uses its stiff fins to walk around on the bottom of the ocean:

Some beautiful hydrothermal chimneys:

Giant tube worms:

Show transcript:

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

It’s been a while since we did a deep-sea episode. This week let’s find out about some strange fish discovered in the Pacific Ocean off the coast of Mexico. Thanks to Hally for the suggestion!

The Gulf of California, also called the Sea of Cortez, is the stretch of water between mainland Mexico and the Baja peninsula. Researchers estimate it started forming over 5 million years ago when tectonic forces separated the strip of land now called Baja peninsula or Baja California from the mainland. It’s still attached to the mainland at its northern edge, where the Colorado River empties into the gulf. The sea is about 700 miles wide, or over 1100 km.

Because the gulf was formed by tectonic forces and undersea volcanos, parts of it are extremely deep—more than 12,500 feet deep in places, or 3,800 meters. It’s full of islands, nearly 1,000 of them, a few of them quite large and some just tiny, some of them volcanic and some not. And it’s rich in ocean life, with many animals found in the Gulf of California that live nowhere else in the world.

For instance, the lollipop catshark! What a cute name. It probably plays ukulele and its best friend plays the xylophone. They should start a band!

The lollipop catshark is actually not super cute, although it is pretty awesome. It’s a small shark, only about 11 inches long, or 28 cm, and it has pinkish gray skin that’s almost gelatinous in texture, although it also has tiny spiky denticles, especially on its back. It gets the name lollipop from its shape. It has a broad head with large gills, but its body tapers to a slender tail so that it’s sort of shaped like a tadpole. Not really lollipop shaped, frankly. Babies are born live instead of hatching from eggs, with a female giving birth to two babies at a time. It eats crustaceans and fish.

The reason the lollipop catshark has such big gills is that it lives at the bottom of the ocean where there’s not much oxygen. The Gulf of California is especially oxygen-poor in its deepest areas, so when a team of scientists sent a submersible to the deepest parts of the gulf in 2015, they didn’t expect to find that many fish or other animals. But not only were there a lot of lollipop catsharks, there were lots of other animals too.

The submersible found the most fish in a part of the gulf called the Carralvo Trough, which is nearly 3,300 feet deep, or 1,000 meters. A few years before, a submersible had discovered the bodies of dozens of dead squid in the trough, and researchers determined that the squid were all females that had laid eggs and then died and sunk to the bottom. The dead squid are usually eaten by scavengers within 24 hours of dying, including crabs and sea stars, brittle stars, and acorn worms, as well as small bottom-dwelling sharks like the lollipop catshark. So it was good timing that the submersible saw so many of them at once.

Another deep-sea animal found in the Gulf of California is the cusk eel. There are lots of species of cusk eel that live throughout the world’s oceans and even some fresh water, and despite the name, cusk eels are fish, not eels. They’re related to cod, although not closely. They live on the bottom of the ocean, usually in shallow water, where they burrow in the sediment and sand at the bottom.

But the cusk eel found in the Carralvo Trough is called the black brotula, and it’s so different from other cusk eels that it has its own genus. The black brotula grows up to 10 inches long, or about 25 cm, and only lives in the depths of the Gulf of California and in some deep areas along the western coast of Mexico and Chile. Not only can it tolerate low-oxygen water, it prefers it. It’s black or dark gray in color–even its intestines are black. And that’s pretty much all we know about it at this point. Cusk eels are generally not very well studied, and the black brotula is hard to study because it lives so deep in the gulf. Researchers don’t even know how it tolerates water with so little oxygen and what it eats down there. We do know that young black brotulas prefer shallower water.

Another deep-sea fish found in the Gulf of California is the grenadier [grin-a-deer]. Grenadiers are some of the most common deep-sea fish in the world, with lots of different species. Some researchers estimate that they may make up as much as 15% of all fish that live in the deep sea. All grendadiers have large heads with big eyes and mouths, slender bodies that taper to such a thin tail that some people call the fish rattail.

The grenadier has barbels under the chin with chemoreceptors on them, and more chemoreceptors on the mouth and head, so it can sense other fish nearby even if it can’t see them. It’s been found as deep as nearly 23,000 feet under the surface, or 7,000 meters, which is just ridiculous. That’s four and a third miles underwater, or seven km. The Gulf of California isn’t that deep, of course, but there are grenadiers swimming around in the deepest areas, eating anything they can catch.

Some grenadiers are eaten, but mostly they have a soft, unpleasant texture and are low in protein. The biggest grenadier, which is common throughout the deep areas of the Pacific Ocean, is the giant grenadier, which can grow to 6 ½ feet long, or 2 meters. It eats vampire squid and other cephalopods. The grenadier most commonly found in the Gulf of California is the smooth grenadier, which only grows to about a foot long, or 30 cm.

A type of batfish that’s common off the western coasts of North, Central, and South America is also found in the deep sea of the Gulf of California. It’s a small type of anglerfish, only about six inches long, or 15 cm, dark in color, with a broad flattened head tapering to a much thinner long tail. Like other anglerfish, it has strong, stiff fins that it uses to crawl around on the ocean floor, where it hunts small animals like polychaete worms and crustaceans as well as fish.

If you look at the pictures I have in the show notes, or if you’ve been paying attention to the descriptions of all these fish, you’ll notice that even though they’re not related, they all share similar features. Their heads are large and usually broad, while their bodies are relatively small with a slender tail. The large head allows the fish to have unusually large gills and eyes, with a broad mouth so it can gulp down any food it finds. You know what this points to? That’s right, convergent evolution, where the fish all share a similar habitat that has influenced certain aspects of the body shape!

Currently, researchers are exploring volcanic vents in the Gulf of California that are the deepest found in the area. The area contains hydrothermal vents, which can heat the water to over 660 degrees F, or 350 degrees Celcius, and cold seeps, which are only called cold because they’re not super heated.

The vents are surrounded by mineral towers called hydrothermal chimneys that are up to 120 feet high, or 37 meters. These deepest vents and chimneys were only discovered in 2015, with others nearby only discovered in 2012. There are two types of chimneys in the area, dark-colored ones that grow the biggest, which are made up of sulfide minerals, and smaller, more delicate ones made up of light-colored carbonate minerals. The only other carbonate chimneys ever found are in the Atlantic. They’re really pretty.

Between the super heated water, the high levels of sulfides and heavy metals from the vents, and the great depth, the area would kill most animal life. But hydrothermal ecosystems are home to extremophiles that thrive in places that are deadly to other animals. The dark-colored chimneys, often called black smokers since they give off plumes of superheated minerals that look like smoke, are home to giant tube worms that can grow nearly eight feet long, or 2.4 meters, although they’re only a little more than an inch and a half wide, or 4 cm.

Giant tube worms don’t have a digestive tract, just a sort of internal pouch to hold the chemosynthetic bacteria that provide nutrients to the worm. The worm gives the bacteria a safe place to live, and the bacteria convert the carbon dioxide, hydrogen sulfide, and other minerals into nutrients that the worm absorbs.

But how do giant tube worms find new hydrothermal vents? Old vents go cold and new ones open up all the time, and giant tube worms can’t move once they’ve attached themselves to a rock or other solid structure. It turns out that newly hatched giant tube worms are free-swimming larvae, and at first they don’t contain any of the symbiotic bacteria that they need later in life. They acquire the bacteria later, when bacteria in the water find the larva and burrow into its skin. The larva swims deeper into the ocean and finds a hydrothermal vent, if it’s lucky, and attaches itself to a rock or something nearby. It then develops rapidly from a larva into the juvenile stage, where its digestive system reforms into a place for the bacteria to live. Then it grows into an adult tube worm.

The carbonate chimneys have a different kind of tube worm that prefers a different range of minerals.

Giant tube worms were only discovered in 1977. No one back then dreamed that anything could live around hydrothermal vents so the team exploring some vents hadn’t even brought along a biologist, just geologists. I like to think that they freaked out when they saw tube worms and other animals living around the vents.

It just goes to show, like they say in Jurassic Park, life finds a way.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 101: Flying Without Wings

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What better way to start out the new year than by learning about some animals that fly (or glide) without wings! Thanks to Llewelly for suggesting the colugo!

Colugo looking startled:

A colugo, flying, which startles everyone else:

Flying fish! ZOOM!

A flying gurnard, not flying:

Flying squid! ZOOM!

Flying squid close-up, mid-zoom:

Show transcript:

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

It’s the first week of a new year, so let’s start it off right and learn about some animals that fly without wings.

The first of our non-winged flying animals is a suggestion from Llewelly, who sent me some links about it and we both freaked out a little because it’s such an awesome animal. It’s called the colugo, and technically it doesn’t fly, it glides. It looks kind of like a big squirrel and kind of like a small lemur, and in fact it’s also sometimes called a flying lemur. But it’s not closely related to squirrels or lemurs. It’s actually not related closely to anything alive today.

Before we learn about the colugo specifically, let me explain a little bit about gliding animals. Gliding animals have a flap of skin called a gliding membrane or patagium. In the case of gliding mammals, like the flying squirrel or the colugo, the patagium connects each foreleg with the hindleg on that side. When the animal wants to glide, it stretches its legs out, which also stretches out the patagium. For a long time scientists assumed that the patagium was just skin and didn’t do anything except increase the animal’s surface area and act as a sort of parachute. But it turns out that the patagium contains tiny muscles like those recently discovered in the membranes of bat wings. And the skin between the fingers of the bat’s forelimbs, which creates the wings, are actually considered patagia. In fact, any gliding membrane, even if it’s part of a real wing, is considered a patagium, so birds actually have them too.

The colugo has a patagium between its legs like other gliding mammals, but it also has a patagium between its hind legs and its tail, and even its fingers and toes are connected with small patagia. It’s the most well-adapted mammal known for gliding, so well-adapted that it can glide incredible distances. One was measured as having glided almost 500 feet in one jump, or 150 meters. This is almost the length of two football fields.

The colugo lives in South Asia and is endangered mainly due to habitat loss. It grows to about 16 inches long, or 40 cm, with a small head, big eyes, and little round ears. It’s gray with some mottled white and black markings that help hide it against tree trunks, and its legs are long and slender. It eats plants. We don’t know a whole lot about the colugo, because it’s shy and lives in the treetops of tropical forests, but what we do know is really weird.

For instance, its babies. If you listened to episode 45 about monotremes, where we also discuss the differences between marsupial and placental mammals, you may remember that placental mammal babies are born mostly developed while marsupial mammal babies are born very early and finish developing outside of the mother, either in a pouch or just clinging to the mother’s fur. Well, the colugo is a placental mammal, but its babies are born extremely early, more like a marsupial. They finish developing outside of the mother, which takes six months or so, and the mother colugo keeps her tail curved up most of the time so that her patagium is wrapped around her babies like a pouch.

The colugo has weird teeth, too. The front teeth, or incisors, are shaped like tiny combs. This is similar to the incisors of lemurs, which look like tiny combs because the lemur uses them as tiny combs to groom its fur. But unlike any other mammal known, some of the colugo’s upper incisors have two roots instead of just one. Why? No one knows.

So what is the colugo related to? For a long time, no one was sure. Researchers even thought it might be a close relation of bats. These days, the two species of colugo make up their own order, Dermoptera. Order is the classification right below mammal so that’s kind of a big deal. While they’re not closely related to anything alive today, researchers place them in the same general group of animals that gave rise to the primates. But they’re about as closely related to rabbits as they are to monkeys.

In 2017 a team of scientists surveying bats in Malaysia picked up a recording of some unusual ultrasonic calls. They weren’t bat calls. Eventually they determined the calls came from colugos in the trees around the microphones, although some researchers have doubts and think the calls may actually be from other animals known to make ultrasonic sounds, like the tarsier. The colugo has been recorded making sounds audible to humans in other studies. There’s no evidence that the colugo uses echolocation like bats do.

Mammals took to gliding very early on. A few years ago, two fossils discovered in China and dated to about 160 million years ago—you know, 100 million years before the dinosaurs died out—show two different species of mammal that were able to glide. We know they could glide because the fossils are so well preserved that researchers can see the patagium between the front and hind legs of both. They’re the earliest known gliding mammals. Both the fossils belonged to a branch of mammals that have completely died out, so they’re not related to the colugo or anything else.

So what other animals fly, or glide, without real wings? You’ve heard of flying fish, of course. Do they really jump out of the water and glide on their fins? They do, and it’s a lot more awesome even than it sounds.

There isn’t just one species of flying fish but over 60, all of them with elongated pectoral fins that act like an airplane’s wings when they jump out of the water. Some species have two pairs of elongated fins. Back in the early 20th century, engineers studied flying fish fins to help design better airplane wings. But the flying fish has a lot of other adaptations that make it good at gliding, including a stiffened body and robust spine, and strong muscles that allow it to jump out of the water at high speeds.

So how well does the flying fish glide? This is where it gets crazy amazing. The longest recorded flight of a flying fish was 1,300 feet, or 400 meters. That’s way better than the colugo. It’s been recorded as reaching 20 feet, or 6 meters, above the water’s surface and flying at speeds of about 45 mph, or 70 km/h. And as if this wasn’t amazing enough, when the fish starts to descend, it can choose to slide back into the water or it can put its tail down and push off against the surface of the water to get back in the air for another glide. It can even change directions when it pushes back off. It will sometimes flap its fins like wings, but so far researchers haven’t found any evidence that this helps it fly. It may just flap its fins to stabilize its flight.

Most flying fish species are fairly small, although the biggest is a respectable 1 1/2 feet long, or about half a meter. Most flying fish live in the ocean, usually in warmer waters, and they’re all extremely slender and streamlined. They mostly eat plankton.

Sometimes flying fish land in boats or even on the decks of small ships. It’s considered a delicacy, with a taste similar to that of a sardine, and many species have started to decline as a result of overfishing.

Gliding flight has evolved in fish more than once in species that aren’t related, so there are more flying fish than there are flying fish, if you see what I mean. No, you don’t. That only made sense to me. The earliest known flying fish is a fossil dated some 240 million  years old, totally unrelated to the flying fish of today. And there are species alive today not related to the various flying fish species that can glide, if not as well as actual flying fish.

One fish that may or may not glide is called the flying gurnard. It’s a bulky fish that grows more than a foot and a half long, or 50 cm, and can weigh four lbs, or 1.8 kg. It lives in the warmer parts of the Atlantic Ocean in shallow coastal areas, where it mostly stays on the seafloor and eats crustaceans, bivalves, and other small invertebrates. It will also eat small fish if it can catch them. It has a face sort of like a frog’s and can be reddish, brown, or greenish, with spots and patches of other colors. But most importantly, its pectoral fins are extremely large, looking more like fan-like wings than fins. The so-called wings are shimmery, semi-transparent, and lined with bright blue. They sort of look like butterfly wings and can be more than 8 inches long, or 20 cm. The fins actually have two parts, a smaller section in front that looks more like an ordinary fin, and the larger wing-like section behind.

The flying gurnard’s popular name refers to its wing-like fins, which it uses to scare potential predators and to walk around on the sea floor with and poke into the sand to find food. But there are stories dating back thousands of years that not only can the flying gurnard jump out of the water to fly, its flight resembles a swallow’s swooping flight. But it’s much too heavy to fly, so those stories are only tall tales. OR ARE THEY? At least one ichthyologist, a Dr. Humphrey Greenwood, reports having seen a flying gurnard leap out of the water, spread its fins, and glide in a controlled manner for a short distance.

The last animal that flies, or glides, without wings is one I bet you would never guess. It’s the flying squid. And yes, I thought it was a made-up animal when I first heard about it. Squid can’t fly! But there one squid that does regularly leap out of the water and glide for short distances.

The Japanese flying squid lives near the ocean’s surface in schools, where it eats fish and crustaceans. Despite its name, it doesn’t just live around Japan but throughout much of the Pacific Ocean. It doesn’t live very long, less than a year, but has a complicated migratory life. Not as complicated as an eel, but pretty complicated. A squid hatches only five days or so after its mother lays the eggs. The baby squid, called a paralarva, eats plankton and doesn’t yet have arms or tentacles, since they’re fused together at first. The fused tentacles split once the baby has grown to about half an inch long, or some 10 mm, which gives you an idea of how tiny it is when it first hatches.

As the baby squid grows, it begins its migration with the other baby squids that hatched at the same time. The migration follows the ocean surface currents and different subspecies have different migration patterns. Males mature first and transfer their packets of sperm, called spermatophores, to the females for later. Then the males die and the females continue their migration back to the same area where they were hatched. They lay a few hundred to a few thousand tiny eggs and then die, leaving the eggs to hatch only a few days later and start the whole process again.

I can hear you thinking, Why yes, Kate, this is all very interesting BUT YOU HAVE NOT TOLD US HOW SQUIDS FLY. Okay, I’ll do that now.

The Japanese flying squid has a mantle, or main part of the body and head, with a pair of fins at the end that stick out quite a bit. Its eight legs and two feeding tentacles are relatively short, shorter than its mantle length of about a foot and a half long in a big female, or 50 cm. Males are smaller. Like all squids and octopuses, the flying squid moves by shooting water out of its siphon, making it jet-propelled. It travels mantle first with the legs trailing behind.

Well, the Japanese flying squid jumps out of the water and shoots through the air this way, with the fins on its mantle helping to stabilize the squid when it’s in the air and keep it flying straight. It also holds its legs and tentacles out so that the membrane between the legs is stretched taut, making a flat surface that it can angle to catch the most air. It can “fly” some 150 feet, or 50 meters, per jump, traveling at about 25 mph, or 11 meters per second. Researchers used to think it only jumped out of the water to avoid predators, but more recent studies show that it’s also a more efficient way to travel long distances than just staying in the water. Oh, and no one knew for sure that the Japanese flying squid could actually fly until about 15 years ago when researchers caught video of it happening.

Like other squids, the Japanese flying squid can change colors and release a cloud of ink to confuse predators. It also has three hearts.

There are other gliding animals and they’re all weird and interesting, so I’ll probably revisit this topic again in the future. In the meantime, if you want to learn about flying snakes, you can go back and listen to episode 56 about strange snakes. Since that’s currently my 8th most popular episode, you may have listened to it already. Thanks.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 096: Strangest Big Fish

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Because there are so many weird fish out there, I’ve narrowed this week’s episode down to weird BIG fish! We’ll cover the smaller ones another time. Thanks to Damian and Sam for suggestions this week!

A manta ray being interviewed by a diver:

A manta ray with white markings:

A mola mola, pancake of the sea, with a diver:

The flathead catfish head. So many teeth:

A Wels catfish with Jeremy Wade:

A couple of red cornetfish:

Howick Falls in South Africa. Put that on my endless list of places I want to visit:

Further reading:

Karl Shuker’s blog post about the black and white manta rays

Show transcript:

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

It’s another listener suggestion week! Recently, Damian sent a list of excellent topic suggestions, one of which was weirdest fish, and I am ALL OVER that! But because there are so many weird fish, I’m going to only look at weird humongous fish this time, including a mystery fish.

We’ll start with a fish that doesn’t actually look very fishlike. Rays are closely related to sharks but if you didn’t know what they were and saw one, you’d probably start to freak out and think you were seeing some kind of water alien or a sea monster. The ray has a broad, flattened body that extends on both sides into wings that it uses to fly through the water, so to speak. The wings are actually fins, although they don’t look like most fish fins. Like sharks, rays have no bones, only cartilage. Rays are so weird that I’m probably going to give them their own episode one day, but for now let’s just look at one, the manta ray.

There are two species of manta ray alive today. The reef manta can grow 18 feet from wingtip to wingtip, or 5.5 meters. Manta birostris is even bigger, up to 29 feet across, or 8.8 meters, which is why it’s called the giant manta ray. This is just colossally huge. I didn’t realize how big manta rays were until just now. Both species live in warm oceans throughout the world and both eat plankton, krill, and tiny fish. Sometimes the manta ray is called the devil fish because of its horns, which aren’t horns at all, of course. The two protuberances that stick forward at the manta ray’s front are actually fins that grow on either side of the rectangular mouth. These fins help direct plankton into the mouth. When the manta ray isn’t feeding, it can roll up these fins into points and close its mouth. Its eyes are on the sides of its head.

Manta rays are white underneath and black or dark brown on top. But there is a mystery associated with the giant manta ray, with reports of black and white striped rays dating back to at least 1923. In April of that year, naturalist William Beebe spotted a manta ray near the Galapagos Islands that had white wingtips and a pair of broad white stripes extending from the sides of the head halfway down the back. Beebe thought it might be a new species of manta ray. There are other reports of manta rays with white or grayish V-shaped markings on the back.

Better than that, in the last few decades divers and boaters started to get photographs and even video of these manta rays with white markings. These days, manta rays with white markings are known to be common, although for decades scientists thought all manta rays were unmarked dorsally, or on the back. Since the markings are unique to individuals, it makes it easy for researchers to track individuals they recognize. The manta ray also sometimes has black speckles or blotches on its belly.

But wait, there’s more! According to zoologist Karl Shuker, in 2014, researchers in Florida published a paper discussing the ability of manta rays to actually CHANGE COLOR in minutes when they want to. The color in question that it changes? Its white markings. The markings can be barely visible against its background color, and then will brighten considerably when other manta rays are around or when it’s feeding. I’ll put a link to Shuker’s blog post in the show notes, which contains an excerpt from the article, if you want to read it.

The reef manta mostly lives along coasts, especially around coral reefs, while the giant manta ray sometimes crosses open ocean. Researchers used to think it migrated, but new studies suggest most don’t travel all that far. It does dive deeply, though, sometimes as deep as 3,300 feet, or 1,000 meters.

Another fish with a mostly cartilaginous skeleton instead of bone are the various species of ocean sunfish. The largest is the mola mola, although the southern sunfish is about the same size. Both grow to about 15 feet long, or 4.6 meters, and they are really, really weird.

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. 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.

Because it’s almost round in shape and its body is flattened, it actually kind of looks like a pancake with fins. I would not want to eat it but a lot of people do, with the fish considered a delicacy in some cuisines. These days it’s a protected species in many areas, but it often gets caught in nets set for other fish. It also ends up eating plastic bags and other trash that float like jellyfish.

The mola mola 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. 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. Occasionally it will jump completely out of the water, called breaching, as far as ten feet high, or 3 meters. Since the mola mola is one of the world’s heaviest fish that isn’t actually a shark or ray, sometimes weighing over two tons, or 2,000 kg, you really don’t want to be in a boat near a breaching mola mola. If it lands in your boat, it could sink you, or just squash you as flat as a finch under a giant tortoise.

Some researchers think the mola mola’s internal organs contain a neurotoxin—not a surprise since it’s related to the pufferfish—but we don’t know a whole lot about it yet and other researchers say it’s not toxic at all. Until recently researchers thought it only ate jellyfish, but more recent studies show that jellies only make up a small part of its diet. It feeds near the surface at night, but during the day it dives deeply, warming up between dives by sunning itself at the surface. Instead of a swim bladder, it has a layer of a jelly-like substance under its skin that helps make it neutrally buoyant.

The mola mola looks like it has no tail because it actually has no tail. Its little tail fin is called a pseudotail, or false tail. At some point during its evolution it lost its real tail. As a result, it has fewer vertebrae than any other fish, only 16. It’s a slow and clumsy swimmer but its size means it doesn’t have many natural predators beyond orcas and large sharks. It can grind its teeth together to make a croaking sound when it’s in distress. It can also blink, unlike most fish, and can retract its eyes deeper into their sockets to protect them.

In 2017, a new species of sunfish was named, the hoodwinker sunfish, Mola tecta. It grows up to ten feet long, or 3 meters, and is smooth and silvery with speckles. It’s really pretty. It lives in the southern hemisphere and that is pretty much all we know about it so far.

From the gentle giants of the sea, the manta ray and the mola mola, let’s move on to a weird freshwater fish that’s a lot scarier-looking. A few years ago, the Tennessee Aquarium in Chattanooga, which is an awesome place that is well worth a visit if you’re in the area, was contacted by a man whose dog had found and was chewing on a hideous fish head. It had a wide grinning mouth full of rows and rows of short sharp teeth. He wanted to know what it was, naturally, because while it looked like a catfish, he’d never seen one with teeth.

It turns out that the flathead catfish does have teeth, and that’s what his dog had found. It’s native to parts of the southeastern United States into northern Mexico, but has been introduced in other places as game fish and can become an invasive species. It can grow really big, with the longest specimen ever caught measuring almost six feet long, or 1.75 meters, and weighing just shy of 140 lbs, or 63.45 kg. It eats fish, insects, crustaceans, and pretty much anything else it can catch. It’s yellowish or even purplish in color. The weird thing is that all the descriptions I read of the flathead catfish mentioned how big it is and how people like to fish for it, and how it is supposed to be the best-tasting catfish, but they don’t mention its horrifying teeth! I was going by the picture posted by the Tennessee Aquarium, sent in by the guy whose dog found the ultimate chew toy. That picture made the teeth look vicious. But I found a description of the teeth finally that said they’re more like sandpaper to human hands if you hold the fish correctly, possibly because the teeth are packed so tightly. I don’t want to put my fingers in a fish’s mouth for any reason, teeth or no teeth.

Big as it is, the flathead isn’t the biggest catfish in the world. That would be the Wels catfish, a topic suggestion by Sam. Thank you, Sam! The first time I heard about the Wels catfish was from the show River Monsters, where the fisherman Jeremy Wade caught several. I hope everyone listening finds a special someone one day who looks at them the way Jeremy Wade looks at gigantic fish. I love that show. The Wels catfish is native to parts of Europe but like the flathead catfish, it’s been introduced as a game fish in other areas and has become an invasive species.

Like other catfish, the Wels has a skin with no scales, but instead is protected by a layer of slime that has antibacterial properties. This is true for the manta ray and the sunfish too, in fact. It also has barbels that give catfish the name catfish, since the barbels look a little like whiskers. The barbels act as feelers and contain chemical receptors that help the fish taste potential prey in the water.

The Wels catfish likes warm, slow-moving water and can grow up to 16 feet long, or 5 meters, although most are much smaller. It has lots and lots of small teeth but it generally swallows its prey whole, sucking it into its big mouth. It eats fish, crustaceans, insects, worms, and anything else it can catch, but bigger ones will eat frogs, rats, even ducks and other birds. On occasion a Wels will come out of the water to catch a bird on land, but this behavior seems to be from fish that have been introduced to rivers and lakes that aren’t in its native range. The wels is also rumored to drown people and even eat them. There are reports of Wels catfish grabbing anglers by the leg or arm and dragging them into the water.

The red cornetfish lives throughout the world in tropical oceans, although young fish may live in the mouths of rivers that connect with the sea. It’s a long, skinny fish that can grow up to six and a half feet long, or 2 meters, but barely weighs more than ten pounds, or 4.7 kilograms. It can be red, orange, brownish, or even yellowish, sometimes with white or dark stripes or blotches. There’s some evidence that it can actually change its color to match its background. It also has a row of bony plates along its back.

The red cornetfish eats small squid, shrimp, and fish, which it’s able to sneak up on because it’s so incredibly thin. Basically, if it’s swimming straight toward you, all you see is a dot with two bulges for eyes. It also sneaks up on prey by hiding behind harmless fish that are fatter than it is, which is every fish.

The red cornetfish is related to pipefish and seahorses, and like those fish it has a long, pipe-like snout with a tiny mouth at the end that gives it its other common name, flutemouth. Its teeth are also tiny. At the end of its tail, a whip-like filament grows past the tail fin that extends the lateral line, which is a row of sensory cells that helps a fish detect the movements of other fish in the water.

Finally, let’s finish up with a mystery fish from South Africa. It’s called the inkanyamba and is supposed to be some twenty feet long, or six meters. It lives in lakes and near waterfalls and is generally supposed to look like a snake or eel with a horselike head.

The inkanyamba seems to be associated with storms and other severe weather, an association that goes back untold centuries to cave paintings of what are known as rain animals. So it could be that the inkanyamba is like the thunderbird, a creature of spiritual belief rather than a physical one. Groups such as the Xhosa and the Zulu believe that Inkanyamba is a giant winged snake that appears as a tornado as he flies around looking for his mate, who lives in a lake. Houses with metal roofs that aren’t painted are in danger from Inkanyamba since he might mistake the roof for water.

Then again, there are sightings. In 1962 a park ranger saw an eel-like or snake-like creature on a sand bank along the Umgeni River, which slithered into the water as he approached. Another witness sighted the monster twice near Howick Falls in 1971 and 1981. He said it was thirty feet long with a crest along its neck. The waterfall known in English as Howick Falls in South Africa is sacred to the Zulu, who believe it’s the home of Inkanyamba. It’s 310 feet high, or 95 meters, and is situated on the Umgeni River. The only people who are traditionally allowed to approach the pool at the base of the falls, or who can safely approach it, are sangomas, or traditional healers.

One suggestion is that the inkanyamba is a giant mottled eel, which has fins that run all around the tail like a crest. But it only grows to about six and a half feet long at most, or 2 meters. This is pretty big, but not anywhere near twenty or thirty feet. It eats fish, frogs, crustaceans, and other small animals, and isn’t dangerous to humans. It’s nocturnal, spends most of its time at the bottom of the lakebed or riverbed, and migrates from fresh water into the ocean to spawn and lay eggs. You may remember this from episode 49, which goes into the complicated details about eel migration.

I’m not convinced that Inkanyamba is an eel, even a big one. I think it’s more a creature of legend. If you’re lucky enough to visit Howick Falls, don’t get too close to the water, out of respect for a sacred place and just in case there’s something there that could eat you up.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 081: Little Yard Animals

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This week we’re staying at home and looking around our own yards and gardens to learn about some of the little critters we see every day but maybe never pay attention to. Thanks to Richard E. for the topic suggestion, and thanks also to John V. and Richard J. for other animal suggestions I used in the episode!

The common or garden snail:

A couple of robins:

A brown-eared bulbul nomming petals:

An Eastern hognose snake. srsly, no one believes ur dead snek:

The hognose in happier times:

An Australian water dragon. Stripey!!

The edible dormouse. I think you mean the ADORABLE dormouse:

The eastern chipmunk:

A guppy with normal eyes:

Show transcript:

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

I’m out of the country this week, visiting Paris, France and undoubtedly eating my weight in pastries and cheese as you listen to this. Since I’m away from home, though, I’m probably feeling a little homesick. So this week’s episode is all about the ordinary-seeming little animals found in gardens and yards, a suggestion from Richard E. This is also a perfect opportunity to feature some listener-suggested animals that aren’t really complex enough for a full episode but are still really interesting.

But I’m not going to just look at the animals in my yard. Depending on where you live, hopefully I’ll touch on one or two animals you might be able to see for yourself just by going outside and looking around.

It sounds corny, but no matter how boring you think the nearest patch of greenery is, if you look closely enough you’ll see a world of activity. The other day I was sitting on a bench outside the library, enjoying a breeze and the shade of an oak tree, and because I am sort of disgusting and was wearing flip-flops, I was picking at one of my toenails that was partly broken. I pulled the broken part off and flipped it into the grass nearby. A few minutes later I noticed that a couple of ants had found that piece of toenail and were working hard to wrestle it over the grass and twigs and presumably back to their home. Why? Why did they want my toenail? It’s just a piece of keratin, and while keratin is a type of protein, it’s not digestible by most animals.

I looked it up, and guess what. I am not the first person to notice this. No one’s sure why ants take toenail and fingernail clippings, either. They’re not interested in hair, just nails. Hair and nails have different properties so it’s possible the ants are able to digest the keratin in nails but not the keratin in hair.

That was probably not the best story to start with. Try to forget that picture of me and remember that I’m sipping wine at a sidewalk café in Paris right now, or touring the Louvre.

Let’s move on to a small invertebrate that is sometimes eaten as a delicacy in France and other parts of Europe, the common or garden snail. That’s Cornu aspersum, which is native to the Mediterranean and western Europe, but which has been introduced in other parts of the world. It’s pretty big for a snail, with a shell almost 2 inches across, or 5 cm. The shell varies in color and pattern, but it’s usually brown with yellow markings.

The shells almost always coil to the right, or clockwise, but the occasional rare snail will have a left-coiling shell. Researchers have found that left-coiling shells are due to a genetic mutation and only occur about once in a million snails. A famous lefty snail was called Jeremy, who died in October 2017 at the ripe old age of two years. Since snails are hermaphrodites who both fertilize other snails’ eggs and lay their own, a boy name seems like a random choice. Jeremy was discovered by a retired scientist in his London garden, who gave the snail to the University of Nottingham for study. After a public appeal, two other left-handed snails were found by the public, but while the three snails all laid eggs, all the babies had clockwise shells.

The garden snail mostly eats plants, but will sometimes scavenge on small dead animals like drowned worms and squished slugs. When it’s threatened, it can pull itself all the way into its shell, and if it’s too dry out, it will pull itself into its shell and secrete a thin layer of mucus, which dries out to form a seal.

Snails raised to be eaten are kept in special cages, traditionally made from wine-grape vines. I am probably not going to eat any snails while I’m in France, but you never know. I will let you know if I do.

One animal Richard E. suggested as a topic is the robin, specifically the difference between the American robin and European robin. That’s a good one for this episode, because in both North America and Britain, the robin is a really common bird—so common that most people barely pay any attention to it.

The American robin is a type of thrush. It lives year-round in most of the United States and part of Mexico, spends summers in much of Canada, and winters in parts of Mexico. It’s big for a songbird, around 10 inches long, or 25 cm. It’s dark gray on its back, with a rusty red breast, white undertail coverts, and a long yellow bill. It also has white markings around its eyes. Young birds are speckled. It mostly eats insects, worms, and berries. If you see a bird on the ground, running quickly and then stopping, it’s probably a robin. Mostly the robin hunts bugs by sight, but it has good hearing and can actually hear worms moving around underground. You can sometimes see a robin with its head cocked, listening for a worm, before pouncing and pulling it out of the ground, just like in a cartoon.

American robin eggs are a light teal blue, so common and well-known that robin’s-egg-blue is a typical description of that particular color. In the spring after eggs hatch, the mother robin will carry the eggshells away from the nest to drop them, so predators won’t see the shells and know there’s a nest nearby. That’s why you’ll sometimes see half a robin eggshell on the sidewalk. It doesn’t mean something bad happened to the baby, just that the mother bird is doing her job. Both parents feed the chicks, and the parents also carry off the babies’ droppings to scatter them away from the nest.

This is what an American robin’s song sounds like. If you live in North America, you’ve probably heard this song a million times without noticing it.

[robin song]

The American robin was named after the European robin, also called the robin redbreast, but while the European robin does have a rusty red breast, it doesn’t look much like the American robin. The European robin is much smaller, only around 5 inches long, or 13 cm, with a brown back, streaked gray or buff belly, and orange face and breast. It has a short black bill and round black eyes. It eats insects, worms, berries, and seeds. The eggs are pale brown with reddish speckles.

It lives throughout much of Eurasia, but robins in Britain tend to be fairly tame, probably because they were traditionally considered beneficial in Britain and Ireland, so farmers and gardeners wouldn’t hurt them. In other parts of Europe they were hunted and are much more shy. European robins are also common on Christmas cards in Britain and Ireland, possibly because in the olden days, postmen used to wear red jackets. They started to be called robins as a result, and since postmen bring Christmas cards, the bird robin became linked with card delivery and finally just ended up on Christmas cards. Plus, their orange markings are cheerful in winter. And, of course, in the traditional story Babes in the Wood, which is often associated with Christmas pantomimes, robins cover the children’s dead bodies with leaves. Because nothing says Christmas spirit like a story about dead children.

This is what the European robin sounds like. If you live in Britain or parts of Europe, you’ve probably heard this song a million times without noticing it.

[other robin song]

Another common bird in gardens, this one from Japan and other parts of Asia, is the brown-eared bulbul. It’s about the size of the American robin, around 11 inches long, or 28 cm, including its long tail. It’s gray or gray-brown all over, with a speckled breast and belly, a sharp black bill, and a dark brown spot on the sides of its head that gives it its name. It mostly eats plants, including fruit, seeds, flowers, and even leaves. I have a picture in the show notes of one chowing down on a flower, just swallowing petals like it’s in a video game and petals give it a power-up. It likes nectar too, and in spring and summer especially will look like it has a yellow head or yellow markings because of all the pollen on its feathers. It helps pollinate plants as a result. It also sometimes eats insects. It gathers in large flocks at times and many farmers consider it a pest, especially fruit farmers.

It has a loud song and call that many people dislike. I’ll let you decide, if you’re not already familiar with it. I kind of like it, to be honest. This is what a brown-eared bulbul sounds like:

[brown-eared bulbul call]

Listener John V. recently suggested the Eastern Hognose snake for an episode, and tickled me because he referred to it as the “dramatic hognose snake.” The hognose is a common snake in many parts of North America, and can grow almost four feet long, or 116 cm, although about half that length is much more average. Its snout turns up like a little snub nose. It varies in color and pattern, and some snakes are black or gray, some orange, brown, even greenish. Some snakes have no pattern, some snakes have various colored blotches or even a checkered pattern. The belly is usually yellowish but is sometimes gray or almost white. It has a big head that makes some people believe it’s venomous, but it’s actually harmless to humans and most animals.

The only animals that really need to worry about the Eastern hognose are amphibians, like toads and frogs. As it happens, the hognose does have mild venom, but it’s only effective on amphibians. It especially likes to eat toads, and while some toads are toxic, the hognose snake is resistant to toad toxins. A toad will frequently puff itself up to make it appear larger and make it hard for a snake to eat, but the Eastern hognose has a solution for that too. It has big teeth at the rear of its upper jaws, like fangs in the back of its mouth. It uses those teeth to puncture puffed-up toads so they deflate.

But the most memorable thing about the Eastern hognose, and the thing that earns it the drama snake award, is what it does when it feels threatened. Phase one of the dramatics is aggression. The snake will flatten its neck to look more threatening, raise its head like a cobra, and hiss and strike—but without biting. It’s just trying to scare you away. If that doesn’t work, the snake puts phase two into effect. It will flop down and roll onto its back, its tongue hanging out, and emit a foul musky smell from its cloaca, and play dead. If you call its bluff and roll drama queen snake onto its belly, it will turn onto its back again. It is really insistent that it is dead.

A common reptile visitor to yards in Australia is the water dragon. Of course Australia would have a little dragon running around in suburban neighborhoods. Males can grow up to three feet long, or a little over a meter, with females smaller, but those lengths include a tail that’s almost twice the length of the body. Males are more brightly patterned than females. It’s a long-leggedy lizard with a spiky crest along its head and spine. It’s generally a pale greeny-grey with dark stripes, especially on the tail and legs, or gray with white stripes. Depending on the species and individual, it may also have a colorful blotch on the throat, usually white or yellow, but sometimes orange or red.

It’s a fast runner and can even run on its hind legs if it really needs to hurry. It climbs trees well, but it especially likes water and is semi-aquatic. Its long tail helps it swim. It likes to bask on branches overhanging the water, and if something threatens it, it drops into the water, where it hides. It can stay underwater without needing to take another breath for over half an hour. It eats small animals like frogs and worms, crustaceans and mollusks, insects, fruit, and plants.

In areas where it gets cold in winter, such as Sydney, the water dragon will dig a burrow if it doesn’t already have one, close the entrance off with dirt, and hibernate until spring, when it emerges and starts searching for a mate. Males sometimes fight each other, biting and scratching. Once the weather is warm, the female lays 6 to 18 eggs in a hole she digs in sandy soil.

Water dragons will visit yards if there’s cover and a water source nearby, whether it’s a creek or just a dog’s water bowl. Don’t try to pet one, though. Dragons bite.

Now let’s look at a couple of common rodents. The edible dormouse lives throughout much of western Europe and is big, about the size of a squirrel, which it also roughly resembles. It’s grey or grey-brown with paler underparts. In autumn when it’s preparing for hibernation it gets very fat, which is why it’s also called the fat dormouse. The name edible dormouse comes from the Romans, who used to farm them in captivity and eat them as a delicacy. In some parts of Europe, especially Slovenia, wild edible dormice are still trapped and eaten.

The edible dormouse lives in dense forests, caves, and people’s attics, where it can be a real pest. It eats plants, especially fruit and nuts, but will eat bark and leaves, and sometimes bird eggs and insects. It especially likes beech tree seeds. It’s mostly nocturnal. Unlike most rodents, it doesn’t always breed every year.

If a predator grabs the edible dormouse’s tail, the skin and fur will slide off, allowing the dormouse to escape. The exposed tail vertebrae later break off and the wound heals up, making the tail shorter. That is kind of horrifying.

Chipmunks are rodents common throughout North America, although the Siberian chipmunk lives in Asia. The Eastern chipmunk is the one I’m going to talk about today, primarily because I got audio of one calling this morning on my way to work. I spilled coffee all over myself to get the audio, so I definitely want to share it.

The chipmunk is larger than a mouse but smaller than a squirrel. It has reddish-brown fur with stripes down its sides, a white band in between two thinner black bands. It prefers woodlands with lots of brush and rocks to hide in, but it lives in parks, yards, and definitely all over the college campus where I work. It climbs trees well but mostly it stays on the ground. It digs complex burrows with tunnels that can be more than 11 feet long, or 3.5 meters. It even digs a special latrine burrow to keep droppings out of the rest of the burrow system, and will throw nut shells and other trash into the latrine too. When it’s digging a new tunnel or burrow, it carries the dirt it’s dug away from the tunnel entrance in its cheek pouches, so predators won’t notice newly dug soil and come to take a look.

The chipmunk is omnivorous, and eats everything from bird eggs, worms, snails, and insects to seeds, nuts, and mushrooms. It even eats small animals like baby mice and nestling birds. It carries food in its cheek pouches to store for the winter, and helps disperse some plants as a result. It doesn’t hibernate, but in winter it spends most of its time sleeping, which is pretty much what I like to do in winter too.

THIS is what an Eastern chipmunk sounds like! A cup of coffee died to bring you this audio:

[chipmunk sound]

Our final animal isn’t something you’d typically find in your yard or garden—but you might find it in your house, if you have a freshwater aquarium: the guppy. A different Richard suggested this animal, specifically my brother Richard. He texted me a while back about Poecilia reticulata, a “common aquarium fish that can turn its little eyes black.” Then we texted back and forth about how that would be a really neat superpower, and how we would apply it in our lives if we could turn our eyes black.

The guppy is a tropical fish native to parts of South America, although it’s been introduced into the wild in other parts of the world and is an invasive species in many places. In the wild it eats algae, insect larvae, and various tiny animals. It’s usually between one and two inches long, or 3 to 6 cm, with females being larger. Females are gray or silvery in color, while males are gray with spots of bright color. Aquarium enthusiasts breed different strains of guppy that may have bright colors and striking patterns.

So does the guppy turn its eyes black? Yes, it really does. Most of the time guppies have silver eyes, but some species can change their eye color in only seconds. In the wild, guppies that live in dangerous areas with many predators tend to group together and cooperate. But guppies that live in safer areas tend to be loners and more aggressive toward each other. When a guppy is angry at another guppy, it turns its eyes black to indicate that it’s willing to fight. Other guppies may back off at that point, or if the other guppy is bigger, it may attack. Researchers don’t know yet how guppies change their eye color.

Until next week, when I’m home from Paris and hopefully caught up on my sleep, remember to look around at the strange little animals in your own backyard. But watch out if their eyes turn black.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!