Strange Animals Podcast

This week let’s look at the work of a really astonishing number of spiders!

Further reading:

Megaweb!

Some of the webs:

Show transcript:

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

Baltimore, Maryland is a city in the northeastern United States, in North America, with a population of 2.8 million people. In 1993 a new wastewater treatment plant was built called the Back River Wastewater Treatment Plant, which filters water through big sand beds to trap any particles remaining in it after it’s been filtered and treated in other facilities. The plant consists of 48 big sand beds with a corridor down the middle, and in order to keep the sand beds as clean as possible, the whole area has a big metal roof over it held up with steel columns. It doesn’t have walls, though, just a roof. The whole thing covers four acres, or 1.6 hectares, which I think is a metric term. It’s just over 16,000 square meters. It’s big, in other words, and the roof is pretty tall, up to 24 feet high over the walkway, or 7.5 meters.

Obviously, I’m telling you about this place in detail because of an animal that got into the water treatment plant and caused a lot of alarm. It wasn’t a big animal like a bear, though. It wasn’t even a dangerous animal. It was, in fact, a really small animal that’s mostly harmless to humans, various species of orbweaver spider. The problem wasn’t the spider itself but just how many spiders were in the water treatment plant.

The plant had always had problems with lots of orbweavers, but in 2009 there were so many spiders that the workers were worried for their safety. In late October 2009, the managers called for help about “an extreme spider situation.” The problem was way beyond anything that an ordinary pest control business could deal with, so the city put together a team of arachnologists, entomologists, and experts in urban pest control to figure out the best course of action.

The team didn’t just charge in, say, “Wow, that’s a lot of spiders, let’s hose the whole place down.” They were scientists and studied the situation methodically. They consulted the architectural plans of the plant to determine just how much volume was available under the roof, they took samples of the webs and stored them for study, they took over 300 photos, and basically they got as much data as they could.

There were so many spiders that their webs blended together into thick mats that filled almost every space the spiders could reach. These cobweb mats were attached to the rafters, the walkways, everywhere, with the older mats starting to detach and fray. Light fixtures hung down from the tallest point of the roof that were 8 feet long, or 2.44 meters, and there were so many webs attached to them that they were pulled out of alignment. And all the webs were filled with spiders.

The spiders in the web samples were removed and preserved, then examined to see what species they belonged to. The team identified specimens from nine genera in six families, but most of the spiders caught were the species Tetragnatha guatemalensis. This is a type of long-jawed orbweaver native to North and Central America. Females are much larger than males, with a legspan up to 2 inches across, or about 5 cm. Long-jawed orbweavers have long, thin bodies, and one of the ways it hides is by stretching out on a blade of grass or a twig with its legs out straight. It especially likes marshy areas, such as in the rafters above 48 giant sand beds full of water.

A conservative estimate of the number of spiders in the Back River Wastewater Treatment Plant in the first week of November, 2009 was 107 million. 107 million spiders! Since a big percentage of the spiders were newly hatched, there were probably a lot more in the facility than the scientists estimated from the samples they took, so there might easily have been several hundred million spiders total. The sheets of webbing in the ceiling covered an estimated 2 acres total, or about 8,000 square meters, while the cloud-like masses of webbing in other areas was about half that size and would have filled 23 railroad boxcars.

The really interesting thing is that orbweaver spiders are usually solitary. Spiders may build webs near each other, but not usually like this. But these orbweavers lived in a place protected from wind and weather, and close to water, which attracted lots of midges and other small insects, and the presence of humans probably kept a lot of potential spider predators away, like birds. Life was good for these spiders and the scientists observed that they weren’t acting aggressively to each other, even when they were of different species.

After studying the water treatment plant and its spiders, the team came to several conclusions. Since the spiders are harmless to humans, and are doing a really good job controlling the midge population, the scientists decided that pest control was not necessary and would even be a bad idea since the pesticides would inevitably get into the water. Instead, they recommended that web removal be implemented as a normal course of action when the webs started building up too much. They even suggested that the workers should be proud of their record-breaking webs, and that the plant was an ideal site for scientists to study the spiders in detail.

Thanks for your support, and thanks for listening!

DRAMA! Bird drama! Here are some further-reading links if you want to verify that I’m not vilifying anyone:

Buff-breasted Buttonquail: An image claimed to be of this species revealed

Buff-breasted Buttonquail: Smoke & Mirrors

A review of specimens of Buff-breasted Button-quail Turnix olivii suggests serious concern for its conservation outlook

A painted button quail:

Show transcript:

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

Back in episode 136 we talked about the button quail, because that episode was about tiny animals and the button quail is really tiny. But let’s revisit the button quail this month, because we have a mystery associated with a particular species of button quail.

Button quails generally live in grasslands and are 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 short little tail. It eats seeds and insects along with other small 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, while in others her 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 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.

The various species of button quail live in different areas, including Africa, Asia, and Australia. The species we’re talking about today is the buff-breasted button quail, which is native to one small area of Queensland, Australia. It grows about 9 inches long, or 23 cm, which is big for a button quail, most of which are closer to the size of sparrows, and it’s reddish-brown with darker and lighter speckles. It’s critically endangered due to habitat loss and introduced animals like cats and cattle. There are only an estimated 50 individuals alive today.

But that’s only an estimate, because no one has actually for sure seen a buff-breasted button quail since 1922. Also, I’m going to call it the BBBQ from now on because that name is hard to say.

The 1922 specimen was shot by a naturalist who was collecting specimens for a museum, which was regrettably common at the time and led to a lot of endangered species being driven to extinction. The bird was already rare in 1922 and that was the last anyone saw of it until 1985, when someone reported seeing one. People flocked to the area in hopes of spotting it, but while there were lots of sightings, no one got a good picture of a BBBQ. All the pictures, and all the recordings of its calls, turned out to be of another species of button quail, a very similar bird called the painted button quail.

It’s been 100 years since the bird was last seen, so while we have lots of museum specimens, we don’t have any modern sightings. That means two things. Either the buff-breasted button quail is probably extinct…or it never actually existed in the first place.

There are two other species of button quail that live in the same areas where the BBBQ is found, the painted button quail and the brown quail. They’re smaller but otherwise look very similar, especially the painted button quail. Maybe people were mistaking larger individuals of painted button quails as a different species.

In 2018, a team of scientists from the University of Queensland conducted a search for the BBBQ. All they found were painted button quails. But they discovered something surprising that had never been documented before. During the breeding season, the female painted button quail’s feathers are much more reddish-brown, while the rest of the year the feathers on her back are more gray-brown.

The team also studied as many BBBQ skins as they could track down from museums, where they learned something else surprising. It turns out that it’s not any larger than the painted button quail, which grows up to 8 inches long, or 20 cm. So the birds are the same size and during part of the year, they have almost identical plumage. Hmm.

That doesn’t mean the buff-breasted button quail never existed. One very distinctive difference between the painted and the buff-breasted species is eye color, with the former having red eyes and the latter having yellow. As far as I know a genetic study hasn’t been carried out on the museum specimens, but it’s likely that at least some of the specimens—maybe all of them—really are BBBQs. Scientists and bird enthusiasts are still looking for the bird, and that has led to a strange controversy.

In early 2022, a naturalist named John Young published a photo on Facebook of what he said was a male buff-breasted button quail on a nest, a photo taken by a camera trap in a secret location. The location had to be secret so that no one would try to find the birds and scare them away or damage a nest. Young said he had 16 other photos of BBBQs but wasn’t going to share them until he was ready to publish his findings. He was also raising money to continue his studies at the site.

Another naturalist thought there was something fishy about the photo. He discovered that the picture is actually a cropped and flipped photo of a painted button quail bird and nest reportedly taken at a different site—published in 2018 by John Young himself and labeled by him as a painted button quail. Young had reused one of his own photos and assumed no one would notice.

But it gets worse. Back in 2013, Young got photographs of another extremely rare Australian bird, the night parrot. One day we’ll have an episode about it. It was such a big deal that he was offered a job by the Australian Wildlife Conservancy, or AWC, to study the night parrot and the buff-breasted button quail. He documented sightings and produced photos of both birds, but he didn’t stay in that job too long. That’s because some people started getting suspicious of his parrot photos. After an inquiry into the night parrot photos, the AWC concluded that the eggs in a photo of a night parrot nest were probably fake.

And Young’s dubious photos go back even farther. In 2006 he claimed to have discovered a new species of parrot in Queensland, but while initially the Queensland government supported learning about the new species, it withdrew its support when the photo turned out to be…suspicious. It looked like Young had altered the coloration of a bird to make it look like a new species. When an expert requested the original photographs, Young said he’d deleted them.

More recently, the 2018 painted button quail photo and the supposed 2022 BBBQ photo were examined by a forensic photography expert. Young had removed the metadata from both so no one could tell where they were taken, but there’s a little white stone in both pictures that’s identical, along with many other identical details.

The problem with fake sightings and photographs is that it’s actually making things worse for the buff-breasted button quail. The AWC and other conservation groups are trying to get the bird listed as endangered, which means funding for research and conservation. Now all that is in jeopardy because it’s not clear if there have actually been any sightings of the bird at all.

Hopefully the buff-breasted button quail is still around and someone will get genuine photos of it soon so it can be protected and studied. That’s assuming it’s a real bird in the first place.

Thanks for your support, and thanks for listening!

This week let’s learn about some blue frogs!

Further reading:

Scientists make chance discovery of rare blue skin mutation in Kimberley magnificent tree frog

White’s True-Blue Green Tree Frog

Show transcript:

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

When most of us draw a frog, we reach for the green markers, because most frogs are green. That’s true of the magnificent tree frog, also called the splendid tree frog, which is fairly common in the Kimberley region of western Australia. It grows just over 4 inches long, snout to vent, or about 10 and a half cm, and lives in rocky areas. It spends the day hiding in rock crevices, holes in trees, or sometimes in people’s houses, and it comes out at night to hunt for insects and other small invertebrates.

From the name, you might imagine that this is an especially pretty frog, and it is. It’s mostly bright green on top and yellow to white underneath, and it has tiny yellow spots on its head and back. It looks like it has an olive green cap on its head, but that’s actually a large parotoid gland, a skin gland common in frogs and toads that secretes neurotoxins. Most frogs don’t have a parotoid gland at all, and in ones that do you typically will barely notice it, but the magnificent tree frog’s covers the entire top of its head almost to its nostrils and down onto its back.

The skin color of a frog depends on its chemical makeup. Melanophores make black and brown colors, xanthophores make yellow. Blue is different, since it’s not a color that’s actually found in skin pigments. Instead, a green frog’s skin contains iridophores that reflect blue light waves, the same way a bird’s feathers show blue. The combination of yellow and blue makes green, and the addition of melanophore pigments determine how dark or bright the green is.

In July of 2024, two land managers were working in the Charnley River-Artesian Range Wildlife Sanctuary. They were in a workshop when one of them noticed a magnificent tree frog sitting on a bench, not that unusual of an occurrence–except that this frog wasn’t green. It was blue!

The condition is called axanthism, where the yellow pigments in the frog’s skin don’t show up the way they should. Most of them time axanthism in frogs means the animal has little patches of blue or bluish coloration, but this specific frog was blue just about everywhere it should have been green. Its parotoid gland was still olive green and it had yellow on its feet, but mainly it was a very attractive dark blue.

The land managers were stunned. They took photos and sent them to pretty much everyone, and frog experts and ecologists hurried to examine the blue frog. But they decided not to keep the frog in captivity. It was released back into the wild to live out its blue froggy life normally.

Some frogs are naturally blue, like some poison dart frogs of South America. The blue poison dart frog’s legs are dark blue and its body a lighter blue with black spots. It grows less than two inches long, or about 4.5 cm. Poison dart frogs collect toxins in their bodies from some of the toxic insects they eat, and the bright coloration signals to predators that this frog will make you really sick if you eat it.

Axanthism is rare but not all that uncommon in frogs. About the same time that the blue magnificent tree frog was hopping into the workshop in Australia, two little girls playing around a pond in Nova Scotia, Canada found a teal-blue frog. Ironically, the frog is actually called the green frog and it’s ordinarily a dark olive-green all over. The girls named the frog Bluey and released it back into the pond. Another blue green frog was found in New Hampshire, in the United States, also in July 2024. In June 2024 a forest ranger spotted a northern leopard frog in Washington state that had splotches of light blue on its head and back. In May of 2024 a light blue Japanese tree frog was found by a couple on a walk.

The Australian green tree frog is closely related to the magnificent tree frog, although it doesn’t have a parotoid gland hat. It’s mostly green with a white or pale gray belly. It’s sometimes called the dumpy tree frog because it’s a little chonk. Actually, for a frog it’s a pretty big chonk, up to 4 and a half inches long, or over 11 cm. It’s also sometimes called White’s tree frog after John White, who described it in 1790. It was the first Australian frog that was ever scientifically described. But that leads us to a little mystery.

John White named the frog Rana caerulea. Its current scientific name is Ranoidea caerulea. But “caerulea” refers to the color blue, not green, as in cerulean blue.

John White collected the frog in 1788, preserved it in alcohol, and finally described it two years later. He refers to it in his writing as a blue frog and the illustration accompanying it shows frogs that are actually blue. But this frog is supposed to be green!

The main suggestion for why a famously green frog was initially described as blue is that the alcohol that White used to preserve the frog’s body actually destroyed the yellow pigment in its skin. This is something that does sometimes happen with frog specimens in museums. But it’s also possible that White ended up with a blue specimen, much like the blue magnificent tree frog we talked about earlier. He wouldn’t have known that the blue frog had a rare color mutation. That would explain why he referred to the frog as blue and gave it a name that means blue.

That might also explain why White described the Australian green tree frog first. Maybe he just thought it was pretty. Everyone likes the color blue.

Thanks for your support, and thanks for listening! I’m at Dragon Con this weekend, where who knows, I might actually see a blue frog. Anything is possible at Dragon Con.

Further reading:

Parallels for cetacean trap feeding and tread-water feeding in the historical record across two millennia

Haggling over the Hafgufa

Many renditions of the hafgufa/aspidochelone:

Show transcript:

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

Back in the olden days, as much as 1700 years ago and probably more, up through the 14th century or so, various manuscripts about the natural world talked about a sea monster most people today have never heard of. In ancient Greek it was called aspidochelone, contracted to aspido in some translations, while in Old Norse it was called the hafgufa. But it seemed to be the same type of monster no matter who was writing about it.

The animal was a fish, but it was enormous, big enough that it was sometimes mistaken for an island. When its jaws were open they were said to be as wide as the entrance to a fjord. A fjord is an inlet from the sea originally formed by glaciers scraping away at rocks, and then when the glaciers melted the sea filled the bottom of what was then a steep valley. I’m pretty sure the old stories were exaggerating about the sea monster’s mouth size.

The sea monster ate little fish, but it caught them in a strange way. It would open its mouth very wide at the surface of the water and exude a smell that attracted fish, or in one account it would regurgitate a little food to attract the fish. Once there were lots of little fish within its huge mouth, it would close it jaws quickly and swallow them all.

Generally, any sea monster that’s said to be mistaken for an island was inspired by whales, or sometimes by sea turtles. The hafgufa is actually included in an Old Norse poem that lists types of whales, and the aspidochelone was considered to be a type of whale even though the second part of its name refers to a sea turtle. So whatever this sea monster was, we can safely agree that it wasn’t a fish, it was a whale. Up until just a few centuries ago people thought whales were fish because of their shape, but we know now that they’re mammals adapted to marine life.

But the hafgufa’s behavior is really weird and doesn’t seem like something a whale would do. We’ve talked about skim feeding before, where a baleen whale cruises along at the surface with its mouth held open, until it’s gathered enough food in its mouth and can swallow it all at once. But whales aren’t known to hold their mouths open at the surface of the water and just sit there while fish swim in. At least, they weren’t known to do this until 2011.

In 2011, marine biologists studying humpback whales off Canada’s Vancouver Island in North America observed some of the whales catching herring and other small fish in an unusual way. The whales would remain stationary in the water, tails straight down with the head sticking up partly out of the water. A whale opened its mouth very wide and didn’t move until there were a lot of fish in its mouth, which it then swallowed. Soon after, another team of marine biologists studying Bryde’s whales in the Gulf of Thailand in South Asia observed the same activity when the whales were feeding on anchovies at the surface of the water.

The term for this activity is called trap feeding or tread-water feeding, and at first the scientists thought it was a response to polluted water that had caused the fish to stay closer to the surface. But once the two teams of scientists compared notes, they realized that it didn’t appear to have anything to do with pollution. Instead, it’s probably a way to gather food in a low-energy way, especially when there isn’t a big concentration of fish in any particular spot, and when researchers remembered the story of the hafgufa, they realized they’d found the solution to that mystery sea monster.

The only question was whether the accounts were accurate that the hafgufa emitted a smell or regurgitated food to attract fish. Further observation answered that question too, and it turns out that yes, the old stories were at least partially right. The smell has been compared to rotten cabbage, but it isn’t emitted by the whale on purpose. It’s a smell released when phytoplankton is eaten in large numbers, whether by fish or whales or something else, and it does attract other animals.

As for the regurgitation, this is always something that happens to some degree when a baleen whale feeds. The whale fills its mouth with water that contains the fish and other small animals it eats, and it presses its huge tongue upwards to force the water through its baleen, which acts as a sieve. Whatever’s left in its mouth after the water is expelled, it swallows. But baleen is tough and fish are small and delicate in comparison. Often, fish and other small animals get squished to death against the baleen, and parts of them are expelled with the water. This creates a sort of yucky slurry that could be interpreted as a whale regurgitating food to attract more fish. The scientists think that fish are mainly attracted not to any smell or potential food in the water, but to the supposed shelter offered by the whale’s giant mouth.

It appears that trap feeding is a fairly rare behavior in whales, but one that’s been around a lot longer than the last few years. It’s also possible that because whaling drove many species nearly to extinction and whale numbers are only just starting to recover, until recently whales didn’t need to use this feeding strategy. It seems to be used when a preferred food is widely scattered so that chasing after the fish isn’t worth the energy cost, and that’s more likely to happen when there are a lot of whales around.

It’s amazing that this type of feeding strategy has been identified in two different species of whale, and it’s even more amazing that it matches up so well with ancient accounts. It’s easy to assume that in the olden days, people were kind of stupid, but people back then were just as intelligent as people now. They just didn’t have our technology and modern knowledge. They were often extremely observant, though, and luckily for us, sometimes they were able to write their observations down in books that we can still read.

Thanks for your support, and thanks for listening!

Further reading:

I Can Has Mutant Larvae?

200-Year-Old ‘Monster Larva’ Mystery Solved

‘Snakeworm’ mystery yields species new to science

Hearkening back to the hazelworm

Show transcript:

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

A few weeks ago when I was researching big eels, I remembered the mystery eel larva we talked about back in episode 49, and that led me down a fun rabbit hole about other mystery larvae.

Let’s start with that eel larva. Eel larvae can be extremely hard to tell apart, so as a catchall term every eel larva is called a leptocephalus. They’re flattened side to side, which is properly referred to as laterally compressed, and transparent, shaped roughly like a slender leaf, with a tiny head at the front. Depending on the species, an eel may remain in its larval form for more than a year, much longer than most other fish, and when it does metamorphose into its next life stage, it usually grows much longer than its larval form. For instance, the larvae of conger eels are only about 4 inches long, or 10 cm, while an adult conger can grow up to 10 feet long, or 3 meters.

On January 31, 1930, a Danish research ship caught an eel larva 900 feet deep, or about 275 meters, off the coast of South Africa. But the larva was over 6 feet long, or 1.85 meters!

Scientists boggled at the thought that this larva might grow into an eel more than 50 feet long, or 15 meters, raising the possibility that this unknown eel might be the basis of many sea serpent sightings.

The larva was preserved and has been studied extensively. In 1958, a similar eel larva was caught off of New Zealand. It and the 1930 specimen were determined to belong to the same species, which was named Leptocephalus giganteus.

In 1966, two more of the larvae were discovered in the stomach of a western Atlantic lancet fish. They were much smaller than the others, though—only four inches and eleven inches long, or 10 cm and 28 cm respectively. Other than size, they were pretty much identical to Leptocephalus giganteus.

The ichthyologist who examined them determined that the larvae were probably not true eels at all, but larvae of a fish called the spiny eel. Deep-sea spiny eels look superficially like eels but aren’t closely related, and while they do have a larval form that resembles that of a true eel, they’re much different in one important way. Spiny eel larvae grow larger than the adults, then shrink a little when they develop into their mature form. The six-foot eel larva was actually a spiny eel larva that was close to metamorphosing into its adult form.

Not everyone agrees that Leptocephalus giganteus is a spiny eel. Some think it belongs to the genus Coloconger, also called worm eels, which are true eels but which have large larvae that only grow to the same size as adults. But worm eels don’t grow much bigger than about two feet long, or 61 cm. If the mystery larvae does belong to the genus Coloconger, it’s probably a new species. Until scientists identify an adult Leptocephalus giganteus, we can’t know for sure.

Another mystery larva is Planctosphaera pelagica, which sits all alone in its own class because the only thing it resembles are acorn worms, but scientists are pretty sure it isn’t the larva of an acorn worm. It’s not much to look at, since the larva is just a little barrel-shaped blob that grows about 25 mm across. This sounds small compared to the eel larva we just discussed, but it’s actually quite large compared to similar larvae. Acorn worm larvae are usually only about a millimeter long.

Planctosphaera has been classified as a hemichordate, which are related to echinoderms but which show bilateral symmetry instead of radial symmetry. Hemichordates are also closely related to chordates, which include all vertebrates. They’re marine animals that resemble worms but aren’t worms, so it’s likely that Planctosphaera is also wormlike as an adult.

Planctosphaera isn’t encountered very often by scientists. It has limited swimming abilities and mostly floats around near the surface of the open ocean, eating tiny food particles. One suggestion is that it might actually be the larva of a known species, but one where an occasional larva just never metamorphoses into an adult. It just grows and grows until something eats it. So far, attempts to sequence DNA from a Planctosphaera hasn’t succeeded and attempts to raise one to maturity in captivity hasn’t worked either.

Some people have estimated that an adult Planctosphaera might be a type of acorn worm that can grow nine feet long, or 2.75 meters, which isn’t out of the realm of possibility. The largest species of acorn worm known is Balanoglossus gigas, which can grow almost six feet long, or 1.8 meters, and not only is it bioluminescent, its body contains a lot of iodine, so it smells like medicine. It lives in mucus-lined burrows on the sea floor.

Another mystery larva is Facetotecta, which have been found in shallow areas in many oceans around the world. Unlike the other larvae we’ve talked about, they’re genuinely tiny, measured in micrometers, and eleven species have been described. They all have a cephalic shield, meaning a little dome over the head, and scientists have been able to observe several phases of their development but not the adult form. The juvenile form was observed and it looked kind of like a tiny slug with nonfunctioning eyes and weak muscles.

Scientists speculate that facetotecta may actually be the larva of an endoparasite that infests some marine animals. That would explain why no adult form has been identified. Genetic testing has confirmed that Facetotecta is related to a group of parasitic crustaceans.

DNA has solved some mysteries of what larvae belong to which adults. For instance, Cerataspis monstrosa, a larval crustacean that was first described in 1828. It’s over a cm long, pinkish-purple in color with stalked eyes, little swimming leg-like appendages, and neon blue horn-like structures on its head and back which act as armor. The armor doesn’t help too much against big animals like dolphins and tuna, which love to eat it, and in fact that’s where it was initially discovered, in the digestive tract of a dolphin. But scientists had no idea what the monstrous larva eventually grew up to be.

In 2012 the mystery was solved when a team of scientists compared the monster larva’s DNA to that of lots of various types of shrimp, since the larva had long been suspected to be a type of shrimp. It turns out that it’s the larval form of a rare deep-sea aristeid shrimp that can grow up to 9 inches long, or 23 cm.

Let’s finish with another solved mystery, this one from larvae found on land. In 2007, someone sent photos and a bag of little dead worms to Derek Sikes at the University of Alaska Museum. Usually when someone sends you a bag of dead worms, they’re giving you an obscure but distressing message, but Sikes was curator of the insect collection and he was happy to get a bag of mystery worms.

The worms had been collected from an entire column of the creatures that had been crawling over each other so that the group looked like a garden hose on the ground. Sikes thought they were probably fly larvae but he had never heard of larvae traveling in a column. If you’ve listened to the hazelworm episode from August 2018, you might have an idea. The hazelworm was supposed to be a snake or even a dragon that was only seen in times of unrest. It turns out that it the larvae of some species of fungus gnat travel together in long, narrow columns that really do look like a moving snake. But that’s in Europe, not Alaska.

Sikes examined the larvae, but since they were dead he couldn’t guess what type of insect they would grow up to be. Luckily, a few months later he got a call from a forester who had spotted a column of the same worms crossing a road. Sikes got there in time to witness the phenomenon himself.

The larvae were only a few millimeters long each, but there were so many of them that the column stretched right across the road into the forest. He collected some of them carefully and took them back to the museum, where he tended them in hopes that they would pupate successfully.

This they did, and the insects that emerged were a little larger than fruit flies and were black in color. Sikes identified them as fungus gnats, but when he consulted fungus gnat experts in Germany and Japan, they were excited to report that they didn’t recognize the Alaskan gnats. It was a new species, which Sikes described in late 2023. His summer students helped name the species, Sciara serpens, which are better known now as snakeworm gnats. He and his co-authors think the larvae form columns when they cross surfaces like roads and rocks, to help minimize contacting the dry ground. Fungus gnats live in moist areas with lots of organic matter, like forest leaf litter and the edges of ponds.

So the next time you see a huge long snake crossing the road, don’t panic. It might just be a whole lot of tiny, tiny larvae looking for a new home.

Thanks for your support, and thanks for listening!

BONUS: here’s the Hazelworm episode too!

The hazelworm today is a type of reptile, although called the slow worm, blind worm, or deaf adder. It lives in Eurasia, and while it looks like a snake, it’s actually a legless lizard. It can even drop and regrow its tail like a lizard if threatened. It spends most of its time underground in burrows or underneath leaf litter or under logs. It grows almost 2 feet long, or 50 cm, and is brown. Females sometimes have blue racing stripes while males may have blue spots. It eats slugs, worms, and other small animals, so is good for the garden.

But that kind of hazelworm isn’t what we’re talking about here. Back in the middle ages in central Europe, especially in parts of the Alps, there were stories of a big dragonlike serpent that lived in areas where hazel bushes were common. Like its slow-worm namesake, it lived most of its life underground, especially twined around the roots of the hazel. Instead of scales, it had a hairy skin and was frequently white in color. It was supposed to be the same type of snake that had tempted Adam and Eve in the Garden of Eden.

It had a lot of names besides hazelworm, including white worm for its color, paradise worm for its supposed history in the Garden of Eden, and even war worm. That one was because it was only supposed to show itself just before a war broke out.

People really believed it existed, although stories about it sound more like folklore. For instance, anyone who ate hazelworm flesh was supposed to become immortal. It was also supposed to suck milk from dairy cows and spread poison.

Some accounts said it was enormous, as big around as a man’s thigh and some 18 feet long, or 5.5 meters. Sometimes it was even supposed to have feet, or have various bright colors. Sometimes drawings showed wings.

There does seem to be some confusion about stories of the hazelworm and of the tatzelwurm, especially in older accounts. But unlike the tatzelwurm, the mystery of the hazelworm has been solved for a long time—long enough that knowledge of the animal has dropped out of folklore.

Back in the 1770s, a physician named August C. Kuehn pointed out that hazelworm sightings matched up with a real animal…but not a snake. Not even any kind of reptile. Not a fish or a bird or a mammal. Nope, he pointed at the fungus gnat.

The fungus gnat is about 8 mm long and eats decaying plant matter and fungus. You know, sort of exactly not like an 18-foot hairy white snake.

But the larvae of some species of fungus gnat are called army worms. The larvae have white, gray, or brown bodies and black heads, and travel in long, wide columns that do look like a moving snake, especially if seen in poor light or in the distance. I’ve watched videos online of these processions and they are horrifying! They’re also rare, so it’s certainly possible that even people who have lived in one rural area their whole life had never seen an armyworm procession. Naturally, they’d assume they were seeing a monstrous hairy snake of some kind, because that’s what it looks like.

Sightings of smaller hazelworms may be due to the caterpillar of the pine processionary moth, which also travels in a line nose to tail, which looks remarkably like a long, thin, hairy snake. Don’t touch those caterpillars, by the way. They look fuzzy and cute but their hairs can cause painful reactions when touched.

The adult moths lay their eggs in pine trees and when the eggs hatch the larvae eat pine needles and can cause considerable damage to the trees. They overwinter in silk tents, then leave the trees in spring and travel in a snaky conga line to eat pine needles. Eventually they burrow underground to pupate. They emerge from their cocoons as adult moths, mate, lay eggs, and die, all within one day.