Episode 443: Ant Lions and the Horrible Seal Problem

Thanks to Jayson and warblrwatchr for suggesting this week’s invertebrates!

Further reading:

Parasite of the Day: Orthohalarachne attenuata

Trap-jaw ants jump with their jaws to escape the antlion’s den

Get out of my noooooose:

An ant lion pit:

An ant lion larva:

A lovely adult antlion, Nannoleon, which lives in parts of Africa [photo by Alandmanson – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=58068259]:

Show transcript:

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

It’s almost August, and of course we’re doing invertebrate August again this year. Let’s get ready by talking about a few extra invertebrates this week, with suggestions from Jayson and warblrwatchr.

Before we get started, I have some quick housekeeping. First, a big shout-out to Nora who emailed me recently. I just wanted to say hi and I hope you’re having a good day. Next, I’m moving in just a few weeks to Atlanta, Georgia! I know I was talking forever about moving to Bloomington, Indiana, but I changed my mind. The next few episodes are already scheduled so I can concentrate on moving.

I’m about 75% packed at this point and have given away or sold a lot of stuff, including a lot of books. But I have a collection that a listener might be interested in. I offered it to the patrons last month but no one grabbed it, so I’ll offer it here.

I have every issue of the little magazine Flying Snake ever published, 30 in all. They’re a fun hodgepodge of articles, reprinted newspaper clippings, old photos, and other stuff more or less associated with cryptozoology and weirdness in general. I’ve decided they take up too much space on my shelves to take with me to Atlanta. If you’re interested in giving them a home, let me know and I’ll box them up and send them to you for free. The first person who says they’ll take them will get them, but the catch is that you have to take them all. I won’t just send you a few. I’ll also throw in all four volumes of the Journal of Cryptozoology. This offer stands until mid-August when I move, because if I have to move them to my new apartment, I’m just going to keep them.

Okay, now let’s learn about some invertebrates! First, Jayson wanted to learn about a tiny invertebrate called Orthohalarachne attenuata. It doesn’t have a common name because most people will never ever encounter it, or think about it, and I kind of wish I didn’t have to think about it because it’s gross. Thanks a lot, Jayson. It’s a mite that lives in the nasal passages of seals, sea lions, and walruses. It’s incredibly common and usually doesn’t bother the seal very much, although sometimes it can cause the seal to have difficulty breathing if the infestation is heavy.

The adult mite spends its whole life anchored in the seal’s nasal passages with sharp little claws, although it can move around if it wants to. Its larvae are more active. The mite is mainly spread by seals sneezing on each other, which spreads the larvae onto another seal, and the larvae crawl into the new seal’s nose and mouth.

Unless you’re a seal or other pinniped, this might sound gross but probably doesn’t bother you too much. But consider that in 1984, a man went to the doctor when one of his eyes started hurting. The doctor found a mite attached to his eyeball, and yes, it was Orthohalarachne attenuata. The man had visited Sea World two days before he started feeling pain in his eye, and happened to be close to some walruses that were sneezing.

Luckily for pinnipeds kept in captivity in zoos that give their animals proper care, mite infestations can be treated successfully by veterinarians.

Let’s move on quickly to an invertebrate that isn’t a parasite that can get in your eyes, the ant lion! It was suggested by warblrwatchr and I’ve been wanting to cover it for a while. When I was a kid, there was a strip of soft powdery dirt under the eaves of the school gym that always had ant lions in it, and I would squat down during recess and watch to see if any ants would fall in and get caught. Sometimes this did actually happen and the resulting battle between ant and ant lion was exciting and kind of horrible to witness.

The ant lion is actually the larva of antlion lacewing, which look like a small damselfly that is mainly active at dusk. Ant lions live throughout the world, with more than 2,000 species known. Some wait for prey while hidden in leaf litter, while some hide in rock crevices and become camouflaged by lichens growing on them. Many others dig little pits in sand or soft dirt. They’re also called the doodlebug in some places, because when they’re looking for a place to dig a little pit, they make a loopy pattern in the dirt as they’re walking around.

The ant lion’s body is robust and has little backwards-pointing bristles that help it dig itself into the dirt and stay there without moving until it needs to. It waits at the bottom of the pit, hidden underground with just its long, sharp jaws showing through the dirt, until an ant or other insect falls in. The ant can’t climb out because the sides of the pit are so sharply angled that they start to cave in, sending the ant down to the bottom of the pit. If that doesn’t work, the ant lion kicks dirt at the ant so that it falls. Then the ant lion grabs the ant in its fearsome jaws and injects venom and digestive enzymes into it, and that is the end of the ant. The jaws actually have little projections that are hollow and act like horrible little straws, so that the ant lion sucks the liquefied ant insides into its digestive system.

One species of ant, the trap-jaw ant, can sometimes escape the ant lion’s pit by using its own fearsome jaws as a spring to bounce itself to safety. There are many species of trap-jaw ant that live in tropical and subtropical areas throughout much of the world, including Africa, Asia, Australia, and much of the Americas. Its long jaws can snap closed extremely quickly and with a lot of force, allowing it to kill prey, bite pieces off of food, and lots of other activities. They can also jump with their jaws, and this improves their ability to bounce right out of the ant lion pit.

The ant lion can remain in its larval stage for years, maturing slowly. It has no anus but it doesn’t expel the waste products that it can’t digest, it just stores them in its body. When it does finally pupate, it uses a lot of the waste to produce silk for its cocoon. Whatever is left over it leaves behind when it emerges from its cocoon.

The cocoons are naturally hidden underground, and when the adult antlion lacewing emerges, it digs its way to the surface and rests while its wings open. Compared to the tough little larva, the adult is delicate and not very robust. It doesn’t live very long, usually no more than a few weeks, and most species eat pollen or nectar, or maybe tiny insects. It mainly just seeks out a mate, and the female lays her eggs in soft soil. When they hatch, they build their first tiny pits and the cycle starts again. And nobody gets into anybody’s eyeballs.

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

Thanks for listening!

Episode 221: Arachnids in the Antarctic!

Thanks to Ella for this week’s suggestion. There may not technically be spiders in the Antarctic, but there are mites.

A nunatak (note the size of the research vehicles at the bottom left):

I don’t have any pictures of the Antarctic mites, so here are some red velvet mites, although they’re giants compared to their Antarctic cousins:

Show transcript:

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

This week we’re going to have a short episode, because I get my second Covid-19 vaccine on the Thursday before this episode goes live and I want to have the episode all finished before then. That way if I feel bad afterwards I can rest. Thanks to Ella for this week’s suggestion!

Back in episode 90, about some mystery spiders, I mentioned that spiders live everywhere in the world except Antarctica. Well, guess what. Ella sent me some links about spiders that live in…Antarctica!

Antarctica is a landmass at the South Pole, specifically a continent about twice the size of Australia. It looks bigger than it really is because ice projects out from the land and is only supported by water, called an ice shelf. It’s not a little bit of ice, either. It’s over a mile thick, or nearly 2 km. The ice is called the Antarctic ice sheet and it covers 98% of the continent. The only places not covered in ice are some rock outcroppings and a few valleys, called dry valleys because they basically get no precipitation, not even snow and certainly not rain. Researchers estimate that it hasn’t rained in these dry valleys in almost two million years. There are no plants, just gravel. There are no animals but some bacterial life that live inside rocks and under at least one glacier. Scientists have used these dry valleys to test equipment designed for Mars. This is not a hospitable land. Everything that lives in Antarctica is considered an extremophile.

That doesn’t mean there’s no life in Antarctica, though, just that it’s only found in a few places, mostly along the coast or on nearby islands. Emperor penguins and Adelie penguins, several species of seal, and some sea birds live at least part of their lives in and around Antarctica, as do some whales. There are lichens, algae, and a few low-growing plants like liverwort and moss. And there are some invertebrates, although not very many and not large at all. The largest is a flightless midge that only grows 6 mm long. But what we’re interested in today are mites found only in Antarctica.

We talked about mites in episode 186 when we learned about the red velvet mite. Mites are arachnids, although they’re not technically spiders, but frankly we’re just quibbling at this point. It has eight legs and is in the class Arachnida, so I say there are spiders in Antarctica. Or close enough.

There are 30 species of mite in Antarctica. They mostly live on islands throughout the Antarctic peninsula, which sticks out from one side of the continent like a tail pointing at the very tip of South America. All the mites eat moss, algae, and decomposing lichens. They’re also teeny-tiny, less than a millimeter long.

One type of mite is found on the mainland of East Antarctica instead of just on islands. It’s called Maudheimia and it only lives on big rock outcroppings that stick up through the ice. These rocks are called nunataks and are covered with lichens. But nunataks are far apart, sometimes hundreds of miles apart, and the mites are so tiny they’re just about microscopic. How did they get from one nunatak to the next?

To find out, we have to learn some history about Antarctica. It hasn’t always been at the South Pole. It was once part of the supercontinent Gondwana, and 500 million years ago it was right smack on the equator. You know, tropical. As the centuries passed and the continents continued their slow, constant dance around the Earth, Gondwana drifted southward and broke apart. Antarctica was still connected to Australia on one side and South America on the other, and was still subtropical. Then it broke off from Australia around 40 million years ago, drifted farther southward, and ultimately, about 25 million years ago, separated from South America. Ever since it’s been isolated at the South Pole, and by 15 million years ago it was ice-covered.

Fossils of dinosaurs and other ancient animals have been discovered in Antarctica, but it’s hard to find fossils and excavate them when the ground is under a mile of ice. The animals and plants that once lived in Antarctica went extinct gradually as its climate became less and less hospitable, and most of the remaining holdouts went extinct when the ice age began and the continent’s climate was even colder and harsher than it is now.

But one animal remains, toughing it out on rock outcroppings where the temperature can drop to -31 degrees Fahrenheit, or -35 Celsius. Maudheimia, the brave little mite.

Maudheimia was probably common throughout Antarctica’s mountains before the big freeze happened, and would have already been well adapted to the cold of high elevations. As the continent grew colder and colder, the little mite adapted even more. The fluids in its body contain an organic antifreeze agent so it doesn’t freeze solid. As the ice covered more of its home, it migrated, in its tiny way, to the rocks that stayed ice-free and allowed lichen to survive too. It’s reasonably common despite its restricted habitat, which is good because the female Maudheimia only lays one egg every year or two. There are four species known.

Maudheimia probably isn’t the only animal that survived Antarctica’s ice age, though. Species of springtail only found in Antarctica live alongside Maudheimia, and there are tardigrades and tiny nematode worms around too. All these were probably around long before the end of the ice age around 12,000 years ago.

There may be other microscopic or nearly microscopic animals we haven’t discovered yet. The Antarctic is the only place in the world that humans have never colonized, although a small number of people live in scientific outposts while conducting research of various kinds. There’s a lot we don’t know about the continent.

For instance, there are at least 400 subglacial lakes in Antarctica. The lakes form between the bedrock and the ice sheet, like a little bubble of water. Iceland, Greenland, and Canada have some too. They’re hard to study, naturally, because it requires drilling through over a mile of ice to get a water sample. So far researchers have discovered extremophile microbes in these lakes, but so few samples have been taken that we certainly don’t know everything that’s down there. Most of the lakes occasionally overflow into nearby subglacial lakes, but at least some appear to have been isolated under the ice for potentially millions of years. They may contain bacteria and other microbial life that are radically different from modern species.

There’s one other place that we know has a subglacial lake, discovered in 2018. It’s on the planet Mars. I wonder if there’s anything living in that one.

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

Thanks for listening!